Merge branch 'master' of github.com:grpc/grpc into oauth2_access_token

BUILD

@@ -1,5 +1,5 @@
 # GRPC Bazel BUILD file.
-# This currently builds C and C++ code.
+# This currently builds C, C++ and Objective-C code.
 # This file has been automatically generated from a template file.
 # Please look at the templates directory instead.
 # This file can be regenerated from the template by running
@@ -138,6 +138,7 @@ cc_library(
     "src/core/security/base64.h",
     "src/core/security/credentials.h",
     "src/core/security/json_token.h",
+    "src/core/security/jwt_verifier.h",
     "src/core/security/secure_endpoint.h",
     "src/core/security/secure_transport_setup.h",
     "src/core/security/security_connector.h",
@@ -150,14 +151,24 @@ cc_library(
     "src/core/channel/census_filter.h",
     "src/core/channel/channel_args.h",
     "src/core/channel/channel_stack.h",
-    "src/core/channel/child_channel.h",
     "src/core/channel/client_channel.h",
-    "src/core/channel/client_setup.h",
     "src/core/channel/connected_channel.h",
     "src/core/channel/context.h",
     "src/core/channel/http_client_filter.h",
     "src/core/channel/http_server_filter.h",
     "src/core/channel/noop_filter.h",
+    "src/core/client_config/client_config.h",
+    "src/core/client_config/connector.h",
+    "src/core/client_config/lb_policies/pick_first.h",
+    "src/core/client_config/lb_policy.h",
+    "src/core/client_config/resolver.h",
+    "src/core/client_config/resolver_factory.h",
+    "src/core/client_config/resolver_registry.h",
+    "src/core/client_config/resolvers/dns_resolver.h",
+    "src/core/client_config/resolvers/unix_resolver_posix.h",
+    "src/core/client_config/subchannel.h",
+    "src/core/client_config/subchannel_factory.h",
+    "src/core/client_config/uri_parser.h",
     "src/core/compression/message_compress.h",
     "src/core/debug/trace.h",
     "src/core/iomgr/alarm.h",
@@ -200,7 +211,6 @@ cc_library(
     "src/core/surface/byte_buffer_queue.h",
     "src/core/surface/call.h",
     "src/core/surface/channel.h",
-    "src/core/surface/client.h",
     "src/core/surface/completion_queue.h",
     "src/core/surface/event_string.h",
     "src/core/surface/init.h",
@@ -227,6 +237,7 @@ cc_library(
     "src/core/transport/chttp2/timeout_encoding.h",
     "src/core/transport/chttp2/varint.h",
     "src/core/transport/chttp2_transport.h",
+    "src/core/transport/connectivity_state.h",
     "src/core/transport/metadata.h",
     "src/core/transport/stream_op.h",
     "src/core/transport/transport.h",
@@ -244,6 +255,7 @@ cc_library(
     "src/core/security/credentials_win32.c",
     "src/core/security/google_default_credentials.c",
     "src/core/security/json_token.c",
+    "src/core/security/jwt_verifier.c",
     "src/core/security/secure_endpoint.c",
     "src/core/security/secure_transport_setup.c",
     "src/core/security/security_connector.c",
@@ -258,13 +270,23 @@ cc_library(
     "src/core/census/grpc_context.c",
     "src/core/channel/channel_args.c",
     "src/core/channel/channel_stack.c",
-    "src/core/channel/child_channel.c",
     "src/core/channel/client_channel.c",
-    "src/core/channel/client_setup.c",
     "src/core/channel/connected_channel.c",
     "src/core/channel/http_client_filter.c",
     "src/core/channel/http_server_filter.c",
     "src/core/channel/noop_filter.c",
+    "src/core/client_config/client_config.c",
+    "src/core/client_config/connector.c",
+    "src/core/client_config/lb_policies/pick_first.c",
+    "src/core/client_config/lb_policy.c",
+    "src/core/client_config/resolver.c",
+    "src/core/client_config/resolver_factory.c",
+    "src/core/client_config/resolver_registry.c",
+    "src/core/client_config/resolvers/dns_resolver.c",
+    "src/core/client_config/resolvers/unix_resolver_posix.c",
+    "src/core/client_config/subchannel.c",
+    "src/core/client_config/subchannel_factory.c",
+    "src/core/client_config/uri_parser.c",
     "src/core/compression/algorithm.c",
     "src/core/compression/message_compress.c",
     "src/core/debug/trace.c",
@@ -317,7 +339,6 @@ cc_library(
     "src/core/surface/call_log_batch.c",
     "src/core/surface/channel.c",
     "src/core/surface/channel_create.c",
-    "src/core/surface/client.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",
@@ -348,6 +369,7 @@ cc_library(
     "src/core/transport/chttp2/varint.c",
     "src/core/transport/chttp2/writing.c",
     "src/core/transport/chttp2_transport.c",
+    "src/core/transport/connectivity_state.c",
     "src/core/transport/metadata.c",
     "src/core/transport/stream_op.c",
     "src/core/transport/transport.c",
@@ -382,14 +404,24 @@ cc_library(
     "src/core/channel/census_filter.h",
     "src/core/channel/channel_args.h",
     "src/core/channel/channel_stack.h",
-    "src/core/channel/child_channel.h",
     "src/core/channel/client_channel.h",
-    "src/core/channel/client_setup.h",
     "src/core/channel/connected_channel.h",
     "src/core/channel/context.h",
     "src/core/channel/http_client_filter.h",
     "src/core/channel/http_server_filter.h",
     "src/core/channel/noop_filter.h",
+    "src/core/client_config/client_config.h",
+    "src/core/client_config/connector.h",
+    "src/core/client_config/lb_policies/pick_first.h",
+    "src/core/client_config/lb_policy.h",
+    "src/core/client_config/resolver.h",
+    "src/core/client_config/resolver_factory.h",
+    "src/core/client_config/resolver_registry.h",
+    "src/core/client_config/resolvers/dns_resolver.h",
+    "src/core/client_config/resolvers/unix_resolver_posix.h",
+    "src/core/client_config/subchannel.h",
+    "src/core/client_config/subchannel_factory.h",
+    "src/core/client_config/uri_parser.h",
     "src/core/compression/message_compress.h",
     "src/core/debug/trace.h",
     "src/core/iomgr/alarm.h",
@@ -432,7 +464,6 @@ cc_library(
     "src/core/surface/byte_buffer_queue.h",
     "src/core/surface/call.h",
     "src/core/surface/channel.h",
-    "src/core/surface/client.h",
     "src/core/surface/completion_queue.h",
     "src/core/surface/event_string.h",
     "src/core/surface/init.h",
@@ -459,6 +490,7 @@ cc_library(
     "src/core/transport/chttp2/timeout_encoding.h",
     "src/core/transport/chttp2/varint.h",
     "src/core/transport/chttp2_transport.h",
+    "src/core/transport/connectivity_state.h",
     "src/core/transport/metadata.h",
     "src/core/transport/stream_op.h",
     "src/core/transport/transport.h",
@@ -468,13 +500,23 @@ cc_library(
     "src/core/census/grpc_context.c",
     "src/core/channel/channel_args.c",
     "src/core/channel/channel_stack.c",
-    "src/core/channel/child_channel.c",
     "src/core/channel/client_channel.c",
-    "src/core/channel/client_setup.c",
     "src/core/channel/connected_channel.c",
     "src/core/channel/http_client_filter.c",
     "src/core/channel/http_server_filter.c",
     "src/core/channel/noop_filter.c",
+    "src/core/client_config/client_config.c",
+    "src/core/client_config/connector.c",
+    "src/core/client_config/lb_policies/pick_first.c",
+    "src/core/client_config/lb_policy.c",
+    "src/core/client_config/resolver.c",
+    "src/core/client_config/resolver_factory.c",
+    "src/core/client_config/resolver_registry.c",
+    "src/core/client_config/resolvers/dns_resolver.c",
+    "src/core/client_config/resolvers/unix_resolver_posix.c",
+    "src/core/client_config/subchannel.c",
+    "src/core/client_config/subchannel_factory.c",
+    "src/core/client_config/uri_parser.c",
     "src/core/compression/algorithm.c",
     "src/core/compression/message_compress.c",
     "src/core/debug/trace.c",
@@ -527,7 +569,6 @@ cc_library(
     "src/core/surface/call_log_batch.c",
     "src/core/surface/channel.c",
     "src/core/surface/channel_create.c",
-    "src/core/surface/client.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",
@@ -558,6 +599,7 @@ cc_library(
     "src/core/transport/chttp2/varint.c",
     "src/core/transport/chttp2/writing.c",
     "src/core/transport/chttp2_transport.c",
+    "src/core/transport/connectivity_state.c",
     "src/core/transport/metadata.c",
     "src/core/transport/stream_op.c",
     "src/core/transport/transport.c",
@@ -906,6 +948,7 @@ objc_library(
     "src/core/security/credentials_win32.c",
     "src/core/security/google_default_credentials.c",
     "src/core/security/json_token.c",
+    "src/core/security/jwt_verifier.c",
     "src/core/security/secure_endpoint.c",
     "src/core/security/secure_transport_setup.c",
     "src/core/security/security_connector.c",
@@ -920,13 +963,23 @@ objc_library(
     "src/core/census/grpc_context.c",
     "src/core/channel/channel_args.c",
     "src/core/channel/channel_stack.c",
-    "src/core/channel/child_channel.c",
     "src/core/channel/client_channel.c",
-    "src/core/channel/client_setup.c",
     "src/core/channel/connected_channel.c",
     "src/core/channel/http_client_filter.c",
     "src/core/channel/http_server_filter.c",
     "src/core/channel/noop_filter.c",
+    "src/core/client_config/client_config.c",
+    "src/core/client_config/connector.c",
+    "src/core/client_config/lb_policies/pick_first.c",
+    "src/core/client_config/lb_policy.c",
+    "src/core/client_config/resolver.c",
+    "src/core/client_config/resolver_factory.c",
+    "src/core/client_config/resolver_registry.c",
+    "src/core/client_config/resolvers/dns_resolver.c",
+    "src/core/client_config/resolvers/unix_resolver_posix.c",
+    "src/core/client_config/subchannel.c",
+    "src/core/client_config/subchannel_factory.c",
+    "src/core/client_config/uri_parser.c",
     "src/core/compression/algorithm.c",
     "src/core/compression/message_compress.c",
     "src/core/debug/trace.c",
@@ -979,7 +1032,6 @@ objc_library(
     "src/core/surface/call_log_batch.c",
     "src/core/surface/channel.c",
     "src/core/surface/channel_create.c",
-    "src/core/surface/client.c",
     "src/core/surface/completion_queue.c",
     "src/core/surface/event_string.c",
     "src/core/surface/init.c",
@@ -1010,6 +1062,7 @@ objc_library(
     "src/core/transport/chttp2/varint.c",
     "src/core/transport/chttp2/writing.c",
     "src/core/transport/chttp2_transport.c",
+    "src/core/transport/connectivity_state.c",
     "src/core/transport/metadata.c",
     "src/core/transport/stream_op.c",
     "src/core/transport/transport.c",
@@ -1033,6 +1086,7 @@ objc_library(
     "src/core/security/base64.h",
     "src/core/security/credentials.h",
     "src/core/security/json_token.h",
+    "src/core/security/jwt_verifier.h",
     "src/core/security/secure_endpoint.h",
     "src/core/security/secure_transport_setup.h",
     "src/core/security/security_connector.h",
@@ -1045,14 +1099,24 @@ objc_library(
     "src/core/channel/census_filter.h",
     "src/core/channel/channel_args.h",
     "src/core/channel/channel_stack.h",
-    "src/core/channel/child_channel.h",
     "src/core/channel/client_channel.h",
-    "src/core/channel/client_setup.h",
     "src/core/channel/connected_channel.h",
     "src/core/channel/context.h",
     "src/core/channel/http_client_filter.h",
     "src/core/channel/http_server_filter.h",
     "src/core/channel/noop_filter.h",
+    "src/core/client_config/client_config.h",
+    "src/core/client_config/connector.h",
+    "src/core/client_config/lb_policies/pick_first.h",
+    "src/core/client_config/lb_policy.h",
+    "src/core/client_config/resolver.h",
+    "src/core/client_config/resolver_factory.h",
+    "src/core/client_config/resolver_registry.h",
+    "src/core/client_config/resolvers/dns_resolver.h",
+    "src/core/client_config/resolvers/unix_resolver_posix.h",
+    "src/core/client_config/subchannel.h",
+    "src/core/client_config/subchannel_factory.h",
+    "src/core/client_config/uri_parser.h",
     "src/core/compression/message_compress.h",
     "src/core/debug/trace.h",
     "src/core/iomgr/alarm.h",
@@ -1095,7 +1159,6 @@ objc_library(
     "src/core/surface/byte_buffer_queue.h",
     "src/core/surface/call.h",
     "src/core/surface/channel.h",
-    "src/core/surface/client.h",
     "src/core/surface/completion_queue.h",
     "src/core/surface/event_string.h",
     "src/core/surface/init.h",
@@ -1122,6 +1185,7 @@ objc_library(
     "src/core/transport/chttp2/timeout_encoding.h",
     "src/core/transport/chttp2/varint.h",
     "src/core/transport/chttp2_transport.h",
+    "src/core/transport/connectivity_state.h",
     "src/core/transport/metadata.h",
     "src/core/transport/stream_op.h",
     "src/core/transport/transport.h",

build.json

@@ -111,14 +111,24 @@
         "src/core/channel/census_filter.h",
         "src/core/channel/channel_args.h",
         "src/core/channel/channel_stack.h",
-        "src/core/channel/child_channel.h",
         "src/core/channel/client_channel.h",
-        "src/core/channel/client_setup.h",
         "src/core/channel/connected_channel.h",
         "src/core/channel/context.h",
         "src/core/channel/http_client_filter.h",
         "src/core/channel/http_server_filter.h",
         "src/core/channel/noop_filter.h",
+        "src/core/client_config/client_config.h",
+        "src/core/client_config/connector.h",
+        "src/core/client_config/lb_policies/pick_first.h",
+        "src/core/client_config/lb_policy.h",
+        "src/core/client_config/resolver.h",
+        "src/core/client_config/resolver_factory.h",
+        "src/core/client_config/resolver_registry.h",
+        "src/core/client_config/resolvers/dns_resolver.h",
+        "src/core/client_config/resolvers/unix_resolver_posix.h",
+        "src/core/client_config/subchannel.h",
+        "src/core/client_config/subchannel_factory.h",
+        "src/core/client_config/uri_parser.h",
         "src/core/compression/message_compress.h",
         "src/core/debug/trace.h",
         "src/core/iomgr/alarm.h",
@@ -161,7 +171,6 @@
         "src/core/surface/byte_buffer_queue.h",
         "src/core/surface/call.h",
         "src/core/surface/channel.h",
-        "src/core/surface/client.h",
         "src/core/surface/completion_queue.h",
         "src/core/surface/event_string.h",
         "src/core/surface/init.h",
@@ -188,6 +197,7 @@
         "src/core/transport/chttp2/timeout_encoding.h",
         "src/core/transport/chttp2/varint.h",
         "src/core/transport/chttp2_transport.h",
+        "src/core/transport/connectivity_state.h",
         "src/core/transport/metadata.h",
         "src/core/transport/stream_op.h",
         "src/core/transport/transport.h",
@@ -197,13 +207,23 @@
         "src/core/census/grpc_context.c",
         "src/core/channel/channel_args.c",
         "src/core/channel/channel_stack.c",
-        "src/core/channel/child_channel.c",
         "src/core/channel/client_channel.c",
-        "src/core/channel/client_setup.c",
         "src/core/channel/connected_channel.c",
         "src/core/channel/http_client_filter.c",
         "src/core/channel/http_server_filter.c",
         "src/core/channel/noop_filter.c",
+        "src/core/client_config/client_config.c",
+        "src/core/client_config/connector.c",
+        "src/core/client_config/lb_policies/pick_first.c",
+        "src/core/client_config/lb_policy.c",
+        "src/core/client_config/resolver.c",
+        "src/core/client_config/resolver_factory.c",
+        "src/core/client_config/resolver_registry.c",
+        "src/core/client_config/resolvers/dns_resolver.c",
+        "src/core/client_config/resolvers/unix_resolver_posix.c",
+        "src/core/client_config/subchannel.c",
+        "src/core/client_config/subchannel_factory.c",
+        "src/core/client_config/uri_parser.c",
         "src/core/compression/algorithm.c",
         "src/core/compression/message_compress.c",
         "src/core/debug/trace.c",
@@ -256,7 +276,6 @@
         "src/core/surface/call_log_batch.c",
         "src/core/surface/channel.c",
         "src/core/surface/channel_create.c",
-        "src/core/surface/client.c",
         "src/core/surface/completion_queue.c",
         "src/core/surface/event_string.c",
         "src/core/surface/init.c",
@@ -287,6 +306,7 @@
         "src/core/transport/chttp2/varint.c",
         "src/core/transport/chttp2/writing.c",
         "src/core/transport/chttp2_transport.c",
+        "src/core/transport/connectivity_state.c",
         "src/core/transport/metadata.c",
         "src/core/transport/stream_op.c",
         "src/core/transport/transport.c",
@@ -431,6 +451,7 @@
         "src/core/security/base64.h",
         "src/core/security/credentials.h",
         "src/core/security/json_token.h",
+        "src/core/security/jwt_verifier.h",
         "src/core/security/secure_endpoint.h",
         "src/core/security/secure_transport_setup.h",
         "src/core/security/security_connector.h",
@@ -453,6 +474,7 @@
         "src/core/security/credentials_win32.c",
         "src/core/security/google_default_credentials.c",
         "src/core/security/json_token.c",
+        "src/core/security/jwt_verifier.c",
         "src/core/security/secure_endpoint.c",
         "src/core/security/secure_transport_setup.c",
         "src/core/security/security_connector.c",
@@ -748,6 +770,7 @@
         "test/cpp/qps/driver.h",
         "test/cpp/qps/histogram.h",
         "test/cpp/qps/interarrival.h",
+        "test/cpp/qps/perf_db_client.h",
         "test/cpp/qps/qps_worker.h",
         "test/cpp/qps/report.h",
         "test/cpp/qps/server.h",
@@ -757,9 +780,11 @@
       ],
       "src": [
         "test/cpp/qps/qpstest.proto",
+        "test/cpp/qps/perf_db.proto",
         "test/cpp/qps/client_async.cc",
         "test/cpp/qps/client_sync.cc",
         "test/cpp/qps/driver.cc",
+        "test/cpp/qps/perf_db_client.cc",
         "test/cpp/qps/qps_worker.cc",
         "test/cpp/qps/report.cc",
         "test/cpp/qps/server_async.cc",
@@ -1333,6 +1358,20 @@
         "gpr"
       ]
     },
+    {
+      "name": "grpc_jwt_verifier_test",
+      "build": "test",
+      "language": "c",
+      "src": [
+        "test/core/security/jwt_verifier_test.c"
+      ],
+      "deps": [
+        "grpc_test_util",
+        "grpc",
+        "gpr_test_util",
+        "gpr"
+      ]
+    },
     {
       "name": "grpc_print_google_default_creds_token",
       "build": "tool",
@@ -1375,6 +1414,20 @@
         "gpr"
       ]
     },
+    {
+      "name": "grpc_verify_jwt",
+      "build": "tool",
+      "language": "c",
+      "src": [
+        "test/core/security/verify_jwt.c"
+      ],
+      "deps": [
+        "grpc_test_util",
+        "grpc",
+        "gpr_test_util",
+        "gpr"
+      ]
+    },
     {
       "name": "hpack_parser_test",
       "build": "test",
@@ -1779,6 +1832,20 @@
         "gpr"
       ]
     },
+    {
+      "name": "uri_parser_test",
+      "build": "test",
+      "language": "c",
+      "src": [
+        "test/core/client_config/uri_parser_test.c"
+      ],
+      "deps": [
+        "grpc_test_util",
+        "grpc",
+        "gpr_test_util",
+        "gpr"
+      ]
+    },
     {
       "name": "async_end2end_test",
       "build": "test",

gRPC.podspec

@@ -140,6 +140,7 @@ Pod::Spec.new do |s|
                       'src/core/security/base64.h',
                       'src/core/security/credentials.h',
                       'src/core/security/json_token.h',
+                      'src/core/security/jwt_verifier.h',
                       'src/core/security/secure_endpoint.h',
                       'src/core/security/secure_transport_setup.h',
                       'src/core/security/security_connector.h',
@@ -152,14 +153,24 @@ Pod::Spec.new do |s|
                       'src/core/channel/census_filter.h',
                       'src/core/channel/channel_args.h',
                       'src/core/channel/channel_stack.h',
-                      'src/core/channel/child_channel.h',
                       'src/core/channel/client_channel.h',
-                      'src/core/channel/client_setup.h',
                       'src/core/channel/connected_channel.h',
                       'src/core/channel/context.h',
                       'src/core/channel/http_client_filter.h',
                       'src/core/channel/http_server_filter.h',
                       'src/core/channel/noop_filter.h',
+                      'src/core/client_config/client_config.h',
+                      'src/core/client_config/connector.h',
+                      'src/core/client_config/lb_policies/pick_first.h',
+                      'src/core/client_config/lb_policy.h',
+                      'src/core/client_config/resolver.h',
+                      'src/core/client_config/resolver_factory.h',
+                      'src/core/client_config/resolver_registry.h',
+                      'src/core/client_config/resolvers/dns_resolver.h',
+                      'src/core/client_config/resolvers/unix_resolver_posix.h',
+                      'src/core/client_config/subchannel.h',
+                      'src/core/client_config/subchannel_factory.h',
+                      'src/core/client_config/uri_parser.h',
                       'src/core/compression/message_compress.h',
                       'src/core/debug/trace.h',
                       'src/core/iomgr/alarm.h',
@@ -202,7 +213,6 @@ Pod::Spec.new do |s|
                       'src/core/surface/byte_buffer_queue.h',
                       'src/core/surface/call.h',
                       'src/core/surface/channel.h',
-                      'src/core/surface/client.h',
                       'src/core/surface/completion_queue.h',
                       'src/core/surface/event_string.h',
                       'src/core/surface/init.h',
@@ -229,6 +239,7 @@ Pod::Spec.new do |s|
                       'src/core/transport/chttp2/timeout_encoding.h',
                       'src/core/transport/chttp2/varint.h',
                       'src/core/transport/chttp2_transport.h',
+                      'src/core/transport/connectivity_state.h',
                       'src/core/transport/metadata.h',
                       'src/core/transport/stream_op.h',
                       'src/core/transport/transport.h',
@@ -253,6 +264,7 @@ Pod::Spec.new do |s|
                       'src/core/security/credentials_win32.c',
                       'src/core/security/google_default_credentials.c',
                       'src/core/security/json_token.c',
+                      'src/core/security/jwt_verifier.c',
                       'src/core/security/secure_endpoint.c',
                       'src/core/security/secure_transport_setup.c',
                       'src/core/security/security_connector.c',
@@ -267,13 +279,23 @@ Pod::Spec.new do |s|
                       'src/core/census/grpc_context.c',
                       'src/core/channel/channel_args.c',
                       'src/core/channel/channel_stack.c',
-                      'src/core/channel/child_channel.c',
                       'src/core/channel/client_channel.c',
-                      'src/core/channel/client_setup.c',
                       'src/core/channel/connected_channel.c',
                       'src/core/channel/http_client_filter.c',
                       'src/core/channel/http_server_filter.c',
                       'src/core/channel/noop_filter.c',
+                      'src/core/client_config/client_config.c',
+                      'src/core/client_config/connector.c',
+                      'src/core/client_config/lb_policies/pick_first.c',
+                      'src/core/client_config/lb_policy.c',
+                      'src/core/client_config/resolver.c',
+                      'src/core/client_config/resolver_factory.c',
+                      'src/core/client_config/resolver_registry.c',
+                      'src/core/client_config/resolvers/dns_resolver.c',
+                      'src/core/client_config/resolvers/unix_resolver_posix.c',
+                      'src/core/client_config/subchannel.c',
+                      'src/core/client_config/subchannel_factory.c',
+                      'src/core/client_config/uri_parser.c',
                       'src/core/compression/algorithm.c',
                       'src/core/compression/message_compress.c',
                       'src/core/debug/trace.c',
@@ -326,7 +348,6 @@ Pod::Spec.new do |s|
                       'src/core/surface/call_log_batch.c',
                       'src/core/surface/channel.c',
                       'src/core/surface/channel_create.c',
-                      'src/core/surface/client.c',
                       'src/core/surface/completion_queue.c',
                       'src/core/surface/event_string.c',
                       'src/core/surface/init.c',
@@ -357,6 +378,7 @@ Pod::Spec.new do |s|
                       'src/core/transport/chttp2/varint.c',
                       'src/core/transport/chttp2/writing.c',
                       'src/core/transport/chttp2_transport.c',
+                      'src/core/transport/connectivity_state.c',
                       'src/core/transport/metadata.c',
                       'src/core/transport/stream_op.c',
                       'src/core/transport/transport.c',
@@ -378,6 +400,7 @@ Pod::Spec.new do |s|
                               'src/core/security/base64.h',
                               'src/core/security/credentials.h',
                               'src/core/security/json_token.h',
+                              'src/core/security/jwt_verifier.h',
                               'src/core/security/secure_endpoint.h',
                               'src/core/security/secure_transport_setup.h',
                               'src/core/security/security_connector.h',
@@ -390,14 +413,24 @@ Pod::Spec.new do |s|
                               'src/core/channel/census_filter.h',
                               'src/core/channel/channel_args.h',
                               'src/core/channel/channel_stack.h',
-                              'src/core/channel/child_channel.h',
                               'src/core/channel/client_channel.h',
-                              'src/core/channel/client_setup.h',
                               'src/core/channel/connected_channel.h',
                               'src/core/channel/context.h',
                               'src/core/channel/http_client_filter.h',
                               'src/core/channel/http_server_filter.h',
                               'src/core/channel/noop_filter.h',
+                              'src/core/client_config/client_config.h',
+                              'src/core/client_config/connector.h',
+                              'src/core/client_config/lb_policies/pick_first.h',
+                              'src/core/client_config/lb_policy.h',
+                              'src/core/client_config/resolver.h',
+                              'src/core/client_config/resolver_factory.h',
+                              'src/core/client_config/resolver_registry.h',
+                              'src/core/client_config/resolvers/dns_resolver.h',
+                              'src/core/client_config/resolvers/unix_resolver_posix.h',
+                              'src/core/client_config/subchannel.h',
+                              'src/core/client_config/subchannel_factory.h',
+                              'src/core/client_config/uri_parser.h',
                               'src/core/compression/message_compress.h',
                               'src/core/debug/trace.h',
                               'src/core/iomgr/alarm.h',
@@ -440,7 +473,6 @@ Pod::Spec.new do |s|
                               'src/core/surface/byte_buffer_queue.h',
                               'src/core/surface/call.h',
                               'src/core/surface/channel.h',
-                              'src/core/surface/client.h',
                               'src/core/surface/completion_queue.h',
                               'src/core/surface/event_string.h',
                               'src/core/surface/init.h',
@@ -467,6 +499,7 @@ Pod::Spec.new do |s|
                               'src/core/transport/chttp2/timeout_encoding.h',
                               'src/core/transport/chttp2/varint.h',
                               'src/core/transport/chttp2_transport.h',
+                              'src/core/transport/connectivity_state.h',
                               'src/core/transport/metadata.h',
                               'src/core/transport/stream_op.h',
                               'src/core/transport/transport.h',
@@ -494,9 +527,9 @@ Pod::Spec.new do |s|
     BAD_TIME="$DIR_TIME/time.h"
     GOOD_TIME="$DIR_TIME/grpc_time.h"
     grep -rl "$BAD_TIME" grpc src/core src/objective-c/GRPCClient | xargs sed -i '' -e s@$BAD_TIME@$GOOD_TIME@g
-    if [ -f "include/$BAD_TIME" ];
+    if [ -f "$BAD_TIME" ];
     then
-      mv -f "include/$BAD_TIME" "include/$GOOD_TIME"
+      mv -f "$BAD_TIME" "$GOOD_TIME"
     fi
 
     DIR_STRING="src/core/support"

grpc.bzl

@@ -0,0 +1,128 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""
+Bazel macros to declare gRPC libraries automatically generated from proto files.
+
+This file declares two macros:
+- objc_proto_library
+- objc_grpc_library
+"""
+
+def _lower_underscore_to_upper_camel(str):
+  humps = []
+  for hump in str.split('_'):
+    humps += [hump[0].upper() + hump[1:]]
+  return "".join(humps)
+
+def _file_to_upper_camel(src):
+  elements = src.rpartition('/')
+  upper_camel = _lower_underscore_to_upper_camel(elements[-1])
+  return "".join(elements[:-1] + [upper_camel])
+
+def _file_with_extension(src, ext):
+  elements = src.rpartition('/')
+  basename = elements[-1].partition('.')[0]
+  return "".join(elements[:-1] + [basename, ext])
+
+def _protoc_invocation(srcs, flags):
+  """Returns a command line to invoke protoc from a genrule, on the given
+  sources, using the given flags.
+  """
+  protoc_command = "$(location //external:protoc) -I . "
+  srcs_params = ""
+  for src in srcs:
+    srcs_params += " $(location %s)" % (src)
+  return protoc_command + flags + srcs_params
+
+def objc_proto_library(name, srcs, visibility=None):
+  """Declares an objc_library for the code generated by protoc from the given
+  proto sources. This generated code doesn't include proto services.
+  """
+  h_files = []
+  m_files = []
+  for src in srcs:
+    src = _file_to_upper_camel(src)
+    h_files += [_file_with_extension(src, ".pbobjc.h")]
+    m_files += [_file_with_extension(src, ".pbobjc.m")]
+
+  protoc_flags = "--objc_out=$(GENDIR)"
+
+  native.genrule(
+    name = name + "_codegen",
+    srcs = srcs + ["//external:protoc"],
+    outs = h_files + m_files,
+    cmd = _protoc_invocation(srcs, protoc_flags),
+  )
+  native.objc_library(
+    name = name,
+    hdrs = h_files,
+    includes = ["."],
+    non_arc_srcs = m_files,
+    deps = ["//external:protobuf_objc"],
+    visibility = visibility,
+  )
+
+def objc_grpc_library(name, services, other_messages, visibility=None):
+  """Declares an objc_library for the code generated by gRPC and protoc from the
+  given proto sources (services and other_messages). The generated code doesn't
+  include proto services of the files passed as other_messages.
+  """
+  objc_proto_library(name + "_messages", services + other_messages)
+
+  h_files = []
+  m_files = []
+  for src in services:
+    src = _file_to_upper_camel(src)
+    h_files += [_file_with_extension(src, ".pbrpc.h")]
+    m_files += [_file_with_extension(src, ".pbrpc.m")]
+
+  protoc_flags = ("--grpc_out=$(GENDIR) --plugin=" +
+      "protoc-gen-grpc=$(location //external:grpc_protoc_plugin_objc)")
+
+  native.genrule(
+    name = name + "_codegen",
+    srcs = services + [
+      "//external:grpc_protoc_plugin_objc",
+      "//external:protoc",
+    ],
+    outs = h_files + m_files,
+    cmd = _protoc_invocation(services, protoc_flags),
+  )
+  native.objc_library(
+    name = name,
+    hdrs = h_files,
+    includes = ["."],
+    srcs = m_files,
+    deps = [
+      ":" + name + "_messages",
+      "//external:proto_objc_rpc",
+    ],
+    visibility = visibility,
+  )

include/grpc++/client_context.h

@@ -46,6 +46,7 @@
 
 struct grpc_call;
 struct grpc_completion_queue;
+struct census_context;
 
 namespace grpc {
 
@@ -107,6 +108,10 @@ class ClientContext {
     creds_ = creds;
   }
 
+  // Get and set census context
+  void set_census_context(census_context* ccp) { census_context_ = ccp; }
+  census_context* get_census_context() const { return census_context_; }
+
   void TryCancel();
 
  private:
@@ -154,6 +159,7 @@ class ClientContext {
   gpr_timespec deadline_;
   grpc::string authority_;
   std::shared_ptr<Credentials> creds_;
+  census_context* census_context_;
   std::multimap<grpc::string, grpc::string> send_initial_metadata_;
   std::multimap<grpc::string, grpc::string> recv_initial_metadata_;
   std::multimap<grpc::string, grpc::string> trailing_metadata_;

include/grpc/byte_buffer.h

@@ -102,6 +102,10 @@ void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
 int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
                                  gpr_slice *slice);
 
+/** Returns a RAW byte buffer instance from the output of \a reader. */
+grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader);
+
 #ifdef __cplusplus
 }
 #endif

include/grpc/census.h

@@ -61,6 +61,10 @@ enum census_functions {
 int census_initialize(int functions);
 void census_shutdown();
 
+/* If any census feature has been initialized, this funtion will return a
+ * non-zero value. */
+int census_available();
+
 /* Internally, Census relies on a context, which should be propagated across
  * RPC's. From the RPC subsystems viewpoint, this is an opaque data structure.
  * A context must be used as the first argument to all other census

include/grpc/grpc.h

@@ -118,6 +118,20 @@ typedef struct {
 #define GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER \
   "grpc.http2.initial_sequence_number"
 
+/** Connectivity state of a channel. */
+typedef enum {
+  /** channel is idle */
+  GRPC_CHANNEL_IDLE,
+  /** channel is connecting */
+  GRPC_CHANNEL_CONNECTING,
+  /** channel is ready for work */
+  GRPC_CHANNEL_READY,
+  /** channel has seen a failure but expects to recover */
+  GRPC_CHANNEL_TRANSIENT_FAILURE,
+  /** channel has seen a failure that it cannot recover from */
+  GRPC_CHANNEL_FATAL_FAILURE
+} grpc_connectivity_state;
+
 /* Result of a grpc call. If the caller satisfies the prerequisites of a
    particular operation, the grpc_call_error returned will be GRPC_CALL_OK.
    Receiving any other value listed here is an indication of a bug in the
@@ -427,7 +441,7 @@ void grpc_channel_destroy(grpc_channel *channel);
    has been made. */
 
 /* Called by clients to cancel an RPC on the server.
-   Can be called multiple times, from any thread. 
+   Can be called multiple times, from any thread.
    THREAD-SAFETY grpc_call_cancel and grpc_call_cancel_with_status
    are thread-safe, and can be called at any point before grpc_call_destroy
    is called.*/
@@ -443,7 +457,7 @@ grpc_call_error grpc_call_cancel_with_status(grpc_call *call,
                                              grpc_status_code status,
                                              const char *description);
 
-/* Destroy a call. 
+/* Destroy a call.
    THREAD SAFETY: grpc_call_destroy is thread-compatible */
 void grpc_call_destroy(grpc_call *call);
 

include/grpc/support/atm_win32.h

@@ -37,8 +37,6 @@
 /* Win32 variant of atm_platform.h */
 #include <grpc/support/port_platform.h>
 
-#include <windows.h>
-
 typedef gpr_intptr gpr_atm;
 
 #define gpr_atm_full_barrier MemoryBarrier

include/grpc/support/log_win32.h

@@ -34,8 +34,6 @@
 #ifndef GRPC_SUPPORT_LOG_WIN32_H
 #define GRPC_SUPPORT_LOG_WIN32_H
 
-#include <windows.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif

include/grpc/support/port_platform.h

@@ -34,6 +34,38 @@
 #ifndef GRPC_SUPPORT_PORT_PLATFORM_H
 #define GRPC_SUPPORT_PORT_PLATFORM_H
 
+/* Get windows.h included everywhere (we need it) */
+#if defined(_WIN64) || defined(WIN64) || defined(_WIN32) || defined(WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
+#define GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#define WIN32_LEAN_AND_MEAN
+#endif /* WIN32_LEAN_AND_MEAN */
+
+#ifndef NOMINMAX
+#define GRPC_NOMINMX_WAS_NOT_DEFINED
+#define NOMINMAX
+#endif /* NOMINMAX */
+
+#if defined(_WIN32_WINNT)
+#if _WIN32_WINNT < 0x0600
+#undef _WIN32_WINNT
+#define _WIN32_WINNT 0x0600
+#endif /* _WIN32_WINNT < 0x0600 */
+#endif /* defined(_WIN32_WINNT) */
+
+#include <windows.h>
+
+#ifdef GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#undef GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#undef WIN32_LEAN_AND_MEAN
+#endif /* GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED */
+
+#ifdef GRPC_NOMINMAX_WAS_NOT_DEFINED
+#undef GRPC_NOMINMAX_WAS_NOT_DEFINED
+#undef NOMINMAX
+#endif /* GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED */
+#endif /* defined(_WIN64) || defined(WIN64) || defined(_WIN32) || defined(WIN32) */
+
 /* Override this file with one for your platform if you need to redefine
    things.  */
 

include/grpc/support/sync_win32.h

@@ -36,8 +36,6 @@
 
 #include <grpc/support/sync_generic.h>
 
-#include <windows.h>
-
 typedef struct {
   CRITICAL_SECTION cs; /* Not an SRWLock until Vista is unsupported */
   int locked;

src/core/census/grpc_context.c

@@ -34,12 +34,28 @@
 #include <grpc/census.h>
 #include "src/core/census/grpc_context.h"
 
-void *grpc_census_context_create() {
-  census_context *context;
-  census_context_deserialize(NULL, &context);
-  return (void *)context;
+static void grpc_census_context_destroy(void *context) {
+  census_context_destroy((census_context *)context);
 }
 
-void grpc_census_context_destroy(void *context) {
-  census_context_destroy((census_context *)context);
+void grpc_census_call_set_context(grpc_call *call, census_context *context) {
+  if (!census_available()) {
+    return;
+  }
+  if (context == NULL) {
+    if (grpc_call_is_client(call)) {
+      census_context *context_ptr;
+      census_context_deserialize(NULL, &context_ptr);
+      grpc_call_context_set(call, GRPC_CONTEXT_TRACING, context_ptr,
+                            grpc_census_context_destroy);
+    } else {
+      /* TODO(aveitch): server side context code to be implemented. */
+    }
+  } else {
+    grpc_call_context_set(call, GRPC_CONTEXT_TRACING, context, NULL);
+  }
+}
+
+census_context *grpc_census_call_get_context(grpc_call *call) {
+  return (census_context *)grpc_call_context_get(call, GRPC_CONTEXT_TRACING);
 }

src/core/census/grpc_context.h

@@ -36,7 +36,22 @@
 #ifndef CENSUS_GRPC_CONTEXT_H
 #define CENSUS_GRPC_CONTEXT_H
 
-void *grpc_census_context_create();
-void grpc_census_context_destroy(void *context);
+#include <grpc/census.h>
+#include "src/core/surface/call.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Set census context for the call; Must be called before first call to
+   grpc_call_start_batch(). */
+void grpc_census_call_set_context(grpc_call *call, census_context *context);
+
+/* Retrieve the calls current census context. */
+census_context *grpc_census_call_get_context(grpc_call *call);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* CENSUS_GRPC_CONTEXT_H */

src/core/census/initialize.c

@@ -48,3 +48,5 @@ int census_initialize(int functions) {
 }
 
 void census_shutdown() { census_fns_enabled = CENSUS_NONE; }
+
+int census_available() { return (census_fns_enabled != CENSUS_NONE); }

src/core/channel/census_filter.c

@@ -84,7 +84,8 @@ static void extract_and_annotate_method_tag(grpc_stream_op_buffer* sopb,
   }
 }
 
-static void client_mutate_op(grpc_call_element* elem, grpc_transport_op* op) {
+static void client_mutate_op(grpc_call_element* elem,
+                             grpc_transport_stream_op* op) {
   call_data* calld = elem->call_data;
   channel_data* chand = elem->channel_data;
   if (op->send_ops) {
@@ -93,7 +94,7 @@ static void client_mutate_op(grpc_call_element* elem, grpc_transport_op* op) {
 }
 
 static void client_start_transport_op(grpc_call_element* elem,
-                                      grpc_transport_op* op) {
+                                      grpc_transport_stream_op* op) {
   call_data* calld = elem->call_data;
   GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0));
   client_mutate_op(elem, op);
@@ -110,7 +111,8 @@ static void server_on_done_recv(void* ptr, int success) {
   calld->on_done_recv(calld->recv_user_data, success);
 }
 
-static void server_mutate_op(grpc_call_element* elem, grpc_transport_op* op) {
+static void server_mutate_op(grpc_call_element* elem,
+                             grpc_transport_stream_op* op) {
   call_data* calld = elem->call_data;
   if (op->recv_ops) {
     /* substitute our callback for the op callback */
@@ -123,7 +125,7 @@ static void server_mutate_op(grpc_call_element* elem, grpc_transport_op* op) {
 }
 
 static void server_start_transport_op(grpc_call_element* elem,
-                                      grpc_transport_op* op) {
+                                      grpc_transport_stream_op* op) {
   call_data* calld = elem->call_data;
   GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0));
   server_mutate_op(elem, op);
@@ -145,7 +147,7 @@ static void channel_op(grpc_channel_element* elem,
 
 static void client_init_call_elem(grpc_call_element* elem,
                                   const void* server_transport_data,
-                                  grpc_transport_op* initial_op) {
+                                  grpc_transport_stream_op* initial_op) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
   init_rpc_stats(&d->stats);
@@ -163,7 +165,7 @@ static void client_destroy_call_elem(grpc_call_element* elem) {
 
 static void server_init_call_elem(grpc_call_element* elem,
                                   const void* server_transport_data,
-                                  grpc_transport_op* initial_op) {
+                                  grpc_transport_stream_op* initial_op) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
   init_rpc_stats(&d->stats);
@@ -200,11 +202,23 @@ static void destroy_channel_elem(grpc_channel_element* elem) {
 }
 
 const grpc_channel_filter grpc_client_census_filter = {
-    client_start_transport_op, channel_op, sizeof(call_data),
-    client_init_call_elem, client_destroy_call_elem, sizeof(channel_data),
-    init_channel_elem, destroy_channel_elem, "census-client"};
+    client_start_transport_op,
+    channel_op,
+    sizeof(call_data),
+    client_init_call_elem,
+    client_destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    "census-client"};
 
 const grpc_channel_filter grpc_server_census_filter = {
-    server_start_transport_op, channel_op, sizeof(call_data),
-    server_init_call_elem, server_destroy_call_elem, sizeof(channel_data),
-    init_channel_elem, destroy_channel_elem, "census-server"};
+    server_start_transport_op,
+    channel_op,
+    sizeof(call_data),
+    server_init_call_elem,
+    server_destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    "census-server"};

src/core/channel/channel_args.c

@@ -62,7 +62,8 @@ static grpc_arg copy_arg(const grpc_arg *src) {
 }
 
 grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
-                                                  const grpc_arg *to_add) {
+                                                  const grpc_arg *to_add,
+                                                  size_t num_to_add) {
   grpc_channel_args *dst = gpr_malloc(sizeof(grpc_channel_args));
   size_t i;
   size_t src_num_args = (src == NULL) ? 0 : src->num_args;
@@ -71,17 +72,24 @@ grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
     dst->args = NULL;
     return dst;
   }
-  dst->num_args = src_num_args + ((to_add == NULL) ? 0 : 1);
+  dst->num_args = src_num_args + num_to_add;
   dst->args = gpr_malloc(sizeof(grpc_arg) * dst->num_args);
   for (i = 0; i < src_num_args; i++) {
     dst->args[i] = copy_arg(&src->args[i]);
   }
-  if (to_add != NULL) dst->args[src_num_args] = copy_arg(to_add);
+  for (i = 0; i < num_to_add; i++) {
+    dst->args[i + src_num_args] = copy_arg(&to_add[i]);
+  }
   return dst;
 }
 
 grpc_channel_args *grpc_channel_args_copy(const grpc_channel_args *src) {
-  return grpc_channel_args_copy_and_add(src, NULL);
+  return grpc_channel_args_copy_and_add(src, NULL, 0);
+}
+
+grpc_channel_args *grpc_channel_args_merge(const grpc_channel_args *a,
+                                           const grpc_channel_args *b) {
+  return grpc_channel_args_copy_and_add(a, b->args, b->num_args);
 }
 
 void grpc_channel_args_destroy(grpc_channel_args *a) {
@@ -131,11 +139,11 @@ grpc_compression_level grpc_channel_args_get_compression_level(
   return GRPC_COMPRESS_LEVEL_NONE;
 }
 
-void grpc_channel_args_set_compression_level(
-    grpc_channel_args **a, grpc_compression_level level) {
+void grpc_channel_args_set_compression_level(grpc_channel_args **a,
+                                             grpc_compression_level level) {
   grpc_arg tmp;
   tmp.type = GRPC_ARG_INTEGER;
   tmp.key = GRPC_COMPRESSION_LEVEL_ARG;
   tmp.value.integer = level;
-  *a = grpc_channel_args_copy_and_add(*a, &tmp);
+  *a = grpc_channel_args_copy_and_add(*a, &tmp, 1);
 }

src/core/channel/channel_args.h

@@ -43,7 +43,12 @@ grpc_channel_args *grpc_channel_args_copy(const grpc_channel_args *src);
 /** Copy some arguments and add the to_add parameter in the end.
    If to_add is NULL, it is equivalent to call grpc_channel_args_copy. */
 grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
-                                                  const grpc_arg *to_add);
+                                                  const grpc_arg *to_add,
+                                                  size_t num_to_add);
+
+/** Copy args from a then args from b into a new channel args */
+grpc_channel_args *grpc_channel_args_merge(const grpc_channel_args *a,
+                                           const grpc_channel_args *b);
 
 /** Destroy arguments created by grpc_channel_args_copy */
 void grpc_channel_args_destroy(grpc_channel_args *a);
@@ -58,7 +63,7 @@ grpc_compression_level grpc_channel_args_get_compression_level(
 
 /** Sets the compression level in \a a to \a level. Setting it to
  * GRPC_COMPRESS_LEVEL_NONE disables compression for the channel. */
-void grpc_channel_args_set_compression_level(
-    grpc_channel_args **a, grpc_compression_level level);
+void grpc_channel_args_set_compression_level(grpc_channel_args **a,
+                                             grpc_compression_level level);
 
-#endif  /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H */
+#endif /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H */

src/core/channel/channel_stack.c

@@ -102,7 +102,8 @@ grpc_call_element *grpc_call_stack_element(grpc_call_stack *call_stack,
 }
 
 void grpc_channel_stack_init(const grpc_channel_filter **filters,
-                             size_t filter_count, const grpc_channel_args *args,
+                             size_t filter_count, grpc_channel *master,
+                             const grpc_channel_args *args,
                              grpc_mdctx *metadata_context,
                              grpc_channel_stack *stack) {
   size_t call_size =
@@ -122,8 +123,9 @@ void grpc_channel_stack_init(const grpc_channel_filter **filters,
   for (i = 0; i < filter_count; i++) {
     elems[i].filter = filters[i];
     elems[i].channel_data = user_data;
-    elems[i].filter->init_channel_elem(&elems[i], args, metadata_context,
-                                       i == 0, i == (filter_count - 1));
+    elems[i].filter->init_channel_elem(&elems[i], master, args,
+                                       metadata_context, i == 0,
+                                       i == (filter_count - 1));
     user_data += ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
     call_size += ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_call_data);
   }
@@ -148,7 +150,7 @@ void grpc_channel_stack_destroy(grpc_channel_stack *stack) {
 
 void grpc_call_stack_init(grpc_channel_stack *channel_stack,
                           const void *transport_server_data,
-                          grpc_transport_op *initial_op,
+                          grpc_transport_stream_op *initial_op,
                           grpc_call_stack *call_stack) {
   grpc_channel_element *channel_elems = CHANNEL_ELEMS_FROM_STACK(channel_stack);
   size_t count = channel_stack->count;
@@ -184,14 +186,14 @@ void grpc_call_stack_destroy(grpc_call_stack *stack) {
   }
 }
 
-void grpc_call_next_op(grpc_call_element *elem, grpc_transport_op *op) {
+void grpc_call_next_op(grpc_call_element *elem, grpc_transport_stream_op *op) {
   grpc_call_element *next_elem = elem + 1;
-  next_elem->filter->start_transport_op(next_elem, op);
+  next_elem->filter->start_transport_stream_op(next_elem, op);
 }
 
-void grpc_channel_next_op(grpc_channel_element *elem, grpc_channel_op *op) {
-  grpc_channel_element *next_elem = elem + op->dir;
-  next_elem->filter->channel_op(next_elem, elem, op);
+void grpc_channel_next_op(grpc_channel_element *elem, grpc_transport_op *op) {
+  grpc_channel_element *next_elem = elem + 1;
+  next_elem->filter->start_transport_op(next_elem, op);
 }
 
 grpc_channel_stack *grpc_channel_stack_from_top_element(
@@ -206,7 +208,7 @@ grpc_call_stack *grpc_call_stack_from_top_element(grpc_call_element *elem) {
 }
 
 void grpc_call_element_send_cancel(grpc_call_element *cur_elem) {
-  grpc_transport_op op;
+  grpc_transport_stream_op op;
   memset(&op, 0, sizeof(op));
   op.cancel_with_status = GRPC_STATUS_CANCELLED;
   grpc_call_next_op(cur_elem, &op);

src/core/channel/channel_stack.h

@@ -51,45 +51,6 @@
 typedef struct grpc_channel_element grpc_channel_element;
 typedef struct grpc_call_element grpc_call_element;
 
-/* The direction of the call.
-   The values of the enums (1, -1) matter here - they are used to increment
-   or decrement a pointer to find the next element to call */
-typedef enum { GRPC_CALL_DOWN = 1, GRPC_CALL_UP = -1 } grpc_call_dir;
-
-typedef enum {
-  /* send a goaway message to remote channels indicating that we are going
-     to disconnect in the future */
-  GRPC_CHANNEL_GOAWAY,
-  /* disconnect any underlying transports */
-  GRPC_CHANNEL_DISCONNECT,
-  /* transport received a new call */
-  GRPC_ACCEPT_CALL,
-  /* an underlying transport was closed */
-  GRPC_TRANSPORT_CLOSED,
-  /* an underlying transport is about to be closed */
-  GRPC_TRANSPORT_GOAWAY
-} grpc_channel_op_type;
-
-/* A single filterable operation to be performed on a channel */
-typedef struct {
-  /* The type of operation we're performing */
-  grpc_channel_op_type type;
-  /* The directionality of this call - is it bubbling up the stack, or down? */
-  grpc_call_dir dir;
-
-  /* Argument data, matching up with grpc_channel_op_type names */
-  union {
-    struct {
-      grpc_transport *transport;
-      const void *transport_server_data;
-    } accept_call;
-    struct {
-      grpc_status_code status;
-      gpr_slice message;
-    } goaway;
-  } data;
-} grpc_channel_op;
-
 /* Channel filters specify:
    1. the amount of memory needed in the channel & call (via the sizeof_XXX
       members)
@@ -103,12 +64,12 @@ typedef struct {
 typedef struct {
   /* Called to eg. send/receive data on a call.
      See grpc_call_next_op on how to call the next element in the stack */
-  void (*start_transport_op)(grpc_call_element *elem, grpc_transport_op *op);
+  void (*start_transport_stream_op)(grpc_call_element *elem,
+                                    grpc_transport_stream_op *op);
   /* Called to handle channel level operations - e.g. new calls, or transport
      closure.
      See grpc_channel_next_op on how to call the next element in the stack */
-  void (*channel_op)(grpc_channel_element *elem,
-                     grpc_channel_element *from_elem, grpc_channel_op *op);
+  void (*start_transport_op)(grpc_channel_element *elem, grpc_transport_op *op);
 
   /* sizeof(per call data) */
   size_t sizeof_call_data;
@@ -122,7 +83,7 @@ typedef struct {
      argument.*/
   void (*init_call_elem)(grpc_call_element *elem,
                          const void *server_transport_data,
-                         grpc_transport_op *initial_op);
+                         grpc_transport_stream_op *initial_op);
   /* Destroy per call data.
      The filter does not need to do any chaining */
   void (*destroy_call_elem)(grpc_call_element *elem);
@@ -135,7 +96,7 @@ typedef struct {
      is_first, is_last designate this elements position in the stack, and are
      useful for asserting correct configuration by upper layer code.
      The filter does not need to do any chaining */
-  void (*init_channel_elem)(grpc_channel_element *elem,
+  void (*init_channel_elem)(grpc_channel_element *elem, grpc_channel *master,
                             const grpc_channel_args *args,
                             grpc_mdctx *metadata_context, int is_first,
                             int is_last);
@@ -190,7 +151,8 @@ size_t grpc_channel_stack_size(const grpc_channel_filter **filters,
                                size_t filter_count);
 /* Initialize a channel stack given some filters */
 void grpc_channel_stack_init(const grpc_channel_filter **filters,
-                             size_t filter_count, const grpc_channel_args *args,
+                             size_t filter_count, grpc_channel *master,
+                             const grpc_channel_args *args,
                              grpc_mdctx *metadata_context,
                              grpc_channel_stack *stack);
 /* Destroy a channel stack */
@@ -201,16 +163,16 @@ void grpc_channel_stack_destroy(grpc_channel_stack *stack);
    server. */
 void grpc_call_stack_init(grpc_channel_stack *channel_stack,
                           const void *transport_server_data,
-                          grpc_transport_op *initial_op,
+                          grpc_transport_stream_op *initial_op,
                           grpc_call_stack *call_stack);
 /* Destroy a call stack */
 void grpc_call_stack_destroy(grpc_call_stack *stack);
 
 /* Call the next operation in a call stack */
-void grpc_call_next_op(grpc_call_element *elem, grpc_transport_op *op);
+void grpc_call_next_op(grpc_call_element *elem, grpc_transport_stream_op *op);
 /* Call the next operation (depending on call directionality) in a channel
    stack */
-void grpc_channel_next_op(grpc_channel_element *elem, grpc_channel_op *op);
+void grpc_channel_next_op(grpc_channel_element *elem, grpc_transport_op *op);
 
 /* Given the top element of a channel stack, get the channel stack itself */
 grpc_channel_stack *grpc_channel_stack_from_top_element(
@@ -219,7 +181,7 @@ grpc_channel_stack *grpc_channel_stack_from_top_element(
 grpc_call_stack *grpc_call_stack_from_top_element(grpc_call_element *elem);
 
 void grpc_call_log_op(char *file, int line, gpr_log_severity severity,
-                      grpc_call_element *elem, grpc_transport_op *op);
+                      grpc_call_element *elem, grpc_transport_stream_op *op);
 
 void grpc_call_element_send_cancel(grpc_call_element *cur_elem);
 

src/core/channel/child_channel.c

@@ -1,308 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/channel/child_channel.h"
-#include "src/core/iomgr/iomgr.h"
-#include <grpc/support/alloc.h>
-
-/* Link back filter: passes up calls to the client channel, pushes down calls
-   down */
-
-static void maybe_destroy_channel(grpc_child_channel *channel);
-
-typedef struct {
-  gpr_mu mu;
-  gpr_cv cv;
-  grpc_channel_element *back;
-  /* # of active calls on the channel */
-  gpr_uint32 active_calls;
-  /* has grpc_child_channel_destroy been called? */
-  gpr_uint8 destroyed;
-  /* has the transport reported itself disconnected? */
-  gpr_uint8 disconnected;
-  /* are we calling 'back' - our parent channel */
-  gpr_uint8 calling_back;
-  /* have we or our parent sent goaway yet? - dup suppression */
-  gpr_uint8 sent_goaway;
-  /* are we currently sending farewell (in this file: goaway + disconnect) */
-  gpr_uint8 sending_farewell;
-  /* have we sent farewell (goaway + disconnect) */
-  gpr_uint8 sent_farewell;
-
-  grpc_iomgr_closure finally_destroy_channel_closure;
-  grpc_iomgr_closure send_farewells_closure;
-} lb_channel_data;
-
-typedef struct { grpc_child_channel *channel; } lb_call_data;
-
-static void lb_start_transport_op(grpc_call_element *elem,
-                                  grpc_transport_op *op) {
-  grpc_call_next_op(elem, op);
-}
-
-/* Currently we assume all channel operations should just be pushed up. */
-static void lb_channel_op(grpc_channel_element *elem,
-                          grpc_channel_element *from_elem,
-                          grpc_channel_op *op) {
-  lb_channel_data *chand = elem->channel_data;
-  grpc_channel_element *back;
-  int calling_back = 0;
-
-  switch (op->dir) {
-    case GRPC_CALL_UP:
-      gpr_mu_lock(&chand->mu);
-      back = chand->back;
-      if (back) {
-        chand->calling_back++;
-        calling_back = 1;
-      }
-      gpr_mu_unlock(&chand->mu);
-      if (back) {
-        back->filter->channel_op(chand->back, elem, op);
-      } else if (op->type == GRPC_TRANSPORT_GOAWAY) {
-        gpr_slice_unref(op->data.goaway.message);
-      }
-      break;
-    case GRPC_CALL_DOWN:
-      grpc_channel_next_op(elem, op);
-      break;
-  }
-
-  gpr_mu_lock(&chand->mu);
-  switch (op->type) {
-    case GRPC_TRANSPORT_CLOSED:
-      chand->disconnected = 1;
-      maybe_destroy_channel(grpc_channel_stack_from_top_element(elem));
-      break;
-    case GRPC_CHANNEL_GOAWAY:
-      chand->sent_goaway = 1;
-      break;
-    case GRPC_CHANNEL_DISCONNECT:
-    case GRPC_TRANSPORT_GOAWAY:
-    case GRPC_ACCEPT_CALL:
-      break;
-  }
-
-  if (calling_back) {
-    chand->calling_back--;
-    gpr_cv_signal(&chand->cv);
-    maybe_destroy_channel(grpc_channel_stack_from_top_element(elem));
-  }
-  gpr_mu_unlock(&chand->mu);
-}
-
-/* Constructor for call_data */
-static void lb_init_call_elem(grpc_call_element *elem,
-                              const void *server_transport_data,
-                              grpc_transport_op *initial_op) {}
-
-/* Destructor for call_data */
-static void lb_destroy_call_elem(grpc_call_element *elem) {}
-
-/* Constructor for channel_data */
-static void lb_init_channel_elem(grpc_channel_element *elem,
-                                 const grpc_channel_args *args,
-                                 grpc_mdctx *metadata_context, int is_first,
-                                 int is_last) {
-  lb_channel_data *chand = elem->channel_data;
-  GPR_ASSERT(is_first);
-  GPR_ASSERT(!is_last);
-  gpr_mu_init(&chand->mu);
-  gpr_cv_init(&chand->cv);
-  chand->back = NULL;
-  chand->destroyed = 0;
-  chand->disconnected = 0;
-  chand->active_calls = 0;
-  chand->sent_goaway = 0;
-  chand->calling_back = 0;
-  chand->sending_farewell = 0;
-  chand->sent_farewell = 0;
-}
-
-/* Destructor for channel_data */
-static void lb_destroy_channel_elem(grpc_channel_element *elem) {
-  lb_channel_data *chand = elem->channel_data;
-  gpr_mu_destroy(&chand->mu);
-  gpr_cv_destroy(&chand->cv);
-}
-
-const grpc_channel_filter grpc_child_channel_top_filter = {
-    lb_start_transport_op,   lb_channel_op,
-    sizeof(lb_call_data),    lb_init_call_elem,    lb_destroy_call_elem,
-    sizeof(lb_channel_data), lb_init_channel_elem, lb_destroy_channel_elem,
-    "child-channel",
-};
-
-/* grpc_child_channel proper */
-
-#define LINK_BACK_ELEM_FROM_CHANNEL(channel) \
-  grpc_channel_stack_element((channel), 0)
-
-#define LINK_BACK_ELEM_FROM_CALL(call) grpc_call_stack_element((call), 0)
-
-static void finally_destroy_channel(void *c, int success) {
-  /* ignore success or not... this is a destruction callback and will only
-     happen once - the only purpose here is to release resources */
-  grpc_child_channel *channel = c;
-  lb_channel_data *chand = LINK_BACK_ELEM_FROM_CHANNEL(channel)->channel_data;
-  /* wait for the initiator to leave the mutex */
-  gpr_mu_lock(&chand->mu);
-  gpr_mu_unlock(&chand->mu);
-  grpc_channel_stack_destroy(channel);
-  gpr_free(channel);
-}
-
-static void send_farewells(void *c, int success) {
-  grpc_child_channel *channel = c;
-  grpc_channel_element *lbelem = LINK_BACK_ELEM_FROM_CHANNEL(channel);
-  lb_channel_data *chand = lbelem->channel_data;
-  int send_goaway;
-  grpc_channel_op op;
-
-  gpr_mu_lock(&chand->mu);
-  send_goaway = !chand->sent_goaway;
-  chand->sent_goaway = 1;
-  gpr_mu_unlock(&chand->mu);
-
-  if (send_goaway) {
-    op.type = GRPC_CHANNEL_GOAWAY;
-    op.dir = GRPC_CALL_DOWN;
-    op.data.goaway.status = GRPC_STATUS_OK;
-    op.data.goaway.message = gpr_slice_from_copied_string("Client disconnect");
-    grpc_channel_next_op(lbelem, &op);
-  }
-
-  op.type = GRPC_CHANNEL_DISCONNECT;
-  op.dir = GRPC_CALL_DOWN;
-  grpc_channel_next_op(lbelem, &op);
-
-  gpr_mu_lock(&chand->mu);
-  chand->sending_farewell = 0;
-  chand->sent_farewell = 1;
-  maybe_destroy_channel(channel);
-  gpr_mu_unlock(&chand->mu);
-}
-
-static void maybe_destroy_channel(grpc_child_channel *channel) {
-  lb_channel_data *chand = LINK_BACK_ELEM_FROM_CHANNEL(channel)->channel_data;
-  if (chand->destroyed && chand->disconnected && chand->active_calls == 0 &&
-      !chand->sending_farewell && !chand->calling_back) {
-    chand->finally_destroy_channel_closure.cb = finally_destroy_channel;
-    chand->finally_destroy_channel_closure.cb_arg = channel;
-    grpc_iomgr_add_callback(&chand->finally_destroy_channel_closure);
-  } else if (chand->destroyed && !chand->disconnected &&
-             chand->active_calls == 0 && !chand->sending_farewell &&
-             !chand->sent_farewell) {
-    chand->sending_farewell = 1;
-    chand->send_farewells_closure.cb = send_farewells;
-    chand->send_farewells_closure.cb_arg = channel;
-    grpc_iomgr_add_callback(&chand->send_farewells_closure);
-  }
-}
-
-grpc_child_channel *grpc_child_channel_create(
-    grpc_channel_element *parent, const grpc_channel_filter **filters,
-    size_t filter_count, const grpc_channel_args *args,
-    grpc_mdctx *metadata_context) {
-  grpc_channel_stack *stk =
-      gpr_malloc(grpc_channel_stack_size(filters, filter_count));
-  lb_channel_data *lb;
-
-  grpc_channel_stack_init(filters, filter_count, args, metadata_context, stk);
-
-  lb = LINK_BACK_ELEM_FROM_CHANNEL(stk)->channel_data;
-  gpr_mu_lock(&lb->mu);
-  lb->back = parent;
-  gpr_mu_unlock(&lb->mu);
-
-  return stk;
-}
-
-void grpc_child_channel_destroy(grpc_child_channel *channel,
-                                int wait_for_callbacks) {
-  grpc_channel_element *lbelem = LINK_BACK_ELEM_FROM_CHANNEL(channel);
-  lb_channel_data *chand = lbelem->channel_data;
-
-  gpr_mu_lock(&chand->mu);
-  while (wait_for_callbacks && chand->calling_back) {
-    gpr_cv_wait(&chand->cv, &chand->mu, gpr_inf_future);
-  }
-
-  chand->back = NULL;
-  chand->destroyed = 1;
-  maybe_destroy_channel(channel);
-  gpr_mu_unlock(&chand->mu);
-}
-
-void grpc_child_channel_handle_op(grpc_child_channel *channel,
-                                  grpc_channel_op *op) {
-  grpc_channel_next_op(LINK_BACK_ELEM_FROM_CHANNEL(channel), op);
-}
-
-grpc_child_call *grpc_child_channel_create_call(grpc_child_channel *channel,
-                                                grpc_call_element *parent,
-                                                grpc_transport_op *initial_op) {
-  grpc_call_stack *stk = gpr_malloc((channel)->call_stack_size);
-  grpc_call_element *lbelem;
-  lb_call_data *lbcalld;
-  lb_channel_data *lbchand;
-
-  grpc_call_stack_init(channel, NULL, initial_op, stk);
-  lbelem = LINK_BACK_ELEM_FROM_CALL(stk);
-  lbchand = lbelem->channel_data;
-  lbcalld = lbelem->call_data;
-  lbcalld->channel = channel;
-
-  gpr_mu_lock(&lbchand->mu);
-  lbchand->active_calls++;
-  gpr_mu_unlock(&lbchand->mu);
-
-  return stk;
-}
-
-void grpc_child_call_destroy(grpc_child_call *call) {
-  grpc_call_element *lbelem = LINK_BACK_ELEM_FROM_CALL(call);
-  lb_call_data *calld = lbelem->call_data;
-  lb_channel_data *chand = lbelem->channel_data;
-  grpc_child_channel *channel = calld->channel;
-  grpc_call_stack_destroy(call);
-  gpr_free(call);
-  gpr_mu_lock(&chand->mu);
-  chand->active_calls--;
-  maybe_destroy_channel(channel);
-  gpr_mu_unlock(&chand->mu);
-}
-
-grpc_call_element *grpc_child_call_get_top_element(grpc_child_call *call) {
-  return LINK_BACK_ELEM_FROM_CALL(call);
-}

src/core/channel/child_channel.h

@@ -1,65 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CHILD_CHANNEL_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CHILD_CHANNEL_H
-
-#include "src/core/channel/channel_stack.h"
-
-/* helper for filters that need to host child channel stacks... handles
-   lifetime and upwards propagation cleanly */
-
-extern const grpc_channel_filter grpc_child_channel_top_filter;
-
-typedef grpc_channel_stack grpc_child_channel;
-typedef grpc_call_stack grpc_child_call;
-
-/* filters[0] must be &grpc_child_channel_top_filter */
-grpc_child_channel *grpc_child_channel_create(
-    grpc_channel_element *parent, const grpc_channel_filter **filters,
-    size_t filter_count, const grpc_channel_args *args,
-    grpc_mdctx *metadata_context);
-void grpc_child_channel_handle_op(grpc_child_channel *channel,
-                                  grpc_channel_op *op);
-grpc_channel_element *grpc_child_channel_get_bottom_element(
-    grpc_child_channel *channel);
-void grpc_child_channel_destroy(grpc_child_channel *channel,
-                                int wait_for_callbacks);
-
-grpc_child_call *grpc_child_channel_create_call(grpc_child_channel *channel,
-                                                grpc_call_element *parent,
-                                                grpc_transport_op *initial_op);
-grpc_call_element *grpc_child_call_get_top_element(grpc_child_call *call);
-void grpc_child_call_destroy(grpc_child_call *call);
-
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CHILD_CHANNEL_H */

src/core/channel/client_channel.c

@@ -34,13 +34,15 @@
 #include "src/core/channel/client_channel.h"
 
 #include <stdio.h>
+#include <string.h>
 
 #include "src/core/channel/channel_args.h"
-#include "src/core/channel/child_channel.h"
 #include "src/core/channel/connected_channel.h"
+#include "src/core/surface/channel.h"
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/iomgr/pollset_set.h"
 #include "src/core/support/string.h"
+#include "src/core/transport/connectivity_state.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
@@ -51,31 +53,38 @@
 typedef struct call_data call_data;
 
 typedef struct {
-  /* protects children, child_count, child_capacity, active_child,
-     transport_setup_initiated
-     does not protect channel stacks held by children
-     transport_setup is assumed to be set once during construction */
-  gpr_mu mu;
-
-  /* the sending child (may be null) */
-  grpc_child_channel *active_child;
+  /** metadata context for this channel */
   grpc_mdctx *mdctx;
-
-  /* calls waiting for a channel to be ready */
-  call_data **waiting_children;
-  size_t waiting_child_count;
-  size_t waiting_child_capacity;
-
-  /* transport setup for this channel */
-  grpc_transport_setup *transport_setup;
-  int transport_setup_initiated;
-
-  grpc_channel_args *args;
+  /** resolver for this channel */
+  grpc_resolver *resolver;
+  /** master channel - the grpc_channel instance that ultimately owns
+      this channel_data via its channel stack.
+      We occasionally use this to bump the refcount on the master channel
+      to keep ourselves alive through an asynchronous operation. */
+  grpc_channel *master;
+
+  /** mutex protecting client configuration, including all
+      variables below in this data structure */
+  gpr_mu mu_config;
+  /** currently active load balancer - guarded by mu_config */
+  grpc_lb_policy *lb_policy;
+  /** incoming configuration - set by resolver.next
+      guarded by mu_config */
+  grpc_client_config *incoming_configuration;
+  /** a list of closures that are all waiting for config to come in */
+  grpc_iomgr_closure *waiting_for_config_closures;
+  /** resolver callback */
+  grpc_iomgr_closure on_config_changed;
+  /** connectivity state being tracked */
+  grpc_connectivity_state_tracker state_tracker;
 } channel_data;
 
 typedef enum {
   CALL_CREATED,
-  CALL_WAITING,
+  CALL_WAITING_FOR_SEND,
+  CALL_WAITING_FOR_CONFIG,
+  CALL_WAITING_FOR_PICK,
+  CALL_WAITING_FOR_CALL,
   CALL_ACTIVE,
   CALL_CANCELLED
 } call_state;
@@ -84,75 +93,25 @@ struct call_data {
   /* owning element */
   grpc_call_element *elem;
 
+  gpr_mu mu_state;
+
   call_state state;
   gpr_timespec deadline;
-  union {
-    struct {
-      /* our child call stack */
-      grpc_child_call *child_call;
-    } active;
-    grpc_transport_op waiting_op;
-    struct {
-      grpc_linked_mdelem status;
-      grpc_linked_mdelem details;
-    } cancelled;
-  } s;
+  grpc_subchannel *picked_channel;
+  grpc_iomgr_closure async_setup_task;
+  grpc_transport_stream_op waiting_op;
+  /* our child call stack */
+  grpc_subchannel_call *subchannel_call;
+  grpc_linked_mdelem status;
+  grpc_linked_mdelem details;
 };
 
-static int prepare_activate(grpc_call_element *elem,
-                            grpc_child_channel *on_child) {
-  call_data *calld = elem->call_data;
-  channel_data *chand = elem->channel_data;
-  if (calld->state == CALL_CANCELLED) return 0;
-
-  /* no more access to calld->s.waiting allowed */
-  GPR_ASSERT(calld->state == CALL_WAITING);
-
-  if (calld->s.waiting_op.bind_pollset) {
-    grpc_transport_setup_del_interested_party(chand->transport_setup,
-                                              calld->s.waiting_op.bind_pollset);
-  }
-
-  calld->state = CALL_ACTIVE;
-
-  /* create a child call */
-  /* TODO(ctiller): pass the waiting op down here */
-  calld->s.active.child_call =
-      grpc_child_channel_create_call(on_child, elem, NULL);
-
-  return 1;
-}
-
-static void complete_activate(grpc_call_element *elem, grpc_transport_op *op) {
-  call_data *calld = elem->call_data;
-  grpc_call_element *child_elem =
-      grpc_child_call_get_top_element(calld->s.active.child_call);
-
-  GPR_ASSERT(calld->state == CALL_ACTIVE);
-
-  /* continue the start call down the stack, this nees to happen after metadata
-     are flushed*/
-  child_elem->filter->start_transport_op(child_elem, op);
-}
-
-static void remove_waiting_child(channel_data *chand, call_data *calld) {
-  size_t new_count;
-  size_t i;
-  for (i = 0, new_count = 0; i < chand->waiting_child_count; i++) {
-    if (chand->waiting_children[i] == calld) {
-      grpc_transport_setup_del_interested_party(
-          chand->transport_setup, calld->s.waiting_op.bind_pollset);
-      continue;
-    }
-    chand->waiting_children[new_count++] = chand->waiting_children[i];
-  }
-  GPR_ASSERT(new_count == chand->waiting_child_count - 1 ||
-             new_count == chand->waiting_child_count);
-  chand->waiting_child_count = new_count;
-}
+static grpc_iomgr_closure *merge_into_waiting_op(
+    grpc_call_element *elem,
+    grpc_transport_stream_op *new_op) GRPC_MUST_USE_RESULT;
 
 static void handle_op_after_cancellation(grpc_call_element *elem,
-                                         grpc_transport_op *op) {
+                                         grpc_transport_stream_op *op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   if (op->send_ops) {
@@ -163,15 +122,15 @@ static void handle_op_after_cancellation(grpc_call_element *elem,
     char status[GPR_LTOA_MIN_BUFSIZE];
     grpc_metadata_batch mdb;
     gpr_ltoa(GRPC_STATUS_CANCELLED, status);
-    calld->s.cancelled.status.md =
+    calld->status.md =
         grpc_mdelem_from_strings(chand->mdctx, "grpc-status", status);
-    calld->s.cancelled.details.md =
+    calld->details.md =
         grpc_mdelem_from_strings(chand->mdctx, "grpc-message", "Cancelled");
-    calld->s.cancelled.status.prev = calld->s.cancelled.details.next = NULL;
-    calld->s.cancelled.status.next = &calld->s.cancelled.details;
-    calld->s.cancelled.details.prev = &calld->s.cancelled.status;
-    mdb.list.head = &calld->s.cancelled.status;
-    mdb.list.tail = &calld->s.cancelled.details;
+    calld->status.prev = calld->details.next = NULL;
+    calld->status.next = &calld->details;
+    calld->details.prev = &calld->status;
+    mdb.list.head = &calld->status;
+    mdb.list.tail = &calld->details;
     mdb.garbage.head = mdb.garbage.tail = NULL;
     mdb.deadline = gpr_inf_future;
     grpc_sopb_add_metadata(op->recv_ops, mdb);
@@ -183,192 +142,372 @@ static void handle_op_after_cancellation(grpc_call_element *elem,
   }
 }
 
-static void cc_start_transport_op(grpc_call_element *elem,
-                                  grpc_transport_op *op) {
+typedef struct {
+  grpc_iomgr_closure closure;
+  grpc_call_element *elem;
+} waiting_call;
+
+static void perform_transport_stream_op(grpc_call_element *elem,
+                                        grpc_transport_stream_op *op,
+                                        int continuation);
+
+static void continue_with_pick(void *arg, int iomgr_success) {
+  waiting_call *wc = arg;
+  call_data *calld = wc->elem->call_data;
+  perform_transport_stream_op(wc->elem, &calld->waiting_op, 1);
+  gpr_free(wc);
+}
+
+static void add_to_lb_policy_wait_queue_locked_state_config(
+    grpc_call_element *elem) {
+  channel_data *chand = elem->channel_data;
+  waiting_call *wc = gpr_malloc(sizeof(*wc));
+  grpc_iomgr_closure_init(&wc->closure, continue_with_pick, wc);
+  wc->elem = elem;
+  wc->closure.next = chand->waiting_for_config_closures;
+  chand->waiting_for_config_closures = &wc->closure;
+}
+
+static int is_empty(void *p, int len) {
+  char *ptr = p;
+  int i;
+  for (i = 0; i < len; i++) {
+    if (ptr[i] != 0) return 0;
+  }
+  return 1;
+}
+
+static void started_call(void *arg, int iomgr_success) {
+  call_data *calld = arg;
+  grpc_transport_stream_op op;
+  int have_waiting;
+
+  gpr_mu_lock(&calld->mu_state);
+  if (calld->state == CALL_CANCELLED && calld->subchannel_call != NULL) {
+    memset(&op, 0, sizeof(op));
+    op.cancel_with_status = GRPC_STATUS_CANCELLED;
+    gpr_mu_unlock(&calld->mu_state);
+    grpc_subchannel_call_process_op(calld->subchannel_call, &op);
+  } else if (calld->state == CALL_WAITING_FOR_CALL) {
+    have_waiting = !is_empty(&calld->waiting_op, sizeof(calld->waiting_op));
+    if (calld->subchannel_call != NULL) {
+      calld->state = CALL_ACTIVE;
+      gpr_mu_unlock(&calld->mu_state);
+      if (have_waiting) {
+        grpc_subchannel_call_process_op(calld->subchannel_call,
+                                        &calld->waiting_op);
+      }
+    } else {
+      calld->state = CALL_CANCELLED;
+      gpr_mu_unlock(&calld->mu_state);
+      if (have_waiting) {
+        handle_op_after_cancellation(calld->elem, &calld->waiting_op);
+      }
+    }
+  } else {
+    GPR_ASSERT(calld->state == CALL_CANCELLED);
+    gpr_mu_unlock(&calld->mu_state);
+  }
+}
+
+static void picked_target(void *arg, int iomgr_success) {
+  call_data *calld = arg;
+  grpc_pollset *pollset;
+
+  if (calld->picked_channel == NULL) {
+    /* treat this like a cancellation */
+    calld->waiting_op.cancel_with_status = GRPC_STATUS_UNAVAILABLE;
+    perform_transport_stream_op(calld->elem, &calld->waiting_op, 1);
+  } else {
+    gpr_mu_lock(&calld->mu_state);
+    if (calld->state == CALL_CANCELLED) {
+      gpr_mu_unlock(&calld->mu_state);
+      handle_op_after_cancellation(calld->elem, &calld->waiting_op);
+    } else {
+      GPR_ASSERT(calld->state == CALL_WAITING_FOR_PICK);
+      calld->state = CALL_WAITING_FOR_CALL;
+      pollset = calld->waiting_op.bind_pollset;
+      gpr_mu_unlock(&calld->mu_state);
+      grpc_iomgr_closure_init(&calld->async_setup_task, started_call, calld);
+      grpc_subchannel_create_call(calld->picked_channel, pollset,
+                                  &calld->subchannel_call,
+                                  &calld->async_setup_task);
+    }
+  }
+}
+
+static void pick_target(grpc_lb_policy *lb_policy, call_data *calld) {
+  grpc_metadata_batch *initial_metadata;
+  grpc_transport_stream_op *op = &calld->waiting_op;
+
+  GPR_ASSERT(op->bind_pollset);
+  GPR_ASSERT(op->send_ops);
+  GPR_ASSERT(op->send_ops->nops >= 1);
+  GPR_ASSERT(op->send_ops->ops[0].type == GRPC_OP_METADATA);
+  initial_metadata = &op->send_ops->ops[0].data.metadata;
+
+  grpc_iomgr_closure_init(&calld->async_setup_task, picked_target, calld);
+  grpc_lb_policy_pick(lb_policy, op->bind_pollset, initial_metadata,
+                      &calld->picked_channel, &calld->async_setup_task);
+}
+
+static grpc_iomgr_closure *merge_into_waiting_op(
+    grpc_call_element *elem, grpc_transport_stream_op *new_op) {
+  call_data *calld = elem->call_data;
+  grpc_iomgr_closure *consumed_op = NULL;
+  grpc_transport_stream_op *waiting_op = &calld->waiting_op;
+  GPR_ASSERT((waiting_op->send_ops != NULL) + (new_op->send_ops != NULL) <= 1);
+  GPR_ASSERT((waiting_op->recv_ops != NULL) + (new_op->recv_ops != NULL) <= 1);
+  if (new_op->send_ops != NULL) {
+    waiting_op->send_ops = new_op->send_ops;
+    waiting_op->is_last_send = new_op->is_last_send;
+    waiting_op->on_done_send = new_op->on_done_send;
+  }
+  if (new_op->recv_ops != NULL) {
+    waiting_op->recv_ops = new_op->recv_ops;
+    waiting_op->recv_state = new_op->recv_state;
+    waiting_op->on_done_recv = new_op->on_done_recv;
+  }
+  if (new_op->on_consumed != NULL) {
+    if (waiting_op->on_consumed != NULL) {
+      consumed_op = waiting_op->on_consumed;
+    }
+    waiting_op->on_consumed = new_op->on_consumed;
+  }
+  if (new_op->cancel_with_status != GRPC_STATUS_OK) {
+    waiting_op->cancel_with_status = new_op->cancel_with_status;
+  }
+  return consumed_op;
+}
+
+static void perform_transport_stream_op(grpc_call_element *elem,
+                                        grpc_transport_stream_op *op,
+                                        int continuation) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
-  grpc_call_element *child_elem;
-  grpc_transport_op waiting_op;
+  grpc_subchannel_call *subchannel_call;
+  grpc_lb_policy *lb_policy;
+  grpc_transport_stream_op op2;
+  grpc_iomgr_closure *consumed_op = NULL;
   GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
 
-  gpr_mu_lock(&chand->mu);
+  gpr_mu_lock(&calld->mu_state);
   switch (calld->state) {
     case CALL_ACTIVE:
-      child_elem = grpc_child_call_get_top_element(calld->s.active.child_call);
-      gpr_mu_unlock(&chand->mu);
-      child_elem->filter->start_transport_op(child_elem, op);
+      GPR_ASSERT(!continuation);
+      subchannel_call = calld->subchannel_call;
+      gpr_mu_unlock(&calld->mu_state);
+      grpc_subchannel_call_process_op(subchannel_call, op);
       break;
-    case CALL_CREATED:
-      if (op->cancel_with_status != GRPC_STATUS_OK) {
-        calld->state = CALL_CANCELLED;
-        gpr_mu_unlock(&chand->mu);
-        handle_op_after_cancellation(elem, op);
-      } else {
-        calld->state = CALL_WAITING;
-        calld->s.waiting_op.bind_pollset = NULL;
-        if (chand->active_child) {
-          /* channel is connected - use the connected stack */
-          if (prepare_activate(elem, chand->active_child)) {
-            gpr_mu_unlock(&chand->mu);
-            /* activate the request (pass it down) outside the lock */
-            complete_activate(elem, op);
-          } else {
-            gpr_mu_unlock(&chand->mu);
+    case CALL_CANCELLED:
+      gpr_mu_unlock(&calld->mu_state);
+      handle_op_after_cancellation(elem, op);
+      break;
+    case CALL_WAITING_FOR_SEND:
+      GPR_ASSERT(!continuation);
+      consumed_op = merge_into_waiting_op(elem, op);
+      if (!calld->waiting_op.send_ops &&
+          calld->waiting_op.cancel_with_status == GRPC_STATUS_OK) {
+        gpr_mu_unlock(&calld->mu_state);
+        break;
+      }
+      *op = calld->waiting_op;
+      memset(&calld->waiting_op, 0, sizeof(calld->waiting_op));
+      continuation = 1;
+    /* fall through */
+    case CALL_WAITING_FOR_CONFIG:
+    case CALL_WAITING_FOR_PICK:
+    case CALL_WAITING_FOR_CALL:
+      if (!continuation) {
+        if (op->cancel_with_status != GRPC_STATUS_OK) {
+          calld->state = CALL_CANCELLED;
+          op2 = calld->waiting_op;
+          memset(&calld->waiting_op, 0, sizeof(calld->waiting_op));
+          if (op->on_consumed) {
+            calld->waiting_op.on_consumed = op->on_consumed;
+            op->on_consumed = NULL;
+          } else if (op2.on_consumed) {
+            calld->waiting_op.on_consumed = op2.on_consumed;
+            op2.on_consumed = NULL;
           }
+          gpr_mu_unlock(&calld->mu_state);
+          handle_op_after_cancellation(elem, op);
+          handle_op_after_cancellation(elem, &op2);
         } else {
-          /* check to see if we should initiate a connection (if we're not
-             already),
-             but don't do so until outside the lock to avoid re-entrancy
-             problems if
-             the callback is immediate */
-          int initiate_transport_setup = 0;
-          if (!chand->transport_setup_initiated) {
-            chand->transport_setup_initiated = 1;
-            initiate_transport_setup = 1;
-          }
-          /* add this call to the waiting set to be resumed once we have a child
-             channel stack, growing the waiting set if needed */
-          if (chand->waiting_child_count == chand->waiting_child_capacity) {
-            chand->waiting_child_capacity =
-                GPR_MAX(chand->waiting_child_capacity * 2, 8);
-            chand->waiting_children = gpr_realloc(
-                chand->waiting_children,
-                chand->waiting_child_capacity * sizeof(call_data *));
-          }
-          calld->s.waiting_op = *op;
-          chand->waiting_children[chand->waiting_child_count++] = calld;
-          grpc_transport_setup_add_interested_party(chand->transport_setup,
-                                                    op->bind_pollset);
-          gpr_mu_unlock(&chand->mu);
-
-          /* finally initiate transport setup if needed */
-          if (initiate_transport_setup) {
-            grpc_transport_setup_initiate(chand->transport_setup);
-          }
+          consumed_op = merge_into_waiting_op(elem, op);
+          gpr_mu_unlock(&calld->mu_state);
         }
+        break;
       }
-      break;
-    case CALL_WAITING:
+    /* fall through */
+    case CALL_CREATED:
       if (op->cancel_with_status != GRPC_STATUS_OK) {
-        waiting_op = calld->s.waiting_op;
-        remove_waiting_child(chand, calld);
         calld->state = CALL_CANCELLED;
-        gpr_mu_unlock(&chand->mu);
-        handle_op_after_cancellation(elem, &waiting_op);
+        gpr_mu_unlock(&calld->mu_state);
         handle_op_after_cancellation(elem, op);
       } else {
-        GPR_ASSERT((calld->s.waiting_op.send_ops == NULL) !=
-                   (op->send_ops == NULL));
-        GPR_ASSERT((calld->s.waiting_op.recv_ops == NULL) !=
-                   (op->recv_ops == NULL));
-        if (op->send_ops) {
-          calld->s.waiting_op.send_ops = op->send_ops;
-          calld->s.waiting_op.is_last_send = op->is_last_send;
-          calld->s.waiting_op.on_done_send = op->on_done_send;
-        }
-        if (op->recv_ops) {
-          calld->s.waiting_op.recv_ops = op->recv_ops;
-          calld->s.waiting_op.recv_state = op->recv_state;
-          calld->s.waiting_op.on_done_recv = op->on_done_recv;
-        }
-        gpr_mu_unlock(&chand->mu);
-        if (op->on_consumed) {
-          op->on_consumed->cb(op->on_consumed->cb_arg, 0);
+        calld->waiting_op = *op;
+
+        if (op->send_ops == NULL) {
+          /* need to have some send ops before we can select the
+             lb target */
+          calld->state = CALL_WAITING_FOR_SEND;
+          gpr_mu_unlock(&calld->mu_state);
+        } else {
+          gpr_mu_lock(&chand->mu_config);
+          lb_policy = chand->lb_policy;
+          if (lb_policy) {
+            GRPC_LB_POLICY_REF(lb_policy, "pick");
+            gpr_mu_unlock(&chand->mu_config);
+            calld->state = CALL_WAITING_FOR_PICK;
+            gpr_mu_unlock(&calld->mu_state);
+
+            pick_target(lb_policy, calld);
+
+            GRPC_LB_POLICY_UNREF(lb_policy, "pick");
+          } else if (chand->resolver != NULL) {
+            calld->state = CALL_WAITING_FOR_CONFIG;
+            add_to_lb_policy_wait_queue_locked_state_config(elem);
+            gpr_mu_unlock(&chand->mu_config);
+            gpr_mu_unlock(&calld->mu_state);
+          } else {
+            calld->state = CALL_CANCELLED;
+            gpr_mu_unlock(&chand->mu_config);
+            gpr_mu_unlock(&calld->mu_state);
+            handle_op_after_cancellation(elem, op);
+          }
         }
       }
       break;
-    case CALL_CANCELLED:
-      gpr_mu_unlock(&chand->mu);
-      handle_op_after_cancellation(elem, op);
-      break;
   }
+
+  if (consumed_op != NULL) {
+    consumed_op->cb(consumed_op->cb_arg, 1);
+  }
+}
+
+static void cc_start_transport_stream_op(grpc_call_element *elem,
+                                         grpc_transport_stream_op *op) {
+  perform_transport_stream_op(elem, op, 0);
+}
+
+static void cc_on_config_changed(void *arg, int iomgr_success) {
+  channel_data *chand = arg;
+  grpc_lb_policy *lb_policy = NULL;
+  grpc_lb_policy *old_lb_policy;
+  grpc_resolver *old_resolver;
+  grpc_iomgr_closure *wakeup_closures = NULL;
+
+  if (chand->incoming_configuration != NULL) {
+    lb_policy = grpc_client_config_get_lb_policy(chand->incoming_configuration);
+    GRPC_LB_POLICY_REF(lb_policy, "channel");
+
+    grpc_client_config_unref(chand->incoming_configuration);
+  }
+
+  chand->incoming_configuration = NULL;
+
+  gpr_mu_lock(&chand->mu_config);
+  old_lb_policy = chand->lb_policy;
+  chand->lb_policy = lb_policy;
+  if (lb_policy != NULL || chand->resolver == NULL /* disconnected */) {
+    wakeup_closures = chand->waiting_for_config_closures;
+    chand->waiting_for_config_closures = NULL;
+  }
+  gpr_mu_unlock(&chand->mu_config);
+
+  if (old_lb_policy) {
+    GRPC_LB_POLICY_UNREF(old_lb_policy, "channel");
+  }
+
+  gpr_mu_lock(&chand->mu_config);
+  if (iomgr_success && chand->resolver) {
+    grpc_resolver *resolver = chand->resolver;
+    GRPC_RESOLVER_REF(resolver, "channel-next");
+    gpr_mu_unlock(&chand->mu_config);
+    GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+    grpc_resolver_next(resolver, &chand->incoming_configuration,
+                       &chand->on_config_changed);
+    GRPC_RESOLVER_UNREF(resolver, "channel-next");
+  } else {
+    old_resolver = chand->resolver;
+    chand->resolver = NULL;
+    grpc_connectivity_state_set(&chand->state_tracker,
+                                GRPC_CHANNEL_FATAL_FAILURE);
+    gpr_mu_unlock(&chand->mu_config);
+    if (old_resolver != NULL) {
+      grpc_resolver_shutdown(old_resolver);
+      GRPC_RESOLVER_UNREF(old_resolver, "channel");
+    }
+  }
+
+  while (wakeup_closures) {
+    grpc_iomgr_closure *next = wakeup_closures->next;
+    grpc_iomgr_add_callback(wakeup_closures);
+    wakeup_closures = next;
+  }
+
+  GRPC_CHANNEL_INTERNAL_UNREF(chand->master, "resolver");
 }
 
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
+static void cc_start_transport_op(grpc_channel_element *elem,
+                                  grpc_transport_op *op) {
+  grpc_lb_policy *lb_policy = NULL;
   channel_data *chand = elem->channel_data;
-  grpc_child_channel *child_channel;
-  grpc_channel_op rop;
-  GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
+  grpc_resolver *destroy_resolver = NULL;
+  grpc_iomgr_closure *on_consumed = op->on_consumed;
+  op->on_consumed = NULL;
+
+  GPR_ASSERT(op->set_accept_stream == NULL);
+  GPR_ASSERT(op->bind_pollset == NULL);
+
+  gpr_mu_lock(&chand->mu_config);
+  if (op->on_connectivity_state_change != NULL) {
+    grpc_connectivity_state_notify_on_state_change(
+        &chand->state_tracker, op->connectivity_state,
+        op->on_connectivity_state_change);
+    op->on_connectivity_state_change = NULL;
+    op->connectivity_state = NULL;
+  }
 
-  switch (op->type) {
-    case GRPC_CHANNEL_GOAWAY:
-      /* sending goaway: clear out the active child on the way through */
-      gpr_mu_lock(&chand->mu);
-      child_channel = chand->active_child;
-      chand->active_child = NULL;
-      gpr_mu_unlock(&chand->mu);
-      if (child_channel) {
-        grpc_child_channel_handle_op(child_channel, op);
-        grpc_child_channel_destroy(child_channel, 1);
-      } else {
-        gpr_slice_unref(op->data.goaway.message);
-      }
-      break;
-    case GRPC_CHANNEL_DISCONNECT:
-      /* sending disconnect: clear out the active child on the way through */
-      gpr_mu_lock(&chand->mu);
-      child_channel = chand->active_child;
-      chand->active_child = NULL;
-      gpr_mu_unlock(&chand->mu);
-      if (child_channel) {
-        grpc_child_channel_destroy(child_channel, 1);
-      }
-      /* fake a transport closed to satisfy the refcounting in client */
-      rop.type = GRPC_TRANSPORT_CLOSED;
-      rop.dir = GRPC_CALL_UP;
-      grpc_channel_next_op(elem, &rop);
-      break;
-    case GRPC_TRANSPORT_GOAWAY:
-      /* receiving goaway: if it's from our active child, drop the active child;
-         in all cases consume the event here */
-      gpr_mu_lock(&chand->mu);
-      child_channel = grpc_channel_stack_from_top_element(from_elem);
-      if (child_channel == chand->active_child) {
-        chand->active_child = NULL;
-      } else {
-        child_channel = NULL;
-      }
-      gpr_mu_unlock(&chand->mu);
-      if (child_channel) {
-        grpc_child_channel_destroy(child_channel, 0);
-      }
-      gpr_slice_unref(op->data.goaway.message);
-      break;
-    case GRPC_TRANSPORT_CLOSED:
-      /* receiving disconnect: if it's from our active child, drop the active
-         child; in all cases consume the event here */
-      gpr_mu_lock(&chand->mu);
-      child_channel = grpc_channel_stack_from_top_element(from_elem);
-      if (child_channel == chand->active_child) {
-        chand->active_child = NULL;
-      } else {
-        child_channel = NULL;
-      }
-      gpr_mu_unlock(&chand->mu);
-      if (child_channel) {
-        grpc_child_channel_destroy(child_channel, 0);
-      }
-      break;
-    default:
-      switch (op->dir) {
-        case GRPC_CALL_UP:
-          grpc_channel_next_op(elem, op);
-          break;
-        case GRPC_CALL_DOWN:
-          gpr_log(GPR_ERROR, "unhandled channel op: %d", op->type);
-          abort();
-          break;
-      }
-      break;
+  if (op->disconnect && chand->resolver != NULL) {
+    grpc_connectivity_state_set(&chand->state_tracker,
+                                GRPC_CHANNEL_FATAL_FAILURE);
+    destroy_resolver = chand->resolver;
+    chand->resolver = NULL;
+    if (chand->lb_policy != NULL) {
+      grpc_lb_policy_shutdown(chand->lb_policy);
+    }
+  }
+
+  if (!is_empty(op, sizeof(*op))) {
+    lb_policy = chand->lb_policy;
+    if (lb_policy) {
+      GRPC_LB_POLICY_REF(lb_policy, "broadcast");
+    }
+  }
+  gpr_mu_unlock(&chand->mu_config);
+
+  if (destroy_resolver) {
+    grpc_resolver_shutdown(destroy_resolver);
+    GRPC_RESOLVER_UNREF(destroy_resolver, "channel");
+  }
+
+  if (lb_policy) {
+    grpc_lb_policy_broadcast(lb_policy, op);
+    GRPC_LB_POLICY_UNREF(lb_policy, "broadcast");
+  }
+
+  if (on_consumed) {
+    grpc_iomgr_add_callback(on_consumed);
   }
 }
 
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   call_data *calld = elem->call_data;
 
   /* TODO(ctiller): is there something useful we can do here? */
@@ -376,6 +515,7 @@ static void init_call_elem(grpc_call_element *elem,
 
   GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
   GPR_ASSERT(server_transport_data == NULL);
+  gpr_mu_init(&calld->mu_state);
   calld->elem = elem;
   calld->state = CALL_CREATED;
   calld->deadline = gpr_inf_future;
@@ -384,161 +524,88 @@ static void init_call_elem(grpc_call_element *elem,
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_call_element *elem) {
   call_data *calld = elem->call_data;
-  channel_data *chand = elem->channel_data;
+  grpc_subchannel_call *subchannel_call;
 
   /* if the call got activated, we need to destroy the child stack also, and
      remove it from the in-flight requests tracked by the child_entry we
      picked */
-  gpr_mu_lock(&chand->mu);
+  gpr_mu_lock(&calld->mu_state);
   switch (calld->state) {
     case CALL_ACTIVE:
-      gpr_mu_unlock(&chand->mu);
-      grpc_child_call_destroy(calld->s.active.child_call);
+      subchannel_call = calld->subchannel_call;
+      gpr_mu_unlock(&calld->mu_state);
+      GRPC_SUBCHANNEL_CALL_UNREF(subchannel_call, "client_channel");
       break;
-    case CALL_WAITING:
-      remove_waiting_child(chand, calld);
-      gpr_mu_unlock(&chand->mu);
+    case CALL_CREATED:
+    case CALL_CANCELLED:
+      gpr_mu_unlock(&calld->mu_state);
       break;
-    default:
-      gpr_mu_unlock(&chand->mu);
+    case CALL_WAITING_FOR_PICK:
+    case CALL_WAITING_FOR_CONFIG:
+    case CALL_WAITING_FOR_CALL:
+    case CALL_WAITING_FOR_SEND:
+      gpr_log(GPR_ERROR, "should never reach here");
+      abort();
       break;
   }
-  GPR_ASSERT(calld->state != CALL_WAITING);
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args,
                               grpc_mdctx *metadata_context, int is_first,
                               int is_last) {
   channel_data *chand = elem->channel_data;
 
-  GPR_ASSERT(!is_first);
+  memset(chand, 0, sizeof(*chand));
+
   GPR_ASSERT(is_last);
   GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
 
-  gpr_mu_init(&chand->mu);
-  chand->active_child = NULL;
-  chand->waiting_children = NULL;
-  chand->waiting_child_count = 0;
-  chand->waiting_child_capacity = 0;
-  chand->transport_setup = NULL;
-  chand->transport_setup_initiated = 0;
-  chand->args = grpc_channel_args_copy(args);
+  gpr_mu_init(&chand->mu_config);
   chand->mdctx = metadata_context;
+  chand->master = master;
+  grpc_iomgr_closure_init(&chand->on_config_changed, cc_on_config_changed,
+                          chand);
+
+  grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE);
 }
 
 /* Destructor for channel_data */
 static void destroy_channel_elem(grpc_channel_element *elem) {
   channel_data *chand = elem->channel_data;
 
-  grpc_transport_setup_cancel(chand->transport_setup);
-
-  if (chand->active_child) {
-    grpc_child_channel_destroy(chand->active_child, 1);
-    chand->active_child = NULL;
+  if (chand->resolver != NULL) {
+    grpc_resolver_shutdown(chand->resolver);
+    GRPC_RESOLVER_UNREF(chand->resolver, "channel");
   }
-
-  grpc_channel_args_destroy(chand->args);
-
-  gpr_mu_destroy(&chand->mu);
-  GPR_ASSERT(chand->waiting_child_count == 0);
-  gpr_free(chand->waiting_children);
+  if (chand->lb_policy != NULL) {
+    GRPC_LB_POLICY_UNREF(chand->lb_policy, "channel");
+  }
+  gpr_mu_destroy(&chand->mu_config);
 }
 
 const grpc_channel_filter grpc_client_channel_filter = {
-    cc_start_transport_op, channel_op,           sizeof(call_data),
-    init_call_elem,        destroy_call_elem,    sizeof(channel_data),
-    init_channel_elem,     destroy_channel_elem, "client-channel",
+    cc_start_transport_stream_op,
+    cc_start_transport_op,
+    sizeof(call_data),
+    init_call_elem,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    "client-channel",
 };
 
-grpc_transport_setup_result grpc_client_channel_transport_setup_complete(
-    grpc_channel_stack *channel_stack, grpc_transport *transport,
-    grpc_channel_filter const **channel_filters, size_t num_channel_filters,
-    grpc_mdctx *mdctx) {
-  /* we just got a new transport: lets create a child channel stack for it */
-  grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack);
-  channel_data *chand = elem->channel_data;
-  size_t num_child_filters = 2 + num_channel_filters;
-  grpc_channel_filter const **child_filters;
-  grpc_transport_setup_result result;
-  grpc_child_channel *old_active = NULL;
-  call_data **waiting_children;
-  size_t waiting_child_count;
-  size_t i;
-  grpc_transport_op *call_ops;
-
-  /* build the child filter stack */
-  child_filters = gpr_malloc(sizeof(grpc_channel_filter *) * num_child_filters);
-  /* we always need a link back filter to get back to the connected channel */
-  child_filters[0] = &grpc_child_channel_top_filter;
-  for (i = 0; i < num_channel_filters; i++) {
-    child_filters[i + 1] = channel_filters[i];
-  }
-  /* and we always need a connected channel to talk to the transport */
-  child_filters[num_child_filters - 1] = &grpc_connected_channel_filter;
-
-  GPR_ASSERT(elem->filter == &grpc_client_channel_filter);
-
-  /* BEGIN LOCKING CHANNEL */
-  gpr_mu_lock(&chand->mu);
-  chand->transport_setup_initiated = 0;
-
-  if (chand->active_child) {
-    old_active = chand->active_child;
-  }
-  chand->active_child = grpc_child_channel_create(
-      elem, child_filters, num_child_filters, chand->args, mdctx);
-  result =
-      grpc_connected_channel_bind_transport(chand->active_child, transport);
-
-  /* capture the waiting children - we'll activate them outside the lock
-     to avoid re-entrancy problems */
-  waiting_children = chand->waiting_children;
-  waiting_child_count = chand->waiting_child_count;
-  /* bumping up inflight_requests here avoids taking a lock per rpc below */
-
-  chand->waiting_children = NULL;
-  chand->waiting_child_count = 0;
-  chand->waiting_child_capacity = 0;
-
-  call_ops = gpr_malloc(sizeof(*call_ops) * waiting_child_count);
-
-  for (i = 0; i < waiting_child_count; i++) {
-    call_ops[i] = waiting_children[i]->s.waiting_op;
-    if (!prepare_activate(waiting_children[i]->elem, chand->active_child)) {
-      waiting_children[i] = NULL;
-      grpc_transport_op_finish_with_failure(&call_ops[i]);
-    }
-  }
-
-  /* END LOCKING CHANNEL */
-  gpr_mu_unlock(&chand->mu);
-
-  /* activate any pending operations - this is safe to do as we guarantee one
-     and only one write operation per request at the surface api - if we lose
-     that guarantee we need to do some curly locking here */
-  for (i = 0; i < waiting_child_count; i++) {
-    if (waiting_children[i]) {
-      complete_activate(waiting_children[i]->elem, &call_ops[i]);
-    }
-  }
-  gpr_free(waiting_children);
-  gpr_free(call_ops);
-  gpr_free(child_filters);
-
-  if (old_active) {
-    grpc_child_channel_destroy(old_active, 1);
-  }
-
-  return result;
-}
-
-void grpc_client_channel_set_transport_setup(grpc_channel_stack *channel_stack,
-                                             grpc_transport_setup *setup) {
+void grpc_client_channel_set_resolver(grpc_channel_stack *channel_stack,
+                                      grpc_resolver *resolver) {
   /* post construction initialization: set the transport setup pointer */
   grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack);
   channel_data *chand = elem->channel_data;
-  GPR_ASSERT(!chand->transport_setup);
-  chand->transport_setup = setup;
+  GPR_ASSERT(!chand->resolver);
+  chand->resolver = resolver;
+  GRPC_CHANNEL_INTERNAL_REF(chand->master, "resolver");
+  GRPC_RESOLVER_REF(resolver, "channel");
+  grpc_resolver_next(resolver, &chand->incoming_configuration,
+                     &chand->on_config_changed);
 }

src/core/channel/client_channel.h

@@ -35,6 +35,7 @@
 #define GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
+#include "src/core/client_config/resolver.h"
 
 /* A client channel is a channel that begins disconnected, and can connect
    to some endpoint on demand. If that endpoint disconnects, it will be
@@ -48,15 +49,7 @@ extern const grpc_channel_filter grpc_client_channel_filter;
 /* post-construction initializer to let the client channel know which
    transport setup it should cancel upon destruction, or initiate when it needs
    a connection */
-void grpc_client_channel_set_transport_setup(grpc_channel_stack *channel_stack,
-                                             grpc_transport_setup *setup);
+void grpc_client_channel_set_resolver(grpc_channel_stack *channel_stack,
+                                      grpc_resolver *resolver);
 
-/* grpc_transport_setup_callback for binding new transports into a client
-   channel - user_data should be the channel stack containing the client
-   channel */
-grpc_transport_setup_result grpc_client_channel_transport_setup_complete(
-    grpc_channel_stack *channel_stack, grpc_transport *transport,
-    grpc_channel_filter const **channel_filters, size_t num_channel_filters,
-    grpc_mdctx *mdctx);
-
-#endif  /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H */
+#endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H */

src/core/channel/client_setup.c

@@ -1,302 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/channel/client_setup.h"
-#include "src/core/channel/channel_args.h"
-#include "src/core/channel/channel_stack.h"
-#include "src/core/iomgr/alarm.h"
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/time.h>
-
-struct grpc_client_setup {
-  grpc_transport_setup base; /* must be first */
-  void (*initiate)(void *user_data, grpc_client_setup_request *request);
-  void (*done)(void *user_data);
-  void *user_data;
-  grpc_channel_args *args;
-  grpc_mdctx *mdctx;
-  grpc_alarm backoff_alarm;
-  gpr_timespec current_backoff_interval;
-  int in_alarm;
-  int in_cb;
-  int cancelled;
-
-  gpr_mu mu;
-  gpr_cv cv;
-  grpc_client_setup_request *active_request;
-  int refs;
-  /** The set of pollsets that are currently interested in this
-      connection being established */
-  grpc_pollset_set interested_parties;
-};
-
-struct grpc_client_setup_request {
-  /* pointer back to the setup object */
-  grpc_client_setup *setup;
-  gpr_timespec deadline;
-};
-
-gpr_timespec grpc_client_setup_request_deadline(grpc_client_setup_request *r) {
-  return r->deadline;
-}
-
-grpc_pollset_set *grpc_client_setup_get_interested_parties(
-    grpc_client_setup_request *r) {
-  return &r->setup->interested_parties;
-}
-
-static void destroy_setup(grpc_client_setup *s) {
-  gpr_mu_destroy(&s->mu);
-  gpr_cv_destroy(&s->cv);
-  s->done(s->user_data);
-  grpc_channel_args_destroy(s->args);
-  grpc_pollset_set_destroy(&s->interested_parties);
-  gpr_free(s);
-}
-
-static void destroy_request(grpc_client_setup_request *r) { gpr_free(r); }
-
-/* initiate handshaking */
-static void setup_initiate(grpc_transport_setup *sp) {
-  grpc_client_setup *s = (grpc_client_setup *)sp;
-  grpc_client_setup_request *r = gpr_malloc(sizeof(grpc_client_setup_request));
-  int in_alarm = 0;
-
-  r->setup = s;
-  r->deadline = gpr_time_add(gpr_now(), gpr_time_from_seconds(60));
-
-  gpr_mu_lock(&s->mu);
-  GPR_ASSERT(s->refs > 0);
-  /* there might be more than one request outstanding if the caller calls
-     initiate in some kind of rapid-fire way: we try to connect each time,
-     and keep track of the latest request (which is the only one that gets
-     to finish) */
-  if (!s->in_alarm) {
-    s->active_request = r;
-    s->refs++;
-  } else {
-    /* TODO(klempner): Maybe do something more clever here */
-    in_alarm = 1;
-  }
-  gpr_mu_unlock(&s->mu);
-
-  if (!in_alarm) {
-    s->initiate(s->user_data, r);
-  } else {
-    destroy_request(r);
-  }
-}
-
-/** implementation of add_interested_party for setup vtable */
-static void setup_add_interested_party(grpc_transport_setup *sp,
-                                       grpc_pollset *pollset) {
-  grpc_client_setup *s = (grpc_client_setup *)sp;
-
-  gpr_mu_lock(&s->mu);
-  grpc_pollset_set_add_pollset(&s->interested_parties, pollset);
-  gpr_mu_unlock(&s->mu);
-}
-
-/** implementation of del_interested_party for setup vtable */
-static void setup_del_interested_party(grpc_transport_setup *sp,
-                                       grpc_pollset *pollset) {
-  grpc_client_setup *s = (grpc_client_setup *)sp;
-
-  gpr_mu_lock(&s->mu);
-  grpc_pollset_set_del_pollset(&s->interested_parties, pollset);
-  gpr_mu_unlock(&s->mu);
-}
-
-/* cancel handshaking: cancel all requests, and shutdown (the caller promises
-   not to initiate again) */
-static void setup_cancel(grpc_transport_setup *sp) {
-  grpc_client_setup *s = (grpc_client_setup *)sp;
-  int cancel_alarm = 0;
-
-  gpr_mu_lock(&s->mu);
-  s->cancelled = 1;
-  while (s->in_cb) {
-    gpr_cv_wait(&s->cv, &s->mu, gpr_inf_future);
-  }
-
-  GPR_ASSERT(s->refs > 0);
-  /* effectively cancels the current request (if any) */
-  s->active_request = NULL;
-  if (s->in_alarm) {
-    cancel_alarm = 1;
-  }
-  if (--s->refs == 0) {
-    gpr_mu_unlock(&s->mu);
-    destroy_setup(s);
-  } else {
-    gpr_mu_unlock(&s->mu);
-  }
-  if (cancel_alarm) {
-    grpc_alarm_cancel(&s->backoff_alarm);
-  }
-}
-
-int grpc_client_setup_cb_begin(grpc_client_setup_request *r,
-                               const char *reason) {
-  gpr_mu_lock(&r->setup->mu);
-  if (r->setup->cancelled) {
-    gpr_mu_unlock(&r->setup->mu);
-    return 0;
-  }
-  r->setup->in_cb++;
-  gpr_mu_unlock(&r->setup->mu);
-  return 1;
-}
-
-void grpc_client_setup_cb_end(grpc_client_setup_request *r,
-                              const char *reason) {
-  gpr_mu_lock(&r->setup->mu);
-  r->setup->in_cb--;
-  if (r->setup->cancelled) gpr_cv_signal(&r->setup->cv);
-  gpr_mu_unlock(&r->setup->mu);
-}
-
-/* vtable for transport setup */
-static const grpc_transport_setup_vtable setup_vtable = {
-    setup_initiate, setup_add_interested_party, setup_del_interested_party,
-    setup_cancel};
-
-void grpc_client_setup_create_and_attach(
-    grpc_channel_stack *newly_minted_channel, const grpc_channel_args *args,
-    grpc_mdctx *mdctx,
-    void (*initiate)(void *user_data, grpc_client_setup_request *request),
-    void (*done)(void *user_data), void *user_data) {
-  grpc_client_setup *s = gpr_malloc(sizeof(grpc_client_setup));
-
-  s->base.vtable = &setup_vtable;
-  gpr_mu_init(&s->mu);
-  gpr_cv_init(&s->cv);
-  s->refs = 1;
-  s->mdctx = mdctx;
-  s->initiate = initiate;
-  s->done = done;
-  s->user_data = user_data;
-  s->active_request = NULL;
-  s->args = grpc_channel_args_copy(args);
-  s->current_backoff_interval = gpr_time_from_micros(1000000);
-  s->in_alarm = 0;
-  s->in_cb = 0;
-  s->cancelled = 0;
-  grpc_pollset_set_init(&s->interested_parties);
-
-  grpc_client_channel_set_transport_setup(newly_minted_channel, &s->base);
-}
-
-int grpc_client_setup_request_should_continue(grpc_client_setup_request *r,
-                                              const char *reason) {
-  int result;
-  if (gpr_time_cmp(gpr_now(), r->deadline) > 0) {
-    result = 0;
-  } else {
-    gpr_mu_lock(&r->setup->mu);
-    result = r->setup->active_request == r;
-    gpr_mu_unlock(&r->setup->mu);
-  }
-  return result;
-}
-
-static void backoff_alarm_done(void *arg /* grpc_client_setup_request */, 
-                               int success) {
-  grpc_client_setup_request *r = arg;
-  grpc_client_setup *s = r->setup;
-  /* Handle status cancelled? */
-  gpr_mu_lock(&s->mu);
-  s->in_alarm = 0;
-  if (s->active_request != NULL || !success) {
-    if (0 == --s->refs) {
-      gpr_mu_unlock(&s->mu);
-      destroy_setup(s);
-      destroy_request(r);
-      return;
-    } else {
-      gpr_mu_unlock(&s->mu);
-      destroy_request(r);
-      return;
-    }
-  }
-  s->active_request = r;
-  gpr_mu_unlock(&s->mu);
-  s->initiate(s->user_data, r);
-}
-
-void grpc_client_setup_request_finish(grpc_client_setup_request *r,
-                                      int was_successful) {
-  int retry = !was_successful;
-  grpc_client_setup *s = r->setup;
-
-  gpr_mu_lock(&s->mu);
-  if (s->active_request == r) {
-    s->active_request = NULL;
-  } else {
-    retry = 0;
-  }
-
-  if (!retry && 0 == --s->refs) {
-    gpr_mu_unlock(&s->mu);
-    destroy_setup(s);
-    destroy_request(r);
-  } else if (retry) {
-    /* TODO(klempner): Replace these values with further consideration. 2x is
-       probably too aggressive of a backoff. */
-    gpr_timespec max_backoff = gpr_time_from_minutes(2);
-    gpr_timespec now = gpr_now();
-    gpr_timespec deadline = gpr_time_add(s->current_backoff_interval, now);
-    GPR_ASSERT(!s->in_alarm);
-    s->in_alarm = 1;
-    grpc_alarm_init(&s->backoff_alarm, deadline, backoff_alarm_done, r, now);
-    s->current_backoff_interval =
-        gpr_time_add(s->current_backoff_interval, s->current_backoff_interval);
-    if (gpr_time_cmp(s->current_backoff_interval, max_backoff) > 0) {
-      s->current_backoff_interval = max_backoff;
-    }
-    gpr_mu_unlock(&s->mu);
-  } else {
-    gpr_mu_unlock(&s->mu);
-    destroy_request(r);
-  }
-}
-
-const grpc_channel_args *grpc_client_setup_get_channel_args(
-    grpc_client_setup_request *r) {
-  return r->setup->args;
-}
-
-grpc_mdctx *grpc_client_setup_get_mdctx(grpc_client_setup_request *r) {
-  return r->setup->mdctx;
-}

src/core/channel/client_setup.h

@@ -1,77 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CLIENT_SETUP_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CLIENT_SETUP_H
-
-#include "src/core/channel/client_channel.h"
-#include "src/core/transport/metadata.h"
-#include <grpc/support/time.h>
-
-/* Convenience API's to simplify transport setup */
-
-typedef struct grpc_client_setup grpc_client_setup;
-typedef struct grpc_client_setup_request grpc_client_setup_request;
-
-void grpc_client_setup_create_and_attach(
-    grpc_channel_stack *newly_minted_channel, const grpc_channel_args *args,
-    grpc_mdctx *mdctx,
-    void (*initiate)(void *user_data, grpc_client_setup_request *request),
-    void (*done)(void *user_data), void *user_data);
-
-/* Check that r is the active request: needs to be performed at each callback.
-   If this races, we'll have two connection attempts running at once and the
-   old one will get cleaned up in due course, which is fine. */
-int grpc_client_setup_request_should_continue(grpc_client_setup_request *r,
-                                              const char *reason);
-void grpc_client_setup_request_finish(grpc_client_setup_request *r,
-                                      int was_successful);
-const grpc_channel_args *grpc_client_setup_get_channel_args(
-    grpc_client_setup_request *r);
-
-/* Call before calling back into the setup listener, and call only if
-   this function returns 1. If it returns 1, also promise to call
-   grpc_client_setup_cb_end */
-int grpc_client_setup_cb_begin(grpc_client_setup_request *r,
-                               const char *reason);
-void grpc_client_setup_cb_end(grpc_client_setup_request *r, const char *reason);
-
-/* Get the deadline for a request passed in to initiate. Implementations should
-   make a best effort to honor this deadline. */
-gpr_timespec grpc_client_setup_request_deadline(grpc_client_setup_request *r);
-grpc_pollset_set *grpc_client_setup_get_interested_parties(
-    grpc_client_setup_request *r);
-
-grpc_mdctx *grpc_client_setup_get_mdctx(grpc_client_setup_request *r);
-
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_SETUP_H */

src/core/channel/connected_channel.c

@@ -61,42 +61,27 @@ typedef struct connected_channel_call_data { void *unused; } call_data;
 
 /* Intercept a call operation and either push it directly up or translate it
    into transport stream operations */
-static void con_start_transport_op(grpc_call_element *elem,
-                                   grpc_transport_op *op) {
+static void con_start_transport_stream_op(grpc_call_element *elem,
+                                          grpc_transport_stream_op *op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
 
-  grpc_transport_perform_op(chand->transport,
-                            TRANSPORT_STREAM_FROM_CALL_DATA(calld), op);
+  grpc_transport_perform_stream_op(chand->transport,
+                                   TRANSPORT_STREAM_FROM_CALL_DATA(calld), op);
 }
 
-/* Currently we assume all channel operations should just be pushed up. */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
+static void con_start_transport_op(grpc_channel_element *elem,
+                                   grpc_transport_op *op) {
   channel_data *chand = elem->channel_data;
-  GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
-
-  switch (op->type) {
-    case GRPC_CHANNEL_GOAWAY:
-      grpc_transport_goaway(chand->transport, op->data.goaway.status,
-                            op->data.goaway.message);
-      break;
-    case GRPC_CHANNEL_DISCONNECT:
-      grpc_transport_close(chand->transport);
-      break;
-    default:
-      GPR_ASSERT(op->dir == GRPC_CALL_UP);
-      grpc_channel_next_op(elem, op);
-      break;
-  }
+  grpc_transport_perform_op(chand->transport, op);
 }
 
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   int r;
@@ -118,11 +103,10 @@ static void destroy_call_elem(grpc_call_element *elem) {
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   channel_data *cd = (channel_data *)elem->channel_data;
-  GPR_ASSERT(!is_first);
   GPR_ASSERT(is_last);
   GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
   cd->transport = NULL;
@@ -136,70 +120,23 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
 }
 
 const grpc_channel_filter grpc_connected_channel_filter = {
-    con_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "connected",
+    con_start_transport_stream_op,
+    con_start_transport_op,
+    sizeof(call_data),
+    init_call_elem,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    "connected",
 };
 
-/* Transport callback to accept a new stream... calls up to handle it */
-static void accept_stream(void *user_data, grpc_transport *transport,
-                          const void *transport_server_data) {
-  grpc_channel_element *elem = user_data;
-  channel_data *chand = elem->channel_data;
-  grpc_channel_op op;
-
-  GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
-  GPR_ASSERT(chand->transport == transport);
-
-  op.type = GRPC_ACCEPT_CALL;
-  op.dir = GRPC_CALL_UP;
-  op.data.accept_call.transport = transport;
-  op.data.accept_call.transport_server_data = transport_server_data;
-  channel_op(elem, NULL, &op);
-}
-
-static void transport_goaway(void *user_data, grpc_transport *transport,
-                             grpc_status_code status, gpr_slice debug) {
-  /* transport got goaway ==> call up and handle it */
-  grpc_channel_element *elem = user_data;
-  channel_data *chand = elem->channel_data;
-  grpc_channel_op op;
-
-  GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
-  GPR_ASSERT(chand->transport == transport);
-
-  op.type = GRPC_TRANSPORT_GOAWAY;
-  op.dir = GRPC_CALL_UP;
-  op.data.goaway.status = status;
-  op.data.goaway.message = debug;
-  channel_op(elem, NULL, &op);
-}
-
-static void transport_closed(void *user_data, grpc_transport *transport) {
-  /* transport was closed ==> call up and handle it */
-  grpc_channel_element *elem = user_data;
-  channel_data *chand = elem->channel_data;
-  grpc_channel_op op;
-
-  GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
-  GPR_ASSERT(chand->transport == transport);
-
-  op.type = GRPC_TRANSPORT_CLOSED;
-  op.dir = GRPC_CALL_UP;
-  channel_op(elem, NULL, &op);
-}
-
-const grpc_transport_callbacks connected_channel_transport_callbacks = {
-    accept_stream, transport_goaway, transport_closed,
-};
-
-grpc_transport_setup_result grpc_connected_channel_bind_transport(
-    grpc_channel_stack *channel_stack, grpc_transport *transport) {
+void grpc_connected_channel_bind_transport(grpc_channel_stack *channel_stack,
+                                           grpc_transport *transport) {
   /* Assumes that the connected channel filter is always the last filter
      in a channel stack */
   grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack);
   channel_data *cd = (channel_data *)elem->channel_data;
-  grpc_transport_setup_result ret;
   GPR_ASSERT(elem->filter == &grpc_connected_channel_filter);
   GPR_ASSERT(cd->transport == NULL);
   cd->transport = transport;
@@ -211,8 +148,4 @@ grpc_transport_setup_result grpc_connected_channel_bind_transport(
      the last call element, and the last call element MUST be the connected
      channel. */
   channel_stack->call_stack_size += grpc_transport_stream_size(transport);
-
-  ret.user_data = elem;
-  ret.callbacks = &connected_channel_transport_callbacks;
-  return ret;
 }

src/core/channel/connected_channel.h

@@ -43,7 +43,7 @@ extern const grpc_channel_filter grpc_connected_channel_filter;
 
 /* Post construction fixup: set the transport in the connected channel.
    Must be called before any call stack using this filter is used. */
-grpc_transport_setup_result grpc_connected_channel_bind_transport(
-    grpc_channel_stack *channel_stack, grpc_transport *transport);
+void grpc_connected_channel_bind_transport(grpc_channel_stack *channel_stack,
+                                           grpc_transport *transport);
 
-#endif  /* GRPC_INTERNAL_CORE_CHANNEL_CONNECTED_CHANNEL_H */
+#endif /* GRPC_INTERNAL_CORE_CHANNEL_CONNECTED_CHANNEL_H */

src/core/channel/http_client_filter.c

@@ -92,7 +92,8 @@ static void hc_on_recv(void *user_data, int success) {
   calld->on_done_recv->cb(calld->on_done_recv->cb_arg, success);
 }
 
-static void hc_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
+static void hc_mutate_op(grpc_call_element *elem,
+                         grpc_transport_stream_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
@@ -127,33 +128,16 @@ static void hc_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
 }
 
 static void hc_start_transport_op(grpc_call_element *elem,
-                                  grpc_transport_op *op) {
+                                  grpc_transport_stream_op *op) {
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
   hc_mutate_op(elem, op);
   grpc_call_next_op(elem, op);
 }
 
-/* Called on special channel events, such as disconnection or new incoming
-   calls on the server */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
-  /* grab pointers to our data from the channel element */
-  channel_data *channeld = elem->channel_data;
-
-  ignore_unused(channeld);
-
-  switch (op->type) {
-    default:
-      /* pass control up or down the stack depending on op->dir */
-      grpc_channel_next_op(elem, op);
-      break;
-  }
-}
-
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   call_data *calld = elem->call_data;
   calld->sent_initial_metadata = 0;
   calld->got_initial_metadata = 0;
@@ -186,7 +170,7 @@ static const char *scheme_from_args(const grpc_channel_args *args) {
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   /* grab pointers to our data from the channel element */
@@ -195,7 +179,6 @@ static void init_channel_elem(grpc_channel_element *elem,
   /* The first and the last filters tend to be implemented differently to
      handle the case that there's no 'next' filter to call on the up or down
      path */
-  GPR_ASSERT(!is_first);
   GPR_ASSERT(!is_last);
 
   /* initialize members */
@@ -221,6 +204,6 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
 }
 
 const grpc_channel_filter grpc_http_client_filter = {
-    hc_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "http-client"};
+    hc_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem,        destroy_call_elem,    sizeof(channel_data),
+    init_channel_elem,     destroy_channel_elem, "http-client"};

src/core/channel/http_server_filter.c

@@ -72,9 +72,6 @@ typedef struct channel_data {
   grpc_mdctx *mdctx;
 } channel_data;
 
-/* used to silence 'variable not used' warnings */
-static void ignore_unused(void *ignored) {}
-
 static grpc_mdelem *server_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   channel_data *channeld = elem->channel_data;
@@ -181,7 +178,8 @@ static void hs_on_recv(void *user_data, int success) {
   calld->on_done_recv->cb(calld->on_done_recv->cb_arg, success);
 }
 
-static void hs_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
+static void hs_mutate_op(grpc_call_element *elem,
+                         grpc_transport_stream_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
@@ -209,33 +207,16 @@ static void hs_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
 }
 
 static void hs_start_transport_op(grpc_call_element *elem,
-                                  grpc_transport_op *op) {
+                                  grpc_transport_stream_op *op) {
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
   hs_mutate_op(elem, op);
   grpc_call_next_op(elem, op);
 }
 
-/* Called on special channel events, such as disconnection or new incoming
-   calls on the server */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
-  /* grab pointers to our data from the channel element */
-  channel_data *channeld = elem->channel_data;
-
-  ignore_unused(channeld);
-
-  switch (op->type) {
-    default:
-      /* pass control up or down the stack depending on op->dir */
-      grpc_channel_next_op(elem, op);
-      break;
-  }
-}
-
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   /* initialize members */
@@ -248,7 +229,7 @@ static void init_call_elem(grpc_call_element *elem,
 static void destroy_call_elem(grpc_call_element *elem) {}
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   /* grab pointers to our data from the channel element */
@@ -297,6 +278,6 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
 }
 
 const grpc_channel_filter grpc_http_server_filter = {
-    hs_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "http-server"};
+    hs_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem,        destroy_call_elem,    sizeof(channel_data),
+    init_channel_elem,     destroy_channel_elem, "http-server"};

src/core/channel/noop_filter.c

@@ -45,7 +45,8 @@ typedef struct channel_data {
 /* used to silence 'variable not used' warnings */
 static void ignore_unused(void *ignored) {}
 
-static void noop_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
+static void noop_mutate_op(grpc_call_element *elem,
+                           grpc_transport_stream_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
@@ -61,35 +62,18 @@ static void noop_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
      - a network event (or similar) from below, to receive something
    op contains type and call direction information, in addition to the data
    that is being sent or received. */
-static void noop_start_transport_op(grpc_call_element *elem,
-                                    grpc_transport_op *op) {
+static void noop_start_transport_stream_op(grpc_call_element *elem,
+                                           grpc_transport_stream_op *op) {
   noop_mutate_op(elem, op);
 
   /* pass control down the stack */
   grpc_call_next_op(elem, op);
 }
 
-/* Called on special channel events, such as disconnection or new incoming
-   calls on the server */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
-  /* grab pointers to our data from the channel element */
-  channel_data *channeld = elem->channel_data;
-
-  ignore_unused(channeld);
-
-  switch (op->type) {
-    default:
-      /* pass control up or down the stack depending on op->dir */
-      grpc_channel_next_op(elem, op);
-      break;
-  }
-}
-
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
@@ -111,7 +95,7 @@ static void destroy_call_elem(grpc_call_element *elem) {
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   /* grab pointers to our data from the channel element */
@@ -135,7 +119,12 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
   ignore_unused(channeld);
 }
 
-const grpc_channel_filter grpc_no_op_filter = {
-    noop_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "no-op"};
+const grpc_channel_filter grpc_no_op_filter = {noop_start_transport_stream_op,
+                                               grpc_channel_next_op,
+                                               sizeof(call_data),
+                                               init_call_elem,
+                                               destroy_call_elem,
+                                               sizeof(channel_data),
+                                               init_channel_elem,
+                                               destroy_channel_elem,
+                                               "no-op"};

src/core/client_config/README.md

@@ -0,0 +1,60 @@
+Client Configuration Support for GRPC
+=====================================
+
+This library provides high level configuration machinery to construct client 
+channels and load balance between them.
+
+Each grpc_channel is created with a grpc_resolver. It is the resolver's duty
+to resolve a name into configuration data for the channel. Such configuration
+data might include:
+
+- a list of (ip, port) addresses to connect to
+- a load balancing policy to decide which server to send a request to
+- a set of filters to mutate outgoing requests (say, by adding metadata)
+
+The resolver provides this data as a stream of grpc_client_config objects to
+the channel. We represent configuration as a stream so that it can be changed
+by the resolver during execution, by reacting to external events (such as a
+new configuration file being pushed to some store).
+
+
+Load Balancing
+--------------
+
+Load balancing configuration is provided by a grpc_lb_policy object, stored as
+part of grpc_client_config. 
+
+A load balancing policies primary job is to pick a target server given only the
+initial metadata for a request. It does this by providing a grpc_subchannel 
+object to the owning channel.
+
+
+Sub-Channels
+------------
+
+A sub-channel provides a connection to a server for a client channel. It has a 
+connectivity state like a regular channel, and so can be connected or 
+disconnected. This connectivity state can be used to inform load balancing 
+decisions (for example, by avoiding disconnected backends).
+
+Configured sub-channels are fully setup to participate in the grpc data plane.
+Their behavior is specified by a set of grpc channel filters defined at their
+construction. To customize this behavior, resolvers build grpc_subchannel_factory 
+objects, which use the decorator pattern to customize construction arguments for 
+concrete grpc_subchannel instances.
+
+
+Naming for GRPC
+===============
+
+Names in GRPC are represented by a URI.
+
+The following schemes are currently supported:
+
+dns:///host:port - dns schemes are currently supported so long as authority is
+                   empty (authority based dns resolution is expected in a future
+                   release)
+
+unix:path        - the unix scheme is used to create and connect to unix domain 
+                   sockets - the authority must be empty, and the path represents
+                   the absolute or relative path to the desired socket

src/core/client_config/client_config.c

@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/client_config.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
+struct grpc_client_config {
+  gpr_refcount refs;
+  grpc_lb_policy *lb_policy;
+};
+
+grpc_client_config *grpc_client_config_create() {
+  grpc_client_config *c = gpr_malloc(sizeof(*c));
+  memset(c, 0, sizeof(*c));
+  gpr_ref_init(&c->refs, 1);
+  return c;
+}
+
+void grpc_client_config_ref(grpc_client_config *c) { gpr_ref(&c->refs); }
+
+void grpc_client_config_unref(grpc_client_config *c) {
+  if (gpr_unref(&c->refs)) {
+    GRPC_LB_POLICY_UNREF(c->lb_policy, "client_config");
+    gpr_free(c);
+  }
+}
+
+void grpc_client_config_set_lb_policy(grpc_client_config *c,
+                                      grpc_lb_policy *lb_policy) {
+  if (lb_policy) {
+    GRPC_LB_POLICY_REF(lb_policy, "client_config");
+  }
+  if (c->lb_policy) {
+    GRPC_LB_POLICY_UNREF(c->lb_policy, "client_config");
+  }
+  c->lb_policy = lb_policy;
+}
+
+grpc_lb_policy *grpc_client_config_get_lb_policy(grpc_client_config *c) {
+  return c->lb_policy;
+}

src/core/client_config/client_config.h

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
+
+#include "src/core/client_config/lb_policy.h"
+
+/** Total configuration for a client. Provided, and updated, by
+    grpc_resolver */
+typedef struct grpc_client_config grpc_client_config;
+
+grpc_client_config *grpc_client_config_create();
+void grpc_client_config_ref(grpc_client_config *client_config);
+void grpc_client_config_unref(grpc_client_config *client_config);
+
+void grpc_client_config_set_lb_policy(grpc_client_config *client_config,
+                                      grpc_lb_policy *lb_policy);
+grpc_lb_policy *grpc_client_config_get_lb_policy(
+    grpc_client_config *client_config);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H */

src/core/client_config/connector.c

@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/connector.h"
+
+void grpc_connector_ref(grpc_connector *connector) {
+  connector->vtable->ref(connector);
+}
+
+void grpc_connector_unref(grpc_connector *connector) {
+  connector->vtable->unref(connector);
+}
+
+void grpc_connector_connect(grpc_connector *connector,
+                            const grpc_connect_in_args *in_args,
+                            grpc_connect_out_args *out_args,
+                            grpc_iomgr_closure *notify) {
+  connector->vtable->connect(connector, in_args, out_args, notify);
+}

src/core/client_config/connector.h

@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_CONNECTOR_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_CONNECTOR_H
+
+#include "src/core/channel/channel_stack.h"
+#include "src/core/iomgr/sockaddr.h"
+#include "src/core/transport/transport.h"
+
+typedef struct grpc_connector grpc_connector;
+typedef struct grpc_connector_vtable grpc_connector_vtable;
+
+struct grpc_connector {
+  const grpc_connector_vtable *vtable;
+};
+
+typedef struct {
+  /** set of pollsets interested in this connection */
+  grpc_pollset_set *interested_parties;
+  /** address to connect to */
+  const struct sockaddr *addr;
+  int addr_len;
+  /** deadline for connection */
+  gpr_timespec deadline;
+  /** channel arguments (to be passed to transport) */
+  const grpc_channel_args *channel_args;
+  /** metadata context */
+  grpc_mdctx *metadata_context;
+} grpc_connect_in_args;
+
+typedef struct {
+  /** the connected transport */
+  grpc_transport *transport;
+  /** any additional filters (owned by the caller of connect) */
+  const grpc_channel_filter **filters;
+  size_t num_filters;
+} grpc_connect_out_args;
+
+struct grpc_connector_vtable {
+  void (*ref)(grpc_connector *connector);
+  void (*unref)(grpc_connector *connector);
+  void (*connect)(grpc_connector *connector,
+                  const grpc_connect_in_args *in_args,
+                  grpc_connect_out_args *out_args, grpc_iomgr_closure *notify);
+};
+
+void grpc_connector_ref(grpc_connector *connector);
+void grpc_connector_unref(grpc_connector *connector);
+void grpc_connector_connect(grpc_connector *connector,
+                            const grpc_connect_in_args *in_args,
+                            grpc_connect_out_args *out_args,
+                            grpc_iomgr_closure *notify);
+
+#endif

src/core/client_config/lb_policies/pick_first.c

@@ -0,0 +1,268 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/lb_policies/pick_first.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include "src/core/transport/connectivity_state.h"
+
+typedef struct pending_pick {
+  struct pending_pick *next;
+  grpc_pollset *pollset;
+  grpc_subchannel **target;
+  grpc_iomgr_closure *on_complete;
+} pending_pick;
+
+typedef struct {
+  /** base policy: must be first */
+  grpc_lb_policy base;
+  /** all our subchannels */
+  grpc_subchannel **subchannels;
+  size_t num_subchannels;
+
+  grpc_iomgr_closure connectivity_changed;
+
+  /** mutex protecting remaining members */
+  gpr_mu mu;
+  /** the selected channel
+      TODO(ctiller): this should be atomically set so we don't
+                     need to take a mutex in the common case */
+  grpc_subchannel *selected;
+  /** have we started picking? */
+  int started_picking;
+  /** which subchannel are we watching? */
+  size_t checking_subchannel;
+  /** what is the connectivity of that channel? */
+  grpc_connectivity_state checking_connectivity;
+  /** list of picks that are waiting on connectivity */
+  pending_pick *pending_picks;
+
+  /** our connectivity state tracker */
+  grpc_connectivity_state_tracker state_tracker;
+} pick_first_lb_policy;
+
+void pf_destroy(grpc_lb_policy *pol) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  size_t i;
+  for (i = 0; i < p->num_subchannels; i++) {
+    GRPC_SUBCHANNEL_UNREF(p->subchannels[i], "pick_first");
+  }
+  gpr_free(p->subchannels);
+  gpr_mu_destroy(&p->mu);
+  gpr_free(p);
+}
+
+void pf_shutdown(grpc_lb_policy *pol) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  pending_pick *pp;
+  gpr_mu_lock(&p->mu);
+  while ((pp = p->pending_picks)) {
+    p->pending_picks = pp->next;
+    *pp->target = NULL;
+    grpc_iomgr_add_delayed_callback(pp->on_complete, 0);
+    gpr_free(pp);
+  }
+  gpr_mu_unlock(&p->mu);
+}
+
+void pf_pick(grpc_lb_policy *pol, grpc_pollset *pollset,
+             grpc_metadata_batch *initial_metadata, grpc_subchannel **target,
+             grpc_iomgr_closure *on_complete) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  pending_pick *pp;
+  gpr_mu_lock(&p->mu);
+  if (p->selected) {
+    gpr_mu_unlock(&p->mu);
+    *target = p->selected;
+    on_complete->cb(on_complete->cb_arg, 1);
+  } else {
+    if (!p->started_picking) {
+      p->started_picking = 1;
+      p->checking_subchannel = 0;
+      p->checking_connectivity = GRPC_CHANNEL_IDLE;
+      GRPC_LB_POLICY_REF(pol, "pick_first_connectivity");
+      grpc_subchannel_notify_on_state_change(
+          p->subchannels[p->checking_subchannel], &p->checking_connectivity,
+          &p->connectivity_changed);
+    }
+    grpc_subchannel_add_interested_party(p->subchannels[p->checking_subchannel],
+                                         pollset);
+    pp = gpr_malloc(sizeof(*pp));
+    pp->next = p->pending_picks;
+    pp->pollset = pollset;
+    pp->target = target;
+    pp->on_complete = on_complete;
+    p->pending_picks = pp;
+    gpr_mu_unlock(&p->mu);
+  }
+}
+
+static void del_interested_parties_locked(pick_first_lb_policy *p) {
+  pending_pick *pp;
+  for (pp = p->pending_picks; pp; pp = pp->next) {
+    grpc_subchannel_del_interested_party(p->subchannels[p->checking_subchannel],
+                                         pp->pollset);
+  }
+}
+
+static void add_interested_parties_locked(pick_first_lb_policy *p) {
+  pending_pick *pp;
+  for (pp = p->pending_picks; pp; pp = pp->next) {
+    grpc_subchannel_add_interested_party(p->subchannels[p->checking_subchannel],
+                                         pp->pollset);
+  }
+}
+
+static void pf_connectivity_changed(void *arg, int iomgr_success) {
+  pick_first_lb_policy *p = arg;
+  pending_pick *pp;
+  int unref = 0;
+
+  gpr_mu_lock(&p->mu);
+loop:
+  switch (p->checking_connectivity) {
+    case GRPC_CHANNEL_READY:
+      p->selected = p->subchannels[p->checking_subchannel];
+      while ((pp = p->pending_picks)) {
+        p->pending_picks = pp->next;
+        *pp->target = p->selected;
+        grpc_subchannel_del_interested_party(p->selected, pp->pollset);
+        grpc_iomgr_add_delayed_callback(pp->on_complete, 1);
+        gpr_free(pp);
+      }
+      unref = 1;
+      break;
+    case GRPC_CHANNEL_TRANSIENT_FAILURE:
+      del_interested_parties_locked(p);
+      p->checking_subchannel =
+          (p->checking_subchannel + 1) % p->num_subchannels;
+      p->checking_connectivity = grpc_subchannel_check_connectivity(
+          p->subchannels[p->checking_subchannel]);
+      add_interested_parties_locked(p);
+      goto loop;
+    case GRPC_CHANNEL_CONNECTING:
+    case GRPC_CHANNEL_IDLE:
+      grpc_subchannel_notify_on_state_change(
+          p->subchannels[p->checking_subchannel], &p->checking_connectivity,
+          &p->connectivity_changed);
+      break;
+    case GRPC_CHANNEL_FATAL_FAILURE:
+      del_interested_parties_locked(p);
+      GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
+               p->subchannels[p->num_subchannels - 1]);
+      p->num_subchannels--;
+      GRPC_SUBCHANNEL_UNREF(p->subchannels[p->num_subchannels], "pick_first");
+      if (p->num_subchannels == 0) {
+        while ((pp = p->pending_picks)) {
+          p->pending_picks = pp->next;
+          *pp->target = NULL;
+          grpc_iomgr_add_delayed_callback(pp->on_complete, 1);
+          gpr_free(pp);
+        }
+        unref = 1;
+      } else {
+        p->checking_subchannel %= p->num_subchannels;
+        p->checking_connectivity = grpc_subchannel_check_connectivity(
+            p->subchannels[p->checking_subchannel]);
+        add_interested_parties_locked(p);
+        goto loop;
+      }
+  }
+  gpr_mu_unlock(&p->mu);
+
+  if (unref) {
+    GRPC_LB_POLICY_UNREF(&p->base, "pick_first_connectivity");
+  }
+}
+
+static void pf_broadcast(grpc_lb_policy *pol, grpc_transport_op *op) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  size_t i;
+  size_t n;
+  grpc_subchannel **subchannels;
+
+  gpr_mu_lock(&p->mu);
+  n = p->num_subchannels;
+  subchannels = gpr_malloc(n * sizeof(*subchannels));
+  for (i = 0; i < n; i++) {
+    subchannels[i] = p->subchannels[i];
+    GRPC_SUBCHANNEL_REF(subchannels[i], "pf_broadcast");
+  }
+  gpr_mu_unlock(&p->mu);
+
+  for (i = 0; i < n; i++) {
+    grpc_subchannel_process_transport_op(subchannels[i], op);
+    GRPC_SUBCHANNEL_UNREF(subchannels[i], "pf_broadcast");
+  }
+  gpr_free(subchannels);
+}
+
+static grpc_connectivity_state pf_check_connectivity(grpc_lb_policy *pol) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  grpc_connectivity_state st;
+  gpr_mu_lock(&p->mu);
+  st = grpc_connectivity_state_check(&p->state_tracker);
+  gpr_mu_unlock(&p->mu);
+  return st;
+}
+
+static void pf_notify_on_state_change(grpc_lb_policy *pol,
+                                      grpc_connectivity_state *current,
+                                      grpc_iomgr_closure *notify) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  gpr_mu_lock(&p->mu);
+  grpc_connectivity_state_notify_on_state_change(&p->state_tracker, current,
+                                                 notify);
+  gpr_mu_unlock(&p->mu);
+}
+
+static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
+    pf_destroy,   pf_shutdown,           pf_pick,
+    pf_broadcast, pf_check_connectivity, pf_notify_on_state_change};
+
+grpc_lb_policy *grpc_create_pick_first_lb_policy(grpc_subchannel **subchannels,
+                                                 size_t num_subchannels) {
+  pick_first_lb_policy *p = gpr_malloc(sizeof(*p));
+  GPR_ASSERT(num_subchannels);
+  memset(p, 0, sizeof(*p));
+  grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable);
+  p->subchannels = gpr_malloc(sizeof(grpc_subchannel *) * num_subchannels);
+  p->num_subchannels = num_subchannels;
+  memcpy(p->subchannels, subchannels,
+         sizeof(grpc_subchannel *) * num_subchannels);
+  grpc_iomgr_closure_init(&p->connectivity_changed, pf_connectivity_changed, p);
+  gpr_mu_init(&p->mu);
+  return &p->base;
+}

src/core/surface/client.h → src/core/client_config/lb_policies/pick_first.h

@@ -31,11 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_CLIENT_H
-#define GRPC_INTERNAL_CORE_SURFACE_CLIENT_H
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_PICK_FIRST_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_PICK_FIRST_H
 
-#include "src/core/channel/channel_stack.h"
+#include "src/core/client_config/lb_policy.h"
 
-extern const grpc_channel_filter grpc_client_surface_filter;
+grpc_lb_policy *grpc_create_pick_first_lb_policy(grpc_subchannel **subchannels,
+                                                 size_t num_subchannels);
 
-#endif  /* GRPC_INTERNAL_CORE_SURFACE_CLIENT_H */
+#endif

src/core/client_config/lb_policy.c

@@ -0,0 +1,79 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/lb_policy.h"
+
+void grpc_lb_policy_init(grpc_lb_policy *policy,
+                         const grpc_lb_policy_vtable *vtable) {
+  policy->vtable = vtable;
+  gpr_ref_init(&policy->refs, 1);
+}
+
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
+                        const char *reason) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY:%p   ref %d -> %d %s",
+          policy, (int)policy->refs.count, (int)policy->refs.count + 1, reason);
+#else
+void grpc_lb_policy_ref(grpc_lb_policy *policy) {
+#endif
+  gpr_ref(&policy->refs);
+}
+
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+void grpc_lb_policy_unref(grpc_lb_policy *policy, const char *file, int line,
+                          const char *reason) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY:%p unref %d -> %d %s",
+          policy, (int)policy->refs.count, (int)policy->refs.count - 1, reason);
+#else
+void grpc_lb_policy_unref(grpc_lb_policy *policy) {
+#endif
+  if (gpr_unref(&policy->refs)) {
+    policy->vtable->destroy(policy);
+  }
+}
+
+void grpc_lb_policy_shutdown(grpc_lb_policy *policy) {
+  policy->vtable->shutdown(policy);
+}
+
+void grpc_lb_policy_pick(grpc_lb_policy *policy, grpc_pollset *pollset,
+                         grpc_metadata_batch *initial_metadata,
+                         grpc_subchannel **target,
+                         grpc_iomgr_closure *on_complete) {
+  policy->vtable->pick(policy, pollset, initial_metadata, target, on_complete);
+}
+
+void grpc_lb_policy_broadcast(grpc_lb_policy *policy, grpc_transport_op *op) {
+  policy->vtable->broadcast(policy, op);
+}

src/core/client_config/lb_policy.h

@@ -0,0 +1,109 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H
+
+#include "src/core/client_config/subchannel.h"
+
+/** A load balancing policy: specified by a vtable and a struct (which
+    is expected to be extended to contain some parameters) */
+typedef struct grpc_lb_policy grpc_lb_policy;
+typedef struct grpc_lb_policy_vtable grpc_lb_policy_vtable;
+
+typedef void (*grpc_lb_completion)(void *cb_arg, grpc_subchannel *subchannel,
+                                   grpc_status_code status, const char *errmsg);
+
+struct grpc_lb_policy {
+  const grpc_lb_policy_vtable *vtable;
+  gpr_refcount refs;
+};
+
+struct grpc_lb_policy_vtable {
+  void (*destroy)(grpc_lb_policy *policy);
+
+  void (*shutdown)(grpc_lb_policy *policy);
+
+  /** implement grpc_lb_policy_pick */
+  void (*pick)(grpc_lb_policy *policy, grpc_pollset *pollset,
+               grpc_metadata_batch *initial_metadata, grpc_subchannel **target,
+               grpc_iomgr_closure *on_complete);
+
+  /** broadcast a transport op to all subchannels */
+  void (*broadcast)(grpc_lb_policy *policy, grpc_transport_op *op);
+
+  /** check the current connectivity of the lb_policy */
+  grpc_connectivity_state (*check_connectivity)(grpc_lb_policy *policy);
+
+  /** call notify when the connectivity state of a channel changes from *state.
+      Updates *state with the new state of the policy */
+  void (*notify_on_state_change)(grpc_lb_policy *policy,
+                                 grpc_connectivity_state *state,
+                                 grpc_iomgr_closure *closure);
+};
+
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+#define GRPC_LB_POLICY_REF(p, r) \
+  grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_UNREF(p, r) \
+  grpc_lb_policy_unref((p), __FILE__, __LINE__, (r))
+void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
+                        const char *reason);
+void grpc_lb_policy_unref(grpc_lb_policy *policy, const char *file, int line,
+                          const char *reason);
+#else
+#define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p))
+#define GRPC_LB_POLICY_UNREF(p, r) grpc_lb_policy_unref((p))
+void grpc_lb_policy_ref(grpc_lb_policy *policy);
+void grpc_lb_policy_unref(grpc_lb_policy *policy);
+#endif
+
+/** called by concrete implementations to initialize the base struct */
+void grpc_lb_policy_init(grpc_lb_policy *policy,
+                         const grpc_lb_policy_vtable *vtable);
+
+/** Start shutting down (fail any pending picks) */
+void grpc_lb_policy_shutdown(grpc_lb_policy *policy);
+
+/** Given initial metadata in \a initial_metadata, find an appropriate
+    target for this rpc, and 'return' it by calling \a on_complete after setting
+    \a target.
+    Picking can be asynchronous. Any IO should be done under \a pollset. */
+void grpc_lb_policy_pick(grpc_lb_policy *policy, grpc_pollset *pollset,
+                         grpc_metadata_batch *initial_metadata,
+                         grpc_subchannel **target,
+                         grpc_iomgr_closure *on_complete);
+
+void grpc_lb_policy_broadcast(grpc_lb_policy *policy, grpc_transport_op *op);
+
+#endif /* GRPC_INTERNAL_CORE_CONFIG_LB_POLICY_H */

src/core/client_config/resolver.c

@@ -0,0 +1,83 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/resolver.h"
+
+void grpc_resolver_init(grpc_resolver *resolver,
+                        const grpc_resolver_vtable *vtable) {
+  resolver->vtable = vtable;
+  gpr_ref_init(&resolver->refs, 1);
+}
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+void grpc_resolver_ref(grpc_resolver *resolver, const char *file, int line,
+                       const char *reason) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p   ref %d -> %d %s",
+          resolver, (int)resolver->refs.count, (int)resolver->refs.count + 1,
+          reason);
+#else
+void grpc_resolver_ref(grpc_resolver *resolver) {
+#endif
+  gpr_ref(&resolver->refs);
+}
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+void grpc_resolver_unref(grpc_resolver *resolver, const char *file, int line,
+                         const char *reason) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p unref %d -> %d %s",
+          resolver, (int)resolver->refs.count, (int)resolver->refs.count - 1,
+          reason);
+#else
+void grpc_resolver_unref(grpc_resolver *resolver) {
+#endif
+  if (gpr_unref(&resolver->refs)) {
+    resolver->vtable->destroy(resolver);
+  }
+}
+
+void grpc_resolver_shutdown(grpc_resolver *resolver) {
+  resolver->vtable->shutdown(resolver);
+}
+
+void grpc_resolver_channel_saw_error(grpc_resolver *resolver,
+                                     struct sockaddr *failing_address,
+                                     int failing_address_len) {
+  resolver->vtable->channel_saw_error(resolver, failing_address,
+                                      failing_address_len);
+}
+
+void grpc_resolver_next(grpc_resolver *resolver,
+                        grpc_client_config **target_config,
+                        grpc_iomgr_closure *on_complete) {
+  resolver->vtable->next(resolver, target_config, on_complete);
+}

src/core/client_config/resolver.h

@@ -0,0 +1,97 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_H
+
+#include "src/core/client_config/client_config.h"
+#include "src/core/iomgr/iomgr.h"
+#include "src/core/iomgr/sockaddr.h"
+
+typedef struct grpc_resolver grpc_resolver;
+typedef struct grpc_resolver_vtable grpc_resolver_vtable;
+
+/** grpc_resolver provides grpc_client_config objects to grpc_channel
+    objects */
+struct grpc_resolver {
+  const grpc_resolver_vtable *vtable;
+  gpr_refcount refs;
+};
+
+struct grpc_resolver_vtable {
+  void (*destroy)(grpc_resolver *resolver);
+  void (*shutdown)(grpc_resolver *resolver);
+  void (*channel_saw_error)(grpc_resolver *resolver,
+                            struct sockaddr *failing_address,
+                            int failing_address_len);
+  void (*next)(grpc_resolver *resolver, grpc_client_config **target_config,
+               grpc_iomgr_closure *on_complete);
+};
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+#define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_RESOLVER_UNREF(p, r) \
+  grpc_resolver_unref((p), __FILE__, __LINE__, (r))
+void grpc_resolver_ref(grpc_resolver *policy, const char *file, int line,
+                       const char *reason);
+void grpc_resolver_unref(grpc_resolver *policy, const char *file, int line,
+                         const char *reason);
+#else
+#define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p))
+#define GRPC_RESOLVER_UNREF(p, r) grpc_resolver_unref((p))
+void grpc_resolver_ref(grpc_resolver *policy);
+void grpc_resolver_unref(grpc_resolver *policy);
+#endif
+
+void grpc_resolver_init(grpc_resolver *resolver,
+                        const grpc_resolver_vtable *vtable);
+
+void grpc_resolver_shutdown(grpc_resolver *resolver);
+
+/** Notification that the channel has seen an error on some address.
+    Can be used as a hint that re-resolution is desirable soon. */
+void grpc_resolver_channel_saw_error(grpc_resolver *resolver,
+                                     struct sockaddr *failing_address,
+                                     int failing_address_len);
+
+/** Get the next client config. Called by the channel to fetch a new
+    configuration. Expected to set *target_config with a new configuration,
+    and then schedule on_complete for execution.
+
+    If resolution is fatally broken, set *target_config to NULL and
+    schedule on_complete. */
+void grpc_resolver_next(grpc_resolver *resolver,
+                        grpc_client_config **target_config,
+                        grpc_iomgr_closure *on_complete);
+
+#endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_H */

src/core/client_config/resolver_factory.c

@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/resolver_factory.h"
+
+void grpc_resolver_factory_ref(grpc_resolver_factory *factory) {
+  factory->vtable->ref(factory);
+}
+
+void grpc_resolver_factory_unref(grpc_resolver_factory *factory) {
+  factory->vtable->unref(factory);
+}
+
+/** Create a resolver instance for a name */
+grpc_resolver *grpc_resolver_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_uri *uri,
+    grpc_subchannel_factory *subchannel_factory) {
+  if (!factory) return NULL;
+  return factory->vtable->create_resolver(factory, uri, subchannel_factory);
+}

src/core/client_config/resolver_factory.h

@@ -0,0 +1,67 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
+
+#include "src/core/client_config/resolver.h"
+#include "src/core/client_config/subchannel_factory.h"
+#include "src/core/client_config/uri_parser.h"
+
+typedef struct grpc_resolver_factory grpc_resolver_factory;
+typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
+
+/** grpc_resolver provides grpc_client_config objects to grpc_channel
+    objects */
+struct grpc_resolver_factory {
+  const grpc_resolver_factory_vtable *vtable;
+};
+
+struct grpc_resolver_factory_vtable {
+  void (*ref)(grpc_resolver_factory *factory);
+  void (*unref)(grpc_resolver_factory *factory);
+
+  grpc_resolver *(*create_resolver)(
+      grpc_resolver_factory *factory, grpc_uri *uri,
+      grpc_subchannel_factory *subchannel_factory);
+};
+
+void grpc_resolver_factory_ref(grpc_resolver_factory *resolver);
+void grpc_resolver_factory_unref(grpc_resolver_factory *resolver);
+
+/** Create a resolver instance for a name */
+grpc_resolver *grpc_resolver_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_uri *uri,
+    grpc_subchannel_factory *subchannel_factory);
+
+#endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_FACTORY_H */

src/core/client_config/resolver_registry.c

@@ -0,0 +1,124 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/resolver_registry.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#define MAX_RESOLVERS 10
+
+typedef struct {
+  char *scheme;
+  grpc_resolver_factory *factory;
+} registered_resolver;
+
+static registered_resolver g_all_of_the_resolvers[MAX_RESOLVERS];
+static int g_number_of_resolvers = 0;
+
+static char *g_default_resolver_scheme;
+
+void grpc_resolver_registry_init(const char *default_resolver_scheme) {
+  g_number_of_resolvers = 0;
+  g_default_resolver_scheme = gpr_strdup(default_resolver_scheme);
+}
+
+void grpc_resolver_registry_shutdown(void) {
+  int i;
+  for (i = 0; i < g_number_of_resolvers; i++) {
+    gpr_free(g_all_of_the_resolvers[i].scheme);
+    grpc_resolver_factory_unref(g_all_of_the_resolvers[i].factory);
+  }
+  gpr_free(g_default_resolver_scheme);
+}
+
+void grpc_register_resolver_type(const char *scheme,
+                                 grpc_resolver_factory *factory) {
+  int i;
+  for (i = 0; i < g_number_of_resolvers; i++) {
+    GPR_ASSERT(0 != strcmp(scheme, g_all_of_the_resolvers[i].scheme));
+  }
+  GPR_ASSERT(g_number_of_resolvers != MAX_RESOLVERS);
+  g_all_of_the_resolvers[g_number_of_resolvers].scheme = gpr_strdup(scheme);
+  grpc_resolver_factory_ref(factory);
+  g_all_of_the_resolvers[g_number_of_resolvers].factory = factory;
+  g_number_of_resolvers++;
+}
+
+static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
+  int i;
+
+  /* handling NULL uri's here simplifies grpc_resolver_create */
+  if (!uri) return NULL;
+
+  for (i = 0; i < g_number_of_resolvers; i++) {
+    if (0 == strcmp(uri->scheme, g_all_of_the_resolvers[i].scheme)) {
+      return g_all_of_the_resolvers[i].factory;
+    }
+  }
+
+  return NULL;
+}
+
+grpc_resolver *grpc_resolver_create(
+    const char *name, grpc_subchannel_factory *subchannel_factory) {
+  grpc_uri *uri;
+  char *tmp;
+  grpc_resolver_factory *factory = NULL;
+  grpc_resolver *resolver;
+
+  uri = grpc_uri_parse(name, 1);
+  factory = lookup_factory(uri);
+  if (factory == NULL && g_default_resolver_scheme != NULL) {
+    grpc_uri_destroy(uri);
+    gpr_asprintf(&tmp, "%s%s", g_default_resolver_scheme, name);
+    uri = grpc_uri_parse(tmp, 1);
+    factory = lookup_factory(uri);
+    if (factory == NULL) {
+      grpc_uri_destroy(grpc_uri_parse(name, 0));
+      grpc_uri_destroy(grpc_uri_parse(tmp, 0));
+      gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", name, tmp);
+    }
+    gpr_free(tmp);
+  } else if (factory == NULL) {
+    grpc_uri_destroy(grpc_uri_parse(name, 0));
+    gpr_log(GPR_ERROR, "don't know how to resolve '%s'", name);
+  }
+  resolver =
+      grpc_resolver_factory_create_resolver(factory, uri, subchannel_factory);
+  grpc_uri_destroy(uri);
+  return resolver;
+}

src/core/client_config/resolver_registry.h

@@ -0,0 +1,62 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+
+#include "src/core/client_config/resolver_factory.h"
+
+void grpc_resolver_registry_init(const char *default_prefix);
+void grpc_resolver_registry_shutdown(void);
+
+/** Register a resolver type.
+    URI's of \a scheme will be resolved with the given resolver.
+    If \a priority is greater than zero, then the resolver will be eligible
+    to resolve names that are passed in with no scheme. Higher priority
+    resolvers will be tried before lower priority schemes. */
+void grpc_register_resolver_type(const char *scheme,
+                                 grpc_resolver_factory *factory);
+
+/** Create a resolver given \a name.
+    First tries to parse \a name as a URI. If this succeeds, tries
+    to locate a registered resolver factory based on the URI scheme.
+    If parsing or location fails, prefixes default_prefix from
+    grpc_resolver_registry_init to name, and tries again (if default_prefix
+    was not NULL).
+    If a resolver factory was found, use it to instantiate a resolver and
+    return it.
+    If a resolver factory was not found, return NULL. */
+grpc_resolver *grpc_resolver_create(
+    const char *name, grpc_subchannel_factory *subchannel_factory);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H */

src/core/client_config/resolvers/dns_resolver.c

@@ -0,0 +1,246 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/resolvers/dns_resolver.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/client_config/lb_policies/pick_first.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/support/string.h"
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** name to resolve */
+  char *name;
+  /** default port to use */
+  char *default_port;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy factory */
+  grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                       size_t num_subchannels);
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** are we currently resolving? */
+  int resolving;
+  /** which version of resolved_config have we published? */
+  int published_version;
+  /** which version of resolved_config is current? */
+  int resolved_version;
+  /** pending next completion, or NULL */
+  grpc_iomgr_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+  /** current (fully resolved) config */
+  grpc_client_config *resolved_config;
+} dns_resolver;
+
+static void dns_destroy(grpc_resolver *r);
+
+static void dns_start_resolving_locked(dns_resolver *r);
+static void dns_maybe_finish_next_locked(dns_resolver *r);
+
+static void dns_shutdown(grpc_resolver *r);
+static void dns_channel_saw_error(grpc_resolver *r,
+                                  struct sockaddr *failing_address,
+                                  int failing_address_len);
+static void dns_next(grpc_resolver *r, grpc_client_config **target_config,
+                     grpc_iomgr_closure *on_complete);
+
+static const grpc_resolver_vtable dns_resolver_vtable = {
+    dns_destroy, dns_shutdown, dns_channel_saw_error, dns_next};
+
+static void dns_shutdown(grpc_resolver *resolver) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_channel_saw_error(grpc_resolver *resolver, struct sockaddr *sa,
+                                  int len) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (!r->resolving) {
+    dns_start_resolving_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_next(grpc_resolver *resolver,
+                     grpc_client_config **target_config,
+                     grpc_iomgr_closure *on_complete) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(!r->next_completion);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  if (r->resolved_version == 0 && !r->resolving) {
+    dns_start_resolving_locked(r);
+  } else {
+    dns_maybe_finish_next_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_on_resolved(void *arg, grpc_resolved_addresses *addresses) {
+  dns_resolver *r = arg;
+  grpc_client_config *config = NULL;
+  grpc_subchannel **subchannels;
+  grpc_subchannel_args args;
+  grpc_lb_policy *lb_policy;
+  size_t i;
+  if (addresses) {
+    config = grpc_client_config_create();
+    subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
+    for (i = 0; i < addresses->naddrs; i++) {
+      memset(&args, 0, sizeof(args));
+      args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
+      args.addr_len = addresses->addrs[i].len;
+      subchannels[i] = grpc_subchannel_factory_create_subchannel(
+          r->subchannel_factory, &args);
+    }
+    lb_policy = r->lb_policy_factory(subchannels, addresses->naddrs);
+    grpc_client_config_set_lb_policy(config, lb_policy);
+    GRPC_LB_POLICY_UNREF(lb_policy, "construction");
+    grpc_resolved_addresses_destroy(addresses);
+    gpr_free(subchannels);
+  }
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->resolving);
+  r->resolving = 0;
+  if (r->resolved_config) {
+    grpc_client_config_unref(r->resolved_config);
+  }
+  r->resolved_config = config;
+  r->resolved_version++;
+  dns_maybe_finish_next_locked(r);
+  gpr_mu_unlock(&r->mu);
+
+  GRPC_RESOLVER_UNREF(&r->base, "dns-resolving");
+}
+
+static void dns_start_resolving_locked(dns_resolver *r) {
+  GRPC_RESOLVER_REF(&r->base, "dns-resolving");
+  GPR_ASSERT(!r->resolving);
+  r->resolving = 1;
+  grpc_resolve_address(r->name, r->default_port, dns_on_resolved, r);
+}
+
+static void dns_maybe_finish_next_locked(dns_resolver *r) {
+  if (r->next_completion != NULL &&
+      r->resolved_version != r->published_version) {
+    *r->target_config = r->resolved_config;
+    if (r->resolved_config) {
+      grpc_client_config_ref(r->resolved_config);
+    }
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+    r->published_version = r->resolved_version;
+  }
+}
+
+static void dns_destroy(grpc_resolver *gr) {
+  dns_resolver *r = (dns_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  if (r->resolved_config) {
+    grpc_client_config_unref(r->resolved_config);
+  }
+  grpc_subchannel_factory_unref(r->subchannel_factory);
+  gpr_free(r->name);
+  gpr_free(r->default_port);
+  gpr_free(r);
+}
+
+static grpc_resolver *dns_create(
+    grpc_uri *uri, const char *default_port,
+    grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                         size_t num_subchannels),
+    grpc_subchannel_factory *subchannel_factory) {
+  dns_resolver *r;
+  const char *path = uri->path;
+
+  if (0 != strcmp(uri->authority, "")) {
+    gpr_log(GPR_ERROR, "authority based uri's not supported");
+    return NULL;
+  }
+
+  if (path[0] == '/') ++path;
+
+  r = gpr_malloc(sizeof(dns_resolver));
+  memset(r, 0, sizeof(*r));
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &dns_resolver_vtable);
+  r->name = gpr_strdup(path);
+  r->default_port = gpr_strdup(default_port);
+  r->subchannel_factory = subchannel_factory;
+  r->lb_policy_factory = lb_policy_factory;
+  grpc_subchannel_factory_ref(subchannel_factory);
+  return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void dns_factory_ref(grpc_resolver_factory *factory) {}
+
+static void dns_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *dns_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_uri *uri,
+    grpc_subchannel_factory *subchannel_factory) {
+  return dns_create(uri, "https", grpc_create_pick_first_lb_policy,
+                    subchannel_factory);
+}
+
+static const grpc_resolver_factory_vtable dns_factory_vtable = {
+    dns_factory_ref, dns_factory_unref, dns_factory_create_resolver};
+static grpc_resolver_factory dns_resolver_factory = {&dns_factory_vtable};
+
+grpc_resolver_factory *grpc_dns_resolver_factory_create() {
+  return &dns_resolver_factory;
+}

src/objective-c/GRPCClient/private/GRPCMethodName+HTTP2Encoding.h → src/core/client_config/resolvers/dns_resolver.h

@@ -31,10 +31,12 @@
  *
  */
 
-#import <Foundation/Foundation.h>
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
 
-#import "GRPCClient/GRPCMethodName.h"
+#include "src/core/client_config/resolver_factory.h"
 
-@interface GRPCMethodName (HTTP2Encoding)
-- (NSString *)HTTP2Path;
-@end
+/** Create a dns resolver factory */
+grpc_resolver_factory *grpc_dns_resolver_factory_create(void);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H */

src/core/client_config/resolvers/unix_resolver_posix.c

@@ -0,0 +1,195 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/client_config/resolvers/unix_resolver_posix.h"
+
+#include <string.h>
+#include <sys/un.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/client_config/lb_policies/pick_first.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/support/string.h"
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy factory */
+  grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                       size_t num_subchannels);
+
+  /** the address that we've 'resolved' */
+  struct sockaddr_un addr;
+  int addr_len;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** have we published? */
+  int published;
+  /** pending next completion, or NULL */
+  grpc_iomgr_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+} unix_resolver;
+
+static void unix_destroy(grpc_resolver *r);
+
+static void unix_maybe_finish_next_locked(unix_resolver *r);
+
+static void unix_shutdown(grpc_resolver *r);
+static void unix_channel_saw_error(grpc_resolver *r,
+                                   struct sockaddr *failing_address,
+                                   int failing_address_len);
+static void unix_next(grpc_resolver *r, grpc_client_config **target_config,
+                      grpc_iomgr_closure *on_complete);
+
+static const grpc_resolver_vtable unix_resolver_vtable = {
+    unix_destroy, unix_shutdown, unix_channel_saw_error, unix_next};
+
+static void unix_shutdown(grpc_resolver *resolver) {
+  unix_resolver *r = (unix_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    /* TODO(ctiller): add delayed callback */
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void unix_channel_saw_error(grpc_resolver *resolver, struct sockaddr *sa,
+                                   int len) {}
+
+static void unix_next(grpc_resolver *resolver,
+                      grpc_client_config **target_config,
+                      grpc_iomgr_closure *on_complete) {
+  unix_resolver *r = (unix_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(!r->next_completion);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  unix_maybe_finish_next_locked(r);
+  gpr_mu_unlock(&r->mu);
+}
+
+static void unix_maybe_finish_next_locked(unix_resolver *r) {
+  grpc_client_config *cfg;
+  grpc_lb_policy *lb_policy;
+  grpc_subchannel *subchannel;
+  grpc_subchannel_args args;
+
+  if (r->next_completion != NULL && !r->published) {
+    cfg = grpc_client_config_create();
+    memset(&args, 0, sizeof(args));
+    args.addr = (struct sockaddr *)&r->addr;
+    args.addr_len = r->addr_len;
+    subchannel =
+        grpc_subchannel_factory_create_subchannel(r->subchannel_factory, &args);
+    lb_policy = r->lb_policy_factory(&subchannel, 1);
+    grpc_client_config_set_lb_policy(cfg, lb_policy);
+    GRPC_LB_POLICY_UNREF(lb_policy, "unix");
+    r->published = 1;
+    *r->target_config = cfg;
+    grpc_iomgr_add_callback(r->next_completion);
+    r->next_completion = NULL;
+  }
+}
+
+static void unix_destroy(grpc_resolver *gr) {
+  unix_resolver *r = (unix_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  grpc_subchannel_factory_unref(r->subchannel_factory);
+  gpr_free(r);
+}
+
+static grpc_resolver *unix_create(
+    grpc_uri *uri,
+    grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+                                         size_t num_subchannels),
+    grpc_subchannel_factory *subchannel_factory) {
+  unix_resolver *r;
+
+  if (0 != strcmp(uri->authority, "")) {
+    gpr_log(GPR_ERROR, "authority based uri's not supported");
+    return NULL;
+  }
+
+  r = gpr_malloc(sizeof(unix_resolver));
+  memset(r, 0, sizeof(*r));
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &unix_resolver_vtable);
+  r->subchannel_factory = subchannel_factory;
+  r->lb_policy_factory = lb_policy_factory;
+
+  r->addr.sun_family = AF_UNIX;
+  strcpy(r->addr.sun_path, uri->path);
+  r->addr_len = strlen(r->addr.sun_path) + sizeof(r->addr.sun_family) + 1;
+
+  grpc_subchannel_factory_ref(subchannel_factory);
+  return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void unix_factory_ref(grpc_resolver_factory *factory) {}
+
+static void unix_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *unix_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_uri *uri,
+    grpc_subchannel_factory *subchannel_factory) {
+  return unix_create(uri, grpc_create_pick_first_lb_policy, subchannel_factory);
+}
+
+static const grpc_resolver_factory_vtable unix_factory_vtable = {
+    unix_factory_ref, unix_factory_unref, unix_factory_create_resolver};
+static grpc_resolver_factory unix_resolver_factory = {&unix_factory_vtable};
+
+grpc_resolver_factory *grpc_unix_resolver_factory_create() {
+  return &unix_resolver_factory;
+}
+
+#endif

src/core/client_config/resolvers/unix_resolver_posix.h

@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/client_config/resolver_factory.h"
+
+/** Create a unix resolver factory */
+grpc_resolver_factory *grpc_unix_resolver_factory_create(void);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H */

src/core/client_config/subchannel.c

@@ -0,0 +1,659 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/subchannel.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
+#include "src/core/channel/channel_args.h"
+#include "src/core/channel/connected_channel.h"
+#include "src/core/iomgr/alarm.h"
+#include "src/core/transport/connectivity_state.h"
+
+typedef struct {
+  /* all fields protected by subchannel->mu */
+  /** refcount */
+  int refs;
+  /** parent subchannel */
+  grpc_subchannel *subchannel;
+} connection;
+
+typedef struct {
+  grpc_iomgr_closure closure;
+  size_t version;
+  grpc_subchannel *subchannel;
+  grpc_connectivity_state connectivity_state;
+} state_watcher;
+
+typedef struct waiting_for_connect {
+  struct waiting_for_connect *next;
+  grpc_iomgr_closure *notify;
+  grpc_pollset *pollset;
+  grpc_subchannel_call **target;
+  grpc_subchannel *subchannel;
+  grpc_iomgr_closure continuation;
+} waiting_for_connect;
+
+struct grpc_subchannel {
+  grpc_connector *connector;
+
+  /** non-transport related channel filters */
+  const grpc_channel_filter **filters;
+  size_t num_filters;
+  /** channel arguments */
+  grpc_channel_args *args;
+  /** address to connect to */
+  struct sockaddr *addr;
+  size_t addr_len;
+  /** metadata context */
+  grpc_mdctx *mdctx;
+  /** master channel - the grpc_channel instance that ultimately owns
+      this channel_data via its channel stack.
+      We occasionally use this to bump the refcount on the master channel
+      to keep ourselves alive through an asynchronous operation. */
+  grpc_channel *master;
+  /** have we seen a disconnection? */
+  int disconnected;
+
+  /** set during connection */
+  grpc_connect_out_args connecting_result;
+
+  /** callback for connection finishing */
+  grpc_iomgr_closure connected;
+
+  /** pollset_set tracking who's interested in a connection
+      being setup */
+  grpc_pollset_set pollset_set;
+
+  /** mutex protecting remaining elements */
+  gpr_mu mu;
+
+  /** active connection */
+  connection *active;
+  /** version number for the active connection */
+  size_t active_version;
+  /** refcount */
+  int refs;
+  /** are we connecting */
+  int connecting;
+  /** things waiting for a connection */
+  waiting_for_connect *waiting;
+  /** connectivity state tracking */
+  grpc_connectivity_state_tracker state_tracker;
+
+  /** next connect attempt time */
+  gpr_timespec next_attempt;
+  /** amount to backoff each failure */
+  gpr_timespec backoff_delta;
+  /** do we have an active alarm? */
+  int have_alarm;
+  /** our alarm */
+  grpc_alarm alarm;
+};
+
+struct grpc_subchannel_call {
+  connection *connection;
+  gpr_refcount refs;
+};
+
+#define SUBCHANNEL_CALL_TO_CALL_STACK(call) ((grpc_call_stack *)((call) + 1))
+#define CHANNEL_STACK_FROM_CONNECTION(con) ((grpc_channel_stack *)((con) + 1))
+
+static grpc_subchannel_call *create_call(connection *con);
+static void connectivity_state_changed_locked(grpc_subchannel *c);
+static grpc_connectivity_state compute_connectivity_locked(grpc_subchannel *c);
+static gpr_timespec compute_connect_deadline(grpc_subchannel *c);
+static void subchannel_connected(void *subchannel, int iomgr_success);
+
+static void subchannel_ref_locked(
+    grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+static int subchannel_unref_locked(
+    grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) GRPC_MUST_USE_RESULT;
+static void connection_ref_locked(connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+static grpc_subchannel *connection_unref_locked(
+    connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) GRPC_MUST_USE_RESULT;
+static void subchannel_destroy(grpc_subchannel *c);
+
+#ifdef GRPC_SUBCHANNEL_REFCOUNT_DEBUG
+#define SUBCHANNEL_REF_LOCKED(p, r) \
+  subchannel_ref_locked((p), __FILE__, __LINE__, (r))
+#define SUBCHANNEL_UNREF_LOCKED(p, r) \
+  subchannel_unref_locked((p), __FILE__, __LINE__, (r))
+#define CONNECTION_REF_LOCKED(p, r) \
+  connection_ref_locked((p), __FILE__, __LINE__, (r))
+#define CONNECTION_UNREF_LOCKED(p, r) \
+  connection_unref_locked((p), __FILE__, __LINE__, (r))
+#define REF_PASS_ARGS , file, line, reason
+#define REF_LOG(name, p)                                                  \
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p   ref %d -> %d %s", \
+          (name), (p), (p)->refs, (p)->refs + 1, reason)
+#define UNREF_LOG(name, p)                                                \
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p unref %d -> %d %s", \
+          (name), (p), (p)->refs, (p)->refs - 1, reason)
+#else
+#define SUBCHANNEL_REF_LOCKED(p, r) subchannel_ref_locked((p))
+#define SUBCHANNEL_UNREF_LOCKED(p, r) subchannel_unref_locked((p))
+#define CONNECTION_REF_LOCKED(p, r) connection_ref_locked((p))
+#define CONNECTION_UNREF_LOCKED(p, r) connection_unref_locked((p))
+#define REF_PASS_ARGS
+#define REF_LOG(name, p) \
+  do {                   \
+  } while (0)
+#define UNREF_LOG(name, p) \
+  do {                     \
+  } while (0)
+#endif
+
+/*
+ * connection implementation
+ */
+
+static void connection_destroy(connection *c) {
+  GPR_ASSERT(c->refs == 0);
+  grpc_channel_stack_destroy(CHANNEL_STACK_FROM_CONNECTION(c));
+  gpr_free(c);
+}
+
+static void connection_ref_locked(
+    connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  REF_LOG("CONNECTION", c);
+  subchannel_ref_locked(c->subchannel REF_PASS_ARGS);
+  ++c->refs;
+}
+
+static grpc_subchannel *connection_unref_locked(
+    connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  grpc_subchannel *destroy = NULL;
+  UNREF_LOG("CONNECTION", c);
+  if (subchannel_unref_locked(c->subchannel REF_PASS_ARGS)) {
+    destroy = c->subchannel;
+  }
+  if (--c->refs == 0 && c->subchannel->active != c) {
+    connection_destroy(c);
+  }
+  return destroy;
+}
+
+/*
+ * grpc_subchannel implementation
+ */
+
+static void subchannel_ref_locked(
+    grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  REF_LOG("SUBCHANNEL", c);
+  ++c->refs;
+}
+
+static int subchannel_unref_locked(
+    grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  UNREF_LOG("SUBCHANNEL", c);
+  return --c->refs == 0;
+}
+
+void grpc_subchannel_ref(grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  gpr_mu_lock(&c->mu);
+  subchannel_ref_locked(c REF_PASS_ARGS);
+  gpr_mu_unlock(&c->mu);
+}
+
+void grpc_subchannel_unref(grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  int destroy;
+  gpr_mu_lock(&c->mu);
+  destroy = subchannel_unref_locked(c REF_PASS_ARGS);
+  gpr_mu_unlock(&c->mu);
+  if (destroy) subchannel_destroy(c);
+}
+
+static void subchannel_destroy(grpc_subchannel *c) {
+  if (c->active != NULL) {
+    connection_destroy(c->active);
+  }
+  gpr_free(c->filters);
+  grpc_channel_args_destroy(c->args);
+  gpr_free(c->addr);
+  grpc_mdctx_unref(c->mdctx);
+  grpc_pollset_set_destroy(&c->pollset_set);
+  grpc_connectivity_state_destroy(&c->state_tracker);
+  grpc_connector_unref(c->connector);
+  gpr_free(c);
+}
+
+void grpc_subchannel_add_interested_party(grpc_subchannel *c,
+                                          grpc_pollset *pollset) {
+  grpc_pollset_set_add_pollset(&c->pollset_set, pollset);
+}
+
+void grpc_subchannel_del_interested_party(grpc_subchannel *c,
+                                          grpc_pollset *pollset) {
+  grpc_pollset_set_del_pollset(&c->pollset_set, pollset);
+}
+
+grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
+                                        grpc_subchannel_args *args) {
+  grpc_subchannel *c = gpr_malloc(sizeof(*c));
+  memset(c, 0, sizeof(*c));
+  c->refs = 1;
+  c->connector = connector;
+  grpc_connector_ref(c->connector);
+  c->num_filters = args->filter_count;
+  c->filters = gpr_malloc(sizeof(grpc_channel_filter *) * c->num_filters);
+  memcpy(c->filters, args->filters,
+         sizeof(grpc_channel_filter *) * c->num_filters);
+  c->addr = gpr_malloc(args->addr_len);
+  memcpy(c->addr, args->addr, args->addr_len);
+  c->addr_len = args->addr_len;
+  c->args = grpc_channel_args_copy(args->args);
+  c->mdctx = args->mdctx;
+  c->master = args->master;
+  grpc_mdctx_ref(c->mdctx);
+  grpc_pollset_set_init(&c->pollset_set);
+  grpc_iomgr_closure_init(&c->connected, subchannel_connected, c);
+  grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE);
+  gpr_mu_init(&c->mu);
+  return c;
+}
+
+static void continue_connect(grpc_subchannel *c) {
+  grpc_connect_in_args args;
+
+  args.interested_parties = &c->pollset_set;
+  args.addr = c->addr;
+  args.addr_len = c->addr_len;
+  args.deadline = compute_connect_deadline(c);
+  args.channel_args = c->args;
+  args.metadata_context = c->mdctx;
+
+  grpc_connector_connect(c->connector, &args, &c->connecting_result,
+                         &c->connected);
+}
+
+static void start_connect(grpc_subchannel *c) {
+  gpr_timespec now = gpr_now();
+  c->next_attempt = now;
+  c->backoff_delta = gpr_time_from_seconds(1);
+
+  continue_connect(c);
+}
+
+static void continue_creating_call(void *arg, int iomgr_success) {
+  waiting_for_connect *w4c = arg;
+  grpc_subchannel_create_call(w4c->subchannel, w4c->pollset, w4c->target,
+                              w4c->notify);
+  GRPC_SUBCHANNEL_UNREF(w4c->subchannel, "waiting_for_connect");
+  gpr_free(w4c);
+}
+
+void grpc_subchannel_create_call(grpc_subchannel *c, grpc_pollset *pollset,
+                                 grpc_subchannel_call **target,
+                                 grpc_iomgr_closure *notify) {
+  connection *con;
+  gpr_mu_lock(&c->mu);
+  if (c->active != NULL) {
+    con = c->active;
+    CONNECTION_REF_LOCKED(con, "call");
+    gpr_mu_unlock(&c->mu);
+
+    *target = create_call(con);
+    notify->cb(notify->cb_arg, 1);
+  } else {
+    waiting_for_connect *w4c = gpr_malloc(sizeof(*w4c));
+    w4c->next = c->waiting;
+    w4c->notify = notify;
+    w4c->pollset = pollset;
+    w4c->target = target;
+    w4c->subchannel = c;
+    /* released when clearing w4c */
+    SUBCHANNEL_REF_LOCKED(c, "waiting_for_connect");
+    grpc_iomgr_closure_init(&w4c->continuation, continue_creating_call, w4c);
+    c->waiting = w4c;
+    grpc_subchannel_add_interested_party(c, pollset);
+    if (!c->connecting) {
+      c->connecting = 1;
+      connectivity_state_changed_locked(c);
+      /* released by connection */
+      SUBCHANNEL_REF_LOCKED(c, "connecting");
+      gpr_mu_unlock(&c->mu);
+
+      start_connect(c);
+    } else {
+      gpr_mu_unlock(&c->mu);
+    }
+  }
+}
+
+grpc_connectivity_state grpc_subchannel_check_connectivity(grpc_subchannel *c) {
+  grpc_connectivity_state state;
+  gpr_mu_lock(&c->mu);
+  state = grpc_connectivity_state_check(&c->state_tracker);
+  gpr_mu_unlock(&c->mu);
+  return state;
+}
+
+void grpc_subchannel_notify_on_state_change(grpc_subchannel *c,
+                                            grpc_connectivity_state *state,
+                                            grpc_iomgr_closure *notify) {
+  int do_connect = 0;
+  gpr_mu_lock(&c->mu);
+  if (grpc_connectivity_state_notify_on_state_change(&c->state_tracker, state,
+                                                     notify)) {
+    do_connect = 1;
+    c->connecting = 1;
+    /* released by connection */
+    SUBCHANNEL_REF_LOCKED(c, "connecting");
+    connectivity_state_changed_locked(c);
+  }
+  gpr_mu_unlock(&c->mu);
+  if (do_connect) {
+    start_connect(c);
+  }
+}
+
+void grpc_subchannel_process_transport_op(grpc_subchannel *c,
+                                          grpc_transport_op *op) {
+  connection *con = NULL;
+  grpc_subchannel *destroy;
+  int cancel_alarm = 0;
+  gpr_mu_lock(&c->mu);
+  if (op->disconnect) {
+    c->disconnected = 1;
+    connectivity_state_changed_locked(c);
+    if (c->have_alarm) {
+      cancel_alarm = 1;
+    }
+  }
+  if (c->active != NULL) {
+    con = c->active;
+    CONNECTION_REF_LOCKED(con, "transport-op");
+  }
+  gpr_mu_unlock(&c->mu);
+
+  if (con != NULL) {
+    grpc_channel_stack *channel_stack = CHANNEL_STACK_FROM_CONNECTION(con);
+    grpc_channel_element *top_elem =
+        grpc_channel_stack_element(channel_stack, 0);
+    top_elem->filter->start_transport_op(top_elem, op);
+
+    gpr_mu_lock(&c->mu);
+    destroy = CONNECTION_UNREF_LOCKED(con, "transport-op");
+    gpr_mu_unlock(&c->mu);
+    if (destroy) {
+      subchannel_destroy(destroy);
+    }
+  }
+
+  if (cancel_alarm) {
+    grpc_alarm_cancel(&c->alarm);
+  }
+}
+
+static void on_state_changed(void *p, int iomgr_success) {
+  state_watcher *sw = p;
+  grpc_subchannel *c = sw->subchannel;
+  gpr_mu *mu = &c->mu;
+  int destroy;
+  grpc_transport_op op;
+  grpc_channel_element *elem;
+  connection *destroy_connection = NULL;
+
+  gpr_mu_lock(mu);
+
+  /* if we failed or there is a version number mismatch, just leave
+     this closure */
+  if (!iomgr_success || sw->subchannel->active_version != sw->version) {
+    goto done;
+  }
+
+  switch (sw->connectivity_state) {
+    case GRPC_CHANNEL_CONNECTING:
+    case GRPC_CHANNEL_READY:
+    case GRPC_CHANNEL_IDLE:
+      /* all is still good: keep watching */
+      memset(&op, 0, sizeof(op));
+      op.connectivity_state = &sw->connectivity_state;
+      op.on_connectivity_state_change = &sw->closure;
+      elem = grpc_channel_stack_element(
+          CHANNEL_STACK_FROM_CONNECTION(c->active), 0);
+      elem->filter->start_transport_op(elem, &op);
+      /* early out */
+      gpr_mu_unlock(mu);
+      return;
+    case GRPC_CHANNEL_FATAL_FAILURE:
+    case GRPC_CHANNEL_TRANSIENT_FAILURE:
+      /* things have gone wrong, deactivate and enter idle */
+      if (sw->subchannel->active->refs == 0) {
+        destroy_connection = sw->subchannel->active;
+      }
+      sw->subchannel->active = NULL;
+      grpc_connectivity_state_set(&c->state_tracker,
+                                  GRPC_CHANNEL_TRANSIENT_FAILURE);
+      break;
+  }
+
+done:
+  connectivity_state_changed_locked(c);
+  destroy = SUBCHANNEL_UNREF_LOCKED(c, "state_watcher");
+  gpr_free(sw);
+  gpr_mu_unlock(mu);
+  if (destroy) {
+    subchannel_destroy(c);
+  }
+  if (destroy_connection != NULL) {
+    connection_destroy(destroy_connection);
+  }
+}
+
+static void publish_transport(grpc_subchannel *c) {
+  size_t channel_stack_size;
+  connection *con;
+  grpc_channel_stack *stk;
+  size_t num_filters;
+  const grpc_channel_filter **filters;
+  waiting_for_connect *w4c;
+  grpc_transport_op op;
+  state_watcher *sw;
+  connection *destroy_connection = NULL;
+  grpc_channel_element *elem;
+
+  /* build final filter list */
+  num_filters = c->num_filters + c->connecting_result.num_filters + 1;
+  filters = gpr_malloc(sizeof(*filters) * num_filters);
+  memcpy(filters, c->filters, sizeof(*filters) * c->num_filters);
+  memcpy(filters + c->num_filters, c->connecting_result.filters,
+         sizeof(*filters) * c->connecting_result.num_filters);
+  filters[num_filters - 1] = &grpc_connected_channel_filter;
+
+  /* construct channel stack */
+  channel_stack_size = grpc_channel_stack_size(filters, num_filters);
+  con = gpr_malloc(sizeof(connection) + channel_stack_size);
+  stk = (grpc_channel_stack *)(con + 1);
+  con->refs = 0;
+  con->subchannel = c;
+  grpc_channel_stack_init(filters, num_filters, c->master, c->args, c->mdctx,
+                          stk);
+  grpc_connected_channel_bind_transport(stk, c->connecting_result.transport);
+  gpr_free(c->connecting_result.filters);
+  memset(&c->connecting_result, 0, sizeof(c->connecting_result));
+
+  /* initialize state watcher */
+  sw = gpr_malloc(sizeof(*sw));
+  grpc_iomgr_closure_init(&sw->closure, on_state_changed, sw);
+  sw->subchannel = c;
+  sw->connectivity_state = GRPC_CHANNEL_READY;
+
+  gpr_mu_lock(&c->mu);
+
+  if (c->disconnected) {
+    gpr_mu_unlock(&c->mu);
+    gpr_free(sw);
+    gpr_free(filters);
+    grpc_channel_stack_destroy(stk);
+    return;
+  }
+
+  /* publish */
+  if (c->active != NULL && c->active->refs == 0) {
+    destroy_connection = c->active;
+  }
+  c->active = con;
+  c->active_version++;
+  sw->version = c->active_version;
+  c->connecting = 0;
+
+  /* watch for changes; subchannel ref for connecting is donated
+     to the state watcher */
+  memset(&op, 0, sizeof(op));
+  op.connectivity_state = &sw->connectivity_state;
+  op.on_connectivity_state_change = &sw->closure;
+  SUBCHANNEL_REF_LOCKED(c, "state_watcher");
+  GPR_ASSERT(!SUBCHANNEL_UNREF_LOCKED(c, "connecting"));
+  elem =
+      grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(c->active), 0);
+  elem->filter->start_transport_op(elem, &op);
+
+  /* signal completion */
+  connectivity_state_changed_locked(c);
+  while ((w4c = c->waiting)) {
+    c->waiting = w4c->next;
+    grpc_iomgr_add_callback(&w4c->continuation);
+  }
+
+  gpr_mu_unlock(&c->mu);
+
+  gpr_free(filters);
+
+  if (destroy_connection != NULL) {
+    connection_destroy(destroy_connection);
+  }
+}
+
+static void on_alarm(void *arg, int iomgr_success) {
+  grpc_subchannel *c = arg;
+  gpr_mu_lock(&c->mu);
+  c->have_alarm = 0;
+  if (c->disconnected) {
+    iomgr_success = 0;
+  }
+  connectivity_state_changed_locked(c);
+  gpr_mu_unlock(&c->mu);
+  if (iomgr_success) {
+    continue_connect(c);
+  } else {
+    GRPC_SUBCHANNEL_UNREF(c, "connecting");
+  }
+}
+
+static void subchannel_connected(void *arg, int iomgr_success) {
+  grpc_subchannel *c = arg;
+  if (c->connecting_result.transport != NULL) {
+    publish_transport(c);
+  } else {
+    gpr_mu_lock(&c->mu);
+    connectivity_state_changed_locked(c);
+    GPR_ASSERT(!c->have_alarm);
+    c->have_alarm = 1;
+    c->next_attempt = gpr_time_add(c->next_attempt, c->backoff_delta);
+    c->backoff_delta = gpr_time_add(c->backoff_delta, c->backoff_delta);
+    grpc_alarm_init(&c->alarm, c->next_attempt, on_alarm, c, gpr_now());
+    gpr_mu_unlock(&c->mu);
+  }
+}
+
+static gpr_timespec compute_connect_deadline(grpc_subchannel *c) {
+  return gpr_time_add(c->next_attempt, c->backoff_delta);
+}
+
+static grpc_connectivity_state compute_connectivity_locked(grpc_subchannel *c) {
+  if (c->disconnected) {
+    return GRPC_CHANNEL_FATAL_FAILURE;
+  }
+  if (c->connecting) {
+    if (c->have_alarm) {
+      return GRPC_CHANNEL_TRANSIENT_FAILURE;
+    }
+    return GRPC_CHANNEL_CONNECTING;
+  }
+  if (c->active) {
+    return GRPC_CHANNEL_READY;
+  }
+  return GRPC_CHANNEL_IDLE;
+}
+
+static void connectivity_state_changed_locked(grpc_subchannel *c) {
+  grpc_connectivity_state current = compute_connectivity_locked(c);
+  grpc_connectivity_state_set(&c->state_tracker, current);
+}
+
+/*
+ * grpc_subchannel_call implementation
+ */
+
+void grpc_subchannel_call_ref(
+    grpc_subchannel_call *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  gpr_ref(&c->refs);
+}
+
+void grpc_subchannel_call_unref(
+    grpc_subchannel_call *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+  if (gpr_unref(&c->refs)) {
+    gpr_mu *mu = &c->connection->subchannel->mu;
+    grpc_subchannel *destroy;
+    grpc_call_stack_destroy(SUBCHANNEL_CALL_TO_CALL_STACK(c));
+    gpr_mu_lock(mu);
+    destroy = CONNECTION_UNREF_LOCKED(c->connection, "call");
+    gpr_mu_unlock(mu);
+    gpr_free(c);
+    if (destroy != NULL) {
+      subchannel_destroy(destroy);
+    }
+  }
+}
+
+void grpc_subchannel_call_process_op(grpc_subchannel_call *call,
+                                     grpc_transport_stream_op *op) {
+  grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
+  grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
+  top_elem->filter->start_transport_stream_op(top_elem, op);
+}
+
+grpc_subchannel_call *create_call(connection *con) {
+  grpc_channel_stack *chanstk = CHANNEL_STACK_FROM_CONNECTION(con);
+  grpc_subchannel_call *call =
+      gpr_malloc(sizeof(grpc_subchannel_call) + chanstk->call_stack_size);
+  grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK(call);
+  call->connection = con;
+  gpr_ref_init(&call->refs, 1);
+  grpc_call_stack_init(chanstk, NULL, NULL, callstk);
+  return call;
+}

src/core/client_config/subchannel.h

@@ -0,0 +1,124 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H
+
+#include "src/core/channel/channel_stack.h"
+#include "src/core/client_config/connector.h"
+
+/** A (sub-)channel that knows how to connect to exactly one target
+    address. Provides a target for load balancing. */
+typedef struct grpc_subchannel grpc_subchannel;
+typedef struct grpc_subchannel_call grpc_subchannel_call;
+typedef struct grpc_subchannel_args grpc_subchannel_args;
+
+#ifdef GRPC_SUBCHANNEL_REFCOUNT_DEBUG
+#define GRPC_SUBCHANNEL_REF(p, r) \
+  grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_UNREF(p, r) \
+  grpc_subchannel_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_REF(p, r) \
+  grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) \
+  grpc_subchannel_call_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS \
+  , const char *file, int line, const char *reason
+#else
+#define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
+#define GRPC_SUBCHANNEL_UNREF(p, r) grpc_subchannel_unref((p))
+#define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) grpc_subchannel_call_unref((p))
+#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS
+#endif
+
+void grpc_subchannel_ref(
+    grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_unref(
+    grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_ref(
+    grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_unref(
+    grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+
+/** construct a call (possibly asynchronously) */
+void grpc_subchannel_create_call(grpc_subchannel *subchannel,
+                                 grpc_pollset *pollset,
+                                 grpc_subchannel_call **target,
+                                 grpc_iomgr_closure *notify);
+
+/** process a transport level op */
+void grpc_subchannel_process_transport_op(grpc_subchannel *subchannel,
+                                          grpc_transport_op *op);
+
+/** poll the current connectivity state of a channel */
+grpc_connectivity_state grpc_subchannel_check_connectivity(
+    grpc_subchannel *channel);
+
+/** call notify when the connectivity state of a channel changes from *state.
+    Updates *state with the new state of the channel */
+void grpc_subchannel_notify_on_state_change(grpc_subchannel *channel,
+                                            grpc_connectivity_state *state,
+                                            grpc_iomgr_closure *notify);
+
+void grpc_subchannel_add_interested_party(grpc_subchannel *channel,
+                                          grpc_pollset *pollset);
+void grpc_subchannel_del_interested_party(grpc_subchannel *channel,
+                                          grpc_pollset *pollset);
+
+/** continue processing a transport op */
+void grpc_subchannel_call_process_op(grpc_subchannel_call *subchannel_call,
+                                     grpc_transport_stream_op *op);
+
+struct grpc_subchannel_args {
+  /** Channel filters for this channel - wrapped factories will likely
+      want to mutate this */
+  const grpc_channel_filter **filters;
+  /** The number of filters in the above array */
+  size_t filter_count;
+  /** Channel arguments to be supplied to the newly created channel */
+  const grpc_channel_args *args;
+  /** Address to connect to */
+  struct sockaddr *addr;
+  size_t addr_len;
+  /** metadata context to use */
+  grpc_mdctx *mdctx;
+  /** master channel */
+  grpc_channel *master;
+};
+
+/** create a subchannel given a connector */
+grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
+                                        grpc_subchannel_args *args);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H */

src/core/client_config/subchannel_factory.c

@@ -0,0 +1,46 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/subchannel_factory.h"
+
+void grpc_subchannel_factory_ref(grpc_subchannel_factory *factory) {
+  factory->vtable->ref(factory);
+}
+void grpc_subchannel_factory_unref(grpc_subchannel_factory *factory) {
+  factory->vtable->unref(factory);
+}
+
+grpc_subchannel *grpc_subchannel_factory_create_subchannel(
+    grpc_subchannel_factory *factory, grpc_subchannel_args *args) {
+  return factory->vtable->create_subchannel(factory, args);
+}

src/core/client_config/subchannel_factory.h

@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+
+#include "src/core/channel/channel_stack.h"
+#include "src/core/client_config/subchannel.h"
+
+typedef struct grpc_subchannel_factory grpc_subchannel_factory;
+typedef struct grpc_subchannel_factory_vtable grpc_subchannel_factory_vtable;
+
+/** Constructor for new configured channels.
+    Creating decorators around this type is encouraged to adapt behavior. */
+struct grpc_subchannel_factory {
+  const grpc_subchannel_factory_vtable *vtable;
+};
+
+struct grpc_subchannel_factory_vtable {
+  void (*ref)(grpc_subchannel_factory *factory);
+  void (*unref)(grpc_subchannel_factory *factory);
+  grpc_subchannel *(*create_subchannel)(grpc_subchannel_factory *factory,
+                                        grpc_subchannel_args *args);
+};
+
+void grpc_subchannel_factory_ref(grpc_subchannel_factory *factory);
+void grpc_subchannel_factory_unref(grpc_subchannel_factory *factory);
+
+/** Create a new grpc_subchannel */
+grpc_subchannel *grpc_subchannel_factory_create_subchannel(
+    grpc_subchannel_factory *factory, grpc_subchannel_args *args);
+
+#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */

src/core/client_config/uri_parser.c

@@ -0,0 +1,149 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/uri_parser.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+static grpc_uri *bad_uri(const char *uri_text, int pos, const char *section,
+                         int suppress_errors) {
+  char *line_prefix;
+  int pfx_len;
+
+  if (!suppress_errors) {
+    gpr_asprintf(&line_prefix, "bad uri.%s: '", section);
+    pfx_len = strlen(line_prefix) + pos;
+    gpr_log(GPR_ERROR, "%s%s'", line_prefix, uri_text);
+    gpr_free(line_prefix);
+
+    line_prefix = gpr_malloc(pfx_len + 1);
+    memset(line_prefix, ' ', pfx_len);
+    line_prefix[pfx_len] = 0;
+    gpr_log(GPR_ERROR, "%s^ here", line_prefix);
+    gpr_free(line_prefix);
+  }
+
+  return NULL;
+}
+
+static char *copy_fragment(const char *src, int begin, int end) {
+  char *out = gpr_malloc(end - begin + 1);
+  memcpy(out, src + begin, end - begin);
+  out[end - begin] = 0;
+  return out;
+}
+
+grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors) {
+  grpc_uri *uri;
+  int scheme_begin = 0;
+  int scheme_end = -1;
+  int authority_begin = -1;
+  int authority_end = -1;
+  int path_begin = -1;
+  int path_end = -1;
+  int i;
+
+  for (i = scheme_begin; uri_text[i] != 0; i++) {
+    if (uri_text[i] == ':') {
+      scheme_end = i;
+      break;
+    }
+    if (uri_text[i] >= 'a' && uri_text[i] <= 'z') continue;
+    if (uri_text[i] >= 'A' && uri_text[i] <= 'Z') continue;
+    if (i != scheme_begin) {
+      if (uri_text[i] >= '0' && uri_text[i] <= '9') continue;
+      if (uri_text[i] == '+') continue;
+      if (uri_text[i] == '-') continue;
+      if (uri_text[i] == '.') continue;
+    }
+    break;
+  }
+  if (scheme_end == -1) {
+    return bad_uri(uri_text, i, "scheme", suppress_errors);
+  }
+
+  if (uri_text[scheme_end + 1] == '/' && uri_text[scheme_end + 2] == '/') {
+    authority_begin = scheme_end + 3;
+    for (i = authority_begin; uri_text[i] != 0; i++) {
+      if (uri_text[i] == '/') {
+        authority_end = i;
+      }
+      if (uri_text[i] == '?') {
+        return bad_uri(uri_text, i, "query_not_supported", suppress_errors);
+      }
+      if (uri_text[i] == '#') {
+        return bad_uri(uri_text, i, "fragment_not_supported", suppress_errors);
+      }
+    }
+    if (authority_end == -1 && uri_text[i] == 0) {
+      authority_end = i;
+    }
+    if (authority_end == -1) {
+      return bad_uri(uri_text, i, "authority", suppress_errors);
+    }
+    /* TODO(ctiller): parse the authority correctly */
+    path_begin = authority_end;
+  } else {
+    path_begin = scheme_end + 1;
+  }
+
+  for (i = path_begin; uri_text[i] != 0; i++) {
+    if (uri_text[i] == '?') {
+      return bad_uri(uri_text, i, "query_not_supported", suppress_errors);
+    }
+    if (uri_text[i] == '#') {
+      return bad_uri(uri_text, i, "fragment_not_supported", suppress_errors);
+    }
+  }
+  path_end = i;
+
+  uri = gpr_malloc(sizeof(*uri));
+  memset(uri, 0, sizeof(*uri));
+  uri->scheme = copy_fragment(uri_text, scheme_begin, scheme_end);
+  uri->authority = copy_fragment(uri_text, authority_begin, authority_end);
+  uri->path = copy_fragment(uri_text, path_begin, path_end);
+
+  return uri;
+}
+
+void grpc_uri_destroy(grpc_uri *uri) {
+  if (!uri) return;
+  gpr_free(uri->scheme);
+  gpr_free(uri->authority);
+  gpr_free(uri->path);
+  gpr_free(uri);
+}

src/objective-c/GRPCClient/private/GRPCMethodName+HTTP2Encoding.m → src/core/client_config/uri_parser.h

@@ -31,14 +31,19 @@
  *
  */
 
-#import "GRPCMethodName+HTTP2Encoding.h"
+#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_URI_PARSER_H
+#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_URI_PARSER_H
 
-@implementation GRPCMethodName (HTTP2Encoding)
-- (NSString *)HTTP2Path {
-  if (self.package) {
-    return [NSString stringWithFormat:@"/%@.%@/%@", self.package, self.interface, self.method];
-  } else {
-    return [NSString stringWithFormat:@"/%@/%@", self.interface, self.method];
-  }
-}
-@end
+typedef struct {
+  char *scheme;
+  char *authority;
+  char *path;
+} grpc_uri;
+
+/** parse a uri, return NULL on failure */
+grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors);
+
+/** destroy a uri */
+void grpc_uri_destroy(grpc_uri *uri);
+
+#endif

src/core/httpcli/httpcli.c

@@ -198,7 +198,7 @@ static void on_connected(void *arg, grpc_endpoint *tcp) {
                GRPC_SECURITY_OK);
     grpc_setup_secure_transport(&sc->base, tcp, on_secure_transport_setup_done,
                                 req);
-    grpc_security_connector_unref(&sc->base);
+    GRPC_SECURITY_CONNECTOR_UNREF(&sc->base, "httpcli");
   } else {
     start_write(req);
   }

src/core/httpcli/httpcli.h

@@ -85,7 +85,7 @@ typedef struct grpc_httpcli_response {
   char *body;
 } grpc_httpcli_response;
 
-/* Callback for grpc_httpcli_get */
+/* Callback for grpc_httpcli_get and grpc_httpcli_post. */
 typedef void (*grpc_httpcli_response_cb)(void *user_data,
                                          const grpc_httpcli_response *response);
 
@@ -100,8 +100,6 @@ void grpc_httpcli_context_destroy(grpc_httpcli_context *context);
    'request' contains request parameters - these are caller owned and can be
      destroyed once the call returns
    'deadline' contains a deadline for the request (or gpr_inf_future)
-   'em' points to a caller owned event manager that must be alive for the
-     lifetime of the request
    'on_response' is a callback to report results to (and 'user_data' is a user
      supplied pointer to pass to said call) */
 void grpc_httpcli_get(grpc_httpcli_context *context, grpc_pollset *pollset,

src/core/iomgr/alarm.h

@@ -41,9 +41,9 @@
 typedef struct grpc_alarm {
   gpr_timespec deadline;
   gpr_uint32 heap_index; /* INVALID_HEAP_INDEX if not in heap */
+  int triggered;
   struct grpc_alarm *next;
   struct grpc_alarm *prev;
-  int triggered;
   grpc_iomgr_cb_func cb;
   void *cb_arg;
 } grpc_alarm;

src/core/iomgr/fd_posix.c

@@ -74,6 +74,7 @@ static void freelist_fd(grpc_fd *fd) {
   gpr_mu_lock(&fd_freelist_mu);
   fd->freelist_next = fd_freelist;
   fd_freelist = fd;
+  grpc_iomgr_unregister_object(&fd->iomgr_object);
   gpr_mu_unlock(&fd_freelist_mu);
 }
 
@@ -115,7 +116,7 @@ static void destroy(grpc_fd *fd) {
 #define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
 static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file,
                    int line) {
-  gpr_log(GPR_DEBUG, "FD %d %p  ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
+  gpr_log(GPR_DEBUG, "FD %d %p   ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
           gpr_atm_no_barrier_load(&fd->refst),
           gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
 #else
@@ -139,7 +140,6 @@ static void unref_by(grpc_fd *fd, int n) {
 #endif
   old = gpr_atm_full_fetch_add(&fd->refst, -n);
   if (old == n) {
-    grpc_iomgr_unregister_object(&fd->iomgr_object);
     freelist_fd(fd);
   } else {
     GPR_ASSERT(old > n);
@@ -198,7 +198,8 @@ static void wake_all_watchers_locked(grpc_fd *fd) {
 }
 
 static int has_watchers(grpc_fd *fd) {
-  return fd->read_watcher != NULL || fd->write_watcher != NULL || fd->inactive_watcher_root.next != &fd->inactive_watcher_root;
+  return fd->read_watcher != NULL || fd->write_watcher != NULL ||
+         fd->inactive_watcher_root.next != &fd->inactive_watcher_root;
 }
 
 void grpc_fd_orphan(grpc_fd *fd, grpc_iomgr_closure *on_done,
@@ -368,16 +369,17 @@ gpr_uint32 grpc_fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
     watcher->fd = NULL;
     watcher->pollset = NULL;
     gpr_mu_unlock(&fd->watcher_mu);
+    GRPC_FD_UNREF(fd, "poll");
     return 0;
   }
   /* if there is nobody polling for read, but we need to, then start doing so */
-  if (!fd->read_watcher && gpr_atm_acq_load(&fd->readst) > READY) {
+  if (read_mask && !fd->read_watcher && gpr_atm_acq_load(&fd->readst) > READY) {
     fd->read_watcher = watcher;
     mask |= read_mask;
   }
   /* if there is nobody polling for write, but we need to, then start doing so
    */
-  if (!fd->write_watcher && gpr_atm_acq_load(&fd->writest) > READY) {
+  if (write_mask && !fd->write_watcher && gpr_atm_acq_load(&fd->writest) > READY) {
     fd->write_watcher = watcher;
     mask |= write_mask;
   }

src/core/iomgr/iocp_windows.h

@@ -34,7 +34,6 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_IOCP_WINDOWS_H
 #define GRPC_INTERNAL_CORE_IOMGR_IOCP_WINDOWS_H
 
-#include <windows.h>
 #include <grpc/support/sync.h>
 
 #include "src/core/iomgr/socket_windows.h"

src/core/iomgr/iomgr.c

@@ -158,7 +158,7 @@ void grpc_iomgr_shutdown(void) {
                 "memory leaks are likely",
                 count_objects());
         for (obj = g_root_object.next; obj != &g_root_object; obj = obj->next) {
-          gpr_log(GPR_DEBUG, "LEAKED OBJECT: %s", obj->name);
+          gpr_log(GPR_DEBUG, "LEAKED OBJECT: %s %p", obj->name, obj);
         }
         break;
       }
@@ -177,8 +177,8 @@ void grpc_iomgr_shutdown(void) {
 }
 
 void grpc_iomgr_register_object(grpc_iomgr_object *obj, const char *name) {
-  gpr_mu_lock(&g_mu);
   obj->name = gpr_strdup(name);
+  gpr_mu_lock(&g_mu);
   obj->next = &g_root_object;
   obj->prev = obj->next->prev;
   obj->next->prev = obj->prev->next = obj;
@@ -189,9 +189,9 @@ void grpc_iomgr_unregister_object(grpc_iomgr_object *obj) {
   gpr_mu_lock(&g_mu);
   obj->next->prev = obj->prev;
   obj->prev->next = obj->next;
-  gpr_free(obj->name);
   gpr_cv_signal(&g_rcv);
   gpr_mu_unlock(&g_mu);
+  gpr_free(obj->name);
 }
 
 void grpc_iomgr_closure_init(grpc_iomgr_closure *closure, grpc_iomgr_cb_func cb,
@@ -201,9 +201,21 @@ void grpc_iomgr_closure_init(grpc_iomgr_closure *closure, grpc_iomgr_cb_func cb,
   closure->next = NULL;
 }
 
+static void assert_not_scheduled_locked(grpc_iomgr_closure *closure) {
+#ifndef NDEBUG
+  grpc_iomgr_closure *c;
+
+  for (c = g_cbs_head; c; c = c->next) {
+    GPR_ASSERT(c != closure);
+  }
+#endif
+}
+
 void grpc_iomgr_add_delayed_callback(grpc_iomgr_closure *closure, int success) {
   closure->success = success;
+  GPR_ASSERT(closure->cb);
   gpr_mu_lock(&g_mu);
+  assert_not_scheduled_locked(closure);
   closure->next = NULL;
   if (!g_cbs_tail) {
     g_cbs_head = g_cbs_tail = closure;

src/core/iomgr/pollset_multipoller_with_epoll.c

@@ -54,17 +54,25 @@ static void multipoll_with_epoll_pollset_add_fd(grpc_pollset *pollset,
   pollset_hdr *h = pollset->data.ptr;
   struct epoll_event ev;
   int err;
-
-  ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
-  ev.data.ptr = fd;
-  err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev);
-  if (err < 0) {
-    /* FDs may be added to a pollset multiple times, so EEXIST is normal. */
-    if (errno != EEXIST) {
-      gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd,
-              strerror(errno));
+  grpc_fd_watcher watcher;
+
+  /* We pretend to be polling whilst adding an fd to keep the fd from being
+     closed during the add. This may result in a spurious wakeup being assigned
+     to this pollset whilst adding, but that should be benign. */
+  GPR_ASSERT(grpc_fd_begin_poll(fd, pollset, 0, 0, &watcher) == 0);
+  if (watcher.fd != NULL) {
+    ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
+    ev.data.ptr = fd;
+    err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev);
+    if (err < 0) {
+      /* FDs may be added to a pollset multiple times, so EEXIST is normal. */
+      if (errno != EEXIST) {
+        gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd,
+                strerror(errno));
+      }
     }
   }
+  grpc_fd_end_poll(&watcher, 0, 0);
 }
 
 static void multipoll_with_epoll_pollset_del_fd(grpc_pollset *pollset,

src/core/iomgr/pollset_multipoller_with_poll_posix.c

@@ -179,6 +179,9 @@ static void multipoll_with_poll_pollset_maybe_work(
       grpc_pollset_kick_consume(&pollset->kick_state, kfd);
     }
     for (i = 1; i < np; i++) {
+      if (h->watchers[i].fd == NULL) {
+        continue;
+      }
       if (h->pfds[i].revents & (POLLIN | POLLHUP | POLLERR)) {
         grpc_fd_become_readable(h->watchers[i].fd, allow_synchronous_callback);
       }

src/core/iomgr/pollset_posix.c

@@ -249,7 +249,8 @@ static void basic_do_promote(void *args, int success) {
   pollset->in_flight_cbs--;
   if (pollset->shutting_down) {
     /* We don't care about this pollset anymore. */
-    if (pollset->in_flight_cbs == 0 && pollset->counter == 0) {
+    if (pollset->in_flight_cbs == 0 && pollset->counter == 0 && !pollset->called_shutdown) {
+      pollset->called_shutdown = 1;
       do_shutdown_cb = 1;
     }
   } else if (grpc_fd_is_orphaned(fd)) {

src/core/iomgr/pollset_set_posix.c

@@ -114,7 +114,7 @@ void grpc_pollset_set_del_fd(grpc_pollset_set *pollset_set, grpc_fd *fd) {
     if (pollset_set->fds[i] == fd) {
       pollset_set->fd_count--;
       GPR_SWAP(grpc_fd *, pollset_set->fds[i],
-               pollset_set->fds[pollset_set->pollset_count]);
+               pollset_set->fds[pollset_set->fd_count]);
       GRPC_FD_UNREF(fd, "pollset_set");
       break;
     }

src/core/iomgr/pollset_windows.h

@@ -34,7 +34,6 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H
 #define GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H
 
-#include <windows.h>
 #include <grpc/support/sync.h>
 
 #include "src/core/iomgr/socket_windows.h"

src/core/iomgr/resolve_address_posix.c

@@ -155,9 +155,9 @@ static void do_request(void *rp) {
   grpc_resolve_cb cb = r->cb;
   gpr_free(r->name);
   gpr_free(r->default_port);
+  cb(arg, resolved);
   grpc_iomgr_unregister_object(&r->iomgr_object);
   gpr_free(r);
-  cb(arg, resolved);
 }
 
 void grpc_resolved_addresses_destroy(grpc_resolved_addresses *addrs) {

src/core/iomgr/sockaddr_win32.h

@@ -34,8 +34,8 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_WIN32_H
 #define GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_WIN32_H
 
-#include <ws2tcpip.h>
 #include <winsock2.h>
+#include <ws2tcpip.h>
 #include <mswsock.h>
 
 #ifdef __MINGW32__

src/core/iomgr/socket_windows.h

@@ -34,7 +34,8 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
 #define GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
 
-#include <windows.h>
+#include <grpc/support/port_platform.h>
+#include <winsock2.h>
 
 #include <grpc/support/sync.h>
 #include <grpc/support/atm.h>

src/core/iomgr/tcp_client_posix.c

@@ -63,6 +63,7 @@ typedef struct {
   grpc_alarm alarm;
   int refs;
   grpc_iomgr_closure write_closure;
+  grpc_pollset_set *interested_parties;
 } async_connect;
 
 static int prepare_socket(const struct sockaddr *addr, int fd) {
@@ -152,6 +153,7 @@ static void on_writable(void *acp, int success) {
         goto finish;
       }
     } else {
+      grpc_pollset_set_del_fd(ac->interested_parties, ac->fd);
       ep = grpc_tcp_create(ac->fd, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
       goto finish;
     }
@@ -165,6 +167,7 @@ static void on_writable(void *acp, int success) {
 finish:
   gpr_mu_lock(&ac->mu);
   if (!ep) {
+    grpc_pollset_set_del_fd(ac->interested_parties, ac->fd);
     grpc_fd_orphan(ac->fd, NULL, "tcp_client_orphan");
   }
   done = (--ac->refs == 0);
@@ -240,6 +243,7 @@ void grpc_tcp_client_connect(void (*cb)(void *arg, grpc_endpoint *ep),
   ac->cb = cb;
   ac->cb_arg = arg;
   ac->fd = fdobj;
+  ac->interested_parties = interested_parties;
   gpr_mu_init(&ac->mu);
   ac->refs = 2;
   ac->write_closure.cb = on_writable;

src/core/iomgr/tcp_posix.c

@@ -313,9 +313,7 @@ static void call_read_cb(grpc_tcp *tcp, gpr_slice *slices, size_t nslices,
     size_t i;
     gpr_log(GPR_DEBUG, "read: status=%d", status);
     for (i = 0; i < nslices; i++) {
-      char *dump =
-          gpr_hexdump((char *)GPR_SLICE_START_PTR(slices[i]),
-                      GPR_SLICE_LENGTH(slices[i]), GPR_HEXDUMP_PLAINTEXT);
+      char *dump = gpr_dump_slice(slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "READ: %s", dump);
       gpr_free(dump);
     }
@@ -540,9 +538,7 @@ static grpc_endpoint_write_status grpc_tcp_write(grpc_endpoint *ep,
     size_t i;
 
     for (i = 0; i < nslices; i++) {
-      char *data =
-          gpr_hexdump((char *)GPR_SLICE_START_PTR(slices[i]),
-                      GPR_SLICE_LENGTH(slices[i]), GPR_HEXDUMP_PLAINTEXT);
+      char *data = gpr_dump_slice(slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "WRITE %p: %s", tcp, data);
       gpr_free(data);
     }

src/core/json/json.h

@@ -53,7 +53,7 @@ typedef struct grpc_json {
 } grpc_json;
 
 /* The next two functions are going to parse the input string, and
- * destroy it in the process, in order to use its space to store
+ * modify it in the process, in order to use its space to store
  * all of the keys and values for the returned object tree.
  *
  * They assume UTF-8 input stream, and will output UTF-8 encoded

src/core/security/base64.c

@@ -120,7 +120,68 @@ char *grpc_base64_encode(const void *vdata, size_t data_size, int url_safe,
 }
 
 gpr_slice grpc_base64_decode(const char *b64, int url_safe) {
-  size_t b64_len = strlen(b64);
+  return grpc_base64_decode_with_len(b64, strlen(b64), url_safe);
+}
+
+static void decode_one_char(const unsigned char *codes, unsigned char *result,
+                            size_t *result_offset) {
+  gpr_uint32 packed = (codes[0] << 2) | (codes[1] >> 4);
+  result[(*result_offset)++] = (unsigned char)packed;
+}
+
+static void decode_two_chars(const unsigned char *codes, unsigned char *result,
+                             size_t *result_offset) {
+  gpr_uint32 packed = (codes[0] << 10) | (codes[1] << 4) | (codes[2] >> 2);
+  result[(*result_offset)++] = (unsigned char)(packed >> 8);
+  result[(*result_offset)++] = (unsigned char)(packed);
+}
+
+static int decode_group(const unsigned char *codes, size_t num_codes,
+                        unsigned char *result, size_t *result_offset) {
+  GPR_ASSERT(num_codes <= 4);
+
+  /* Short end groups that may not have padding. */
+  if (num_codes == 1) {
+    gpr_log(GPR_ERROR, "Invalid group. Must be at least 2 bytes.");
+    return 0;
+  }
+  if (num_codes == 2) {
+    decode_one_char(codes, result, result_offset);
+    return 1;
+  }
+  if (num_codes == 3) {
+    decode_two_chars(codes, result, result_offset);
+    return 1;
+  }
+
+  /* Regular 4 byte groups with padding or not. */
+  GPR_ASSERT(num_codes == 4);
+  if (codes[0] == GRPC_BASE64_PAD_BYTE || codes[1] == GRPC_BASE64_PAD_BYTE) {
+    gpr_log(GPR_ERROR, "Invalid padding detected.");
+    return 0;
+  }
+  if (codes[2] == GRPC_BASE64_PAD_BYTE) {
+    if (codes[3] == GRPC_BASE64_PAD_BYTE) {
+      decode_one_char(codes, result, result_offset);
+    } else {
+      gpr_log(GPR_ERROR, "Invalid padding detected.");
+      return 0;
+    }
+  } else if (codes[3] == GRPC_BASE64_PAD_BYTE) {
+    decode_two_chars(codes, result, result_offset);
+  } else {
+    /* No padding. */
+    gpr_uint32 packed =
+        (codes[0] << 18) | (codes[1] << 12) | (codes[2] << 6) | codes[3];
+    result[(*result_offset)++] = (unsigned char)(packed >> 16);
+    result[(*result_offset)++] = (unsigned char)(packed >> 8);
+    result[(*result_offset)++] = (unsigned char)(packed);
+  }
+  return 1;
+}
+
+gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len,
+                                      int url_safe) {
   gpr_slice result = gpr_slice_malloc(b64_len);
   unsigned char *current = GPR_SLICE_START_PTR(result);
   size_t result_size = 0;
@@ -151,43 +212,15 @@ gpr_slice grpc_base64_decode(const char *b64, int url_safe) {
     } else {
       codes[num_codes++] = (unsigned char)code;
       if (num_codes == 4) {
-        if (codes[0] == GRPC_BASE64_PAD_BYTE ||
-            codes[1] == GRPC_BASE64_PAD_BYTE) {
-          gpr_log(GPR_ERROR, "Invalid padding detected.");
-          goto fail;
-        }
-        if (codes[2] == GRPC_BASE64_PAD_BYTE) {
-          if (codes[3] == GRPC_BASE64_PAD_BYTE) {
-            /* Double padding. */
-            gpr_uint32 packed = (gpr_uint32)((codes[0] << 2) | (codes[1] >> 4));
-            current[result_size++] = (unsigned char)packed;
-          } else {
-            gpr_log(GPR_ERROR, "Invalid padding detected.");
-            goto fail;
-          }
-        } else if (codes[3] == GRPC_BASE64_PAD_BYTE) {
-          /* Single padding. */
-          gpr_uint32 packed =
-              (gpr_uint32)((codes[0] << 10) | (codes[1] << 4) | (codes[2] >> 2));
-          current[result_size++] = (unsigned char)(packed >> 8);
-          current[result_size++] = (unsigned char)(packed);
-        } else {
-          /* No padding. */
-          gpr_uint32 packed =
-              (gpr_uint32)((codes[0] << 18) | (codes[1] << 12) | (codes[2] << 6) | codes[3]);
-          current[result_size++] = (unsigned char)(packed >> 16);
-          current[result_size++] = (unsigned char)(packed >> 8);
-          current[result_size++] = (unsigned char)(packed);
-        }
+        if (!decode_group(codes, num_codes, current, &result_size)) goto fail;
         num_codes = 0;
       }
     }
   }
 
-  if (num_codes != 0) {
-    gpr_log(GPR_ERROR, "Invalid base64.");
-    gpr_slice_unref(result);
-    return gpr_empty_slice();
+  if (num_codes != 0 &&
+      !decode_group(codes, num_codes, current, &result_size)) {
+    goto fail;
   }
   GPR_SLICE_SET_LENGTH(result, result_size);
   return result;

src/core/security/base64.h

@@ -45,4 +45,8 @@ char *grpc_base64_encode(const void *data, size_t data_size, int url_safe,
    slice in case of failure. */
 gpr_slice grpc_base64_decode(const char *b64, int url_safe);
 
+/* Same as above except that the length is provided by the caller. */
+gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len,
+                                      int url_safe);
+
 #endif  /* GRPC_INTERNAL_CORE_SECURITY_BASE64_H */

src/core/security/client_auth_filter.c

@@ -58,7 +58,7 @@ typedef struct {
      so that work can progress when this call wants work to
      progress */
   grpc_pollset *pollset;
-  grpc_transport_op op;
+  grpc_transport_stream_op op;
   size_t op_md_idx;
   int sent_initial_metadata;
   grpc_linked_mdelem md_links[MAX_CREDENTIALS_METADATA_COUNT];
@@ -77,7 +77,7 @@ typedef struct {
 static void bubble_up_error(grpc_call_element *elem, const char *error_msg) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
-  grpc_transport_op_add_cancellation(
+  grpc_transport_stream_op_add_cancellation(
       &calld->op, GRPC_STATUS_UNAUTHENTICATED,
       grpc_mdstr_from_string(chand->md_ctx, error_msg));
   grpc_call_next_op(elem, &calld->op);
@@ -90,7 +90,7 @@ static void on_credentials_metadata(void *user_data,
   grpc_call_element *elem = (grpc_call_element *)user_data;
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
-  grpc_transport_op *op = &calld->op;
+  grpc_transport_stream_op *op = &calld->op;
   grpc_metadata_batch *mdb;
   size_t i;
   if (status != GRPC_CREDENTIALS_OK) {
@@ -131,7 +131,7 @@ static char *build_service_url(const char *url_scheme, call_data *calld) {
 }
 
 static void send_security_metadata(grpc_call_element *elem,
-                                   grpc_transport_op *op) {
+                                   grpc_transport_stream_op *op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   grpc_client_security_context *ctx =
@@ -193,7 +193,7 @@ static void on_host_checked(void *user_data, grpc_security_status status) {
    op contains type and call direction information, in addition to the data
    that is being sent or received. */
 static void auth_start_transport_op(grpc_call_element *elem,
-                                    grpc_transport_op *op) {
+                                    grpc_transport_stream_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
@@ -253,17 +253,10 @@ static void auth_start_transport_op(grpc_call_element *elem,
   grpc_call_next_op(elem, op);
 }
 
-/* Called on special channel events, such as disconnection or new incoming
-   calls on the server */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
-  grpc_channel_next_op(elem, op);
-}
-
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   call_data *calld = elem->call_data;
   calld->creds = NULL;
   calld->host = NULL;
@@ -287,7 +280,7 @@ static void destroy_call_elem(grpc_call_element *elem) {
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args,
                               grpc_mdctx *metadata_context, int is_first,
                               int is_last) {
@@ -298,14 +291,14 @@ static void init_channel_elem(grpc_channel_element *elem,
   /* The first and the last filters tend to be implemented differently to
      handle the case that there's no 'next' filter to call on the up or down
      path */
-  GPR_ASSERT(!is_first);
   GPR_ASSERT(!is_last);
   GPR_ASSERT(sc != NULL);
 
   /* initialize members */
   GPR_ASSERT(sc->is_client_side);
   chand->security_connector =
-      (grpc_channel_security_connector *)grpc_security_connector_ref(sc);
+      (grpc_channel_security_connector *)GRPC_SECURITY_CONNECTOR_REF(
+          sc, "client_auth_filter");
   chand->md_ctx = metadata_context;
   chand->authority_string = grpc_mdstr_from_string(chand->md_ctx, ":authority");
   chand->path_string = grpc_mdstr_from_string(chand->md_ctx, ":path");
@@ -318,7 +311,8 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
   /* grab pointers to our data from the channel element */
   channel_data *chand = elem->channel_data;
   grpc_channel_security_connector *ctx = chand->security_connector;
-  if (ctx != NULL) grpc_security_connector_unref(&ctx->base);
+  if (ctx != NULL)
+    GRPC_SECURITY_CONNECTOR_UNREF(&ctx->base, "client_auth_filter");
   if (chand->authority_string != NULL) {
     grpc_mdstr_unref(chand->authority_string);
   }
@@ -334,6 +328,6 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
 }
 
 const grpc_channel_filter grpc_client_auth_filter = {
-    auth_start_transport_op, channel_op,           sizeof(call_data),
+    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
     init_call_elem,          destroy_call_elem,    sizeof(channel_data),
     init_channel_elem,       destroy_channel_elem, "client-auth"};

src/core/security/credentials.c

@@ -225,7 +225,7 @@ static grpc_security_status ssl_create_security_connector(
   arg.type = GRPC_ARG_STRING;
   arg.key = GRPC_ARG_HTTP2_SCHEME;
   arg.value.string = "https";
-  *new_args = grpc_channel_args_copy_and_add(args, &arg);
+  *new_args = grpc_channel_args_copy_and_add(args, &arg, 1);
   return status;
 }
 
@@ -461,7 +461,6 @@ typedef struct {
   grpc_credentials_md_store *access_token_md;
   gpr_timespec token_expiration;
   grpc_httpcli_context httpcli_context;
-  grpc_pollset_set pollset_set;
   grpc_fetch_oauth2_func fetch_func;
 } grpc_oauth2_token_fetcher_credentials;
 
@@ -635,7 +634,7 @@ static void init_oauth2_token_fetcher(grpc_oauth2_token_fetcher_credentials *c,
   gpr_mu_init(&c->mu);
   c->token_expiration = gpr_inf_past;
   c->fetch_func = fetch_func;
-  grpc_pollset_set_init(&c->pollset_set);
+  grpc_httpcli_context_init(&c->httpcli_context);
 }
 
 /* -- ComputeEngine credentials. -- */

src/core/security/jwt_verifier.c

@@ -0,0 +1,830 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimser.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimser
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/security/jwt_verifier.h"
+
+#include <string.h>
+
+#include "src/core/httpcli/httpcli.h"
+#include "src/core/security/base64.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+#include <openssl/pem.h>
+
+/* --- Utils. --- */
+
+const char *grpc_jwt_verifier_status_to_string(
+    grpc_jwt_verifier_status status) {
+  switch (status) {
+    case GRPC_JWT_VERIFIER_OK:
+      return "OK";
+    case GRPC_JWT_VERIFIER_BAD_SIGNATURE:
+      return "BAD_SIGNATURE";
+    case GRPC_JWT_VERIFIER_BAD_FORMAT:
+      return "BAD_FORMAT";
+    case GRPC_JWT_VERIFIER_BAD_AUDIENCE:
+      return "BAD_AUDIENCE";
+    case GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR:
+      return "KEY_RETRIEVAL_ERROR";
+    case GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE:
+      return "TIME_CONSTRAINT_FAILURE";
+    case GRPC_JWT_VERIFIER_GENERIC_ERROR:
+      return "GENERIC_ERROR";
+    default:
+      return "UNKNOWN";
+  }
+}
+
+static const EVP_MD *evp_md_from_alg(const char *alg) {
+  if (strcmp(alg, "RS256") == 0) {
+    return EVP_sha256();
+  } else if (strcmp(alg, "RS384") == 0) {
+    return EVP_sha384();
+  } else if (strcmp(alg, "RS512") == 0) {
+    return EVP_sha512();
+  } else {
+    return NULL;
+  }
+}
+
+static grpc_json *parse_json_part_from_jwt(const char *str, size_t len,
+                                           gpr_slice *buffer) {
+  grpc_json *json;
+
+  *buffer = grpc_base64_decode_with_len(str, len, 1);
+  if (GPR_SLICE_IS_EMPTY(*buffer)) {
+    gpr_log(GPR_ERROR, "Invalid base64.");
+    return NULL;
+  }
+  json = grpc_json_parse_string_with_len((char *)GPR_SLICE_START_PTR(*buffer),
+                                         GPR_SLICE_LENGTH(*buffer));
+  if (json == NULL) {
+    gpr_slice_unref(*buffer);
+    gpr_log(GPR_ERROR, "JSON parsing error.");
+  }
+  return json;
+}
+
+static const char *validate_string_field(const grpc_json *json,
+                                         const char *key) {
+  if (json->type != GRPC_JSON_STRING) {
+    gpr_log(GPR_ERROR, "Invalid %s field [%s]", key, json->value);
+    return NULL;
+  }
+  return json->value;
+}
+
+static gpr_timespec validate_time_field(const grpc_json *json,
+                                        const char *key) {
+  gpr_timespec result = gpr_time_0;
+  if (json->type != GRPC_JSON_NUMBER) {
+    gpr_log(GPR_ERROR, "Invalid %s field [%s]", key, json->value);
+    return result;
+  }
+  result.tv_sec = strtol(json->value, NULL, 10);
+  return result;
+}
+
+/* --- JOSE header. see http://tools.ietf.org/html/rfc7515#section-4 --- */
+
+typedef struct {
+  const char *alg;
+  const char *kid;
+  const char *typ;
+  /* TODO(jboeuf): Add others as needed (jku, jwk, x5u, x5c and so on...). */
+  gpr_slice buffer;
+} jose_header;
+
+static void jose_header_destroy(jose_header *h) {
+  gpr_slice_unref(h->buffer);
+  gpr_free(h);
+}
+
+/* Takes ownership of json and buffer. */
+static jose_header *jose_header_from_json(grpc_json *json, gpr_slice buffer) {
+  grpc_json *cur;
+  jose_header *h = gpr_malloc(sizeof(jose_header));
+  memset(h, 0, sizeof(jose_header));
+  h->buffer = buffer;
+  for (cur = json->child; cur != NULL; cur = cur->next) {
+    if (strcmp(cur->key, "alg") == 0) {
+      /* We only support RSA-1.5 signatures for now.
+         Beware of this if we add HMAC support:
+         https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/
+      */
+      if (cur->type != GRPC_JSON_STRING || strncmp(cur->value, "RS", 2) ||
+          evp_md_from_alg(cur->value) == NULL) {
+        gpr_log(GPR_ERROR, "Invalid alg field [%s]", cur->value);
+        goto error;
+      }
+      h->alg = cur->value;
+    } else if (strcmp(cur->key, "typ") == 0) {
+      h->typ = validate_string_field(cur, "typ");
+      if (h->typ == NULL) goto error;
+    } else if (strcmp(cur->key, "kid") == 0) {
+      h->kid = validate_string_field(cur, "kid");
+      if (h->kid == NULL) goto error;
+    }
+  }
+  if (h->alg == NULL) {
+    gpr_log(GPR_ERROR, "Missing alg field.");
+    goto error;
+  }
+  grpc_json_destroy(json);
+  h->buffer = buffer;
+  return h;
+
+error:
+  grpc_json_destroy(json);
+  jose_header_destroy(h);
+  return NULL;
+}
+
+/* --- JWT claims. see http://tools.ietf.org/html/rfc7519#section-4.1 */
+
+struct grpc_jwt_claims {
+  /* Well known properties already parsed. */
+  const char *sub;
+  const char *iss;
+  const char *aud;
+  const char *jti;
+  gpr_timespec iat;
+  gpr_timespec exp;
+  gpr_timespec nbf;
+
+  grpc_json *json;
+  gpr_slice buffer;
+};
+
+
+void grpc_jwt_claims_destroy(grpc_jwt_claims *claims) {
+  grpc_json_destroy(claims->json);
+  gpr_slice_unref(claims->buffer);
+  gpr_free(claims);
+}
+
+const grpc_json *grpc_jwt_claims_json(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return NULL;
+  return claims->json;
+}
+
+const char *grpc_jwt_claims_subject(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return NULL;
+  return claims->sub;
+}
+
+const char *grpc_jwt_claims_issuer(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return NULL;
+  return claims->iss;
+}
+
+const char *grpc_jwt_claims_id(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return NULL;
+  return claims->jti;
+}
+
+const char *grpc_jwt_claims_audience(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return NULL;
+  return claims->aud;
+}
+
+gpr_timespec grpc_jwt_claims_issued_at(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return gpr_inf_past;
+  return claims->iat;
+}
+
+gpr_timespec grpc_jwt_claims_expires_at(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return gpr_inf_future;
+  return claims->exp;
+}
+
+gpr_timespec grpc_jwt_claims_not_before(const grpc_jwt_claims *claims) {
+  if (claims == NULL) return gpr_inf_past;
+  return claims->nbf;
+}
+
+/* Takes ownership of json and buffer even in case of failure. */
+grpc_jwt_claims *grpc_jwt_claims_from_json(grpc_json *json, gpr_slice buffer) {
+  grpc_json *cur;
+  grpc_jwt_claims *claims = gpr_malloc(sizeof(grpc_jwt_claims));
+  memset(claims, 0, sizeof(grpc_jwt_claims));
+  claims->json = json;
+  claims->buffer = buffer;
+  claims->iat = gpr_inf_past;
+  claims->nbf = gpr_inf_past;
+  claims->exp = gpr_inf_future;
+
+  /* Per the spec, all fields are optional. */
+  for (cur = json->child; cur != NULL; cur = cur->next) {
+    if (strcmp(cur->key, "sub") == 0) {
+      claims->sub = validate_string_field(cur, "sub");
+      if (claims->sub == NULL) goto error;
+    } else if (strcmp(cur->key, "iss") == 0) {
+      claims->iss = validate_string_field(cur, "iss");
+      if (claims->iss == NULL) goto error;
+    } else if (strcmp(cur->key, "aud") == 0) {
+      claims->aud = validate_string_field(cur, "aud");
+      if (claims->aud == NULL) goto error;
+    } else if (strcmp(cur->key, "jti") == 0) {
+      claims->jti = validate_string_field(cur, "jti");
+      if (claims->jti == NULL) goto error;
+    } else if (strcmp(cur->key, "iat") == 0) {
+      claims->iat = validate_time_field(cur, "iat");
+      if (gpr_time_cmp(claims->iat, gpr_time_0) == 0) goto error;
+    } else if (strcmp(cur->key, "exp") == 0) {
+      claims->exp = validate_time_field(cur, "exp");
+      if (gpr_time_cmp(claims->exp, gpr_time_0) == 0) goto error;
+    } else if (strcmp(cur->key, "nbf") == 0) {
+      claims->nbf = validate_time_field(cur, "nbf");
+      if (gpr_time_cmp(claims->nbf, gpr_time_0) == 0) goto error;
+    }
+  }
+  return claims;
+
+error:
+  grpc_jwt_claims_destroy(claims);
+  return NULL;
+}
+
+grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
+                                               const char *audience) {
+  gpr_timespec skewed_now;
+  int audience_ok;
+
+  GPR_ASSERT(claims != NULL);
+
+  skewed_now = gpr_time_add(gpr_now(), grpc_jwt_verifier_clock_skew);
+  if (gpr_time_cmp(skewed_now, claims->nbf) < 0) {
+    gpr_log(GPR_ERROR, "JWT is not valid yet.");
+    return GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE;
+  }
+  skewed_now = gpr_time_sub(gpr_now(), grpc_jwt_verifier_clock_skew);
+  if (gpr_time_cmp(skewed_now, claims->exp) > 0) {
+    gpr_log(GPR_ERROR, "JWT is expired.");
+    return GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE;
+  }
+
+  if (audience == NULL) {
+    audience_ok = claims->aud == NULL;
+  } else {
+    audience_ok = claims->aud != NULL && strcmp(audience, claims->aud) == 0;
+  }
+  if (!audience_ok) {
+    gpr_log(GPR_ERROR, "Audience mismatch: expected %s and found %s.",
+            audience == NULL ? "NULL" : audience,
+            claims->aud == NULL ? "NULL" : claims->aud);
+    return GRPC_JWT_VERIFIER_BAD_AUDIENCE;
+  }
+  return GRPC_JWT_VERIFIER_OK;
+}
+
+/* --- verifier_cb_ctx object. --- */
+
+typedef struct {
+  grpc_jwt_verifier *verifier;
+  grpc_pollset *pollset;
+  jose_header *header;
+  grpc_jwt_claims *claims;
+  char *audience;
+  gpr_slice signature;
+  gpr_slice signed_data;
+  void *user_data;
+  grpc_jwt_verification_done_cb user_cb;
+} verifier_cb_ctx;
+
+/* Takes ownership of the header, claims and signature. */
+static verifier_cb_ctx *verifier_cb_ctx_create(
+    grpc_jwt_verifier *verifier, grpc_pollset *pollset,
+    jose_header * header, grpc_jwt_claims *claims, const char *audience,
+    gpr_slice signature, const char *signed_jwt, size_t signed_jwt_len,
+    void *user_data, grpc_jwt_verification_done_cb cb) {
+  verifier_cb_ctx *ctx = gpr_malloc(sizeof(verifier_cb_ctx));
+  memset(ctx, 0, sizeof(verifier_cb_ctx));
+  ctx->verifier = verifier;
+  ctx->pollset = pollset;
+  ctx->header = header;
+  ctx->audience = gpr_strdup(audience);
+  ctx->claims = claims;
+  ctx->signature = signature;
+  ctx->signed_data = gpr_slice_from_copied_buffer(signed_jwt, signed_jwt_len);
+  ctx->user_data = user_data;
+  ctx->user_cb = cb;
+  return ctx;
+}
+
+void verifier_cb_ctx_destroy(verifier_cb_ctx *ctx) {
+  if (ctx->audience != NULL) gpr_free(ctx->audience);
+  if (ctx->claims != NULL) grpc_jwt_claims_destroy(ctx->claims);
+  gpr_slice_unref(ctx->signature);
+  gpr_slice_unref(ctx->signed_data);
+  jose_header_destroy(ctx->header);
+  /* TODO: see what to do with claims... */
+  gpr_free(ctx);
+}
+
+/* --- grpc_jwt_verifier object. --- */
+
+/* Clock skew defaults to one minute. */
+gpr_timespec grpc_jwt_verifier_clock_skew = {60, 0};
+
+/* Max delay defaults to one minute. */
+gpr_timespec grpc_jwt_verifier_max_delay = {60, 0};
+
+typedef struct {
+  char *email_domain;
+  char *key_url_prefix;
+} email_key_mapping;
+
+struct grpc_jwt_verifier {
+  email_key_mapping *mappings;
+  size_t num_mappings; /* Should be very few, linear search ok. */
+  size_t allocated_mappings;
+  grpc_httpcli_context http_ctx;
+};
+
+static grpc_json *json_from_http(const grpc_httpcli_response *response) {
+  grpc_json *json = NULL;
+
+  if (response == NULL) {
+    gpr_log(GPR_ERROR, "HTTP response is NULL.");
+    return NULL;
+  }
+  if (response->status != 200) {
+    gpr_log(GPR_ERROR, "Call to http server failed with error %d.",
+            response->status);
+    return NULL;
+  }
+
+  json = grpc_json_parse_string_with_len(response->body, response->body_length);
+  if (json == NULL) {
+    gpr_log(GPR_ERROR, "Invalid JSON found in response.");
+  }
+  return json;
+}
+
+static const grpc_json *find_property_by_name(const grpc_json *json,
+                                              const char *name) {
+  const grpc_json *cur;
+  for (cur = json->child; cur != NULL; cur = cur->next) {
+    if (strcmp(cur->key, name) == 0) return cur;
+  }
+  return NULL;
+}
+
+static EVP_PKEY *extract_pkey_from_x509(const char *x509_str) {
+  X509 *x509 = NULL;
+  EVP_PKEY *result = NULL;
+  BIO *bio = BIO_new(BIO_s_mem());
+  BIO_write(bio, x509_str, strlen(x509_str));
+  x509 = PEM_read_bio_X509(bio, NULL, NULL, NULL);
+  if (x509 == NULL) {
+    gpr_log(GPR_ERROR, "Unable to parse x509 cert.");
+    goto end;
+  }
+  result = X509_get_pubkey(x509);
+  if (result == NULL) {
+    gpr_log(GPR_ERROR, "Cannot find public key in X509 cert.");
+  }
+
+end:
+  BIO_free(bio);
+  if (x509 != NULL) X509_free(x509);
+  return result;
+}
+
+static BIGNUM *bignum_from_base64(const char *b64) {
+  BIGNUM *result = NULL;
+  gpr_slice bin;
+
+  if (b64 == NULL) return NULL;
+  bin = grpc_base64_decode(b64, 1);
+  if (GPR_SLICE_IS_EMPTY(bin)) {
+    gpr_log(GPR_ERROR, "Invalid base64 for big num.");
+    return NULL;
+  }
+  result = BN_bin2bn(GPR_SLICE_START_PTR(bin), GPR_SLICE_LENGTH(bin), NULL);
+  gpr_slice_unref(bin);
+  return result;
+}
+
+static EVP_PKEY *pkey_from_jwk(const grpc_json *json, const char *kty) {
+  const grpc_json *key_prop;
+  RSA *rsa = NULL;
+  EVP_PKEY *result = NULL;
+
+  GPR_ASSERT(kty != NULL && json != NULL);
+  if (strcmp(kty, "RSA") != 0) {
+    gpr_log(GPR_ERROR, "Unsupported key type %s.", kty);
+    goto end;
+  }
+  rsa = RSA_new();
+  if (rsa == NULL) {
+    gpr_log(GPR_ERROR, "Could not create rsa key.");
+    goto end;
+  }
+  for (key_prop = json->child; key_prop != NULL; key_prop = key_prop->next) {
+    if (strcmp(key_prop->key, "n") == 0) {
+      rsa->n = bignum_from_base64(validate_string_field(key_prop, "n"));
+      if (rsa->n == NULL) goto end;
+    } else if (strcmp(key_prop->key, "e") == 0) {
+      rsa->e = bignum_from_base64(validate_string_field(key_prop, "e"));
+      if (rsa->e == NULL) goto end;
+    }
+  }
+  if (rsa->e == NULL || rsa->n == NULL) {
+    gpr_log(GPR_ERROR, "Missing RSA public key field.");
+    goto end;
+  }
+  result = EVP_PKEY_new();
+  EVP_PKEY_set1_RSA(result, rsa); /* uprefs rsa. */
+
+end:
+  if (rsa != NULL) RSA_free(rsa);
+  return result;
+}
+
+static EVP_PKEY *find_verification_key(const grpc_json *json,
+                                       const char *header_alg,
+                                       const char *header_kid) {
+  const grpc_json *jkey;
+  const grpc_json *jwk_keys;
+  /* Try to parse the json as a JWK set:
+     https://tools.ietf.org/html/rfc7517#section-5. */
+  jwk_keys = find_property_by_name(json, "keys");
+  if (jwk_keys == NULL) {
+    /* Use the google proprietary format which is:
+      { <kid1>: <x5091>, <kid2>: <x5092>, ... } */
+    const grpc_json *cur = find_property_by_name(json, header_kid);
+    if (cur == NULL) return NULL;
+    return extract_pkey_from_x509(cur->value);
+  }
+
+  if (jwk_keys->type != GRPC_JSON_ARRAY) {
+    gpr_log(GPR_ERROR,
+            "Unexpected value type of keys property in jwks key set.");
+    return NULL;
+  }
+  /* Key format is specified in:
+     https://tools.ietf.org/html/rfc7518#section-6. */
+  for (jkey = jwk_keys->child; jkey != NULL; jkey = jkey->next) {
+    grpc_json *key_prop;
+    const char *alg = NULL;
+    const char *kid = NULL;
+    const char *kty = NULL;
+
+    if (jkey->type != GRPC_JSON_OBJECT) continue;
+    for (key_prop = jkey->child; key_prop != NULL; key_prop = key_prop->next) {
+      if (strcmp(key_prop->key, "alg") == 0 &&
+          key_prop->type == GRPC_JSON_STRING) {
+        alg = key_prop->value;
+      } else if (strcmp(key_prop->key, "kid") == 0 &&
+                 key_prop->type == GRPC_JSON_STRING) {
+        kid = key_prop->value;
+      } else if (strcmp(key_prop->key, "kty") == 0 &&
+                 key_prop->type == GRPC_JSON_STRING) {
+        kty = key_prop->value;
+      }
+    }
+    if (alg != NULL && kid != NULL && kty != NULL &&
+        strcmp(kid, header_kid) == 0 && strcmp(alg, header_alg) == 0) {
+      return pkey_from_jwk(jkey, kty);
+    }
+  }
+  gpr_log(GPR_ERROR,
+          "Could not find matching key in key set for kid=%s and alg=%s",
+          header_kid, header_alg);
+  return NULL;
+}
+
+static int verify_jwt_signature(EVP_PKEY *key, const char *alg,
+                                gpr_slice signature, gpr_slice signed_data) {
+  EVP_MD_CTX *md_ctx = EVP_MD_CTX_create();
+  const EVP_MD *md = evp_md_from_alg(alg);
+  int result = 0;
+
+  GPR_ASSERT(md != NULL); /* Checked before. */
+  if (md_ctx == NULL) {
+    gpr_log(GPR_ERROR, "Could not create EVP_MD_CTX.");
+    goto end;
+  }
+  if (EVP_DigestVerifyInit(md_ctx, NULL, md, NULL, key) != 1) {
+    gpr_log(GPR_ERROR, "EVP_DigestVerifyInit failed.");
+    goto end;
+  }
+  if (EVP_DigestVerifyUpdate(md_ctx, GPR_SLICE_START_PTR(signed_data),
+                             GPR_SLICE_LENGTH(signed_data)) != 1) {
+    gpr_log(GPR_ERROR, "EVP_DigestVerifyUpdate failed.");
+    goto end;
+  }
+  if (EVP_DigestVerifyFinal(md_ctx, GPR_SLICE_START_PTR(signature),
+                            GPR_SLICE_LENGTH(signature)) != 1) {
+    gpr_log(GPR_ERROR, "JWT signature verification failed.");
+    goto end;
+  }
+  result = 1;
+
+end:
+  if (md_ctx != NULL) EVP_MD_CTX_destroy(md_ctx);
+  return result;
+}
+
+static void on_keys_retrieved(void *user_data,
+                              const grpc_httpcli_response *response) {
+  grpc_json *json = json_from_http(response);
+  verifier_cb_ctx *ctx = (verifier_cb_ctx *)user_data;
+  EVP_PKEY *verification_key = NULL;
+  grpc_jwt_verifier_status status = GRPC_JWT_VERIFIER_GENERIC_ERROR;
+  grpc_jwt_claims *claims = NULL;
+
+  if (json == NULL) {
+    status = GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR;
+    goto end;
+  }
+  verification_key =
+      find_verification_key(json, ctx->header->alg, ctx->header->kid);
+  if (verification_key == NULL) {
+    gpr_log(GPR_ERROR, "Could not find verification key with kid %s.",
+            ctx->header->kid);
+    status = GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR;
+    goto end;
+  }
+
+  if (!verify_jwt_signature(verification_key, ctx->header->alg, ctx->signature,
+                            ctx->signed_data)) {
+    status = GRPC_JWT_VERIFIER_BAD_SIGNATURE;
+    goto end;
+  }
+
+  status = grpc_jwt_claims_check(ctx->claims, ctx->audience);
+  if (status == GRPC_JWT_VERIFIER_OK) {
+    /* Pass ownership. */
+    claims = ctx->claims;
+    ctx->claims = NULL;
+  }
+
+end:
+  if (json != NULL) grpc_json_destroy(json);
+  if (verification_key != NULL) EVP_PKEY_free(verification_key);
+  ctx->user_cb(ctx->user_data, status, claims);
+  verifier_cb_ctx_destroy(ctx);
+}
+
+static void on_openid_config_retrieved(void *user_data,
+                                       const grpc_httpcli_response *response) {
+  const grpc_json* cur;
+  grpc_json *json = json_from_http(response);
+  verifier_cb_ctx *ctx = (verifier_cb_ctx *)user_data;
+  grpc_httpcli_request req;
+  const char *jwks_uri;
+
+  /* TODO(jboeuf): Cache the jwks_uri in order to avoid this hop next time.*/
+  if (json == NULL) goto error;
+  cur = find_property_by_name(json, "jwks_uri");
+  if (cur == NULL) {
+    gpr_log(GPR_ERROR, "Could not find jwks_uri in openid config.");
+    goto error;
+  }
+  jwks_uri = validate_string_field(cur, "jwks_uri");
+  if (jwks_uri == NULL) goto error;
+  if (strstr(jwks_uri, "https://") != jwks_uri) {
+    gpr_log(GPR_ERROR, "Invalid non https jwks_uri: %s.", jwks_uri);
+    goto error;
+  }
+  jwks_uri += 8;
+  req.use_ssl = 1;
+  req.host = gpr_strdup(jwks_uri);
+  req.path = strchr(jwks_uri, '/');
+  if (req.path == NULL) {
+    req.path = "";
+  } else {
+    *(req.host + (req.path - jwks_uri)) = '\0';
+  }
+  grpc_httpcli_get(&ctx->verifier->http_ctx, ctx->pollset, &req,
+                   gpr_time_add(gpr_now(), grpc_jwt_verifier_max_delay),
+                   on_keys_retrieved, ctx);
+  grpc_json_destroy(json);
+  gpr_free(req.host);
+  return;
+
+error:
+  if (json != NULL) grpc_json_destroy(json);
+  ctx->user_cb(ctx->user_data, GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR, NULL);
+  verifier_cb_ctx_destroy(ctx);
+}
+
+static email_key_mapping *verifier_get_mapping(
+    grpc_jwt_verifier *v, const char *email_domain) {
+  size_t i;
+  if (v->mappings == NULL) return NULL;
+  for (i = 0; i < v->num_mappings; i++) {
+    if (strcmp(email_domain, v->mappings[i].email_domain) == 0) {
+      return &v->mappings[i];
+    }
+  }
+  return NULL;
+}
+
+static void verifier_put_mapping(grpc_jwt_verifier *v, const char *email_domain,
+                                 const char *key_url_prefix) {
+  email_key_mapping *mapping = verifier_get_mapping(v, email_domain);
+  GPR_ASSERT(v->num_mappings < v->allocated_mappings);
+  if (mapping != NULL) {
+    gpr_free(mapping->key_url_prefix);
+    mapping->key_url_prefix = gpr_strdup(key_url_prefix);
+    return;
+  }
+  v->mappings[v->num_mappings].email_domain = gpr_strdup(email_domain);
+  v->mappings[v->num_mappings].key_url_prefix = gpr_strdup(key_url_prefix);
+  v->num_mappings++;
+  GPR_ASSERT(v->num_mappings <= v->allocated_mappings);
+}
+
+/* Takes ownership of ctx. */
+static void retrieve_key_and_verify(verifier_cb_ctx *ctx) {
+  const char *at_sign;
+  grpc_httpcli_response_cb http_cb;
+  char *path_prefix = NULL;
+  const char *iss;
+  grpc_httpcli_request req;
+  memset(&req, 0, sizeof(grpc_httpcli_request));
+  req.use_ssl = 1;
+
+  GPR_ASSERT(ctx != NULL && ctx->header != NULL && ctx->claims != NULL);
+  iss = ctx->claims->iss;
+  if (ctx->header->kid == NULL) {
+    gpr_log(GPR_ERROR, "Missing kid in jose header.");
+    goto error;
+  }
+  if (iss == NULL) {
+    gpr_log(GPR_ERROR, "Missing iss in claims.");
+    goto error;
+  }
+
+  /* This code relies on:
+     https://openid.net/specs/openid-connect-discovery-1_0.html
+     Nobody seems to implement the account/email/webfinger part 2. of the spec
+     so we will rely instead on email/url mappings if we detect such an issuer.
+     Part 4, on the other hand is implemented by both google and salesforce. */
+
+  /* Very non-sophisticated way to detect an email address. Should be good
+     enough for now... */
+  at_sign = strchr(iss, '@');
+  if (at_sign != NULL) {
+    email_key_mapping *mapping;
+    const char *email_domain = at_sign + 1;
+    GPR_ASSERT(ctx->verifier != NULL);
+    mapping = verifier_get_mapping(ctx->verifier, email_domain);
+    if (mapping == NULL) {
+      gpr_log(GPR_ERROR, "Missing mapping for issuer email.");
+      goto error;
+    }
+    req.host = gpr_strdup(mapping->key_url_prefix);
+    path_prefix = strchr(req.host, '/');
+    if (path_prefix == NULL) {
+      gpr_asprintf(&req.path, "/%s", iss);
+    } else {
+      *(path_prefix++) = '\0';
+      gpr_asprintf(&req.path, "/%s/%s", path_prefix, iss);
+    }
+    http_cb = on_keys_retrieved;
+  } else {
+    req.host = gpr_strdup(strstr(iss, "https://") == iss ? iss + 8 : iss);
+    path_prefix = strchr(req.host, '/');
+    if (path_prefix == NULL) {
+      req.path = gpr_strdup(GRPC_OPENID_CONFIG_URL_SUFFIX);
+    } else {
+      *(path_prefix++) = 0;
+      gpr_asprintf(&req.path, "/%s%s", path_prefix,
+                   GRPC_OPENID_CONFIG_URL_SUFFIX);
+    }
+    http_cb = on_openid_config_retrieved;
+  }
+
+  grpc_httpcli_get(&ctx->verifier->http_ctx, ctx->pollset, &req,
+                   gpr_time_add(gpr_now(), grpc_jwt_verifier_max_delay),
+                   http_cb, ctx);
+  gpr_free(req.host);
+  gpr_free(req.path);
+  return;
+
+error:
+  ctx->user_cb(ctx->user_data, GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR, NULL);
+  verifier_cb_ctx_destroy(ctx);
+}
+
+void grpc_jwt_verifier_verify(grpc_jwt_verifier *verifier,
+                              grpc_pollset *pollset, const char *jwt,
+                              const char *audience,
+                              grpc_jwt_verification_done_cb cb,
+                              void *user_data) {
+  const char *dot = NULL;
+  grpc_json *json;
+  jose_header *header = NULL;
+  grpc_jwt_claims *claims = NULL;
+  gpr_slice header_buffer;
+  gpr_slice claims_buffer;
+  gpr_slice signature;
+  size_t signed_jwt_len;
+  const char *cur = jwt;
+
+  GPR_ASSERT(verifier != NULL && jwt != NULL && audience != NULL && cb != NULL);
+  dot = strchr(cur, '.');
+  if (dot == NULL) goto error;
+  json = parse_json_part_from_jwt(cur, dot - cur, &header_buffer);
+  if (json == NULL)  goto error;
+  header = jose_header_from_json(json, header_buffer);
+  if (header == NULL) goto error;
+
+  cur = dot + 1;
+  dot = strchr(cur, '.');
+  if (dot == NULL) goto error;
+  json = parse_json_part_from_jwt(cur, dot - cur, &claims_buffer);
+  if (json == NULL)  goto error;
+  claims = grpc_jwt_claims_from_json(json, claims_buffer);
+  if (claims == NULL) goto error;
+
+  signed_jwt_len = (size_t)(dot - jwt);
+  cur = dot + 1;
+  signature = grpc_base64_decode(cur, 1);
+  if (GPR_SLICE_IS_EMPTY(signature)) goto error;
+  retrieve_key_and_verify(
+      verifier_cb_ctx_create(verifier, pollset, header, claims, audience,
+                             signature, jwt, signed_jwt_len, user_data, cb));
+  return;
+
+error:
+  if (header != NULL) jose_header_destroy(header);
+  if (claims != NULL) grpc_jwt_claims_destroy(claims);
+  cb(user_data, GRPC_JWT_VERIFIER_BAD_FORMAT, NULL);
+}
+
+grpc_jwt_verifier *grpc_jwt_verifier_create(
+    const grpc_jwt_verifier_email_domain_key_url_mapping *mappings,
+    size_t num_mappings) {
+  grpc_jwt_verifier *v = gpr_malloc(sizeof(grpc_jwt_verifier));
+  memset(v, 0, sizeof(grpc_jwt_verifier));
+  grpc_httpcli_context_init(&v->http_ctx);
+
+  /* We know at least of one mapping. */
+  v->allocated_mappings = 1 + num_mappings;
+  v->mappings = gpr_malloc(v->allocated_mappings * sizeof(email_key_mapping));
+  verifier_put_mapping(v, GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN,
+                       GRPC_GOOGLE_SERVICE_ACCOUNTS_KEY_URL_PREFIX);
+  /* User-Provided mappings. */
+  if (mappings != NULL) {
+    size_t i;
+    for (i = 0; i < num_mappings; i++) {
+      verifier_put_mapping(v, mappings[i].email_domain,
+                           mappings[i].key_url_prefix);
+    }
+  }
+  return v;
+}
+
+void grpc_jwt_verifier_destroy(grpc_jwt_verifier *v) {
+  size_t i;
+  if (v == NULL) return;
+  grpc_httpcli_context_destroy(&v->http_ctx);
+  if (v->mappings != NULL) {
+    for (i = 0; i < v->num_mappings; i++) {
+      gpr_free(v->mappings[i].email_domain);
+      gpr_free(v->mappings[i].key_url_prefix);
+    }
+    gpr_free(v->mappings);
+  }
+  gpr_free(v);
+}
+

src/core/security/jwt_verifier.h

@@ -0,0 +1,136 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimser.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimser
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H
+#define GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H
+
+#include "src/core/iomgr/pollset.h"
+#include "src/core/json/json.h"
+
+#include <grpc/support/slice.h>
+#include <grpc/support/time.h>
+
+/* --- Constants. --- */
+
+#define GRPC_OPENID_CONFIG_URL_SUFFIX "/.well-known/openid-configuration"
+#define GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN \
+  "developer.gserviceaccount.com"
+#define GRPC_GOOGLE_SERVICE_ACCOUNTS_KEY_URL_PREFIX \
+  "www.googleapis.com/robot/v1/metadata/x509"
+
+/* --- grpc_jwt_verifier_status. --- */
+
+typedef enum {
+  GRPC_JWT_VERIFIER_OK = 0,
+  GRPC_JWT_VERIFIER_BAD_SIGNATURE,
+  GRPC_JWT_VERIFIER_BAD_FORMAT,
+  GRPC_JWT_VERIFIER_BAD_AUDIENCE,
+  GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR,
+  GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE,
+  GRPC_JWT_VERIFIER_GENERIC_ERROR
+} grpc_jwt_verifier_status;
+
+const char *grpc_jwt_verifier_status_to_string(grpc_jwt_verifier_status status);
+
+/* --- grpc_jwt_claims. --- */
+
+typedef struct grpc_jwt_claims grpc_jwt_claims;
+
+void grpc_jwt_claims_destroy(grpc_jwt_claims *claims);
+
+/* Returns the whole JSON tree of the claims. */
+const grpc_json *grpc_jwt_claims_json(const grpc_jwt_claims *claims);
+
+/* Access to registered claims in https://tools.ietf.org/html/rfc7519#page-9 */
+const char *grpc_jwt_claims_subject(const grpc_jwt_claims *claims);
+const char *grpc_jwt_claims_issuer(const grpc_jwt_claims *claims);
+const char *grpc_jwt_claims_id(const grpc_jwt_claims *claims);
+const char *grpc_jwt_claims_audience(const grpc_jwt_claims *claims);
+gpr_timespec grpc_jwt_claims_issued_at(const grpc_jwt_claims *claims);
+gpr_timespec grpc_jwt_claims_expires_at(const grpc_jwt_claims *claims);
+gpr_timespec grpc_jwt_claims_not_before(const grpc_jwt_claims *claims);
+
+/* --- grpc_jwt_verifier. --- */
+
+typedef struct grpc_jwt_verifier grpc_jwt_verifier;
+
+typedef struct {
+  /* The email domain is the part after the @ sign. */
+  const char *email_domain;
+
+  /* The key url prefix will be used to get the public key from the issuer:
+     https://<key_url_prefix>/<issuer_email>
+     Therefore the key_url_prefix must NOT contain https://. */
+  const char *key_url_prefix;
+} grpc_jwt_verifier_email_domain_key_url_mapping;
+
+/* Globals to control the verifier. Not thread-safe. */
+extern gpr_timespec grpc_jwt_verifier_clock_skew;
+extern gpr_timespec grpc_jwt_verifier_max_delay;
+
+/* The verifier can be created with some custom mappings to help with key
+   discovery in the case where the issuer is an email address.
+   mappings can be NULL in which case num_mappings MUST be 0.
+   A verifier object has one built-in mapping (unless overridden):
+   GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN ->
+   GRPC_GOOGLE_SERVICE_ACCOUNTS_KEY_URL_PREFIX.*/
+grpc_jwt_verifier *grpc_jwt_verifier_create(
+    const grpc_jwt_verifier_email_domain_key_url_mapping *mappings,
+    size_t num_mappings);
+
+/*The verifier must not be destroyed if there are still outstanding callbacks.*/
+void grpc_jwt_verifier_destroy(grpc_jwt_verifier *verifier);
+
+/* User provided callback that will be called when the verification of the JWT
+   is done (maybe in another thread).
+   It is the responsibility of the callee to call grpc_jwt_claims_destroy on
+   the claims. */
+typedef void (*grpc_jwt_verification_done_cb)(void *user_data,
+                                              grpc_jwt_verifier_status status,
+                                              grpc_jwt_claims *claims);
+
+/* Verifies for the JWT for the given expected audience. */
+void grpc_jwt_verifier_verify(grpc_jwt_verifier *verifier,
+                              grpc_pollset *pollset, const char *jwt,
+                              const char *audience,
+                              grpc_jwt_verification_done_cb cb,
+                              void *user_data);
+
+/* --- TESTING ONLY exposed functions. --- */
+
+grpc_jwt_claims *grpc_jwt_claims_from_json(grpc_json *json, gpr_slice buffer);
+grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
+                                               const char *audience);
+
+#endif /* GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H */
+

src/core/security/secure_endpoint.c

@@ -101,9 +101,7 @@ static void call_read_cb(secure_endpoint *ep, gpr_slice *slices, size_t nslices,
   if (grpc_trace_secure_endpoint) {
     size_t i;
     for (i = 0; i < nslices; i++) {
-      char *data =
-          gpr_hexdump((char *)GPR_SLICE_START_PTR(slices[i]),
-                      GPR_SLICE_LENGTH(slices[i]), GPR_HEXDUMP_PLAINTEXT);
+      char *data = gpr_dump_slice(slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "READ %p: %s", ep, data);
       gpr_free(data);
     }
@@ -235,9 +233,7 @@ static grpc_endpoint_write_status endpoint_write(grpc_endpoint *secure_ep,
 
   if (grpc_trace_secure_endpoint) {
     for (i = 0; i < nslices; i++) {
-      char *data =
-          gpr_hexdump((char *)GPR_SLICE_START_PTR(slices[i]),
-                      GPR_SLICE_LENGTH(slices[i]), GPR_HEXDUMP_PLAINTEXT);
+      char *data = gpr_dump_slice(slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "WRITE %p: %s", ep, data);
       gpr_free(data);
     }

src/core/security/secure_transport_setup.c

@@ -74,7 +74,7 @@ static void secure_transport_setup_done(grpc_secure_transport_setup *s,
   if (s->handshaker != NULL) tsi_handshaker_destroy(s->handshaker);
   if (s->handshake_buffer != NULL) gpr_free(s->handshake_buffer);
   gpr_slice_buffer_destroy(&s->left_overs);
-  grpc_security_connector_unref(s->connector);
+  GRPC_SECURITY_CONNECTOR_UNREF(s->connector, "secure_transport_setup");
   gpr_free(s);
 }
 
@@ -234,8 +234,9 @@ static void on_handshake_data_received_from_peer(
                          gpr_slice_split_tail(&slices[i], consumed_slice_size));
     gpr_slice_unref(slices[i]); /* split_tail above increments refcount. */
   }
-  gpr_slice_buffer_addn(&s->left_overs, &slices[i + 1],
-                        num_left_overs - (size_t)has_left_overs_in_current_slice);
+  gpr_slice_buffer_addn(
+      &s->left_overs, &slices[i + 1],
+      num_left_overs - (size_t)has_left_overs_in_current_slice);
   check_peer(s);
 }
 
@@ -275,7 +276,8 @@ void grpc_setup_secure_transport(grpc_security_connector *connector,
     secure_transport_setup_done(s, 0);
     return;
   }
-  s->connector = grpc_security_connector_ref(connector);
+  s->connector =
+      GRPC_SECURITY_CONNECTOR_REF(connector, "secure_transport_setup");
   s->handshake_buffer_size = GRPC_INITIAL_HANDSHAKE_BUFFER_SIZE;
   s->handshake_buffer = gpr_malloc(s->handshake_buffer_size);
   s->endpoint = nonsecure_endpoint;

src/core/security/security_connector.c

@@ -84,12 +84,12 @@ static const char *ssl_cipher_suites(void) {
 /* -- Common methods. -- */
 
 /* Returns the first property with that name. */
-const tsi_peer_property *tsi_peer_get_property_by_name(
-    const tsi_peer *peer, const char *name) {
+const tsi_peer_property *tsi_peer_get_property_by_name(const tsi_peer *peer,
+                                                       const char *name) {
   size_t i;
   if (peer == NULL) return NULL;
   for (i = 0; i < peer->property_count; i++) {
-    const tsi_peer_property* property = &peer->properties[i];
+    const tsi_peer_property *property = &peer->properties[i];
     if (name == NULL && property->name == NULL) {
       return property;
     }
@@ -124,24 +124,44 @@ grpc_security_status grpc_channel_security_connector_check_call_host(
   return sc->check_call_host(sc, host, cb, user_data);
 }
 
-void grpc_security_connector_unref(grpc_security_connector *sc) {
-  if (sc == NULL) return;
-  if (gpr_unref(&sc->refcount)) sc->vtable->destroy(sc);
-}
-
+#ifdef GRPC_SECURITY_CONNECTOR_REFCOUNT_DEBUG
+grpc_security_connector *grpc_security_connector_ref(
+    grpc_security_connector *sc, const char *file, int line,
+    const char *reason) {
+  if (sc == NULL) return NULL;
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+          "SECURITY_CONNECTOR:%p   ref %d -> %d %s", sc,
+          (int)sc->refcount.count, (int)sc->refcount.count + 1, reason);
+#else
 grpc_security_connector *grpc_security_connector_ref(
     grpc_security_connector *sc) {
   if (sc == NULL) return NULL;
+#endif
   gpr_ref(&sc->refcount);
   return sc;
 }
 
+#ifdef GRPC_SECURITY_CONNECTOR_REFCOUNT_DEBUG
+void grpc_security_connector_unref(grpc_security_connector *sc,
+                                   const char *file, int line,
+                                   const char *reason) {
+  if (sc == NULL) return;
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+          "SECURITY_CONNECTOR:%p unref %d -> %d %s", sc,
+          (int)sc->refcount.count, (int)sc->refcount.count - 1, reason);
+#else
+void grpc_security_connector_unref(grpc_security_connector *sc) {
+  if (sc == NULL) return;
+#endif
+  if (gpr_unref(&sc->refcount)) sc->vtable->destroy(sc);
+}
+
 static void connector_pointer_arg_destroy(void *p) {
-  grpc_security_connector_unref(p);
+  GRPC_SECURITY_CONNECTOR_UNREF(p, "connector_pointer_arg");
 }
 
 static void *connector_pointer_arg_copy(void *p) {
-  return grpc_security_connector_ref(p);
+  return GRPC_SECURITY_CONNECTOR_REF(p, "connector_pointer_arg");
 }
 
 grpc_arg grpc_security_connector_to_arg(grpc_security_connector *sc) {
@@ -580,7 +600,8 @@ grpc_security_status grpc_ssl_channel_security_connector_create(
       config->pem_private_key, config->pem_private_key_size,
       config->pem_cert_chain, config->pem_cert_chain_size, pem_root_certs,
       pem_root_certs_size, ssl_cipher_suites(), alpn_protocol_strings,
-      alpn_protocol_string_lengths, (uint16_t)num_alpn_protocols, &c->handshaker_factory);
+      alpn_protocol_string_lengths, (uint16_t)num_alpn_protocols,
+      &c->handshaker_factory);
   if (result != TSI_OK) {
     gpr_log(GPR_ERROR, "Handshaker factory creation failed with %s.",
             tsi_result_to_string(result));
@@ -633,8 +654,8 @@ grpc_security_status grpc_ssl_server_security_connector_create(
       (const unsigned char **)config->pem_cert_chains,
       config->pem_cert_chains_sizes, config->num_key_cert_pairs,
       config->pem_root_certs, config->pem_root_certs_size, ssl_cipher_suites(),
-      alpn_protocol_strings, alpn_protocol_string_lengths, (uint16_t)num_alpn_protocols,
-      &c->handshaker_factory);
+      alpn_protocol_strings, alpn_protocol_string_lengths,
+      (uint16_t)num_alpn_protocols, &c->handshaker_factory);
   if (result != TSI_OK) {
     gpr_log(GPR_ERROR, "Handshaker factory creation failed with %s.",
             tsi_result_to_string(result));

src/core/security/security_connector.h

@@ -80,12 +80,25 @@ struct grpc_security_connector {
   grpc_auth_context *auth_context; /* Populated after the peer is checked. */
 };
 
-/* Increments the refcount. */
+/* Refcounting. */
+#ifdef GRPC_SECURITY_CONNECTOR_REFCOUNT_DEBUG
+#define GRPC_SECURITY_CONNECTOR_REF(p, r) \
+  grpc_security_connector_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SECURITY_CONNECTOR_UNREF(p, r) \
+  grpc_security_connector_unref((p), __FILE__, __LINE__, (r))
 grpc_security_connector *grpc_security_connector_ref(
-    grpc_security_connector *sc);
-
-/* Decrements the refcount and destroys the object if it reaches 0. */
-void grpc_security_connector_unref(grpc_security_connector *sc);
+    grpc_security_connector *policy, const char *file, int line,
+    const char *reason);
+void grpc_security_connector_unref(grpc_security_connector *policy,
+                                   const char *file, int line,
+                                   const char *reason);
+#else
+#define GRPC_SECURITY_CONNECTOR_REF(p, r) grpc_security_connector_ref((p))
+#define GRPC_SECURITY_CONNECTOR_UNREF(p, r) grpc_security_connector_unref((p))
+grpc_security_connector *grpc_security_connector_ref(
+    grpc_security_connector *policy);
+void grpc_security_connector_unref(grpc_security_connector *policy);
+#endif
 
 /* Handshake creation. */
 grpc_security_status grpc_security_connector_create_handshaker(
@@ -172,9 +185,9 @@ typedef struct {
   specific error code otherwise.
 */
 grpc_security_status grpc_ssl_channel_security_connector_create(
-    grpc_credentials *request_metadata_creds,
-    const grpc_ssl_config *config, const char *target_name,
-    const char *overridden_target_name, grpc_channel_security_connector **sc);
+    grpc_credentials *request_metadata_creds, const grpc_ssl_config *config,
+    const char *target_name, const char *overridden_target_name,
+    grpc_channel_security_connector **sc);
 
 /* Gets the default ssl roots. */
 size_t grpc_get_default_ssl_roots(const unsigned char **pem_root_certs);
@@ -200,8 +213,8 @@ grpc_security_status grpc_ssl_server_security_connector_create(
     const grpc_ssl_server_config *config, grpc_security_connector **sc);
 
 /* Util. */
-const tsi_peer_property *tsi_peer_get_property_by_name(
-    const tsi_peer *peer, const char *name);
+const tsi_peer_property *tsi_peer_get_property_by_name(const tsi_peer *peer,
+                                                       const char *name);
 
 /* Exposed for testing only. */
 grpc_auth_context *tsi_ssl_peer_to_auth_context(const tsi_peer *peer);

src/core/security/server_auth_filter.c

@@ -51,24 +51,17 @@ typedef struct channel_data {
    op contains type and call direction information, in addition to the data
    that is being sent or received. */
 static void auth_start_transport_op(grpc_call_element *elem,
-                                    grpc_transport_op *op) {
+                                    grpc_transport_stream_op *op) {
   /* TODO(jboeuf): Get the metadata and get a new context from it. */
 
   /* pass control down the stack */
   grpc_call_next_op(elem, op);
 }
 
-/* Called on special channel events, such as disconnection or new incoming
-   calls on the server */
-static void channel_op(grpc_channel_element *elem,
-                       grpc_channel_element *from_elem, grpc_channel_op *op) {
-  grpc_channel_next_op(elem, op);
-}
-
 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
-                           grpc_transport_op *initial_op) {
+                           grpc_transport_stream_op *initial_op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
@@ -95,11 +88,10 @@ static void init_call_elem(grpc_call_element *elem,
 }
 
 /* Destructor for call_data */
-static void destroy_call_elem(grpc_call_element *elem) {
-}
+static void destroy_call_elem(grpc_call_element *elem) {}
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_channel_element *elem,
+static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   grpc_security_connector *sc = grpc_find_security_connector_in_args(args);
@@ -115,17 +107,19 @@ static void init_channel_elem(grpc_channel_element *elem,
 
   /* initialize members */
   GPR_ASSERT(!sc->is_client_side);
-  chand->security_connector = grpc_security_connector_ref(sc);
+  chand->security_connector =
+      GRPC_SECURITY_CONNECTOR_REF(sc, "server_auth_filter");
 }
 
 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_channel_element *elem) {
   /* grab pointers to our data from the channel element */
   channel_data *chand = elem->channel_data;
-  grpc_security_connector_unref(chand->security_connector);
+  GRPC_SECURITY_CONNECTOR_UNREF(chand->security_connector,
+                                "server_auth_filter");
 }
 
 const grpc_channel_filter grpc_server_auth_filter = {
-    auth_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "server-auth"};
+    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem,          destroy_call_elem,    sizeof(channel_data),
+    init_channel_elem,       destroy_channel_elem, "server-auth"};

src/core/security/server_secure_chttp2.c

@@ -70,38 +70,39 @@ static void state_unref(grpc_server_secure_state *state) {
     gpr_mu_lock(&state->mu);
     gpr_mu_unlock(&state->mu);
     /* clean up */
-    grpc_security_connector_unref(state->sc);
+    GRPC_SECURITY_CONNECTOR_UNREF(state->sc, "server");
     gpr_free(state);
   }
 }
 
-static grpc_transport_setup_result setup_transport(void *statep,
-                                                   grpc_transport *transport,
-                                                   grpc_mdctx *mdctx) {
+static void setup_transport(void *statep, grpc_transport *transport,
+                            grpc_mdctx *mdctx) {
   static grpc_channel_filter const *extra_filters[] = {
       &grpc_server_auth_filter, &grpc_http_server_filter};
   grpc_server_secure_state *state = statep;
-  grpc_transport_setup_result result;
   grpc_arg connector_arg = grpc_security_connector_to_arg(state->sc);
   grpc_channel_args *args_copy = grpc_channel_args_copy_and_add(
-      grpc_server_get_channel_args(state->server), &connector_arg);
-  result = grpc_server_setup_transport(state->server, transport, extra_filters,
-                                       GPR_ARRAY_SIZE(extra_filters), mdctx,
-                                       args_copy);
+      grpc_server_get_channel_args(state->server), &connector_arg, 1);
+  grpc_server_setup_transport(state->server, transport, extra_filters,
+                              GPR_ARRAY_SIZE(extra_filters), mdctx, args_copy);
   grpc_channel_args_destroy(args_copy);
-  return result;
 }
 
 static void on_secure_transport_setup_done(void *statep,
                                            grpc_security_status status,
                                            grpc_endpoint *secure_endpoint) {
   grpc_server_secure_state *state = statep;
+  grpc_transport *transport;
+  grpc_mdctx *mdctx;
   if (status == GRPC_SECURITY_OK) {
     gpr_mu_lock(&state->mu);
     if (!state->is_shutdown) {
-      grpc_create_chttp2_transport(
-          setup_transport, state, grpc_server_get_channel_args(state->server),
-          secure_endpoint, NULL, 0, grpc_mdctx_create(), 0);
+      mdctx = grpc_mdctx_create();
+      transport = grpc_create_chttp2_transport(
+          grpc_server_get_channel_args(state->server), secure_endpoint, mdctx,
+          0);
+      setup_transport(state, transport, mdctx);
+      grpc_chttp2_transport_start_reading(transport, NULL, 0);
     } else {
       /* We need to consume this here, because the server may already have gone
        * away. */
@@ -220,7 +221,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
 /* Error path: cleanup and return */
 error:
   if (sc) {
-    grpc_security_connector_unref(sc);
+    GRPC_SECURITY_CONNECTOR_UNREF(sc, "server");
   }
   if (resolved) {
     grpc_resolved_addresses_destroy(resolved);

src/core/support/cpu_windows.c

@@ -34,7 +34,6 @@
 #include <grpc/support/port_platform.h>
 
 #ifdef GPR_WIN32
-#include <windows.h>
 #include <grpc/support/log.h>
 
 unsigned gpr_cpu_num_cores(void) {

src/core/support/log_linux.c

@@ -43,7 +43,9 @@
 
 #ifdef GPR_LINUX
 
+#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -71,6 +73,7 @@ void gpr_log(const char *file, int line, gpr_log_severity severity,
 
 void gpr_default_log(gpr_log_func_args *args) {
   char *final_slash;
+  char *prefix;
   const char *display_file;
   char time_buffer[64];
   gpr_timespec now = gpr_now();
@@ -89,10 +92,12 @@ void gpr_default_log(gpr_log_func_args *args) {
     strcpy(time_buffer, "error:strftime");
   }
 
-  fprintf(stderr, "%s%s.%09d %7ld %s:%d] %s\n",
+  gpr_asprintf(&prefix, "%s%s.%09d %7tu %s:%d]",
           gpr_log_severity_string(args->severity), time_buffer,
-          (int)(now.tv_nsec), gettid(), display_file, args->line,
-          args->message);
+          (int)(now.tv_nsec), gettid(), display_file, args->line);
+
+  fprintf(stderr, "%-60s %s\n", prefix, args->message);
+  gpr_free(prefix);
 }
 
 #endif

src/core/support/slice.c

@@ -325,3 +325,10 @@ int gpr_slice_str_cmp(gpr_slice a, const char *b) {
   if (d != 0) return d;
   return memcmp(GPR_SLICE_START_PTR(a), b, b_length);
 }
+
+char *gpr_slice_to_cstring(gpr_slice slice) {
+  char *result = gpr_malloc(GPR_SLICE_LENGTH(slice) + 1);
+  memcpy(result, GPR_SLICE_START_PTR(slice), GPR_SLICE_LENGTH(slice));
+  result[GPR_SLICE_LENGTH(slice)] = '\0';
+  return result;
+}

src/core/support/string.c

@@ -61,14 +61,14 @@ typedef struct {
   size_t capacity;
   size_t length;
   char *data;
-} hexout;
+} dump_out;
 
-static hexout hexout_create(void) {
-  hexout r = {0, 0, NULL};
+static dump_out dump_out_create(void) {
+  dump_out r = {0, 0, NULL};
   return r;
 }
 
-static void hexout_append(hexout *out, char c) {
+static void dump_out_append(dump_out *out, char c) {
   if (out->length == out->capacity) {
     out->capacity = GPR_MAX(8, 2 * out->capacity);
     out->data = gpr_realloc(out->data, out->capacity);
@@ -76,34 +76,55 @@ static void hexout_append(hexout *out, char c) {
   out->data[out->length++] = c;
 }
 
-char *gpr_hexdump(const char *buf, size_t len, gpr_uint32 flags) {
+static void hexdump(dump_out *out, const char *buf, size_t len) {
   static const char hex[16] = "0123456789abcdef";
-  hexout out = hexout_create();
 
   const gpr_uint8 *const beg = (const gpr_uint8 *)buf;
   const gpr_uint8 *const end = beg + len;
   const gpr_uint8 *cur;
 
   for (cur = beg; cur != end; ++cur) {
-    if (cur != beg) hexout_append(&out, ' ');
-    hexout_append(&out, hex[*cur >> 4]);
-    hexout_append(&out, hex[*cur & 0xf]);
+    if (cur != beg) dump_out_append(out, ' ');
+    dump_out_append(out, hex[*cur >> 4]);
+    dump_out_append(out, hex[*cur & 0xf]);
   }
+}
 
-  if (flags & GPR_HEXDUMP_PLAINTEXT) {
-    if (len) hexout_append(&out, ' ');
-    hexout_append(&out, '\'');
-    for (cur = beg; cur != end; ++cur) {
-      hexout_append(&out, isprint(*cur) ? *(char*)cur : '.');
-    }
-    hexout_append(&out, '\'');
+static void asciidump(dump_out *out, const char *buf, size_t len) {
+  const gpr_uint8 *const beg = (const gpr_uint8 *)buf;
+  const gpr_uint8 *const end = beg + len;
+  const gpr_uint8 *cur;
+  int out_was_empty = (out->length == 0);
+  if (!out_was_empty) {
+    dump_out_append(out, ' ');
+    dump_out_append(out, '\'');
   }
+  for (cur = beg; cur != end; ++cur) {
+    dump_out_append(out, isprint(*cur) ? *(char *)cur : '.');
+  }
+  if (!out_was_empty) {
+    dump_out_append(out, '\'');
+  }
+}
 
-  hexout_append(&out, 0);
-
+char *gpr_dump(const char *buf, size_t len, gpr_uint32 flags) {
+  dump_out out = dump_out_create();
+  if (flags & GPR_DUMP_HEX) {
+    hexdump(&out, buf, len);
+  }
+  if (flags & GPR_DUMP_ASCII) {
+    asciidump(&out, buf, len);
+  }
+  dump_out_append(&out, 0);
   return out.data;
 }
 
+char *gpr_dump_slice(gpr_slice s, gpr_uint32 flags) {
+  return gpr_dump((const char *)GPR_SLICE_START_PTR(s), GPR_SLICE_LENGTH(s),
+                  flags);
+}
+
+
 int gpr_parse_bytes_to_uint32(const char *buf, size_t len, gpr_uint32 *result) {
   gpr_uint32 out = 0;
   gpr_uint32 new;

src/core/support/string.h

@@ -37,6 +37,7 @@
 #include <stddef.h>
 
 #include <grpc/support/port_platform.h>
+#include <grpc/support/slice.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -44,12 +45,16 @@ extern "C" {
 
 /* String utility functions */
 
-/* flag to include plaintext after a hexdump */
-#define GPR_HEXDUMP_PLAINTEXT 0x00000001
+/* Flags for gpr_dump function. */
+#define GPR_DUMP_HEX   0x00000001
+#define GPR_DUMP_ASCII 0x00000002
 
-/* Converts array buf, of length len, into a hexadecimal dump. Result should
-   be freed with gpr_free() */
-char *gpr_hexdump(const char *buf, size_t len, gpr_uint32 flags);
+/* Converts array buf, of length len, into a C string  according to the flags.
+   Result should be freed with gpr_free() */
+char *gpr_dump(const char *buf, size_t len, gpr_uint32 flags);
+
+/* Calls gpr_dump on a slice. */
+char *gpr_dump_slice(gpr_slice slice, gpr_uint32 flags);
 
 /* Parses an array of bytes into an integer (base 10). Returns 1 on success,
    0 on failure. */

src/core/support/string_win32.c

@@ -37,7 +37,6 @@
 
 #ifdef GPR_WIN32
 
-#include <windows.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <string.h>

src/core/support/string_win32.h

@@ -38,8 +38,6 @@
 
 #ifdef GPR_WIN32
 
-#include <windows.h>
-
 /* These allocate new strings using gpr_malloc to convert from and to utf-8. */
 LPTSTR gpr_char_to_tchar(LPCSTR input);
 LPSTR gpr_tchar_to_char(LPCTSTR input);

src/core/support/sync_win32.c

@@ -37,9 +37,6 @@
 
 #ifdef GPR_WIN32
 
-#undef _WIN32_WINNT
-#define _WIN32_WINNT 0x0600
-#include <windows.h>
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>

src/core/support/thd_win32.c

@@ -37,7 +37,6 @@
 
 #ifdef GPR_WIN32
 
-#include <windows.h>
 #include <string.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>

src/core/support/time_win32.c

@@ -39,7 +39,6 @@
 
 #include <grpc/support/time.h>
 #include <sys/timeb.h>
-#include <windows.h>
 
 gpr_timespec gpr_now(void) {
   gpr_timespec now_tv;

src/core/surface/byte_buffer.c

@@ -55,6 +55,20 @@ grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
   return bb;
 }
 
+grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader) {
+  grpc_byte_buffer *bb = malloc(sizeof(grpc_byte_buffer));
+  gpr_slice slice;
+  bb->type = GRPC_BB_RAW;
+  bb->data.raw.compression = GRPC_COMPRESS_NONE;
+  gpr_slice_buffer_init(&bb->data.raw.slice_buffer);
+
+  while (grpc_byte_buffer_reader_next(reader, &slice)) {
+    gpr_slice_buffer_add(&bb->data.raw.slice_buffer, slice);
+  }
+  return bb;
+}
+
 grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb) {
   switch (bb->type) {
     case GRPC_BB_RAW:

src/core/surface/call.c

@@ -76,14 +76,14 @@ typedef struct {
 typedef struct {
   /* Overall status of the operation: starts OK, may degrade to
      non-OK */
-  int success;
-  /* Completion function to call at the end of the operation */
-  grpc_ioreq_completion_func on_complete;
-  void *user_data;
+  gpr_uint8 success;
   /* a bit mask of which request ops are needed (1u << opid) */
   gpr_uint16 need_mask;
   /* a bit mask of which request ops are now completed */
   gpr_uint16 complete_mask;
+  /* Completion function to call at the end of the operation */
+  grpc_ioreq_completion_func on_complete;
+  void *user_data;
 } reqinfo_master;
 
 /* Status data for a request can come from several sources; this
@@ -160,6 +160,8 @@ struct grpc_call {
   gpr_uint8 bound_pollset;
   /* is an error status set */
   gpr_uint8 error_status_set;
+  /** should the alarm be cancelled */
+  gpr_uint8 cancel_alarm;
 
   /* flags with bits corresponding to write states allowing us to determine
      what was sent */
@@ -260,8 +262,8 @@ struct grpc_call {
 static void set_deadline_alarm(grpc_call *call, gpr_timespec deadline);
 static void call_on_done_recv(void *call, int success);
 static void call_on_done_send(void *call, int success);
-static int fill_send_ops(grpc_call *call, grpc_transport_op *op);
-static void execute_op(grpc_call *call, grpc_transport_op *op);
+static int fill_send_ops(grpc_call *call, grpc_transport_stream_op *op);
+static void execute_op(grpc_call *call, grpc_transport_stream_op *op);
 static void recv_metadata(grpc_call *call, grpc_metadata_batch *metadata);
 static void finish_read_ops(grpc_call *call);
 static grpc_call_error cancel_with_status(grpc_call *c, grpc_status_code status,
@@ -277,8 +279,8 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_completion_queue *cq,
                             size_t add_initial_metadata_count,
                             gpr_timespec send_deadline) {
   size_t i;
-  grpc_transport_op initial_op;
-  grpc_transport_op *initial_op_ptr = NULL;
+  grpc_transport_stream_op initial_op;
+  grpc_transport_stream_op *initial_op_ptr = NULL;
   grpc_channel_stack *channel_stack = grpc_channel_get_channel_stack(channel);
   grpc_call *call =
       gpr_malloc(sizeof(grpc_call) + channel_stack->call_stack_size);
@@ -296,8 +298,6 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_completion_queue *cq,
   if (call->is_client) {
     call->request_set[GRPC_IOREQ_SEND_TRAILING_METADATA] = REQSET_DONE;
     call->request_set[GRPC_IOREQ_SEND_STATUS] = REQSET_DONE;
-    call->context[GRPC_CONTEXT_TRACING].value = grpc_census_context_create();
-    call->context[GRPC_CONTEXT_TRACING].destroy = grpc_census_context_destroy;
   }
   GPR_ASSERT(add_initial_metadata_count < MAX_SEND_INITIAL_METADATA_COUNT);
   for (i = 0; i < add_initial_metadata_count; i++) {
@@ -462,16 +462,16 @@ static int need_more_data(grpc_call *call) {
          (is_op_live(call, GRPC_IOREQ_RECV_CLOSE) &&
           grpc_bbq_empty(&call->incoming_queue)) ||
          (call->write_state == WRITE_STATE_INITIAL && !call->is_client) ||
-         (call->cancel_with_status != GRPC_STATUS_OK) ||
-         call->destroy_called;
+         (call->cancel_with_status != GRPC_STATUS_OK) || call->destroy_called;
 }
 
 static void unlock(grpc_call *call) {
-  grpc_transport_op op;
+  grpc_transport_stream_op op;
   completed_request completed_requests[GRPC_IOREQ_OP_COUNT];
   int completing_requests = 0;
   int start_op = 0;
   int i;
+  int cancel_alarm = 0;
 
   memset(&op, 0, sizeof(op));
 
@@ -479,6 +479,9 @@ static void unlock(grpc_call *call) {
   start_op = op.cancel_with_status != GRPC_STATUS_OK;
   call->cancel_with_status = GRPC_STATUS_OK; /* reset */
 
+  cancel_alarm = call->cancel_alarm;
+  call->cancel_alarm = 0;
+
   if (!call->receiving && need_more_data(call)) {
     op.recv_ops = &call->recv_ops;
     op.recv_state = &call->recv_state;
@@ -513,6 +516,10 @@ static void unlock(grpc_call *call) {
 
   gpr_mu_unlock(&call->mu);
 
+  if (cancel_alarm) {
+    grpc_alarm_cancel(&call->alarm);
+  }
+
   if (start_op) {
     execute_op(call, &op);
   }
@@ -805,10 +812,7 @@ static void call_on_done_recv(void *pc, int success) {
     if (call->recv_state == GRPC_STREAM_CLOSED) {
       GPR_ASSERT(call->read_state <= READ_STATE_STREAM_CLOSED);
       call->read_state = READ_STATE_STREAM_CLOSED;
-      if (call->have_alarm) {
-        grpc_alarm_cancel(&call->alarm);
-        call->have_alarm = 0;
-      }
+      call->cancel_alarm |= call->have_alarm;
       GRPC_CALL_INTERNAL_UNREF(call, "closed", 0);
     }
     finish_read_ops(call);
@@ -881,7 +885,7 @@ static void copy_byte_buffer_to_stream_ops(grpc_byte_buffer *byte_buffer,
   }
 }
 
-static int fill_send_ops(grpc_call *call, grpc_transport_op *op) {
+static int fill_send_ops(grpc_call *call, grpc_transport_stream_op *op) {
   grpc_ioreq_data data;
   gpr_uint32 flags;
   grpc_metadata_batch mdb;
@@ -987,7 +991,7 @@ static void finish_read_ops(grpc_call *call) {
 
   switch (call->read_state) {
     case READ_STATE_STREAM_CLOSED:
-      if (empty) {
+      if (empty && !call->have_alarm) {
         finish_ioreq_op(call, GRPC_IOREQ_RECV_CLOSE, 1);
       }
     /* fallthrough */
@@ -1085,10 +1089,7 @@ void grpc_call_destroy(grpc_call *c) {
   lock(c);
   GPR_ASSERT(!c->destroy_called);
   c->destroy_called = 1;
-  if (c->have_alarm) {
-    grpc_alarm_cancel(&c->alarm);
-    c->have_alarm = 0;
-  }
+  c->cancel_alarm |= c->have_alarm;
   cancel = c->read_state != READ_STATE_STREAM_CLOSED;
   unlock(c);
   if (cancel) grpc_call_cancel(c);
@@ -1140,7 +1141,7 @@ static void finished_loose_op_allocated(void *alloc, int success) {
   gpr_free(args);
 }
 
-static void execute_op(grpc_call *call, grpc_transport_op *op) {
+static void execute_op(grpc_call *call, grpc_transport_stream_op *op) {
   grpc_call_element *elem;
 
   GPR_ASSERT(op->on_consumed == NULL);
@@ -1151,14 +1152,15 @@ static void execute_op(grpc_call *call, grpc_transport_op *op) {
     } else {
       finished_loose_op_allocated_args *args = gpr_malloc(sizeof(*args));
       args->call = call;
-      grpc_iomgr_closure_init(&args->closure, finished_loose_op_allocated, args);
+      grpc_iomgr_closure_init(&args->closure, finished_loose_op_allocated,
+                              args);
       op->on_consumed = &args->closure;
     }
   }
 
   elem = CALL_ELEM_FROM_CALL(call, 0);
   op->context = call->context;
-  elem->filter->start_transport_op(elem, op);
+  elem->filter->start_transport_stream_op(elem, op);
 }
 
 grpc_call *grpc_call_from_top_element(grpc_call_element *elem) {
@@ -1167,12 +1169,14 @@ grpc_call *grpc_call_from_top_element(grpc_call_element *elem) {
 
 static void call_alarm(void *arg, int success) {
   grpc_call *call = arg;
+  lock(call);
+  call->have_alarm = 0;
   if (success) {
-    lock(call);
     cancel_with_status(call, GRPC_STATUS_DEADLINE_EXCEEDED,
                        "Deadline Exceeded");
-    unlock(call);
   }
+  finish_read_ops(call);
+  unlock(call);
   GRPC_CALL_INTERNAL_UNREF(call, "alarm", 1);
 }
 
@@ -1223,13 +1227,13 @@ static gpr_uint32 decode_compression(grpc_mdelem *md) {
   } else {
     gpr_uint32 parsed_clevel_bytes;
     if (gpr_parse_bytes_to_uint32(grpc_mdstr_as_c_string(md->value),
-                                   GPR_SLICE_LENGTH(md->value->slice),
-                                   &parsed_clevel_bytes)) {
+                                  GPR_SLICE_LENGTH(md->value->slice),
+                                  &parsed_clevel_bytes)) {
       /* the following cast is safe, as a gpr_uint32 should be able to hold all
        * possible values of the grpc_compression_level enum */
-      clevel = (grpc_compression_level) parsed_clevel_bytes;
+      clevel = (grpc_compression_level)parsed_clevel_bytes;
     } else {
-      clevel = GRPC_COMPRESS_LEVEL_NONE;  /* could not parse, no compression */
+      clevel = GRPC_COMPRESS_LEVEL_NONE; /* could not parse, no compression */
     }
     grpc_mdelem_set_user_data(md, destroy_compression,
                               (void *)(gpr_intptr)(clevel + COMPRESS_OFFSET));
@@ -1252,7 +1256,8 @@ static void recv_metadata(grpc_call *call, grpc_metadata_batch *md) {
       set_status_code(call, STATUS_FROM_WIRE, decode_status(md));
     } else if (key == grpc_channel_get_message_string(call->channel)) {
       set_status_details(call, STATUS_FROM_WIRE, grpc_mdstr_ref(md->value));
-    } else if (key == grpc_channel_get_compresssion_level_string(call->channel)) {
+    } else if (key ==
+               grpc_channel_get_compresssion_level_string(call->channel)) {
       set_decode_compression_level(call, decode_compression(md));
     } else {
       dest = &call->buffered_metadata[is_trailing];

src/core/surface/call.h

@@ -78,8 +78,8 @@ typedef union {
 
 typedef struct {
   grpc_ioreq_op op;
-  grpc_ioreq_data data;
   gpr_uint32 flags; /**< A copy of the write flags from grpc_op */
+  grpc_ioreq_data data;
 } grpc_ioreq;
 
 typedef void (*grpc_ioreq_completion_func)(grpc_call *call, int success,

src/core/surface/call_log_batch.c

@@ -46,8 +46,8 @@ static void add_metadata(gpr_strvec *b, const grpc_metadata *md, size_t count) {
     gpr_strvec_add(b, gpr_strdup(md[i].key));
 
     gpr_strvec_add(b, gpr_strdup(" value="));
-    gpr_strvec_add(b, gpr_hexdump(md[i].value, md[i].value_length,
-                                  GPR_HEXDUMP_PLAINTEXT));
+    gpr_strvec_add(b, gpr_dump(md[i].value, md[i].value_length,
+                               GPR_DUMP_HEX | GPR_DUMP_ASCII));
   }
 }