Merge branch 'master' into turn_it_to_11

Makefile

@@ -1076,6 +1076,7 @@ qps_openloop_test: $(BINDIR)/$(CONFIG)/qps_openloop_test
 qps_worker: $(BINDIR)/$(CONFIG)/qps_worker
 reconnect_interop_client: $(BINDIR)/$(CONFIG)/reconnect_interop_client
 reconnect_interop_server: $(BINDIR)/$(CONFIG)/reconnect_interop_server
+round_robin_end2end_test: $(BINDIR)/$(CONFIG)/round_robin_end2end_test
 secure_auth_context_test: $(BINDIR)/$(CONFIG)/secure_auth_context_test
 secure_sync_unary_ping_pong_test: $(BINDIR)/$(CONFIG)/secure_sync_unary_ping_pong_test
 server_builder_plugin_test: $(BINDIR)/$(CONFIG)/server_builder_plugin_test
@@ -1454,6 +1455,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/qps_worker \
   $(BINDIR)/$(CONFIG)/reconnect_interop_client \
   $(BINDIR)/$(CONFIG)/reconnect_interop_server \
+  $(BINDIR)/$(CONFIG)/round_robin_end2end_test \
   $(BINDIR)/$(CONFIG)/secure_auth_context_test \
   $(BINDIR)/$(CONFIG)/secure_sync_unary_ping_pong_test \
   $(BINDIR)/$(CONFIG)/server_builder_plugin_test \
@@ -1543,6 +1545,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/qps_worker \
   $(BINDIR)/$(CONFIG)/reconnect_interop_client \
   $(BINDIR)/$(CONFIG)/reconnect_interop_server \
+  $(BINDIR)/$(CONFIG)/round_robin_end2end_test \
   $(BINDIR)/$(CONFIG)/secure_auth_context_test \
   $(BINDIR)/$(CONFIG)/secure_sync_unary_ping_pong_test \
   $(BINDIR)/$(CONFIG)/server_builder_plugin_test \
@@ -1852,6 +1855,8 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/proto_server_reflection_test || ( echo test proto_server_reflection_test failed ; exit 1 )
 	$(E) "[RUN]     Testing qps_openloop_test"
 	$(Q) $(BINDIR)/$(CONFIG)/qps_openloop_test || ( echo test qps_openloop_test failed ; exit 1 )
+	$(E) "[RUN]     Testing round_robin_end2end_test"
+	$(Q) $(BINDIR)/$(CONFIG)/round_robin_end2end_test || ( echo test round_robin_end2end_test failed ; exit 1 )
 	$(E) "[RUN]     Testing secure_auth_context_test"
 	$(Q) $(BINDIR)/$(CONFIG)/secure_auth_context_test || ( echo test secure_auth_context_test failed ; exit 1 )
 	$(E) "[RUN]     Testing secure_sync_unary_ping_pong_test"
@@ -12992,6 +12997,49 @@ endif
 $(OBJDIR)/$(CONFIG)/test/cpp/interop/reconnect_interop_server.o: $(GENDIR)/src/proto/grpc/testing/empty.pb.cc $(GENDIR)/src/proto/grpc/testing/empty.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/messages.pb.cc $(GENDIR)/src/proto/grpc/testing/messages.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/test.pb.cc $(GENDIR)/src/proto/grpc/testing/test.grpc.pb.cc
 
 
+ROUND_ROBIN_END2END_TEST_SRC = \
+    test/cpp/end2end/round_robin_end2end_test.cc \
+
+ROUND_ROBIN_END2END_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(ROUND_ROBIN_END2END_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/round_robin_end2end_test: openssl_dep_error
+
+else
+
+
+
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build the protoc plugins or protobuf-enabled targets if you don't have protobuf 3.0.0+.
+
+$(BINDIR)/$(CONFIG)/round_robin_end2end_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/round_robin_end2end_test: $(PROTOBUF_DEP) $(ROUND_ROBIN_END2END_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LDXX) $(LDFLAGS) $(ROUND_ROBIN_END2END_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/round_robin_end2end_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/cpp/end2end/round_robin_end2end_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_round_robin_end2end_test: $(ROUND_ROBIN_END2END_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(ROUND_ROBIN_END2END_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 SECURE_AUTH_CONTEXT_TEST_SRC = \
     test/cpp/common/secure_auth_context_test.cc \
 

build.yaml

@@ -3326,6 +3326,19 @@ targets:
   - gpr_test_util
   - gpr
   - grpc++_test_config
+- name: round_robin_end2end_test
+  gtest: true
+  build: test
+  language: c++
+  src:
+  - test/cpp/end2end/round_robin_end2end_test.cc
+  deps:
+  - grpc++_test_util
+  - grpc_test_util
+  - grpc++
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: secure_auth_context_test
   gtest: true
   build: test

include/grpc++/support/channel_arguments.h

@@ -85,6 +85,11 @@ class ChannelArguments {
   /// The given buffer pool will be attached to the constructed channel
   void SetResourceQuota(const ResourceQuota& resource_quota);
 
+  /// Set LB policy name.
+  /// Note that if the name resolver returns only balancer addresses, the
+  /// grpclb LB policy will be used, regardless of what is specified here.
+  void SetLoadBalancingPolicyName(const grpc::string& lb_policy_name);
+
   // Generic channel argument setters. Only for advanced use cases.
   /// Set an integer argument \a value under \a key.
   void SetInt(const grpc::string& key, int value);

setup.py

@@ -52,6 +52,7 @@ PYTHON_STEM = os.path.join('src', 'python', 'grpcio')
 CORE_INCLUDE = ('include', '.',)
 BORINGSSL_INCLUDE = (os.path.join('third_party', 'boringssl', 'include'),)
 ZLIB_INCLUDE = (os.path.join('third_party', 'zlib'),)
+README = os.path.join(PYTHON_STEM, 'README.rst')
 
 # Ensure we're in the proper directory whether or not we're being used by pip.
 os.chdir(os.path.dirname(os.path.abspath(__file__)))
@@ -259,6 +260,7 @@ setuptools.setup(
   name='grpcio',
   version=grpc_version.VERSION,
   license=LICENSE,
+  long_description=open(README).read(),
   ext_modules=CYTHON_EXTENSION_MODULES,
   packages=list(PACKAGES),
   package_dir=PACKAGE_DIRECTORIES,

src/core/ext/client_channel/lb_policy.h

@@ -109,10 +109,16 @@ struct grpc_lb_policy_vtable {
 
 /*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+
+/* Strong references: the policy will shutdown when they reach zero */
 #define GRPC_LB_POLICY_REF(p, r) \
   grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_LB_POLICY_UNREF(exec_ctx, p, r) \
   grpc_lb_policy_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
+
+/* Weak references: they don't prevent the shutdown of the LB policy. When no
+ * strong references are left but there are still weak ones, shutdown is called.
+ * Once the weak reference also reaches zero, the LB policy is destroyed. */
 #define GRPC_LB_POLICY_WEAK_REF(p, r) \
   grpc_lb_policy_weak_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, p, r) \

src/core/ext/lb_policy/grpclb/grpclb.c

@@ -43,30 +43,23 @@
  * policy to select from this list of LB server backends.
  *
  * The first time the policy gets a request for a pick, a ping, or to exit the
- * idle state, \a query_for_backends() is called. It creates an instance of \a
- * lb_client_data, an internal struct meant to contain the data associated with
- * the internal communication with the LB server. This instance is created via
- * \a lb_client_data_create(). There, the call over lb_channel to pick-first
- * from {a1..an} is created, the \a LoadBalancingRequest message is assembled
- * and all necessary callbacks for the progress of the internal call configured.
+ * idle state, \a query_for_backends_locked() is called. This function sets up
+ * and initiates the internal communication with the LB server. In particular,
+ * it's responsible for instantiating the internal *streaming* call to the LB
+ * server (whichever address from {a1..an} pick-first chose). This call is
+ * serviced by two callbacks, \a lb_on_server_status_received and \a
+ * lb_on_response_received. The former will be called when the call to the LB
+ * server completes. This can happen if the LB server closes the connection or
+ * if this policy itself cancels the call (for example because it's shutting
+ * down). If the internal call times out, the usual behavior of pick-first
+ * applies, continuing to pick from the list {a1..an}.
  *
- * Back in \a query_for_backends(), the internal *streaming* call to the LB
- * server (whichever address from {a1..an} pick-first chose) is kicked off.
- * It'll progress over the callbacks configured in \a lb_client_data_create()
- * (see the field docstrings of \a lb_client_data for more details).
- *
- * If the call fails with UNIMPLEMENTED, the original call will also fail.
- * There's a misconfiguration somewhere: at least one of {a1..an} isn't a LB
- * server, which contradicts the LB bit being set. If the internal call times
- * out, the usual behavior of pick-first applies, continuing to pick from the
- * list {a1..an}.
- *
- * Upon sucesss, a \a LoadBalancingResponse is expected in \a res_recv_cb. An
- * invalid one results in the termination of the streaming call. A new streaming
- * call should be created if possible, failing the original call otherwise.
- * For a valid \a LoadBalancingResponse, the server list of actual backends is
- * extracted. A Round Robin policy will be created from this list. There are two
- * possible scenarios:
+ * Upon sucesss, the incoming \a LoadBalancingResponse is processed by \a
+ * res_recv. An invalid one results in the termination of the streaming call. A
+ * new streaming call should be created if possible, failing the original call
+ * otherwise. For a valid \a LoadBalancingResponse, the server list of actual
+ * backends is extracted. A Round Robin policy will be created from this list.
+ * There are two possible scenarios:
  *
  * 1. This is the first server list received. There was no previous instance of
  *    the Round Robin policy. \a rr_handover_locked() will instantiate the RR
@@ -84,10 +77,10 @@
  * Once a RR policy instance is in place (and getting updated as described),
  * calls to for a pick, a ping or a cancellation will be serviced right away by
  * forwarding them to the RR instance. Any time there's no RR policy available
- * (ie, right after the creation of the gRPCLB policy, if an empty serverlist
- * is received, etc), pick/ping requests are added to a list of pending
- * picks/pings to be flushed and serviced as part of \a rr_handover_locked() the
- * moment the RR policy instance becomes available.
+ * (ie, right after the creation of the gRPCLB policy, if an empty serverlist is
+ * received, etc), pick/ping requests are added to a list of pending picks/pings
+ * to be flushed and serviced as part of \a rr_handover_locked() the moment the
+ * RR policy instance becomes available.
  *
  * \see https://github.com/grpc/grpc/blob/master/doc/load-balancing.md for the
  * high level design and details. */
@@ -120,12 +113,20 @@
 #include "src/core/ext/lb_policy/grpclb/grpclb.h"
 #include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/transport/static_metadata.h"
 
+#define BACKOFF_MULTIPLIER 1.6
+#define BACKOFF_JITTER 0.2
+#define BACKOFF_MIN_SECONDS 10
+#define BACKOFF_MAX_SECONDS 60
+
 int grpc_lb_glb_trace = 0;
 
 /* add lb_token of selected subchannel (address) to the call's initial
@@ -174,13 +175,12 @@ typedef struct wrapped_rr_closure_arg {
 static void wrapped_rr_closure(grpc_exec_ctx *exec_ctx, void *arg,
                                grpc_error *error) {
   wrapped_rr_closure_arg *wc_arg = arg;
-  if (wc_arg->rr_policy != NULL) {
-    if (grpc_lb_glb_trace) {
-      gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")",
-              (intptr_t)wc_arg->rr_policy);
-    }
-    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "wrapped_rr_closure");
 
+  GPR_ASSERT(wc_arg->wrapped_closure != NULL);
+  grpc_exec_ctx_sched(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_REF(error),
+                      NULL);
+
+  if (wc_arg->rr_policy != NULL) {
     /* if target is NULL, no pick has been made by the RR policy (eg, all
      * addresses failed to connect). There won't be any user_data/token
      * available */
@@ -189,10 +189,12 @@ static void wrapped_rr_closure(grpc_exec_ctx *exec_ctx, void *arg,
                                     wc_arg->lb_token_mdelem_storage,
                                     GRPC_MDELEM_REF(wc_arg->lb_token));
     }
+    if (grpc_lb_glb_trace) {
+      gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")",
+              (intptr_t)wc_arg->rr_policy);
+    }
+    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "wrapped_rr_closure");
   }
-  GPR_ASSERT(wc_arg->wrapped_closure != NULL);
-  grpc_exec_ctx_sched(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_REF(error),
-                      NULL);
   GPR_ASSERT(wc_arg->free_when_done != NULL);
   gpr_free(wc_arg->free_when_done);
 }
@@ -264,7 +266,6 @@ static void add_pending_ping(pending_ping **root, grpc_closure *notify) {
  * glb_lb_policy
  */
 typedef struct rr_connectivity_data rr_connectivity_data;
-struct lb_client_data;
 static const grpc_lb_policy_vtable glb_lb_policy_vtable;
 typedef struct glb_lb_policy {
   /** base policy: must be first */
@@ -296,20 +297,47 @@ typedef struct glb_lb_policy {
    * response has arrived. */
   grpc_grpclb_serverlist *serverlist;
 
-  /** addresses from \a serverlist */
-  grpc_lb_addresses *addresses;
-
   /** list of picks that are waiting on RR's policy connectivity */
   pending_pick *pending_picks;
 
   /** list of pings that are waiting on RR's policy connectivity */
   pending_ping *pending_pings;
 
-  /** client data associated with the LB server communication */
-  struct lb_client_data *lb_client;
+  bool shutting_down;
+
+  /************************************************************/
+  /*  client data associated with the LB server communication */
+  /************************************************************/
+  /* Status from the LB server has been received. This signals the end of the LB
+   * call. */
+  grpc_closure lb_on_server_status_received;
+
+  /* A response from the LB server has been received. Process it */
+  grpc_closure lb_on_response_received;
+
+  grpc_call *lb_call; /* streaming call to the LB server, */
+
+  grpc_metadata_array lb_initial_metadata_recv; /* initial MD from LB server */
+  grpc_metadata_array
+      lb_trailing_metadata_recv; /* trailing MD from LB server */
+
+  /* what's being sent to the LB server. Note that its value may vary if the LB
+   * server indicates a redirect. */
+  grpc_byte_buffer *lb_request_payload;
+
+  /* response the LB server, if any. Processed in lb_on_response_received() */
+  grpc_byte_buffer *lb_response_payload;
+
+  /* call status code and details, set in lb_on_server_status_received() */
+  grpc_status_code lb_call_status;
+  char *lb_call_status_details;
+  size_t lb_call_status_details_capacity;
+
+  /** LB call retry backoff state */
+  gpr_backoff lb_call_backoff_state;
 
-  /** for tracking of the RR connectivity */
-  rr_connectivity_data *rr_connectivity;
+  /** LB call retry timer */
+  grpc_timer lb_call_retry_timer;
 } glb_lb_policy;
 
 /* Keeps track and reacts to changes in connectivity of the RR instance */
@@ -358,6 +386,28 @@ static int lb_token_cmp(void *token1, void *token2) {
 static const grpc_lb_user_data_vtable lb_token_vtable = {
     lb_token_copy, lb_token_destroy, lb_token_cmp};
 
+static void parse_server(const grpc_grpclb_server *server,
+                         grpc_resolved_address *addr) {
+  const uint16_t netorder_port = htons((uint16_t)server->port);
+  /* the addresses are given in binary format (a in(6)_addr struct) in
+   * server->ip_address.bytes. */
+  const grpc_grpclb_ip_address *ip = &server->ip_address;
+  memset(addr, 0, sizeof(*addr));
+  if (ip->size == 4) {
+    addr->len = sizeof(struct sockaddr_in);
+    struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr->addr;
+    addr4->sin_family = AF_INET;
+    memcpy(&addr4->sin_addr, ip->bytes, ip->size);
+    addr4->sin_port = netorder_port;
+  } else if (ip->size == 16) {
+    addr->len = sizeof(struct sockaddr_in6);
+    struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr->addr;
+    addr6->sin6_family = AF_INET;
+    memcpy(&addr6->sin6_addr, ip->bytes, ip->size);
+    addr6->sin6_port = netorder_port;
+  }
+}
+
 /* Returns addresses extracted from \a serverlist. */
 static grpc_lb_addresses *process_serverlist(
     const grpc_grpclb_serverlist *serverlist) {
@@ -384,33 +434,18 @@ static grpc_lb_addresses *process_serverlist(
     if (!is_server_valid(serverlist->servers[sl_idx], sl_idx, false)) continue;
 
     /* address processing */
-    const uint16_t netorder_port = htons((uint16_t)server->port);
-    /* the addresses are given in binary format (a in(6)_addr struct) in
-     * server->ip_address.bytes. */
-    const grpc_grpclb_ip_address *ip = &server->ip_address;
     grpc_resolved_address addr;
-    memset(&addr, 0, sizeof(addr));
-    if (ip->size == 4) {
-      addr.len = sizeof(struct sockaddr_in);
-      struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr.addr;
-      addr4->sin_family = AF_INET;
-      memcpy(&addr4->sin_addr, ip->bytes, ip->size);
-      addr4->sin_port = netorder_port;
-    } else if (ip->size == 16) {
-      addr.len = sizeof(struct sockaddr_in6);
-      struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr.addr;
-      addr6->sin6_family = AF_INET;
-      memcpy(&addr6->sin6_addr, ip->bytes, ip->size);
-      addr6->sin6_port = netorder_port;
-    }
+    parse_server(server, &addr);
 
     /* lb token processing */
     void *user_data;
     if (server->has_load_balance_token) {
-      const size_t lb_token_size =
-          GPR_ARRAY_SIZE(server->load_balance_token) - 1;
+      const size_t lb_token_max_length =
+          GPR_ARRAY_SIZE(server->load_balance_token);
+      const size_t lb_token_length =
+          strnlen(server->load_balance_token, lb_token_max_length);
       grpc_mdstr *lb_token_mdstr = grpc_mdstr_from_buffer(
-          (uint8_t *)server->load_balance_token, lb_token_size);
+          (uint8_t *)server->load_balance_token, lb_token_length);
       user_data = grpc_mdelem_from_metadata_strings(GRPC_MDSTR_LB_TOKEN,
                                                     lb_token_mdstr);
     } else {
@@ -427,7 +462,6 @@ static grpc_lb_addresses *process_serverlist(
     ++addr_idx;
   }
   GPR_ASSERT(addr_idx == num_valid);
-
   return lb_addresses;
 }
 
@@ -448,7 +482,7 @@ static bool pick_from_internal_rr_locked(
       gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")",
               (intptr_t)wc_arg->rr_policy);
     }
-    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick");
+    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick_sync");
 
     /* add the load reporting initial metadata */
     initial_metadata_add_lb_token(pick_args->initial_metadata,
@@ -461,7 +495,6 @@ static bool pick_from_internal_rr_locked(
    * pending pick list inside the RR policy (glb_policy->rr_policy).
    * Eventually, wrapped_on_complete will be called, which will -among other
    * things- add the LB token to the call's initial metadata */
-
   return pick_done;
 }
 
@@ -470,54 +503,70 @@ static grpc_lb_policy *create_rr_locked(
     glb_lb_policy *glb_policy) {
   GPR_ASSERT(serverlist != NULL && serverlist->num_servers > 0);
 
-  if (glb_policy->addresses != NULL) {
-    /* dispose of the previous version */
-    grpc_lb_addresses_destroy(glb_policy->addresses);
-  }
-  glb_policy->addresses = process_serverlist(serverlist);
-
   grpc_lb_policy_args args;
   memset(&args, 0, sizeof(args));
   args.client_channel_factory = glb_policy->cc_factory;
+  grpc_lb_addresses *addresses = process_serverlist(serverlist);
 
   // Replace the LB addresses in the channel args that we pass down to
   // the subchannel.
   static const char *keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES};
-  const grpc_arg arg =
-      grpc_lb_addresses_create_channel_arg(glb_policy->addresses);
+  const grpc_arg arg = grpc_lb_addresses_create_channel_arg(addresses);
   args.args = grpc_channel_args_copy_and_add_and_remove(
       glb_policy->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg,
       1);
 
   grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args);
+  GPR_ASSERT(rr != NULL);
+  grpc_lb_addresses_destroy(addresses);
   grpc_channel_args_destroy(args.args);
-
   return rr;
 }
 
+static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error);
+/* glb_policy->rr_policy may be NULL (initial handover) */
 static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
                                glb_lb_policy *glb_policy, grpc_error *error) {
   GPR_ASSERT(glb_policy->serverlist != NULL &&
              glb_policy->serverlist->num_servers > 0);
+
+  if (grpc_lb_glb_trace) {
+    gpr_log(GPR_INFO, "RR handover. Old RR: %p", (void *)glb_policy->rr_policy);
+  }
+  if (glb_policy->rr_policy != NULL) {
+    /* if we are phasing out an existing RR instance, unref it. */
+    GRPC_LB_POLICY_UNREF(exec_ctx, glb_policy->rr_policy, "rr_handover");
+  }
+
   glb_policy->rr_policy =
       create_rr_locked(exec_ctx, glb_policy->serverlist, glb_policy);
-
   if (grpc_lb_glb_trace) {
-    gpr_log(GPR_INFO, "Created RR policy (0x%" PRIxPTR ")",
-            (intptr_t)glb_policy->rr_policy);
+    gpr_log(GPR_INFO, "Created RR policy (%p)", (void *)glb_policy->rr_policy);
   }
+
   GPR_ASSERT(glb_policy->rr_policy != NULL);
   grpc_pollset_set_add_pollset_set(exec_ctx,
                                    glb_policy->rr_policy->interested_parties,
                                    glb_policy->base.interested_parties);
-  glb_policy->rr_connectivity->state = grpc_lb_policy_check_connectivity(
+
+  rr_connectivity_data *rr_connectivity =
+      gpr_malloc(sizeof(rr_connectivity_data));
+  memset(rr_connectivity, 0, sizeof(rr_connectivity_data));
+  grpc_closure_init(&rr_connectivity->on_change, glb_rr_connectivity_changed,
+                    rr_connectivity);
+  rr_connectivity->glb_policy = glb_policy;
+  rr_connectivity->state = grpc_lb_policy_check_connectivity(
       exec_ctx, glb_policy->rr_policy, &error);
-  grpc_lb_policy_notify_on_state_change(
-      exec_ctx, glb_policy->rr_policy, &glb_policy->rr_connectivity->state,
-      &glb_policy->rr_connectivity->on_change);
+
   grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker,
-                              glb_policy->rr_connectivity->state,
-                              GRPC_ERROR_REF(error), "rr_handover");
+                              rr_connectivity->state, GRPC_ERROR_REF(error),
+                              "rr_handover");
+  /* subscribe */
+  GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "rr_connectivity_cb");
+  grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
+                                        &rr_connectivity->state,
+                                        &rr_connectivity->on_change);
   grpc_lb_policy_exit_idle(exec_ctx, glb_policy->rr_policy);
 
   /* flush pending ops */
@@ -551,35 +600,27 @@ static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
 
 static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                         grpc_error *error) {
+  /* If shutdown or error free the arg. Rely on the rest of the code to set the
+   * right grpclb status. */
   rr_connectivity_data *rr_conn_data = arg;
   glb_lb_policy *glb_policy = rr_conn_data->glb_policy;
 
-  if (rr_conn_data->state == GRPC_CHANNEL_SHUTDOWN) {
-    if (glb_policy->serverlist != NULL) {
-      /* a RR policy is shutting down but there's a serverlist available ->
-       * perform a handover */
-      gpr_mu_lock(&glb_policy->mu);
-      rr_handover_locked(exec_ctx, glb_policy, error);
-      gpr_mu_unlock(&glb_policy->mu);
-    } else {
-      /* shutting down and no new serverlist available. Bail out. */
-      gpr_free(rr_conn_data);
-    }
+  if (rr_conn_data->state != GRPC_CHANNEL_SHUTDOWN &&
+      !glb_policy->shutting_down) {
+    gpr_mu_lock(&glb_policy->mu);
+    /* RR not shutting down. Mimic the RR's policy state */
+    grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker,
+                                rr_conn_data->state, GRPC_ERROR_REF(error),
+                                "rr_connectivity_cb");
+    /* resubscribe. Reuse the "rr_connectivity_cb" weak ref. */
+    grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
+                                          &rr_conn_data->state,
+                                          &rr_conn_data->on_change);
+    gpr_mu_unlock(&glb_policy->mu);
   } else {
-    if (error == GRPC_ERROR_NONE) {
-      gpr_mu_lock(&glb_policy->mu);
-      /* RR not shutting down. Mimic the RR's policy state */
-      grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker,
-                                  rr_conn_data->state, GRPC_ERROR_REF(error),
-                                  "glb_rr_connectivity_changed");
-      /* resubscribe */
-      grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
-                                            &rr_conn_data->state,
-                                            &rr_conn_data->on_change);
-      gpr_mu_unlock(&glb_policy->mu);
-    } else { /* error */
-      gpr_free(rr_conn_data);
-    }
+    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                              "rr_connectivity_cb");
+    gpr_free(rr_conn_data);
   }
 }
 
@@ -682,18 +723,11 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
     return NULL;
   }
 
-  rr_connectivity_data *rr_connectivity =
-      gpr_malloc(sizeof(rr_connectivity_data));
-  memset(rr_connectivity, 0, sizeof(rr_connectivity_data));
-  grpc_closure_init(&rr_connectivity->on_change, glb_rr_connectivity_changed,
-                    rr_connectivity);
-  rr_connectivity->glb_policy = glb_policy;
-  glb_policy->rr_connectivity = rr_connectivity;
-
   grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable);
   gpr_mu_init(&glb_policy->mu);
   grpc_connectivity_state_init(&glb_policy->state_tracker, GRPC_CHANNEL_IDLE,
                                "grpclb");
+
   return &glb_policy->base;
 }
 
@@ -710,14 +744,13 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
   gpr_mu_destroy(&glb_policy->mu);
-  grpc_lb_addresses_destroy(glb_policy->addresses);
   gpr_free(glb_policy);
 }
 
-static void lb_client_data_destroy(struct lb_client_data *lb_client);
 static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
   gpr_mu_lock(&glb_policy->mu);
+  glb_policy->shutting_down = true;
 
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
@@ -741,15 +774,16 @@ static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
 
   if (glb_policy->rr_policy) {
-    /* unsubscribe */
-    grpc_lb_policy_notify_on_state_change(
-        exec_ctx, glb_policy->rr_policy, NULL,
-        &glb_policy->rr_connectivity->on_change);
     GRPC_LB_POLICY_UNREF(exec_ctx, glb_policy->rr_policy, "glb_shutdown");
   }
 
-  lb_client_data_destroy(glb_policy->lb_client);
-  glb_policy->lb_client = NULL;
+  if (glb_policy->started_picking) {
+    if (glb_policy->lb_call != NULL) {
+      grpc_call_cancel(glb_policy->lb_call, NULL);
+      /* lb_on_server_status_received will pick up the cancellation and clean up
+       */
+    }
+  }
 
   grpc_connectivity_state_set(
       exec_ctx, &glb_policy->state_tracker, GRPC_CHANNEL_SHUTDOWN,
@@ -780,17 +814,12 @@ static void glb_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_call *lb_client_data_get_call(struct lb_client_data *lb_client);
 static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
                              uint32_t initial_metadata_flags_mask,
                              uint32_t initial_metadata_flags_eq,
                              grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
   gpr_mu_lock(&glb_policy->mu);
-  if (glb_policy->lb_client != NULL) {
-    /* cancel the call to the load balancer service, if any */
-    grpc_call_cancel(lb_client_data_get_call(glb_policy->lb_client), NULL);
-  }
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
   while (pp != NULL) {
@@ -810,18 +839,20 @@ static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   GRPC_ERROR_UNREF(error);
 }
 
-static void query_for_backends(grpc_exec_ctx *exec_ctx,
-                               glb_lb_policy *glb_policy);
-static void start_picking(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy) {
+static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
+                                      glb_lb_policy *glb_policy);
+static void start_picking_locked(grpc_exec_ctx *exec_ctx,
+                                 glb_lb_policy *glb_policy) {
   glb_policy->started_picking = true;
-  query_for_backends(exec_ctx, glb_policy);
+  gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
+  query_for_backends_locked(exec_ctx, glb_policy);
 }
 
 static void glb_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
   gpr_mu_lock(&glb_policy->mu);
   if (!glb_policy->started_picking) {
-    start_picking(exec_ctx, glb_policy);
+    start_picking_locked(exec_ctx, glb_policy);
   }
   gpr_mu_unlock(&glb_policy->mu);
 }
@@ -847,8 +878,8 @@ static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
 
   if (glb_policy->rr_policy != NULL) {
     if (grpc_lb_glb_trace) {
-      gpr_log(GPR_INFO, "about to PICK from 0x%" PRIxPTR "",
-              (intptr_t)glb_policy->rr_policy);
+      gpr_log(GPR_INFO, "grpclb %p about to PICK from RR %p",
+              (void *)glb_policy, (void *)glb_policy->rr_policy);
     }
     GRPC_LB_POLICY_REF(glb_policy->rr_policy, "glb_pick");
 
@@ -865,11 +896,17 @@ static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pick_done = pick_from_internal_rr_locked(exec_ctx, glb_policy->rr_policy,
                                              pick_args, target, wc_arg);
   } else {
+    if (grpc_lb_glb_trace) {
+      gpr_log(GPR_DEBUG,
+              "No RR policy in grpclb instance %p. Adding to grpclb's pending "
+              "picks",
+              (void *)(glb_policy));
+    }
     add_pending_pick(&glb_policy->pending_picks, pick_args, target,
                      on_complete);
 
     if (!glb_policy->started_picking) {
-      start_picking(exec_ctx, glb_policy);
+      start_picking_locked(exec_ctx, glb_policy);
     }
     pick_done = false;
   }
@@ -898,7 +935,7 @@ static void glb_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   } else {
     add_pending_ping(&glb_policy->pending_pings, closure);
     if (!glb_policy->started_picking) {
-      start_picking(exec_ctx, glb_policy);
+      start_picking_locked(exec_ctx, glb_policy);
     }
   }
   gpr_mu_unlock(&glb_policy->mu);
@@ -916,250 +953,182 @@ static void glb_notify_on_state_change(grpc_exec_ctx *exec_ctx,
   gpr_mu_unlock(&glb_policy->mu);
 }
 
-/*
- * lb_client_data
- *
- * Used internally for the client call to the LB */
-typedef struct lb_client_data {
-  gpr_mu mu;
-
-  /* called once initial metadata's been sent */
-  grpc_closure md_sent;
-
-  /* called once the LoadBalanceRequest has been sent to the LB server. See
-   * src/proto/grpc/.../load_balancer.proto */
-  grpc_closure req_sent;
-
-  /* A response from the LB server has been received (or error). Process it */
-  grpc_closure res_rcvd;
-
-  /* After the client has sent a close to the LB server */
-  grpc_closure close_sent;
-
-  /* ... and the status from the LB server has been received */
-  grpc_closure srv_status_rcvd;
-
-  grpc_call *lb_call;    /* streaming call to the LB server, */
-  gpr_timespec deadline; /* for the streaming call to the LB server */
-
-  grpc_metadata_array initial_metadata_recv;  /* initial MD from LB server */
-  grpc_metadata_array trailing_metadata_recv; /* trailing MD from LB server */
-
-  /* what's being sent to the LB server. Note that its value may vary if the LB
-   * server indicates a redirect. */
-  grpc_byte_buffer *request_payload;
-
-  /* response from the LB server, if any. Processed in res_recv_cb() */
-  grpc_byte_buffer *response_payload;
-
-  /* the call's status and status detailset in srv_status_rcvd_cb() */
-  grpc_status_code status;
-  char *status_details;
-  size_t status_details_capacity;
-
-  /* pointer back to the enclosing policy */
-  glb_lb_policy *glb_policy;
-} lb_client_data;
-
-static void md_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
-static void req_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
-static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
-static void close_sent_cb(grpc_exec_ctx *exec_ctx, void *arg,
-                          grpc_error *error);
-static void srv_status_rcvd_cb(grpc_exec_ctx *exec_ctx, void *arg,
-                               grpc_error *error);
-
-static lb_client_data *lb_client_data_create(glb_lb_policy *glb_policy) {
+static void lb_on_server_status_received(grpc_exec_ctx *exec_ctx, void *arg,
+                                         grpc_error *error);
+static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
+                                    grpc_error *error);
+static void lb_call_init(glb_lb_policy *glb_policy) {
   GPR_ASSERT(glb_policy->server_name != NULL);
   GPR_ASSERT(glb_policy->server_name[0] != '\0');
 
-  lb_client_data *lb_client = gpr_malloc(sizeof(lb_client_data));
-  memset(lb_client, 0, sizeof(lb_client_data));
-
-  gpr_mu_init(&lb_client->mu);
-  grpc_closure_init(&lb_client->md_sent, md_sent_cb, lb_client);
-
-  grpc_closure_init(&lb_client->req_sent, req_sent_cb, lb_client);
-  grpc_closure_init(&lb_client->res_rcvd, res_recv_cb, lb_client);
-  grpc_closure_init(&lb_client->close_sent, close_sent_cb, lb_client);
-  grpc_closure_init(&lb_client->srv_status_rcvd, srv_status_rcvd_cb, lb_client);
-
-  lb_client->deadline = glb_policy->deadline;
-
   /* Note the following LB call progresses every time there's activity in \a
    * glb_policy->base.interested_parties, which is comprised of the polling
    * entities from \a client_channel. */
-  lb_client->lb_call = grpc_channel_create_pollset_set_call(
+  glb_policy->lb_call = grpc_channel_create_pollset_set_call(
       glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
       glb_policy->base.interested_parties,
       "/grpc.lb.v1.LoadBalancer/BalanceLoad", glb_policy->server_name,
-      lb_client->deadline, NULL);
+      glb_policy->deadline, NULL);
 
-  grpc_metadata_array_init(&lb_client->initial_metadata_recv);
-  grpc_metadata_array_init(&lb_client->trailing_metadata_recv);
+  grpc_metadata_array_init(&glb_policy->lb_initial_metadata_recv);
+  grpc_metadata_array_init(&glb_policy->lb_trailing_metadata_recv);
 
   grpc_grpclb_request *request =
       grpc_grpclb_request_create(glb_policy->server_name);
   gpr_slice request_payload_slice = grpc_grpclb_request_encode(request);
-  lb_client->request_payload =
+  glb_policy->lb_request_payload =
       grpc_raw_byte_buffer_create(&request_payload_slice, 1);
   gpr_slice_unref(request_payload_slice);
   grpc_grpclb_request_destroy(request);
 
-  lb_client->status_details = NULL;
-  lb_client->status_details_capacity = 0;
-  lb_client->glb_policy = glb_policy;
-  return lb_client;
+  glb_policy->lb_call_status_details = NULL;
+  glb_policy->lb_call_status_details_capacity = 0;
+
+  grpc_closure_init(&glb_policy->lb_on_server_status_received,
+                    lb_on_server_status_received, glb_policy);
+  grpc_closure_init(&glb_policy->lb_on_response_received,
+                    lb_on_response_received, glb_policy);
+
+  gpr_backoff_init(&glb_policy->lb_call_backoff_state, BACKOFF_MULTIPLIER,
+                   BACKOFF_JITTER, BACKOFF_MIN_SECONDS * 1000,
+                   BACKOFF_MAX_SECONDS * 1000);
 }
 
-static void lb_client_data_destroy(lb_client_data *lb_client) {
-  grpc_call_destroy(lb_client->lb_call);
-  grpc_metadata_array_destroy(&lb_client->initial_metadata_recv);
-  grpc_metadata_array_destroy(&lb_client->trailing_metadata_recv);
+static void lb_call_destroy(glb_lb_policy *glb_policy) {
+  GPR_ASSERT(glb_policy->lb_call != NULL);
+  grpc_call_destroy(glb_policy->lb_call);
+  glb_policy->lb_call = NULL;
 
-  grpc_byte_buffer_destroy(lb_client->request_payload);
+  grpc_metadata_array_destroy(&glb_policy->lb_initial_metadata_recv);
+  grpc_metadata_array_destroy(&glb_policy->lb_trailing_metadata_recv);
 
-  gpr_free(lb_client->status_details);
-  gpr_mu_destroy(&lb_client->mu);
-  gpr_free(lb_client);
-}
-static grpc_call *lb_client_data_get_call(lb_client_data *lb_client) {
-  return lb_client->lb_call;
+  grpc_byte_buffer_destroy(glb_policy->lb_request_payload);
+  gpr_free(glb_policy->lb_call_status_details);
 }
 
 /*
  * Auxiliary functions and LB client callbacks.
  */
-static void query_for_backends(grpc_exec_ctx *exec_ctx,
-                               glb_lb_policy *glb_policy) {
+static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
+                                      glb_lb_policy *glb_policy) {
   GPR_ASSERT(glb_policy->lb_channel != NULL);
+  lb_call_init(glb_policy);
+
+  if (grpc_lb_glb_trace) {
+    gpr_log(GPR_INFO, "Query for backends (grpclb: %p, lb_call: %p)",
+            (void *)glb_policy, (void *)glb_policy->lb_call);
+  }
+  GPR_ASSERT(glb_policy->lb_call != NULL);
 
-  glb_policy->lb_client = lb_client_data_create(glb_policy);
   grpc_call_error call_error;
-  grpc_op ops[1];
+  grpc_op ops[4];
   memset(ops, 0, sizeof(ops));
+
   grpc_op *op = ops;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
   op->reserved = NULL;
   op++;
-  call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, glb_policy->lb_client->lb_call, ops, (size_t)(op - ops),
-      &glb_policy->lb_client->md_sent);
-  GPR_ASSERT(GRPC_CALL_OK == call_error);
 
-  op = ops;
-  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
-  op->data.recv_status_on_client.trailing_metadata =
-      &glb_policy->lb_client->trailing_metadata_recv;
-  op->data.recv_status_on_client.status = &glb_policy->lb_client->status;
-  op->data.recv_status_on_client.status_details =
-      &glb_policy->lb_client->status_details;
-  op->data.recv_status_on_client.status_details_capacity =
-      &glb_policy->lb_client->status_details_capacity;
+  op->op = GRPC_OP_RECV_INITIAL_METADATA;
+  op->data.recv_initial_metadata = &glb_policy->lb_initial_metadata_recv;
   op->flags = 0;
   op->reserved = NULL;
   op++;
-  call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, glb_policy->lb_client->lb_call, ops, (size_t)(op - ops),
-      &glb_policy->lb_client->srv_status_rcvd);
-  GPR_ASSERT(GRPC_CALL_OK == call_error);
-}
-
-static void md_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
-  lb_client_data *lb_client = arg;
-  GPR_ASSERT(lb_client->lb_call);
-  grpc_op ops[1];
-  memset(ops, 0, sizeof(ops));
-  grpc_op *op = ops;
 
+  GPR_ASSERT(glb_policy->lb_request_payload != NULL);
   op->op = GRPC_OP_SEND_MESSAGE;
-  op->data.send_message = lb_client->request_payload;
+  op->data.send_message = glb_policy->lb_request_payload;
   op->flags = 0;
   op->reserved = NULL;
   op++;
-  grpc_call_error call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops),
-      &lb_client->req_sent);
-  GPR_ASSERT(GRPC_CALL_OK == call_error);
-}
-
-static void req_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
-  lb_client_data *lb_client = arg;
-  GPR_ASSERT(lb_client->lb_call);
-
-  grpc_op ops[2];
-  memset(ops, 0, sizeof(ops));
-  grpc_op *op = ops;
 
-  op->op = GRPC_OP_RECV_INITIAL_METADATA;
-  op->data.recv_initial_metadata = &lb_client->initial_metadata_recv;
+  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  op->data.recv_status_on_client.trailing_metadata =
+      &glb_policy->lb_trailing_metadata_recv;
+  op->data.recv_status_on_client.status = &glb_policy->lb_call_status;
+  op->data.recv_status_on_client.status_details =
+      &glb_policy->lb_call_status_details;
+  op->data.recv_status_on_client.status_details_capacity =
+      &glb_policy->lb_call_status_details_capacity;
   op->flags = 0;
   op->reserved = NULL;
   op++;
+  /* take a weak ref (won't prevent calling of \a glb_shutdown if the strong ref
+   * count goes to zero) to be unref'd in lb_on_server_status_received */
+  GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "lb_on_server_status_received");
+  call_error = grpc_call_start_batch_and_execute(
+      exec_ctx, glb_policy->lb_call, ops, (size_t)(op - ops),
+      &glb_policy->lb_on_server_status_received);
+  GPR_ASSERT(GRPC_CALL_OK == call_error);
 
+  op = ops;
   op->op = GRPC_OP_RECV_MESSAGE;
-  op->data.recv_message = &lb_client->response_payload;
+  op->data.recv_message = &glb_policy->lb_response_payload;
   op->flags = 0;
   op->reserved = NULL;
   op++;
-  grpc_call_error call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops),
-      &lb_client->res_rcvd);
+  /* take another weak ref to be unref'd in lb_on_response_received */
+  GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "lb_on_response_received");
+  call_error = grpc_call_start_batch_and_execute(
+      exec_ctx, glb_policy->lb_call, ops, (size_t)(op - ops),
+      &glb_policy->lb_on_response_received);
   GPR_ASSERT(GRPC_CALL_OK == call_error);
 }
 
-static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
-  lb_client_data *lb_client = arg;
+static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
+                                    grpc_error *error) {
+  glb_lb_policy *glb_policy = arg;
+
   grpc_op ops[2];
   memset(ops, 0, sizeof(ops));
   grpc_op *op = ops;
-  if (lb_client->response_payload != NULL) {
+  if (glb_policy->lb_response_payload != NULL) {
+    gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
     /* Received data from the LB server. Look inside
-     * lb_client->response_payload, for a serverlist. */
+     * glb_policy->lb_response_payload, for a serverlist. */
     grpc_byte_buffer_reader bbr;
-    grpc_byte_buffer_reader_init(&bbr, lb_client->response_payload);
+    grpc_byte_buffer_reader_init(&bbr, glb_policy->lb_response_payload);
     gpr_slice response_slice = grpc_byte_buffer_reader_readall(&bbr);
-    grpc_byte_buffer_destroy(lb_client->response_payload);
+    grpc_byte_buffer_destroy(glb_policy->lb_response_payload);
     grpc_grpclb_serverlist *serverlist =
         grpc_grpclb_response_parse_serverlist(response_slice);
     if (serverlist != NULL) {
+      GPR_ASSERT(glb_policy->lb_call != NULL);
       gpr_slice_unref(response_slice);
       if (grpc_lb_glb_trace) {
         gpr_log(GPR_INFO, "Serverlist with %lu servers received",
                 (unsigned long)serverlist->num_servers);
+        for (size_t i = 0; i < serverlist->num_servers; ++i) {
+          grpc_resolved_address addr;
+          parse_server(serverlist->servers[i], &addr);
+          char *ipport;
+          grpc_sockaddr_to_string(&ipport, &addr, false);
+          gpr_log(GPR_INFO, "Serverlist[%lu]: %s", (unsigned long)i, ipport);
+          gpr_free(ipport);
+        }
       }
 
       /* update serverlist */
       if (serverlist->num_servers > 0) {
-        gpr_mu_lock(&lb_client->glb_policy->mu);
-        if (grpc_grpclb_serverlist_equals(lb_client->glb_policy->serverlist,
-                                          serverlist)) {
+        gpr_mu_lock(&glb_policy->mu);
+        if (grpc_grpclb_serverlist_equals(glb_policy->serverlist, serverlist)) {
           if (grpc_lb_glb_trace) {
             gpr_log(GPR_INFO,
                     "Incoming server list identical to current, ignoring.");
           }
         } else { /* new serverlist */
-          if (lb_client->glb_policy->serverlist != NULL) {
+          if (glb_policy->serverlist != NULL) {
             /* dispose of the old serverlist */
-            grpc_grpclb_destroy_serverlist(lb_client->glb_policy->serverlist);
+            grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
           }
           /* and update the copy in the glb_lb_policy instance */
-          lb_client->glb_policy->serverlist = serverlist;
-        }
-        if (lb_client->glb_policy->rr_policy == NULL) {
-          /* initial "handover", in this case from a null RR policy, meaning
-           * it'll just create the first RR policy instance */
-          rr_handover_locked(exec_ctx, lb_client->glb_policy, error);
-        } else {
-          /* unref the RR policy, eventually leading to its substitution with a
-           * new one constructed from the received serverlist (see
-           * glb_rr_connectivity_changed) */
-          GRPC_LB_POLICY_UNREF(exec_ctx, lb_client->glb_policy->rr_policy,
-                               "serverlist_received");
+          glb_policy->serverlist = serverlist;
+
+          rr_handover_locked(exec_ctx, glb_policy, error);
         }
-        gpr_mu_unlock(&lb_client->glb_policy->mu);
+        gpr_mu_unlock(&glb_policy->mu);
       } else {
         if (grpc_lb_glb_trace) {
           gpr_log(GPR_INFO,
@@ -1167,60 +1136,94 @@ static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
                   "response with > 0 servers is received");
         }
       }
+    } else { /* serverlist == NULL */
+      gpr_log(GPR_ERROR, "Invalid LB response received: '%s'. Ignoring.",
+              gpr_dump_slice(response_slice, GPR_DUMP_ASCII | GPR_DUMP_HEX));
+      gpr_slice_unref(response_slice);
+    }
 
+    if (!glb_policy->shutting_down) {
       /* keep listening for serverlist updates */
       op->op = GRPC_OP_RECV_MESSAGE;
-      op->data.recv_message = &lb_client->response_payload;
+      op->data.recv_message = &glb_policy->lb_response_payload;
       op->flags = 0;
       op->reserved = NULL;
       op++;
+      /* reuse the "lb_on_response_received" weak ref taken in
+       * query_for_backends_locked() */
       const grpc_call_error call_error = grpc_call_start_batch_and_execute(
-          exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops),
-          &lb_client->res_rcvd); /* loop */
+          exec_ctx, glb_policy->lb_call, ops, (size_t)(op - ops),
+          &glb_policy->lb_on_response_received); /* loop */
       GPR_ASSERT(GRPC_CALL_OK == call_error);
-      return;
     }
-
-    GPR_ASSERT(serverlist == NULL);
-    gpr_log(GPR_ERROR, "Invalid LB response received: '%s'",
-            gpr_dump_slice(response_slice, GPR_DUMP_ASCII));
-    gpr_slice_unref(response_slice);
-
-    /* Disconnect from server returning invalid response. */
-    op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
-    op->flags = 0;
-    op->reserved = NULL;
-    op++;
-    grpc_call_error call_error = grpc_call_start_batch_and_execute(
-        exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops),
-        &lb_client->close_sent);
-    GPR_ASSERT(GRPC_CALL_OK == call_error);
+  } else { /* empty payload: call cancelled. */
+           /* dispose of the "lb_on_response_received" weak ref taken in
+            * query_for_backends_locked() and reused in every reception loop */
+    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                              "lb_on_response_received_empty_payload");
   }
-  /* empty payload: call cancelled by server. Cleanups happening in
-   * srv_status_rcvd_cb */
 }
 
-static void close_sent_cb(grpc_exec_ctx *exec_ctx, void *arg,
-                          grpc_error *error) {
-  if (grpc_lb_glb_trace) {
-    gpr_log(GPR_INFO,
-            "Close from LB client sent. Waiting from server status now");
+static void lb_call_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
+                                   grpc_error *error) {
+  glb_lb_policy *glb_policy = arg;
+  gpr_mu_lock(&glb_policy->mu);
+
+  if (!glb_policy->shutting_down) {
+    if (grpc_lb_glb_trace) {
+      gpr_log(GPR_INFO, "Restaring call to LB server (grpclb %p)",
+              (void *)glb_policy);
+    }
+    GPR_ASSERT(glb_policy->lb_call == NULL);
+    query_for_backends_locked(exec_ctx, glb_policy);
   }
+  gpr_mu_unlock(&glb_policy->mu);
+
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                            "grpclb_on_retry_timer");
 }
 
-static void srv_status_rcvd_cb(grpc_exec_ctx *exec_ctx, void *arg,
-                               grpc_error *error) {
-  lb_client_data *lb_client = arg;
+static void lb_on_server_status_received(grpc_exec_ctx *exec_ctx, void *arg,
+                                         grpc_error *error) {
+  glb_lb_policy *glb_policy = arg;
+  gpr_mu_lock(&glb_policy->mu);
+
+  GPR_ASSERT(glb_policy->lb_call != NULL);
+
   if (grpc_lb_glb_trace) {
-    gpr_log(GPR_INFO,
-            "status from lb server received. Status = %d, Details = '%s', "
-            "Capacity "
-            "= %lu",
-            lb_client->status, lb_client->status_details,
-            (unsigned long)lb_client->status_details_capacity);
+    gpr_log(GPR_DEBUG,
+            "Status from LB server received. Status = %d, Details = '%s', "
+            "(call: %p)",
+            glb_policy->lb_call_status, glb_policy->lb_call_status_details,
+            (void *)glb_policy->lb_call);
+  }
+
+  /* We need to performe cleanups no matter what. */
+  lb_call_destroy(glb_policy);
+
+  if (!glb_policy->shutting_down) {
+    /* if we aren't shutting down, restart the LB client call after some time */
+    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+    gpr_timespec next_try =
+        gpr_backoff_step(&glb_policy->lb_call_backoff_state, now);
+    if (grpc_lb_glb_trace) {
+      gpr_log(GPR_DEBUG, "Connection to LB server lost (grpclb: %p)...",
+              (void *)glb_policy);
+      gpr_timespec timeout = gpr_time_sub(next_try, now);
+      if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
+        gpr_log(GPR_DEBUG, "... retrying in %" PRId64 ".%09d seconds.",
+                timeout.tv_sec, timeout.tv_nsec);
+      } else {
+        gpr_log(GPR_DEBUG, "... retrying immediately.");
+      }
+    }
+    GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_retry_timer");
+    grpc_timer_init(exec_ctx, &glb_policy->lb_call_retry_timer, next_try,
+                    lb_call_on_retry_timer, glb_policy, now);
   }
-  /* TODO(dgq): deal with stream termination properly (fire up another one?
-   * fail the original call?) */
+  gpr_mu_unlock(&glb_policy->mu);
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                            "lb_on_server_status_received");
 }
 
 /* Code wiring the policy with the rest of the core */

src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h

@@ -77,7 +77,7 @@ typedef struct _grpc_lb_v1_Server {
     bool has_port;
     int32_t port;
     bool has_load_balance_token;
-    char load_balance_token[65];
+    char load_balance_token[50];
     bool has_drop_request;
     bool drop_request;
 /* @@protoc_insertion_point(struct:grpc_lb_v1_Server) */
@@ -172,7 +172,7 @@ extern const pb_field_t grpc_lb_v1_Server_fields[5];
 #define grpc_lb_v1_LoadBalanceResponse_size      (98 + grpc_lb_v1_ServerList_size)
 #define grpc_lb_v1_InitialLoadBalanceResponse_size 90
 /* grpc_lb_v1_ServerList_size depends on runtime parameters */
-#define grpc_lb_v1_Server_size                   98
+#define grpc_lb_v1_Server_size                   83
 
 /* Message IDs (where set with "msgid" option) */
 #ifdef PB_MSGID

src/core/ext/lb_policy/round_robin/round_robin.c

@@ -120,6 +120,8 @@ typedef struct {
   grpc_connectivity_state connectivity_state;
   /** the subchannel's target user data */
   void *user_data;
+  /** vtable to operate over \a user_data */
+  const grpc_lb_user_data_vtable *user_data_vtable;
 } subchannel_data;
 
 struct round_robin_lb_policy {
@@ -186,9 +188,13 @@ static void advance_last_picked_locked(round_robin_lb_policy *p) {
   }
 
   if (grpc_lb_round_robin_trace) {
-    gpr_log(GPR_DEBUG, "[READYLIST] ADVANCED LAST PICK. NOW AT NODE %p (SC %p)",
-            (void *)p->ready_list_last_pick,
-            (void *)p->ready_list_last_pick->subchannel);
+    gpr_log(GPR_DEBUG,
+            "[READYLIST, RR: %p] ADVANCED LAST PICK. NOW AT NODE %p (SC %p, "
+            "CSC %p)",
+            (void *)p, (void *)p->ready_list_last_pick,
+            (void *)p->ready_list_last_pick->subchannel,
+            (void *)grpc_subchannel_get_connected_subchannel(
+                p->ready_list_last_pick->subchannel));
   }
 }
 
@@ -255,9 +261,18 @@ static void remove_disconnected_sc_locked(round_robin_lb_policy *p,
 static void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   ready_list *elem;
+
+  if (grpc_lb_round_robin_trace) {
+    gpr_log(GPR_DEBUG, "Destroying Round Robin policy at %p", (void *)pol);
+  }
+
   for (size_t i = 0; i < p->num_subchannels; i++) {
     subchannel_data *sd = p->subchannels[i];
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
+    GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin_destroy");
+    if (sd->user_data != NULL) {
+      GPR_ASSERT(sd->user_data_vtable != NULL);
+      sd->user_data_vtable->destroy(sd->user_data);
+    }
     gpr_free(sd);
   }
 
@@ -285,6 +300,9 @@ static void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   size_t i;
 
   gpr_mu_lock(&p->mu);
+  if (grpc_lb_round_robin_trace) {
+    gpr_log(GPR_DEBUG, "Shutting down Round Robin policy at %p", (void *)pol);
+  }
 
   p->shutdown = 1;
   while ((pp = p->pending_picks)) {
@@ -296,7 +314,7 @@ static void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
   grpc_connectivity_state_set(
       exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
-      GRPC_ERROR_CREATE("Channel Shutdown"), "shutdown");
+      GRPC_ERROR_CREATE("Channel Shutdown"), "rr_shutdown");
   for (i = 0; i < p->num_subchannels; i++) {
     subchannel_data *sd = p->subchannels[i];
     grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
@@ -395,6 +413,11 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   pending_pick *pp;
   ready_list *selected;
   gpr_mu_lock(&p->mu);
+
+  if (grpc_lb_round_robin_trace) {
+    gpr_log(GPR_INFO, "Round Robin %p trying to pick", (void *)pol);
+  }
+
   if ((selected = peek_next_connected_locked(p))) {
     /* readily available, report right away */
     *target = GRPC_CONNECTED_SUBCHANNEL_REF(
@@ -435,7 +458,6 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
   subchannel_data *sd = arg;
   round_robin_lb_policy *p = sd->policy;
   pending_pick *pp;
-  ready_list *selected;
 
   int unref = 0;
 
@@ -456,12 +478,14 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         /* at this point we know there's at least one suitable subchannel. Go
          * ahead and pick one and notify the pending suitors in
          * p->pending_picks. This preemtively replicates rr_pick()'s actions. */
-        selected = peek_next_connected_locked(p);
+        ready_list *selected = peek_next_connected_locked(p);
+        GPR_ASSERT(selected != NULL);
         if (p->pending_picks != NULL) {
           /* if the selected subchannel is going to be used for the pending
            * picks, update the last picked pointer */
           advance_last_picked_locked(p);
         }
+
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
 
@@ -653,7 +677,11 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
       sd->policy = p;
       sd->index = subchannel_idx;
       sd->subchannel = subchannel;
-      sd->user_data = addresses->addresses[i].user_data;
+      sd->user_data_vtable = addresses->user_data_vtable;
+      if (sd->user_data_vtable != NULL) {
+        sd->user_data =
+            sd->user_data_vtable->copy(addresses->addresses[i].user_data);
+      }
       ++subchannel_idx;
       grpc_closure_init(&sd->connectivity_changed_closure,
                         rr_connectivity_changed, sd);

src/core/ext/transport/chttp2/client/secure/secure_channel_create.c

@@ -347,7 +347,7 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
       &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, new_args);
   // Clean up.
   GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
-                                "client_channel_factory_create_channel");
+                                "secure_client_channel_factory_create_channel");
   grpc_channel_args_destroy(new_args);
   grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);

src/core/lib/iomgr/resource_quota.c

@@ -715,3 +715,10 @@ void grpc_resource_user_alloc_slices(
   grpc_resource_user_alloc(exec_ctx, slice_allocator->resource_user,
                            count * length, &slice_allocator->on_allocated);
 }
+
+gpr_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
+                                          grpc_resource_user *resource_user,
+                                          size_t size) {
+  grpc_resource_user_alloc(exec_ctx, resource_user, size, NULL);
+  return ru_slice_create(resource_user, size);
+}

src/core/lib/iomgr/resource_quota.h

@@ -221,4 +221,9 @@ void grpc_resource_user_alloc_slices(
     grpc_resource_user_slice_allocator *slice_allocator, size_t length,
     size_t count, gpr_slice_buffer *dest);
 
+/* Allocate one slice of length \a size synchronously. */
+gpr_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
+                                          grpc_resource_user *resource_user,
+                                          size_t size);
+
 #endif /* GRPC_CORE_LIB_IOMGR_RESOURCE_QUOTA_H */

src/core/lib/iomgr/tcp_client_uv.c

@@ -54,9 +54,12 @@ typedef struct grpc_uv_tcp_connect {
   grpc_endpoint **endpoint;
   int refs;
   char *addr_name;
+  grpc_resource_quota *resource_quota;
 } grpc_uv_tcp_connect;
 
-static void uv_tcp_connect_cleanup(grpc_uv_tcp_connect *connect) {
+static void uv_tcp_connect_cleanup(grpc_exec_ctx *exec_ctx,
+                                   grpc_uv_tcp_connect *connect) {
+  grpc_resource_quota_internal_unref(exec_ctx, connect->resource_quota);
   gpr_free(connect);
 }
 
@@ -74,7 +77,7 @@ static void uv_tc_on_alarm(grpc_exec_ctx *exec_ctx, void *acp,
   }
   done = (--connect->refs == 0);
   if (done) {
-    uv_tcp_connect_cleanup(connect);
+    uv_tcp_connect_cleanup(exec_ctx, connect);
   }
 }
 
@@ -86,8 +89,8 @@ static void uv_tc_on_connect(uv_connect_t *req, int status) {
   grpc_closure *closure = connect->closure;
   grpc_timer_cancel(&exec_ctx, &connect->alarm);
   if (status == 0) {
-    *connect->endpoint =
-        grpc_tcp_create(connect->tcp_handle, connect->addr_name);
+    *connect->endpoint = grpc_tcp_create(
+        connect->tcp_handle, connect->resource_quota, connect->addr_name);
   } else {
     error = GRPC_ERROR_CREATE("Failed to connect to remote host");
     error = grpc_error_set_int(error, GRPC_ERROR_INT_ERRNO, -status);
@@ -105,7 +108,7 @@ static void uv_tc_on_connect(uv_connect_t *req, int status) {
   }
   done = (--connect->refs == 0);
   if (done) {
-    uv_tcp_connect_cleanup(connect);
+    uv_tcp_connect_cleanup(&exec_ctx, connect);
   }
   grpc_exec_ctx_sched(&exec_ctx, closure, error, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
@@ -114,16 +117,31 @@ static void uv_tc_on_connect(uv_connect_t *req, int status) {
 static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
                                     grpc_closure *closure, grpc_endpoint **ep,
                                     grpc_pollset_set *interested_parties,
+                                    const grpc_channel_args *channel_args,
                                     const grpc_resolved_address *resolved_addr,
                                     gpr_timespec deadline) {
   grpc_uv_tcp_connect *connect;
+  grpc_resource_quota *resource_quota = grpc_resource_quota_create(NULL);
+  (void)channel_args;
   (void)interested_parties;
+
+  if (channel_args != NULL) {
+    for (size_t i = 0; i < channel_args->num_args; i++) {
+      if (0 == strcmp(channel_args->args[i].key, GRPC_ARG_RESOURCE_QUOTA)) {
+        grpc_resource_quota_internal_unref(exec_ctx, resource_quota);
+        resource_quota = grpc_resource_quota_internal_ref(
+            channel_args->args[i].value.pointer.p);
+      }
+    }
+  }
+
   connect = gpr_malloc(sizeof(grpc_uv_tcp_connect));
   memset(connect, 0, sizeof(grpc_uv_tcp_connect));
   connect->closure = closure;
   connect->endpoint = ep;
   connect->tcp_handle = gpr_malloc(sizeof(uv_tcp_t));
   connect->addr_name = grpc_sockaddr_to_uri(resolved_addr);
+  connect->resource_quota = resource_quota;
   uv_tcp_init(uv_default_loop(), connect->tcp_handle);
   connect->connect_req.data = connect;
   // TODO(murgatroid99): figure out what the return value here means
@@ -138,16 +156,18 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
 // overridden by api_fuzzer.c
 void (*grpc_tcp_client_connect_impl)(
     grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
-    grpc_pollset_set *interested_parties, const grpc_resolved_address *addr,
+    grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
+    const grpc_resolved_address *addr,
     gpr_timespec deadline) = tcp_client_connect_impl;
 
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                              grpc_endpoint **ep,
                              grpc_pollset_set *interested_parties,
+                             const grpc_channel_args *channel_args,
                              const grpc_resolved_address *addr,
                              gpr_timespec deadline) {
-  grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties, addr,
-                               deadline);
+  grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties,
+                               channel_args, addr, deadline);
 }
 
 #endif /* GRPC_UV */

src/core/lib/iomgr/tcp_server_uv.c

@@ -76,13 +76,30 @@ struct grpc_tcp_server {
 
   /* shutdown callback */
   grpc_closure *shutdown_complete;
+
+  grpc_resource_quota *resource_quota;
 };
 
-grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
+grpc_error *grpc_tcp_server_create(grpc_exec_ctx *exec_ctx,
+                                   grpc_closure *shutdown_complete,
                                    const grpc_channel_args *args,
                                    grpc_tcp_server **server) {
   grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
-  (void)args;
+  s->resource_quota = grpc_resource_quota_create(NULL);
+  for (size_t i = 0; i < (args == NULL ? 0 : args->num_args); i++) {
+    if (0 == strcmp(GRPC_ARG_RESOURCE_QUOTA, args->args[i].key)) {
+      if (args->args[i].type == GRPC_ARG_POINTER) {
+        grpc_resource_quota_internal_unref(exec_ctx, s->resource_quota);
+        s->resource_quota =
+            grpc_resource_quota_internal_ref(args->args[i].value.pointer.p);
+      } else {
+        grpc_resource_quota_internal_unref(exec_ctx, s->resource_quota);
+        gpr_free(s);
+        return GRPC_ERROR_CREATE(GRPC_ARG_RESOURCE_QUOTA
+                                 " must be a pointer to a buffer pool");
+      }
+    }
+  }
   gpr_ref_init(&s->refs, 1);
   s->on_accept_cb = NULL;
   s->on_accept_cb_arg = NULL;
@@ -119,6 +136,7 @@ static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
     gpr_free(sp->handle);
     gpr_free(sp);
   }
+  grpc_resource_quota_internal_unref(exec_ctx, s->resource_quota);
   gpr_free(s);
 }
 
@@ -201,7 +219,7 @@ static void on_connect(uv_stream_t *server, int status) {
     } else {
       gpr_log(GPR_INFO, "uv_tcp_getpeername error: %s", uv_strerror(status));
     }
-    ep = grpc_tcp_create(client, peer_name_string);
+    ep = grpc_tcp_create(client, sp->server->resource_quota, peer_name_string);
     sp->server->on_accept_cb(&exec_ctx, sp->server->on_accept_cb_arg, ep, NULL,
                              &acceptor);
     grpc_exec_ctx_finish(&exec_ctx);

src/core/lib/iomgr/tcp_uv.c

@@ -54,6 +54,9 @@ typedef struct {
   grpc_endpoint base;
   gpr_refcount refcount;
 
+  uv_write_t write_req;
+  uv_shutdown_t shutdown_req;
+
   uv_tcp_t *handle;
 
   grpc_closure *read_cb;
@@ -64,14 +67,23 @@ typedef struct {
   gpr_slice_buffer *write_slices;
   uv_buf_t *write_buffers;
 
+  grpc_resource_user resource_user;
+
   bool shutting_down;
+  bool resource_user_shutting_down;
+
   char *peer_string;
   grpc_pollset *pollset;
 } grpc_tcp;
 
 static void uv_close_callback(uv_handle_t *handle) { gpr_free(handle); }
 
-static void tcp_free(grpc_tcp *tcp) { gpr_free(tcp); }
+static void tcp_free(grpc_tcp *tcp) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_resource_user_destroy(&exec_ctx, &tcp->resource_user);
+  gpr_free(tcp);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
 
 /*#define GRPC_TCP_REFCOUNT_DEBUG*/
 #ifdef GRPC_TCP_REFCOUNT_DEBUG
@@ -106,11 +118,14 @@ static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
 
 static void alloc_uv_buf(uv_handle_t *handle, size_t suggested_size,
                          uv_buf_t *buf) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_tcp *tcp = handle->data;
   (void)suggested_size;
-  tcp->read_slice = gpr_slice_malloc(GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
+  tcp->read_slice = grpc_resource_user_slice_malloc(
+      &exec_ctx, &tcp->resource_user, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
   buf->base = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
   buf->len = GPR_SLICE_LENGTH(tcp->read_slice);
+  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void read_callback(uv_stream_t *stream, ssize_t nread,
@@ -198,7 +213,8 @@ static void write_callback(uv_write_t *req, int status) {
     gpr_log(GPR_DEBUG, "write complete on %p: error=%s", tcp, str);
   }
   gpr_free(tcp->write_buffers);
-  gpr_free(req);
+  grpc_resource_user_free(&exec_ctx, &tcp->resource_user,
+                          sizeof(uv_buf_t) * tcp->write_slices->count);
   grpc_exec_ctx_sched(&exec_ctx, cb, error, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
 }
@@ -243,12 +259,15 @@ static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   tcp->write_cb = cb;
   buffer_count = (unsigned int)tcp->write_slices->count;
   buffers = gpr_malloc(sizeof(uv_buf_t) * buffer_count);
+  grpc_resource_user_alloc(exec_ctx, &tcp->resource_user,
+                           sizeof(uv_buf_t) * buffer_count, NULL);
   for (i = 0; i < buffer_count; i++) {
     slice = &tcp->write_slices->slices[i];
     buffers[i].base = (char *)GPR_SLICE_START_PTR(*slice);
     buffers[i].len = GPR_SLICE_LENGTH(*slice);
   }
-  write_req = gpr_malloc(sizeof(uv_write_t));
+  tcp->write_buffers = buffers;
+  write_req = &tcp->write_req;
   write_req->data = tcp;
   TCP_REF(tcp, "write");
   // TODO(murgatroid99): figure out what the return value here means
@@ -274,13 +293,29 @@ static void uv_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   (void)pollset;
 }
 
-static void shutdown_callback(uv_shutdown_t *req, int status) { gpr_free(req); }
+static void shutdown_callback(uv_shutdown_t *req, int status) {}
+
+static void resource_user_shutdown_done(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error) {
+  TCP_UNREF(arg, "resource_user");
+}
+
+static void uv_resource_user_maybe_shutdown(grpc_exec_ctx *exec_ctx,
+                                            grpc_tcp *tcp) {
+  if (!tcp->resource_user_shutting_down) {
+    tcp->resource_user_shutting_down = true;
+    TCP_REF(tcp, "resource_user");
+    grpc_resource_user_shutdown(
+        exec_ctx, &tcp->resource_user,
+        grpc_closure_create(resource_user_shutdown_done, tcp));
+  }
+}
 
 static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   if (!tcp->shutting_down) {
     tcp->shutting_down = true;
-    uv_shutdown_t *req = gpr_malloc(sizeof(uv_shutdown_t));
+    uv_shutdown_t *req = &tcp->shutdown_req;
     uv_shutdown(req, (uv_stream_t *)tcp->handle, shutdown_callback);
   }
 }
@@ -289,6 +324,7 @@ static void uv_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
   uv_close((uv_handle_t *)tcp->handle, uv_close_callback);
+  uv_resource_user_maybe_shutdown(exec_ctx, tcp);
   TCP_UNREF(tcp, "destroy");
 }
 
@@ -297,18 +333,21 @@ static char *uv_get_peer(grpc_endpoint *ep) {
   return gpr_strdup(tcp->peer_string);
 }
 
+static grpc_resource_user *uv_get_resource_user(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  return &tcp->resource_user;
+}
+
 static grpc_workqueue *uv_get_workqueue(grpc_endpoint *ep) { return NULL; }
 
-static grpc_endpoint_vtable vtable = {uv_endpoint_read,
-                                      uv_endpoint_write,
-                                      uv_get_workqueue,
-                                      uv_add_to_pollset,
-                                      uv_add_to_pollset_set,
-                                      uv_endpoint_shutdown,
-                                      uv_destroy,
-                                      uv_get_peer};
+static grpc_endpoint_vtable vtable = {
+    uv_endpoint_read,  uv_endpoint_write,     uv_get_workqueue,
+    uv_add_to_pollset, uv_add_to_pollset_set, uv_endpoint_shutdown,
+    uv_destroy,        uv_get_resource_user,  uv_get_peer};
 
-grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle, char *peer_string) {
+grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
+                               grpc_resource_quota *resource_quota,
+                               char *peer_string) {
   grpc_tcp *tcp = (grpc_tcp *)gpr_malloc(sizeof(grpc_tcp));
 
   if (grpc_tcp_trace) {
@@ -325,6 +364,8 @@ grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle, char *peer_string) {
   gpr_ref_init(&tcp->refcount, 1);
   tcp->peer_string = gpr_strdup(peer_string);
   tcp->shutting_down = false;
+  tcp->resource_user_shutting_down = false;
+  grpc_resource_user_init(&tcp->resource_user, resource_quota, peer_string);
   /* Tell network status tracking code about the new endpoint */
   grpc_network_status_register_endpoint(&tcp->base);
 

src/core/lib/iomgr/tcp_uv.h

@@ -52,6 +52,8 @@ extern int grpc_tcp_trace;
 
 #define GRPC_TCP_DEFAULT_READ_SLICE_SIZE 8192
 
-grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle, char *peer_string);
+grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
+                               grpc_resource_quota *resource_quota,
+                               char *peer_string);
 
 #endif /* GRPC_CORE_LIB_IOMGR_TCP_UV_H */

src/core/lib/security/transport/security_connector.c

@@ -210,11 +210,11 @@ void grpc_security_connector_unref(grpc_security_connector *sc) {
 }
 
 static void connector_pointer_arg_destroy(void *p) {
-  GRPC_SECURITY_CONNECTOR_UNREF(p, "connector_pointer_arg");
+  GRPC_SECURITY_CONNECTOR_UNREF(p, "connector_pointer_arg_destroy");
 }
 
 static void *connector_pointer_arg_copy(void *p) {
-  return GRPC_SECURITY_CONNECTOR_REF(p, "connector_pointer_arg");
+  return GRPC_SECURITY_CONNECTOR_REF(p, "connector_pointer_arg_copy");
 }
 
 static int connector_pointer_cmp(void *a, void *b) { return GPR_ICMP(a, b); }

src/cpp/common/channel_arguments.cc

@@ -121,6 +121,11 @@ void ChannelArguments::SetResourceQuota(
                        grpc_resource_quota_arg_vtable());
 }
 
+void ChannelArguments::SetLoadBalancingPolicyName(
+    const grpc::string& lb_policy_name) {
+  SetString(GRPC_ARG_LB_POLICY_NAME, lb_policy_name);
+}
+
 void ChannelArguments::SetInt(const grpc::string& key, int value) {
   grpc_arg arg;
   arg.type = GRPC_ARG_INTEGER;

src/proto/grpc/lb/v1/load_balancer.options

@@ -1,6 +1,5 @@
 grpc.lb.v1.InitialLoadBalanceRequest.name max_size:128
-grpc.lb.v1.InitialLoadBalanceResponse.client_config max_size:64
 grpc.lb.v1.InitialLoadBalanceResponse.load_balancer_delegate max_size:64
 grpc.lb.v1.Server.ip_address max_size:16
-grpc.lb.v1.Server.load_balance_token max_size:65
+grpc.lb.v1.Server.load_balance_token max_size:50
 load_balancer.proto no_unions:true

src/proto/grpc/lb/v1/load_balancer.proto

@@ -63,7 +63,8 @@ message LoadBalanceRequest {
 }
 
 message InitialLoadBalanceRequest {
-  // Name of load balanced service (IE, service.grpc.gslb.google.com)
+  // Name of load balanced service (IE, service.grpc.gslb.google.com). Its
+  // length should be less than 256 bytes.
   string name = 1;
 }
 
@@ -95,7 +96,8 @@ message InitialLoadBalanceResponse {
   // This is an application layer redirect that indicates the client should use
   // the specified server for load balancing. When this field is non-empty in
   // the response, the client should open a separate connection to the
-  // load_balancer_delegate and call the BalanceLoad method.
+  // load_balancer_delegate and call the BalanceLoad method. Its length should
+  // be less than 64 bytes.
   string load_balancer_delegate = 1;
 
   // This interval defines how often the client should send the client stats
@@ -130,6 +132,8 @@ message Server {
   // frontend requests for that pick must include the token in its initial
   // metadata. The token is used by the backend to verify the request and to
   // allow the backend to report load to the gRPC LB system.
+  //
+  // Its length is variable but less than 50 bytes.
   string load_balance_token = 3;
 
   // Indicates whether this particular request should be dropped by the client

templates/tools/dockerfile/test/cxx_ubuntu1604_x64/Dockerfile.template

@@ -39,7 +39,7 @@
   # The clang-3.6 symlink for the default clang version was added
   # to Ubuntu 16.04 recently, so make sure it's installed.
   # Also install clang3.7.
-  RUN apt-get update && apt-get -y install clang-3.6 clang-3.7 && apt-get clean
+  RUN apt-get update && apt-get -y install gcc-4.8 gcc-4.8-multilib g++-4.8 g++-4.8-multilib clang-3.6 clang-3.7 && apt-get clean
   
   # Define the default command.
   CMD ["bash"]

test/core/end2end/tests/resource_quota_server.c

@@ -137,17 +137,22 @@ void resource_quota_server(grpc_end2end_test_config config) {
    * will be verified on completion. */
   gpr_slice request_payload_slice = generate_random_slice();
 
-  grpc_call *client_calls[NUM_CALLS];
-  grpc_call *server_calls[NUM_CALLS];
-  grpc_metadata_array initial_metadata_recv[NUM_CALLS];
-  grpc_metadata_array trailing_metadata_recv[NUM_CALLS];
-  grpc_metadata_array request_metadata_recv[NUM_CALLS];
-  grpc_call_details call_details[NUM_CALLS];
-  grpc_status_code status[NUM_CALLS];
-  char *details[NUM_CALLS];
-  size_t details_capacity[NUM_CALLS];
-  grpc_byte_buffer *request_payload_recv[NUM_CALLS];
-  int was_cancelled[NUM_CALLS];
+  grpc_call **client_calls = malloc(sizeof(grpc_call *) * NUM_CALLS);
+  grpc_call **server_calls = malloc(sizeof(grpc_call *) * NUM_CALLS);
+  grpc_metadata_array *initial_metadata_recv =
+      malloc(sizeof(grpc_metadata_array) * NUM_CALLS);
+  grpc_metadata_array *trailing_metadata_recv =
+      malloc(sizeof(grpc_metadata_array) * NUM_CALLS);
+  grpc_metadata_array *request_metadata_recv =
+      malloc(sizeof(grpc_metadata_array) * NUM_CALLS);
+  grpc_call_details *call_details =
+      malloc(sizeof(grpc_call_details) * NUM_CALLS);
+  grpc_status_code *status = malloc(sizeof(grpc_status_code) * NUM_CALLS);
+  char **details = malloc(sizeof(char *) * NUM_CALLS);
+  size_t *details_capacity = malloc(sizeof(size_t) * NUM_CALLS);
+  grpc_byte_buffer **request_payload_recv =
+      malloc(sizeof(grpc_byte_buffer *) * NUM_CALLS);
+  int *was_cancelled = malloc(sizeof(int) * NUM_CALLS);
   grpc_call_error error;
   int pending_client_calls = 0;
   int pending_server_start_calls = 0;
@@ -356,6 +361,18 @@ void resource_quota_server(grpc_end2end_test_config config) {
   gpr_slice_unref(request_payload_slice);
   grpc_resource_quota_unref(resource_quota);
 
+  free(client_calls);
+  free(server_calls);
+  free(initial_metadata_recv);
+  free(trailing_metadata_recv);
+  free(request_metadata_recv);
+  free(call_details);
+  free(status);
+  free(details);
+  free(details_capacity);
+  free(request_payload_recv);
+  free(was_cancelled);
+
   end_test(&f);
   config.tear_down_data(&f);
 }

test/cpp/end2end/round_robin_end2end_test.cc

@@ -0,0 +1,211 @@
+/*
+ *
+ * Copyright 2016, 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 <memory>
+#include <mutex>
+#include <thread>
+
+#include <grpc++/channel.h>
+#include <grpc++/client_context.h>
+#include <grpc++/create_channel.h>
+#include <grpc++/server.h>
+#include <grpc++/server_builder.h>
+#include <grpc/grpc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/thd.h>
+#include <grpc/support/time.h>
+#include <gtest/gtest.h>
+
+#include "src/proto/grpc/testing/echo.grpc.pb.h"
+#include "test/core/util/port.h"
+#include "test/core/util/test_config.h"
+#include "test/cpp/end2end/test_service_impl.h"
+
+using grpc::testing::EchoRequest;
+using grpc::testing::EchoResponse;
+using std::chrono::system_clock;
+
+namespace grpc {
+namespace testing {
+namespace {
+
+// Subclass of TestServiceImpl that increments a request counter for
+// every call to the Echo RPC.
+class MyTestServiceImpl : public TestServiceImpl {
+ public:
+  MyTestServiceImpl() : request_count_(0) {}
+
+  Status Echo(ServerContext* context, const EchoRequest* request,
+              EchoResponse* response) GRPC_OVERRIDE {
+    {
+      unique_lock<mutex> lock(mu_);
+      ++request_count_;
+    }
+    return TestServiceImpl::Echo(context, request, response);
+  }
+
+  int request_count() {
+    unique_lock<mutex> lock(mu_);
+    return request_count_;
+  }
+
+ private:
+  mutex mu_;
+  int request_count_;
+};
+
+class RoundRobinEnd2endTest : public ::testing::Test {
+ protected:
+  RoundRobinEnd2endTest() : server_host_("localhost") {}
+
+  void StartServers(int num_servers) {
+    for (int i = 0; i < num_servers; ++i) {
+      servers_.emplace_back(new ServerData(server_host_));
+    }
+  }
+
+  void TearDown() GRPC_OVERRIDE {
+    for (size_t i = 0; i < servers_.size(); ++i) {
+      servers_[i]->Shutdown();
+    }
+  }
+
+  void ResetStub(bool round_robin) {
+    ChannelArguments args;
+    if (round_robin) args.SetLoadBalancingPolicyName("round_robin");
+    std::ostringstream uri;
+    uri << "ipv4:///";
+    for (size_t i = 0; i < servers_.size() - 1; ++i) {
+      uri << "127.0.0.1:" << servers_[i]->port_ << ",";
+    }
+    uri << "127.0.0.1:" << servers_[servers_.size() - 1]->port_;
+    std::shared_ptr<Channel> channel =
+        CreateCustomChannel(uri.str(), InsecureChannelCredentials(), args);
+    stub_ = grpc::testing::EchoTestService::NewStub(channel);
+  }
+
+  void SendRpc(int num_rpcs) {
+    EchoRequest request;
+    EchoResponse response;
+    request.set_message("Live long and prosper.");
+    for (int i = 0; i < num_rpcs; i++) {
+      ClientContext context;
+      Status status = stub_->Echo(&context, request, &response);
+      EXPECT_TRUE(status.ok());
+      EXPECT_EQ(response.message(), request.message());
+    }
+  }
+
+  struct ServerData {
+    int port_;
+    std::unique_ptr<Server> server_;
+    MyTestServiceImpl service_;
+    std::unique_ptr<std::thread> thread_;
+
+    explicit ServerData(const grpc::string& server_host) {
+      port_ = grpc_pick_unused_port_or_die();
+      gpr_log(GPR_INFO, "starting server on port %d", port_);
+      std::mutex mu;
+      std::condition_variable cond;
+      thread_.reset(new std::thread(
+          std::bind(&ServerData::Start, this, server_host, &mu, &cond)));
+      unique_lock<mutex> lock(mu);
+      cond.wait(lock);
+      gpr_log(GPR_INFO, "server startup complete");
+    }
+
+    void Start(const grpc::string& server_host, std::mutex* mu,
+               std::condition_variable* cond) {
+      std::ostringstream server_address;
+      server_address << server_host << ":" << port_;
+      ServerBuilder builder;
+      builder.AddListeningPort(server_address.str(),
+                               InsecureServerCredentials());
+      builder.RegisterService(&service_);
+      server_ = builder.BuildAndStart();
+      lock_guard<mutex> lock(*mu);
+      cond->notify_one();
+    }
+
+    void Shutdown() {
+      server_->Shutdown();
+      thread_->join();
+    }
+  };
+
+  const grpc::string server_host_;
+  CompletionQueue cli_cq_;
+  std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
+  std::vector<std::unique_ptr<ServerData>> servers_;
+};
+
+TEST_F(RoundRobinEnd2endTest, PickFirst) {
+  // Start servers and send one RPC per server.
+  const int kNumServers = 3;
+  StartServers(kNumServers);
+  ResetStub(false /* round_robin */);
+  SendRpc(kNumServers);
+  // All requests should have gone to a single server.
+  bool found = false;
+  for (size_t i = 0; i < servers_.size(); ++i) {
+    const int request_count = servers_[i]->service_.request_count();
+    if (request_count == kNumServers) {
+      found = true;
+    } else {
+      EXPECT_EQ(0, request_count);
+    }
+  }
+  EXPECT_TRUE(found);
+}
+
+TEST_F(RoundRobinEnd2endTest, RoundRobin) {
+  // Start servers and send one RPC per server.
+  const int kNumServers = 3;
+  StartServers(kNumServers);
+  ResetStub(true /* round_robin */);
+  SendRpc(kNumServers);
+  // One request should have gone to each server.
+  for (size_t i = 0; i < servers_.size(); ++i) {
+    EXPECT_EQ(1, servers_[i]->service_.request_count());
+  }
+}
+
+}  // namespace
+}  // namespace testing
+}  // namespace grpc
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

test/cpp/grpclb/grpclb_test.cc

@@ -76,10 +76,22 @@ extern "C" {
 // - Send a serverlist with faulty ip:port addresses (port > 2^16, etc).
 // - Test reception of invalid serverlist
 // - Test pinging
-// - Test against a non-LB server. That server should return UNIMPLEMENTED and
-//   the call should fail.
+// - Test against a non-LB server.
 // - Random LB server closing the stream unexpectedly.
 // - Test using DNS-resolvable names (localhost?)
+//
+// Findings from end to end testing to be covered here:
+// - Handling of LB servers restart, including reconnection after backing-off
+//   retries.
+// - Destruction of load balanced channel (and therefore of grpclb instance)
+//   while:
+//   1) the internal LB call is still active. This should work by virtue
+//   of the weak reference the LB call holds. The call should be terminated as
+//   part of the grpclb shutdown process.
+//   2) the retry timer is active. Again, the weak reference it holds should
+//   prevent a premature call to \a glb_destroy.
+// - Restart of backend servers with no changes to serverlist. This exercises
+//   the RR handover mechanism.
 
 namespace grpc {
 namespace {
@@ -144,7 +156,6 @@ static gpr_slice build_response_payload_slice(
     // disfunctional implementation of std::to_string in gcc 4.4, which doesn't
     // have a version for int but does have one for long long int.
     string token_data = "token" + std::to_string((long long int)ports[i]);
-    token_data.resize(64, '-');
     server->set_load_balance_token(token_data);
   }
   const grpc::string &enc_resp = response.SerializeAsString();
@@ -333,7 +344,6 @@ static void start_backend_server(server_fixture *sf) {
     // disfunctional implementation of std::to_string in gcc 4.4, which doesn't
     // have a version for int but does have one for long long int.
     string expected_token = "token" + std::to_string((long long int)sf->port);
-    expected_token.resize(64, '-');
     GPR_ASSERT(contains_metadata(&request_metadata_recv, "lb-token",
                                  expected_token.c_str()));
 

tools/dockerfile/test/cxx_ubuntu1604_x64/Dockerfile

@@ -97,7 +97,7 @@ RUN mkdir /var/local/jenkins
 # The clang-3.6 symlink for the default clang version was added
 # to Ubuntu 16.04 recently, so make sure it's installed.
 # Also install clang3.7.
-RUN apt-get update && apt-get -y install clang-3.6 clang-3.7 && apt-get clean
+RUN apt-get update && apt-get -y install gcc-4.8 gcc-4.8-multilib g++-4.8 g++-4.8-multilib clang-3.6 clang-3.7 && apt-get clean
 
 # Define the default command.
 CMD ["bash"]

tools/run_tests/performance/bq_upload_result.py

@@ -122,6 +122,8 @@ def _flatten_result_inplace(scenario_result):
   scenario_result['clientSuccess'] = json.dumps(scenario_result['clientSuccess'])
   scenario_result['serverSuccess'] = json.dumps(scenario_result['serverSuccess'])
   scenario_result['requestResults'] = json.dumps(scenario_result.get('requestResults', []))
+  scenario_result['summary'].pop('successfulRequestsPerSecond', None)
+  scenario_result['summary'].pop('failedRequestsPerSecond', None)
 
 
 def _populate_metadata_inplace(scenario_result):

tools/run_tests/run_tests.py

@@ -332,6 +332,8 @@ class CLanguage(object):
       return ('wheezy', self._gcc_make_options(version_suffix='-4.4'))
     elif compiler == 'gcc4.6':
       return ('wheezy', self._gcc_make_options(version_suffix='-4.6'))
+    elif compiler == 'gcc4.8':
+      return ('ubuntu1604', self._gcc_make_options(version_suffix='-4.8'))
     elif compiler == 'gcc5.3':
       return ('ubuntu1604', [])
     elif compiler == 'clang3.4':
@@ -1061,7 +1063,7 @@ argp.add_argument('--arch',
                   help='Selects architecture to target. For some platforms "default" is the only supported choice.')
 argp.add_argument('--compiler',
                   choices=['default',
-                           'gcc4.4', 'gcc4.6', 'gcc4.9', 'gcc5.3',
+                           'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3',
                            'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7',
                            'vs2010', 'vs2013', 'vs2015',
                            'python2.7', 'python3.4', 'python3.5', 'python3.6', 'pypy', 'pypy3',

tools/run_tests/run_tests_matrix.py

@@ -181,7 +181,17 @@ def _create_portability_test_jobs(extra_args=[], inner_jobs=_DEFAULT_INNER_JOBS)
   # portability C and C++ on x64
   for compiler in ['gcc4.4', 'gcc4.6', 'gcc5.3',
                    'clang3.5', 'clang3.6', 'clang3.7']:
-    test_jobs += _generate_jobs(languages=['c', 'c++'],
+    test_jobs += _generate_jobs(languages=['c'],
+                                configs=['dbg'],
+                                platforms=['linux'],
+                                arch='x64',
+                                compiler=compiler,
+                                labels=['portability'],
+                                extra_args=extra_args,
+                                inner_jobs=inner_jobs)
+  for compiler in ['gcc4.8', 'gcc5.3',
+                   'clang3.5', 'clang3.6', 'clang3.7']:
+    test_jobs += _generate_jobs(languages=['c++'],
                                 configs=['dbg'],
                                 platforms=['linux'],
                                 arch='x64',

tools/run_tests/sources_and_headers.json

@@ -2983,6 +2983,25 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc++", 
+      "grpc++_test_util", 
+      "grpc_test_util"
+    ], 
+    "headers": [], 
+    "is_filegroup": false, 
+    "language": "c++", 
+    "name": "round_robin_end2end_test", 
+    "src": [
+      "test/cpp/end2end/round_robin_end2end_test.cc"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 

tools/run_tests/tests.json

@@ -2823,6 +2823,28 @@
       "posix"
     ]
   }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": true, 
+    "language": "c++", 
+    "name": "round_robin_end2end_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ]
+  }, 
   {
     "args": [], 
     "ci_platforms": [

vsprojects/vcxproj/test/round_robin_end2end_test/round_robin_end2end_test.vcxproj

@@ -0,0 +1,207 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\1.0.204.1.props')" />
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{54B15DF6-42BA-5347-C9B8-2D7F1F2921C6}</ProjectGuid>
+    <IgnoreWarnIntDirInTempDetected>true</IgnoreWarnIntDirInTempDetected>
+    <IntDir>$(SolutionDir)IntDir\$(MSBuildProjectName)\</IntDir>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '10.0'" Label="Configuration">
+    <PlatformToolset>v100</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '11.0'" Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '12.0'" Label="Configuration">
+    <PlatformToolset>v120</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '14.0'" Label="Configuration">
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="$(SolutionDir)\..\vsprojects\cpptest.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\global.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\openssl.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\protobuf.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\winsock.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\zlib.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'">
+    <TargetName>round_robin_end2end_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Debug</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Debug</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <TargetName>round_robin_end2end_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Release</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Release</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\cpp\end2end\round_robin_end2end_test.cc">
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc++_test_util\grpc++_test_util.vcxproj">
+      <Project>{0BE77741-552A-929B-A497-4EF7ECE17A64}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc_test_util\grpc_test_util.vcxproj">
+      <Project>{17BCAFC0-5FDC-4C94-AEB9-95F3E220614B}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc++\grpc++.vcxproj">
+      <Project>{C187A093-A0FE-489D-A40A-6E33DE0F9FEB}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc\grpc.vcxproj">
+      <Project>{29D16885-7228-4C31-81ED-5F9187C7F2A9}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr_test_util\gpr_test_util.vcxproj">
+      <Project>{EAB0A629-17A9-44DB-B5FF-E91A721FE037}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr\gpr.vcxproj">
+      <Project>{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}</Project>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  </ImportGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" />
+  </Target>
+</Project>
+

vsprojects/vcxproj/test/round_robin_end2end_test/round_robin_end2end_test.vcxproj.filters

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\cpp\end2end\round_robin_end2end_test.cc">
+      <Filter>test\cpp\end2end</Filter>
+    </ClCompile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Filter Include="test">
+      <UniqueIdentifier>{e151f47d-6563-5ef9-fae6-70708f9f8ee6}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\cpp">
+      <UniqueIdentifier>{07958594-fd93-28f7-9388-c67c952701b8}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\cpp\end2end">
+      <UniqueIdentifier>{7596a0dd-caa4-b365-a59f-f7ffef38b10d}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+</Project>
+