Revert "Config migration"

This reverts commit 87905ae5ead879a3baff731b3bed5408249beacd.

BUILD

@@ -1562,20 +1562,6 @@ grpc_cc_library(
     ],
 )
 
-grpc_cc_library(
-    name = "grpc_resolver_dns_selection",
-    srcs = [
-        "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc",
-    ],
-    hdrs = [
-        "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h",
-    ],
-    language = "c++",
-    deps = [
-        "grpc_base",
-    ],
-)
-
 grpc_cc_library(
     name = "grpc_resolver_dns_native",
     srcs = [
@@ -1585,7 +1571,6 @@ grpc_cc_library(
     deps = [
         "grpc_base",
         "grpc_client_channel",
-        "grpc_resolver_dns_selection",
     ],
 )
 
@@ -1617,7 +1602,6 @@ grpc_cc_library(
     deps = [
         "grpc_base",
         "grpc_client_channel",
-        "grpc_resolver_dns_selection",
     ],
 )
 

BUILD.gn

@@ -326,8 +326,6 @@ config("grpc_config") {
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc",
-        "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc",
-        "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h",
         "src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc",
         "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc",
         "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h",

CMakeLists.txt

@@ -1308,7 +1308,6 @@ add_library(grpc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
-  src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
   src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
   src/core/ext/filters/census/grpc_context.cc
@@ -2705,7 +2704,6 @@ add_library(grpc_unsecure
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
-  src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
   src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
   src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc

Makefile

@@ -3784,7 +3784,6 @@ LIBGRPC_SRC = \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
-    src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/core/ext/filters/census/grpc_context.cc \
@@ -5129,7 +5128,6 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
-    src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc \

build.yaml

@@ -798,7 +798,6 @@ filegroups:
   uses:
   - grpc_base
   - grpc_client_channel
-  - grpc_resolver_dns_selection
 - name: grpc_resolver_dns_native
   src:
   - src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -806,14 +805,6 @@ filegroups:
   uses:
   - grpc_base
   - grpc_client_channel
-  - grpc_resolver_dns_selection
-- name: grpc_resolver_dns_selection
-  headers:
-  - src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h
-  src:
-  - src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc
-  uses:
-  - grpc_base
 - name: grpc_resolver_fake
   headers:
   - src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h

config.m4

@@ -412,7 +412,6 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
-    src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/core/ext/filters/census/grpc_context.cc \
@@ -696,7 +695,6 @@ if test "$PHP_GRPC" != "no"; then
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/lb_policy/pick_first)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/lb_policy/round_robin)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/lb_policy/xds)
-  PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/resolver/dns)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/resolver/dns/c_ares)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/resolver/dns/native)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel/resolver/fake)

config.w32

@@ -387,7 +387,6 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_libuv_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_posix.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_windows.cc " +
-    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\dns_resolver_selection.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\native\\dns_resolver.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\sockaddr\\sockaddr_resolver.cc " +
     "src\\core\\ext\\filters\\census\\grpc_context.cc " +

gRPC-C++.podspec

@@ -564,7 +564,6 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
-                      'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h',
                       'src/core/ext/filters/max_age/max_age_filter.h',
                       'src/core/ext/filters/message_size/message_size_filter.h',
                       'src/core/ext/filters/http/client_authority_filter.h',

gRPC-Core.podspec

@@ -540,7 +540,6 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
-                      'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h',
                       'src/core/ext/filters/max_age/max_age_filter.h',
                       'src/core/ext/filters/message_size/message_size_filter.h',
                       'src/core/ext/filters/http/client_authority_filter.h',
@@ -871,7 +870,6 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
-                      'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
                       'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
                       'src/core/ext/filters/census/grpc_context.cc',
@@ -1194,7 +1192,6 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
-                              'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h',
                               'src/core/ext/filters/max_age/max_age_filter.h',
                               'src/core/ext/filters/message_size/message_size_filter.h',
                               'src/core/ext/filters/http/client_authority_filter.h',

grpc.gemspec

@@ -474,7 +474,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h )
-  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h )
   s.files += %w( src/core/ext/filters/max_age/max_age_filter.h )
   s.files += %w( src/core/ext/filters/message_size/message_size_filter.h )
   s.files += %w( src/core/ext/filters/http/client_authority_filter.h )
@@ -808,7 +807,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc )
-  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc )
   s.files += %w( src/core/ext/filters/census/grpc_context.cc )

grpc.gyp

@@ -594,7 +594,6 @@
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
-        'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
         'src/core/ext/filters/census/grpc_context.cc',
@@ -1355,7 +1354,6 @@
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
-        'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc',

package.xml

@@ -479,7 +479,6 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h" role="src" />
-    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/max_age/max_age_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/message_size/message_size_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/http/client_authority_filter.h" role="src" />
@@ -813,7 +812,6 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc" role="src" />
-    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/census/grpc_context.cc" role="src" />

src/android/test/interop/app/src/main/cpp/grpc-interop.cc

@@ -18,8 +18,8 @@
 
 #include <grpcpp/grpcpp.h>
 #include <jni.h>
+#include <src/core/lib/gpr/env.h>
 
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/cpp/interop/interop_client.h"
 
 extern "C" JNIEXPORT void JNICALL
@@ -28,7 +28,7 @@ Java_io_grpc_interop_cpp_InteropActivity_configureSslRoots(JNIEnv* env,
                                                            jstring path_raw) {
   const char* path = env->GetStringUTFChars(path_raw, (jboolean*)0);
 
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, path);
+  gpr_setenv("GRPC_DEFAULT_SSL_ROOTS_FILE_PATH", path);
 }
 
 std::shared_ptr<grpc::testing::InteropClient> GetClient(const char* host,
@@ -45,7 +45,7 @@ std::shared_ptr<grpc::testing::InteropClient> GetClient(const char* host,
     credentials = grpc::InsecureChannelCredentials();
   }
 
-  grpc::testing::ChannelCreationFunc channel_creation_func =
+  grpc::testing::ChannelCreationFunc channel_creation_func = 
       std::bind(grpc::CreateChannel, host_port, credentials);
   return std::shared_ptr<grpc::testing::InteropClient>(
       new grpc::testing::InteropClient(channel_creation_func, true, false));

src/core/ext/filters/client_channel/backup_poller.cc

@@ -56,14 +56,9 @@ static backup_poller* g_poller = nullptr;  // guarded by g_poller_mu
 // treated as const.
 static int g_poll_interval_ms = DEFAULT_POLL_INTERVAL_MS;
 
-GPR_GLOBAL_CONFIG_DEFINE_INT32(
-    grpc_client_channel_backup_poll_interval_ms, DEFAULT_POLL_INTERVAL_MS,
-    "Declares the interval in ms between two backup polls on client channels. "
-    "These polls are run in the timer thread so that gRPC can process "
-    "connection failures while there is no active polling thread. "
-    "They help reconnect disconnected client channels (mostly due to "
-    "idleness), so that the next RPC on this channel won't fail. Set to 0 to "
-    "turn off the backup polls.");
+GPR_GLOBAL_CONFIG_DEFINE_INT32(grpc_client_channel_backup_poll_interval_ms,
+                               DEFAULT_POLL_INTERVAL_MS,
+                               "Client channel backup poll interval (ms)");
 
 static void init_globals() {
   gpr_mu_init(&g_poller_mu);

src/core/ext/filters/client_channel/http_connect_handshaker.cc

@@ -31,6 +31,7 @@
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker_registry.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/sync.h"
 #include "src/core/lib/http/format_request.h"

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -32,12 +32,12 @@
 #include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/filters/client_channel/server_address.h"
 #include "src/core/ext/filters/client_channel/service_config.h"
 #include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/manual_constructor.h"
@@ -474,9 +474,8 @@ static bool should_use_ares(const char* resolver_env) {
 #endif /* GRPC_UV */
 
 void grpc_resolver_dns_ares_init() {
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (should_use_ares(resolver.get())) {
+  char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (should_use_ares(resolver_env)) {
     gpr_log(GPR_DEBUG, "Using ares dns resolver");
     address_sorting_init();
     grpc_error* error = grpc_ares_init();
@@ -492,15 +491,16 @@ void grpc_resolver_dns_ares_init() {
         grpc_core::UniquePtr<grpc_core::ResolverFactory>(
             grpc_core::New<grpc_core::AresDnsResolverFactory>()));
   }
+  gpr_free(resolver_env);
 }
 
 void grpc_resolver_dns_ares_shutdown() {
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (should_use_ares(resolver.get())) {
+  char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (should_use_ares(resolver_env)) {
     address_sorting_shutdown();
     grpc_ares_cleanup();
   }
+  gpr_free(resolver_env);
 }
 
 #else /* GRPC_ARES == 1 */

src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc

@@ -1,28 +0,0 @@
-//
-// Copyright 2019 gRPC authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-
-// This is similar to the sockaddr resolver, except that it supports a
-// bunch of query args that are useful for dependency injection in tests.
-
-#include <grpc/support/port_platform.h>
-
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
-
-GPR_GLOBAL_CONFIG_DEFINE_STRING(
-    grpc_dns_resolver, "",
-    "Declares which DNS resolver to use. The default is ares if gRPC is built "
-    "with c-ares support. Otherwise, the value of this environment variable is "
-    "ignored.")

src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h

@@ -1,29 +0,0 @@
-/*
- *
- * Copyright 2019 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_DNS_RESOLVER_SELECTION_H
-#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_DNS_RESOLVER_SELECTION_H
-
-#include <grpc/support/port_platform.h>
-
-#include "src/core/lib/gprpp/global_config.h"
-
-GPR_GLOBAL_CONFIG_DECLARE_STRING(grpc_dns_resolver);
-
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_DNS_RESOLVER_SELECTION_H \
-        */

src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc

@@ -26,11 +26,11 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/filters/client_channel/server_address.h"
 #include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/manual_constructor.h"
@@ -274,9 +274,8 @@ class NativeDnsResolverFactory : public ResolverFactory {
 }  // namespace grpc_core
 
 void grpc_resolver_dns_native_init() {
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (gpr_stricmp(resolver.get(), "native") == 0) {
+  char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver_env != nullptr && gpr_stricmp(resolver_env, "native") == 0) {
     gpr_log(GPR_DEBUG, "Using native dns resolver");
     grpc_core::ResolverRegistry::Builder::RegisterResolverFactory(
         grpc_core::UniquePtr<grpc_core::ResolverFactory>(
@@ -292,6 +291,7 @@ void grpc_resolver_dns_native_init() {
               grpc_core::New<grpc_core::NativeDnsResolverFactory>()));
     }
   }
+  gpr_free(resolver_env);
 }
 
 void grpc_resolver_dns_native_shutdown() {}

src/core/ext/transport/chttp2/transport/chttp2_plugin.cc

@@ -23,11 +23,8 @@
 #include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/transport/metadata.h"
 
-GPR_GLOBAL_CONFIG_DEFINE_BOOL(
-    grpc_experimental_disable_flow_control, false,
-    "If set, flow control will be effectively disabled. Max out all values and "
-    "assume the remote peer does the same. Thus we can ignore any flow control "
-    "bookkeeping, error checking, and decision making");
+GPR_GLOBAL_CONFIG_DEFINE_BOOL(grpc_experimental_disable_flow_control, false,
+                              "Disable flow control");
 
 void grpc_chttp2_plugin_init(void) {
   g_flow_control_enabled =

src/core/lib/debug/trace.cc

@@ -26,11 +26,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-
-GPR_GLOBAL_CONFIG_DEFINE_STRING(
-    grpc_trace, "",
-    "A comma separated list of tracers that provide additional insight into "
-    "how gRPC C core is processing requests via debug logs.");
+#include "src/core/lib/gpr/env.h"
 
 int grpc_tracer_set_enabled(const char* name, int enabled);
 
@@ -137,14 +133,12 @@ static void parse(const char* s) {
   gpr_free(strings);
 }
 
-void grpc_tracer_init(const char* env_var_name) {
-  (void)env_var_name;  // suppress unused variable error
-  grpc_tracer_init();
-}
-
-void grpc_tracer_init() {
-  grpc_core::UniquePtr<char> value = GPR_GLOBAL_CONFIG_GET(grpc_trace);
-  parse(value.get());
+void grpc_tracer_init(const char* env_var) {
+  char* e = gpr_getenv(env_var);
+  if (e != nullptr) {
+    parse(e);
+    gpr_free(e);
+  }
 }
 
 void grpc_tracer_shutdown(void) {}

src/core/lib/debug/trace.h

@@ -24,15 +24,7 @@
 #include <grpc/support/atm.h>
 #include <stdbool.h>
 
-#include "src/core/lib/gprpp/global_config.h"
-
-GPR_GLOBAL_CONFIG_DECLARE_STRING(grpc_trace);
-
-// TODO(veblush): Remove this deprecated function once codes depending on this
-// function are updated in the internal repo.
 void grpc_tracer_init(const char* env_var_name);
-
-void grpc_tracer_init();
 void grpc_tracer_shutdown(void);
 
 #if defined(__has_feature)

src/core/lib/gpr/env.h

@@ -34,6 +34,12 @@ char* gpr_getenv(const char* name);
 /* Sets the environment with the specified name to the specified value. */
 void gpr_setenv(const char* name, const char* value);
 
+/* This is a version of gpr_getenv that does not produce any output if it has to
+   use an insecure version of the function. It is ONLY to be used to solve the
+   problem in which we need to check an env variable to configure the verbosity
+   level of logging. So DO NOT USE THIS. */
+const char* gpr_getenv_silent(const char* name, char** dst);
+
 /* Deletes the variable name from the environment. */
 void gpr_unsetenv(const char* name);
 

src/core/lib/gpr/env_linux.cc

@@ -38,7 +38,7 @@
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/useful.h"
 
-static const char* gpr_getenv_silent(const char* name, char** dst) {
+const char* gpr_getenv_silent(const char* name, char** dst) {
   const char* insecure_func_used = nullptr;
   char* result = nullptr;
 #if defined(GPR_BACKWARDS_COMPATIBILITY_MODE)

src/core/lib/gpr/env_windows.cc

@@ -30,6 +30,11 @@
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/string_windows.h"
 
+const char* gpr_getenv_silent(const char* name, char** dst) {
+  *dst = gpr_getenv(name);
+  return NULL;
+}
+
 char* gpr_getenv(const char* name) {
   char* result = NULL;
   DWORD size;

src/core/lib/gpr/log.cc

@@ -22,15 +22,12 @@
 #include <grpc/support/atm.h>
 #include <grpc/support/log.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
-#include "src/core/lib/gprpp/global_config.h"
 
 #include <stdio.h>
 #include <string.h>
 
-GPR_GLOBAL_CONFIG_DEFINE_STRING(grpc_verbosity, "ERROR",
-                                "Default gRPC logging verbosity")
-
 void gpr_default_log(gpr_log_func_args* args);
 static gpr_atm g_log_func = (gpr_atm)gpr_default_log;
 static gpr_atm g_min_severity_to_print = GPR_LOG_VERBOSITY_UNSET;
@@ -75,22 +72,29 @@ void gpr_set_log_verbosity(gpr_log_severity min_severity_to_print) {
 }
 
 void gpr_log_verbosity_init() {
-  grpc_core::UniquePtr<char> verbosity = GPR_GLOBAL_CONFIG_GET(grpc_verbosity);
+  char* verbosity = nullptr;
+  const char* insecure_getenv = gpr_getenv_silent("GRPC_VERBOSITY", &verbosity);
 
   gpr_atm min_severity_to_print = GPR_LOG_SEVERITY_ERROR;
-  if (strlen(verbosity.get()) > 0) {
-    if (gpr_stricmp(verbosity.get(), "DEBUG") == 0) {
+  if (verbosity != nullptr) {
+    if (gpr_stricmp(verbosity, "DEBUG") == 0) {
       min_severity_to_print = static_cast<gpr_atm>(GPR_LOG_SEVERITY_DEBUG);
-    } else if (gpr_stricmp(verbosity.get(), "INFO") == 0) {
+    } else if (gpr_stricmp(verbosity, "INFO") == 0) {
       min_severity_to_print = static_cast<gpr_atm>(GPR_LOG_SEVERITY_INFO);
-    } else if (gpr_stricmp(verbosity.get(), "ERROR") == 0) {
+    } else if (gpr_stricmp(verbosity, "ERROR") == 0) {
       min_severity_to_print = static_cast<gpr_atm>(GPR_LOG_SEVERITY_ERROR);
     }
+    gpr_free(verbosity);
   }
   if ((gpr_atm_no_barrier_load(&g_min_severity_to_print)) ==
       GPR_LOG_VERBOSITY_UNSET) {
     gpr_atm_no_barrier_store(&g_min_severity_to_print, min_severity_to_print);
   }
+
+  if (insecure_getenv != nullptr) {
+    gpr_log(GPR_DEBUG, "Warning: insecure environment read function '%s' used",
+            insecure_getenv);
+  }
 }
 
 void gpr_set_log_function(gpr_log_func f) {

src/core/lib/gprpp/fork.cc

@@ -26,8 +26,8 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/useful.h"
-#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/gprpp/memory.h"
 
 /*
@@ -35,16 +35,6 @@
  *       AROUND VERY SPECIFIC USE CASES.
  */
 
-#ifdef GRPC_ENABLE_FORK_SUPPORT
-#define GRPC_ENABLE_FORK_SUPPORT_DEFAULT true
-#else
-#define GRPC_ENABLE_FORK_SUPPORT_DEFAULT false
-#endif  // GRPC_ENABLE_FORK_SUPPORT
-
-GPR_GLOBAL_CONFIG_DEFINE_BOOL(grpc_enable_fork_support,
-                              GRPC_ENABLE_FORK_SUPPORT_DEFAULT,
-                              "Enable folk support");
-
 namespace grpc_core {
 namespace internal {
 // The exec_ctx_count has 2 modes, blocked and unblocked.
@@ -168,7 +158,34 @@ class ThreadState {
 
 void Fork::GlobalInit() {
   if (!override_enabled_) {
-    support_enabled_ = GPR_GLOBAL_CONFIG_GET(grpc_enable_fork_support);
+#ifdef GRPC_ENABLE_FORK_SUPPORT
+    support_enabled_ = true;
+#endif
+    bool env_var_set = false;
+    char* env = gpr_getenv("GRPC_ENABLE_FORK_SUPPORT");
+    if (env != nullptr) {
+      static const char* truthy[] = {"yes",  "Yes",  "YES", "true",
+                                     "True", "TRUE", "1"};
+      static const char* falsey[] = {"no",    "No",    "NO", "false",
+                                     "False", "FALSE", "0"};
+      for (size_t i = 0; i < GPR_ARRAY_SIZE(truthy); i++) {
+        if (0 == strcmp(env, truthy[i])) {
+          support_enabled_ = true;
+          env_var_set = true;
+          break;
+        }
+      }
+      if (!env_var_set) {
+        for (size_t i = 0; i < GPR_ARRAY_SIZE(falsey); i++) {
+          if (0 == strcmp(env, falsey[i])) {
+            support_enabled_ = false;
+            env_var_set = true;
+            break;
+          }
+        }
+      }
+      gpr_free(env);
+    }
   }
   if (support_enabled_) {
     exec_ctx_state_ = grpc_core::New<internal::ExecCtxState>();

src/core/lib/iomgr/ev_posix.cc

@@ -31,19 +31,13 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/useful.h"
-#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/iomgr/ev_epoll1_linux.h"
 #include "src/core/lib/iomgr/ev_epollex_linux.h"
 #include "src/core/lib/iomgr/ev_poll_posix.h"
 #include "src/core/lib/iomgr/internal_errqueue.h"
 
-GPR_GLOBAL_CONFIG_DEFINE_STRING(
-    grpc_poll_strategy, "all",
-    "Declares which polling engines to try when starting gRPC. "
-    "This is a comma-separated list of engines, which are tried in priority "
-    "order first -> last.")
-
 grpc_core::TraceFlag grpc_polling_trace(false,
                                         "polling"); /* Disabled by default */
 
@@ -52,15 +46,16 @@ grpc_core::TraceFlag grpc_fd_trace(false, "fd_trace");
 grpc_core::DebugOnlyTraceFlag grpc_trace_fd_refcount(false, "fd_refcount");
 grpc_core::DebugOnlyTraceFlag grpc_polling_api_trace(false, "polling_api");
 
-// Polling API trace only enabled in debug builds
 #ifndef NDEBUG
+
+// Polling API trace only enabled in debug builds
 #define GRPC_POLLING_API_TRACE(format, ...)                  \
   if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_api_trace)) {     \
     gpr_log(GPR_INFO, "(polling-api) " format, __VA_ARGS__); \
   }
 #else
 #define GRPC_POLLING_API_TRACE(...)
-#endif  // NDEBUG
+#endif
 
 /** Default poll() function - a pointer so that it can be overridden by some
  *  tests */
@@ -71,7 +66,7 @@ int aix_poll(struct pollfd fds[], nfds_t nfds, int timeout) {
   return poll(fds, nfds, timeout);
 }
 grpc_poll_function_type grpc_poll_function = aix_poll;
-#endif  // GPR_AIX
+#endif
 
 grpc_wakeup_fd grpc_global_wakeup_fd;
 
@@ -210,11 +205,14 @@ void grpc_register_event_engine_factory(const char* name,
 const char* grpc_get_poll_strategy_name() { return g_poll_strategy_name; }
 
 void grpc_event_engine_init(void) {
-  grpc_core::UniquePtr<char> value = GPR_GLOBAL_CONFIG_GET(grpc_poll_strategy);
+  char* s = gpr_getenv("GRPC_POLL_STRATEGY");
+  if (s == nullptr) {
+    s = gpr_strdup("all");
+  }
 
   char** strings = nullptr;
   size_t nstrings = 0;
-  split(value.get(), &strings, &nstrings);
+  split(s, &strings, &nstrings);
 
   for (size_t i = 0; g_event_engine == nullptr && i < nstrings; i++) {
     try_engine(strings[i]);
@@ -226,10 +224,10 @@ void grpc_event_engine_init(void) {
   gpr_free(strings);
 
   if (g_event_engine == nullptr) {
-    gpr_log(GPR_ERROR, "No event engine could be initialized from %s",
-            value.get());
+    gpr_log(GPR_ERROR, "No event engine could be initialized from %s", s);
     abort();
   }
+  gpr_free(s);
 }
 
 void grpc_event_engine_shutdown(void) {

src/core/lib/iomgr/ev_posix.h

@@ -24,14 +24,11 @@
 #include <poll.h>
 
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 
-GPR_GLOBAL_CONFIG_DECLARE_STRING(grpc_poll_strategy);
-
 extern grpc_core::TraceFlag grpc_fd_trace;      /* Disabled by default */
 extern grpc_core::TraceFlag grpc_polling_trace; /* Disabled by default */
 

src/core/lib/iomgr/fork_posix.cc

@@ -28,6 +28,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gprpp/fork.h"
 #include "src/core/lib/gprpp/thd.h"
 #include "src/core/lib/iomgr/ev_posix.h"

src/core/lib/iomgr/iomgr.cc

@@ -42,8 +42,7 @@
 #include "src/core/lib/iomgr/timer_manager.h"
 
 GPR_GLOBAL_CONFIG_DEFINE_BOOL(grpc_abort_on_leaks, false,
-                              "A debugging aid to cause a call to abort() when "
-                              "gRPC objects are leaked past grpc_shutdown()");
+                              "Abort when leak is found");
 
 static gpr_mu g_mu;
 static gpr_cv g_rcv;

src/core/lib/profiling/basic_timers.cc

@@ -31,8 +31,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "src/core/lib/gprpp/global_config.h"
-#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/gpr/env.h"
 
 typedef enum { BEGIN = '{', END = '}', MARK = '.' } marker_type;
 
@@ -75,16 +74,11 @@ static __thread int g_thread_id;
 static int g_next_thread_id;
 static int g_writing_enabled = 1;
 
-GPR_GLOBAL_CONFIG_DEFINE_STRING(grpc_latency_trace, "latency_trace.txt",
-                                "Output file name for latency trace")
-
 static const char* output_filename() {
   if (output_filename_or_null == NULL) {
-    grpc_core::UniquePtr<char> value =
-        GPR_GLOBAL_CONFIG_GET(grpc_latency_trace);
-    if (strlen(value.get()) > 0) {
-      output_filename_or_null = value.release();
-    } else {
+    output_filename_or_null = gpr_getenv("LATENCY_TRACE");
+    if (output_filename_or_null == NULL ||
+        strlen(output_filename_or_null) == 0) {
       output_filename_or_null = "latency_trace.txt";
     }
   }

src/core/lib/security/security_connector/load_system_roots_linux.cc

@@ -38,15 +38,12 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/useful.h"
-#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/gprpp/inlined_vector.h"
 #include "src/core/lib/iomgr/load_file.h"
 
-GPR_GLOBAL_CONFIG_DEFINE_STRING(grpc_system_ssl_roots_dir, "",
-                                "Custom directory to SSL Roots");
-
 namespace grpc_core {
 namespace {
 
@@ -142,9 +139,10 @@ grpc_slice CreateRootCertsBundle(const char* certs_directory) {
 grpc_slice LoadSystemRootCerts() {
   grpc_slice result = grpc_empty_slice();
   // Prioritize user-specified custom directory if flag is set.
-  UniquePtr<char> custom_dir = GPR_GLOBAL_CONFIG_GET(grpc_system_ssl_roots_dir);
-  if (strlen(custom_dir.get()) > 0) {
-    result = CreateRootCertsBundle(custom_dir.get());
+  char* custom_dir = gpr_getenv("GRPC_SYSTEM_SSL_ROOTS_DIR");
+  if (custom_dir != nullptr) {
+    result = CreateRootCertsBundle(custom_dir);
+    gpr_free(custom_dir);
   }
   // If the custom directory is empty/invalid/not specified, fallback to
   // distribution-specific directory.

src/core/lib/security/security_connector/security_connector.cc

@@ -28,6 +28,7 @@
 #include "src/core/ext/transport/chttp2/alpn/alpn.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/load_file.h"

src/core/lib/security/security_connector/ssl_utils.cc

@@ -27,6 +27,7 @@
 
 #include "src/core/ext/transport/chttp2/alpn/alpn.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/global_config.h"
@@ -45,13 +46,7 @@ static const char* installed_roots_path =
     INSTALL_PREFIX "/share/grpc/roots.pem";
 #endif
 
-/** Config variable that points to the default SSL roots file. This file
-   must be a PEM encoded file with all the roots such as the one that can be
-   downloaded from https://pki.google.com/roots.pem.  */
-GPR_GLOBAL_CONFIG_DEFINE_STRING(grpc_default_ssl_roots_file_path, "",
-                                "Path to the default SSL roots file.");
-
-/** Config variable used as a flag to enable/disable loading system root
+/** Environment variable used as a flag to enable/disable loading system root
     certificates from the OS trust store. */
 GPR_GLOBAL_CONFIG_DEFINE_BOOL(grpc_not_use_system_ssl_roots, false,
                               "Disable loading system root certificates.");
@@ -70,22 +65,20 @@ void grpc_set_ssl_roots_override_callback(grpc_ssl_roots_override_callback cb) {
 
 /* -- Cipher suites. -- */
 
+/* Defines the cipher suites that we accept by default. All these cipher suites
+   are compliant with HTTP2. */
+#define GRPC_SSL_CIPHER_SUITES     \
+  "ECDHE-ECDSA-AES128-GCM-SHA256:" \
+  "ECDHE-ECDSA-AES256-GCM-SHA384:" \
+  "ECDHE-RSA-AES128-GCM-SHA256:"   \
+  "ECDHE-RSA-AES256-GCM-SHA384"
+
 static gpr_once cipher_suites_once = GPR_ONCE_INIT;
 static const char* cipher_suites = nullptr;
 
-// All cipher suites for default are compliant with HTTP2.
-GPR_GLOBAL_CONFIG_DEFINE_STRING(
-    grpc_ssl_cipher_suites,
-    "ECDHE-ECDSA-AES128-GCM-SHA256:"
-    "ECDHE-ECDSA-AES256-GCM-SHA384:"
-    "ECDHE-RSA-AES128-GCM-SHA256:"
-    "ECDHE-RSA-AES256-GCM-SHA384",
-    "A colon separated list of cipher suites to use with OpenSSL")
-
 static void init_cipher_suites(void) {
-  grpc_core::UniquePtr<char> value =
-      GPR_GLOBAL_CONFIG_GET(grpc_ssl_cipher_suites);
-  cipher_suites = value.release();
+  char* overridden = gpr_getenv("GRPC_SSL_CIPHER_SUITES");
+  cipher_suites = overridden != nullptr ? overridden : GRPC_SSL_CIPHER_SUITES;
 }
 
 /* --- Util --- */
@@ -437,12 +430,13 @@ grpc_slice DefaultSslRootStore::ComputePemRootCerts() {
   grpc_slice result = grpc_empty_slice();
   const bool not_use_system_roots =
       GPR_GLOBAL_CONFIG_GET(grpc_not_use_system_ssl_roots);
-  // First try to load the roots from the configuration.
-  UniquePtr<char> default_root_certs_path =
-      GPR_GLOBAL_CONFIG_GET(grpc_default_ssl_roots_file_path);
-  if (strlen(default_root_certs_path.get()) > 0) {
-    GRPC_LOG_IF_ERROR(
-        "load_file", grpc_load_file(default_root_certs_path.get(), 1, &result));
+  // First try to load the roots from the environment.
+  char* default_root_certs_path =
+      gpr_getenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR);
+  if (default_root_certs_path != nullptr) {
+    GRPC_LOG_IF_ERROR("load_file",
+                      grpc_load_file(default_root_certs_path, 1, &result));
+    gpr_free(default_root_certs_path);
   }
   // Try overridden roots if needed.
   grpc_ssl_roots_override_result ovrd_res = GRPC_SSL_ROOTS_OVERRIDE_FAIL;

src/core/lib/security/security_connector/ssl_utils.h

@@ -26,7 +26,6 @@
 #include <grpc/grpc_security.h>
 #include <grpc/slice_buffer.h>
 
-#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/security/security_connector/security_connector.h"
@@ -34,10 +33,7 @@
 #include "src/core/tsi/transport_security.h"
 #include "src/core/tsi/transport_security_interface.h"
 
-GPR_GLOBAL_CONFIG_DECLARE_STRING(grpc_default_ssl_roots_file_path);
-GPR_GLOBAL_CONFIG_DECLARE_BOOL(grpc_not_use_system_ssl_roots);
-
-/* --- Util --- */
+/* --- Util. --- */
 
 /* --- URL schemes. --- */
 #define GRPC_SSL_URL_SCHEME "https"

src/core/lib/surface/init.cc

@@ -154,7 +154,7 @@ void grpc_init(void) {
      * at the appropriate time */
     grpc_register_security_filters();
     register_builtin_channel_init();
-    grpc_tracer_init();
+    grpc_tracer_init("GRPC_TRACE");
     /* no more changes to channel init pipelines */
     grpc_channel_init_finalize();
     grpc_iomgr_start();

src/objective-c/GRPCClient/private/GRPCSecureChannelFactory.m

@@ -61,7 +61,8 @@
     NSBundle *resourceBundle = [NSBundle
         bundleWithURL:[[bundle resourceURL] URLByAppendingPathComponent:resourceBundlePath]];
     NSString *path = [resourceBundle pathForResource:rootsPEM ofType:@"pem"];
-    setenv("GRPC_DEFAULT_SSL_ROOTS_FILE_PATH", [path cStringUsingEncoding:NSUTF8StringEncoding], 1);
+    setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR,
+           [path cStringUsingEncoding:NSUTF8StringEncoding], 1);
   });
 
   NSData *rootsASCII = nil;

src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.mm

@@ -37,11 +37,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
@@ -172,7 +172,7 @@ static char *roots_filename;
   GPR_ASSERT(roots_file != NULL);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
 

src/python/grpcio/grpc_core_dependencies.py

@@ -386,7 +386,6 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
-    'src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc',
     'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
     'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
     'src/core/ext/filters/census/grpc_context.cc',

test/core/bad_connection/close_fd_test.cc

@@ -39,6 +39,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/completion_queue.h"

test/core/bad_ssl/bad_ssl_test.cc

@@ -25,9 +25,9 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/util/port.h"
 #include "test/core/util/subprocess.h"
@@ -133,7 +133,7 @@ int main(int argc, char** argv) {
     strcpy(root, ".");
   }
   if (argc == 2) {
-    GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, argv[1]);
+    gpr_setenv("GRPC_DEFAULT_SSL_ROOTS_FILE_PATH", argv[1]);
   }
   /* figure out our test name */
   tmp = lunder - 1;

test/core/client_channel/resolvers/dns_resolver_test.cc

@@ -21,8 +21,8 @@
 #include <grpc/support/log.h>
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "test/core/util/test_config.h"
@@ -78,13 +78,13 @@ int main(int argc, char** argv) {
   test_succeeds(dns, "dns:10.2.1.1:1234");
   test_succeeds(dns, "dns:www.google.com");
   test_succeeds(dns, "dns:///www.google.com");
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (gpr_stricmp(resolver.get(), "native") == 0) {
+  char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver_env != nullptr && gpr_stricmp(resolver_env, "native") == 0) {
     test_fails(dns, "dns://8.8.8.8/8.8.8.8:8888");
   } else {
     test_succeeds(dns, "dns://8.8.8.8/8.8.8.8:8888");
   }
+  gpr_free(resolver_env);
   {
     grpc_core::ExecCtx exec_ctx;
     GRPC_COMBINER_UNREF(g_combiner, "test");

test/core/end2end/fixtures/h2_full+trace.cc

@@ -33,7 +33,7 @@
 #include "src/core/ext/filters/http/server/http_server_filter.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/connected_channel.h"
-#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/server.h"
@@ -105,7 +105,7 @@ int main(int argc, char** argv) {
 
   /* force tracing on, with a value to force many
      code paths in trace.c to be taken */
-  GPR_GLOBAL_CONFIG_SET(grpc_trace, "doesnt-exist,http,all");
+  gpr_setenv("GRPC_TRACE", "doesnt-exist,http,all");
 
 #ifdef GRPC_POSIX_SOCKET
   g_fixture_slowdown_factor = isatty(STDOUT_FILENO) ? 10 : 1;

test/core/end2end/fixtures/h2_sockpair+trace.cc

@@ -35,7 +35,7 @@
 #include "src/core/ext/filters/http/server/http_server_filter.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/connected_channel.h"
-#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/surface/channel.h"
@@ -133,8 +133,7 @@ int main(int argc, char** argv) {
 
   /* force tracing on, with a value to force many
      code paths in trace.c to be taken */
-  GPR_GLOBAL_CONFIG_SET(grpc_trace, "doesnt-exist,http,all");
-
+  gpr_setenv("GRPC_TRACE", "doesnt-exist,http,all");
 #ifdef GRPC_POSIX_SOCKET
   g_fixture_slowdown_factor = isatty(STDOUT_FILENO) ? 10 : 1;
 #else

test/core/end2end/fixtures/h2_spiffe.cc

@@ -35,7 +35,6 @@
 #include "src/core/lib/gprpp/thd.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/credentials/tls/grpc_tls_credentials_options.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
@@ -278,7 +277,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
   grpc_init();
   for (size_t ind = 0; ind < sizeof(configs) / sizeof(*configs); ind++) {
     grpc_end2end_tests(argc, argv, configs[ind]);

test/core/end2end/fixtures/h2_ssl.cc

@@ -25,11 +25,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
@@ -167,7 +167,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
 

test/core/end2end/fixtures/h2_ssl_cred_reload.cc

@@ -25,11 +25,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
@@ -190,7 +190,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
 

test/core/end2end/fixtures/h2_ssl_proxy.cc

@@ -25,11 +25,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/end2end/fixtures/proxy.h"
 #include "test/core/util/port.h"
@@ -208,7 +208,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
 

test/core/end2end/h2_ssl_cert_test.cc

@@ -25,11 +25,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
@@ -366,7 +366,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
   ::testing::InitGoogleTest(&argc, argv);

test/core/end2end/h2_ssl_session_reuse_test.cc

@@ -25,11 +25,11 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/security/credentials/credentials.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
@@ -265,7 +265,7 @@ int main(int argc, char** argv) {
   GPR_ASSERT(roots_file != nullptr);
   GPR_ASSERT(fwrite(test_root_cert, 1, roots_size, roots_file) == roots_size);
   fclose(roots_file);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, roots_filename);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_filename);
 
   grpc_init();
   ::testing::InitGoogleTest(&argc, argv);

test/core/end2end/tests/keepalive_timeout.cc

@@ -28,15 +28,11 @@
 
 #include "src/core/ext/transport/chttp2/transport/frame_ping.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/iomgr/iomgr.h"
 #include "test/core/end2end/cq_verifier.h"
 
-#ifdef GRPC_POSIX_SOCKET
-#include "src/core/lib/iomgr/ev_posix.h"
-#endif  // GRPC_POSIX_SOCKET
-
 static void* tag(intptr_t t) { return (void*)t; }
 
 static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
@@ -229,13 +225,13 @@ static void test_keepalive_timeout(grpc_end2end_test_config config) {
  * 200ms. In the success case, each ping ack should reset the keepalive timer so
  * that the keepalive ping is never sent. */
 static void test_read_delays_keepalive(grpc_end2end_test_config config) {
-#ifdef GRPC_POSIX_SOCKET
-  grpc_core::UniquePtr<char> poller = GPR_GLOBAL_CONFIG_GET(grpc_poll_strategy);
+  char* poller = gpr_getenv("GRPC_POLL_STRATEGY");
   /* It is hard to get the timing right for the polling engine poll. */
-  if ((0 == strcmp(poller.get(), "poll"))) {
+  if (poller != nullptr && (0 == strcmp(poller, "poll"))) {
+    gpr_free(poller);
     return;
   }
-#endif  // GRPC_POSIX_SOCKET
+  gpr_free(poller);
   const int kPingIntervalMS = 100;
   grpc_arg keepalive_arg_elems[3];
   keepalive_arg_elems[0].type = GRPC_ARG_INTEGER;

test/core/gpr/log_test.cc

@@ -21,14 +21,9 @@
 #include <stdbool.h>
 #include <string.h>
 
-#include "src/core/lib/gprpp/global_config.h"
+#include "src/core/lib/gpr/env.h"
 #include "test/core/util/test_config.h"
 
-// Config declaration is supposed to be located at log.h but
-// log.h doesn't include global_config headers because it has to
-// be a strict C so declaration statement gets to be here.
-GPR_GLOBAL_CONFIG_DECLARE_STRING(grpc_verbosity);
-
 static bool log_func_reached = false;
 
 static void test_callback(gpr_log_func_args* args) {
@@ -72,7 +67,7 @@ int main(int argc, char** argv) {
 
   /* gpr_log_verbosity_init() will be effective only once, and only before
    * gpr_set_log_verbosity() is called */
-  GPR_GLOBAL_CONFIG_SET(grpc_verbosity, "ERROR");
+  gpr_setenv("GRPC_VERBOSITY", "ERROR");
   gpr_log_verbosity_init();
 
   test_log_function_reached(GPR_ERROR);
@@ -80,7 +75,7 @@ int main(int argc, char** argv) {
   test_log_function_unreached(GPR_DEBUG);
 
   /* gpr_log_verbosity_init() should not be effective */
-  GPR_GLOBAL_CONFIG_SET(grpc_verbosity, "DEBUG");
+  gpr_setenv("GRPC_VERBOSITY", "DEBUG");
   gpr_log_verbosity_init();
   test_log_function_reached(GPR_ERROR);
   test_log_function_unreached(GPR_INFO);
@@ -102,7 +97,7 @@ int main(int argc, char** argv) {
   test_log_function_unreached(GPR_DEBUG);
 
   /* gpr_log_verbosity_init() should not be effective */
-  GPR_GLOBAL_CONFIG_SET(grpc_verbosity, "DEBUG");
+  gpr_setenv("GRPC_VERBOSITY", "DEBUG");
   gpr_log_verbosity_init();
   test_log_function_reached(GPR_ERROR);
   test_log_function_unreached(GPR_INFO);

test/core/http/httpscli_test.cc

@@ -29,7 +29,6 @@
 
 #include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/iomgr.h"
-#include "src/core/lib/security/security_connector/ssl_utils.h"
 #include "test/core/util/port.h"
 #include "test/core/util/subprocess.h"
 #include "test/core/util/test_config.h"
@@ -185,7 +184,7 @@ int main(int argc, char** argv) {
   /* Set the environment variable for the SSL certificate file */
   char* pem_file;
   gpr_asprintf(&pem_file, "%s/src/core/tsi/test_creds/ca.pem", root);
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, pem_file);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, pem_file);
   gpr_free(pem_file);
 
   /* start the server */

test/core/iomgr/resolve_address_posix_test.cc

@@ -29,7 +29,6 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/useful.h"
@@ -225,16 +224,15 @@ int main(int argc, char** argv) {
   // --resolver will always be the first one, so only parse the first argument
   // (other arguments may be unknown to cl)
   gpr_cmdline_parse(cl, argc > 2 ? 2 : argc, argv);
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (strlen(resolver.get()) != 0) {
+  const char* cur_resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (cur_resolver != nullptr && strlen(cur_resolver) != 0) {
     gpr_log(GPR_INFO, "Warning: overriding resolver setting of %s",
-            resolver.get());
+            cur_resolver);
   }
   if (gpr_stricmp(resolver_type, "native") == 0) {
-    GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "native");
+    gpr_setenv("GRPC_DNS_RESOLVER", "native");
   } else if (gpr_stricmp(resolver_type, "ares") == 0) {
-    GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "ares");
+    gpr_setenv("GRPC_DNS_RESOLVER", "ares");
   } else {
     gpr_log(GPR_ERROR, "--resolver_type was not set to ares or native");
     abort();
@@ -248,12 +246,12 @@ int main(int argc, char** argv) {
     // c-ares resolver doesn't support UDS (ability for native DNS resolver
     // to handle this is only expected to be used by servers, which
     // unconditionally use the native DNS resolver).
-    grpc_core::UniquePtr<char> resolver =
-        GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-    if (gpr_stricmp(resolver.get(), "native") == 0) {
+    char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
+    if (resolver_env == nullptr || gpr_stricmp(resolver_env, "native") == 0) {
       test_unix_socket();
       test_unix_socket_path_name_too_long();
     }
+    gpr_free(resolver_env);
   }
   gpr_cmdline_destroy(cl);
 

test/core/iomgr/resolve_address_test.cc

@@ -27,7 +27,7 @@
 
 #include <string.h>
 
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr.h"
@@ -347,17 +347,16 @@ int main(int argc, char** argv) {
   // --resolver will always be the first one, so only parse the first argument
   // (other arguments may be unknown to cl)
   gpr_cmdline_parse(cl, argc > 2 ? 2 : argc, argv);
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (strlen(resolver.get()) != 0) {
+  const char* cur_resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (cur_resolver != nullptr && strlen(cur_resolver) != 0) {
     gpr_log(GPR_INFO, "Warning: overriding resolver setting of %s",
-            resolver.get());
+            cur_resolver);
   }
   if (gpr_stricmp(resolver_type, "native") == 0) {
-    GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "native");
+    gpr_setenv("GRPC_DNS_RESOLVER", "native");
   } else if (gpr_stricmp(resolver_type, "ares") == 0) {
 #ifndef GRPC_UV
-    GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "ares");
+    gpr_setenv("GRPC_DNS_RESOLVER", "ares");
 #endif
   } else {
     gpr_log(GPR_ERROR, "--resolver_type was not set to ares or native");

test/core/security/credentials_test.cc

@@ -1161,7 +1161,7 @@ static void test_get_well_known_google_credentials_file_path(void) {
   GPR_ASSERT(path != nullptr);
   gpr_free(path);
 #if defined(GPR_POSIX_ENV) || defined(GPR_LINUX_ENV)
-  gpr_unsetenv("HOME");
+  unsetenv("HOME");
   path = grpc_get_well_known_google_credentials_file_path();
   GPR_ASSERT(path == nullptr);
   gpr_setenv("HOME", home);

test/core/security/security_connector_test.cc

@@ -24,6 +24,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/tmpfile.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
@@ -393,7 +394,7 @@ static void test_default_ssl_roots(void) {
 
   /* First let's get the root through the override: set the env to an invalid
      value. */
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, "");
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, "");
   grpc_set_ssl_roots_override_callback(override_roots_success);
   grpc_slice roots =
       grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
@@ -404,8 +405,7 @@ static void test_default_ssl_roots(void) {
 
   /* Now let's set the env var: We should get the contents pointed value
      instead. */
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path,
-                        roots_env_var_file_path);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, roots_env_var_file_path);
   roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
   roots_contents = grpc_slice_to_c_string(roots);
   grpc_slice_unref(roots);
@@ -414,7 +414,7 @@ static void test_default_ssl_roots(void) {
 
   /* Now reset the env var. We should fall back to the value overridden using
      the api. */
-  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, "");
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, "");
   roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
   roots_contents = grpc_slice_to_c_string(roots);
   grpc_slice_unref(roots);
@@ -423,7 +423,7 @@ static void test_default_ssl_roots(void) {
 
   /* Now setup a permanent failure for the overridden roots and we should get
      an empty slice. */
-  GPR_GLOBAL_CONFIG_SET(grpc_not_use_system_ssl_roots, true);
+  gpr_setenv("GRPC_NOT_USE_SYSTEM_SSL_ROOTS", "true");
   grpc_set_ssl_roots_override_callback(override_roots_permanent_failure);
   roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
   GPR_ASSERT(GRPC_SLICE_IS_EMPTY(roots));

test/core/util/test_config.cc

@@ -28,6 +28,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/surface/init.h"

test/cpp/end2end/async_end2end_test.cc

@@ -33,6 +33,7 @@
 #include <grpcpp/server_context.h>
 
 #include "src/core/ext/filters/client_channel/backup_poller.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/tls.h"
 #include "src/core/lib/iomgr/port.h"
 #include "src/proto/grpc/health/v1/health.grpc.pb.h"
@@ -43,10 +44,6 @@
 #include "test/cpp/util/string_ref_helper.h"
 #include "test/cpp/util/test_credentials_provider.h"
 
-#ifdef GRPC_POSIX_SOCKET
-#include "src/core/lib/iomgr/ev_posix.h"
-#endif  // GRPC_POSIX_SOCKET
-
 #include <gtest/gtest.h>
 
 using grpc::testing::EchoRequest;
@@ -362,14 +359,13 @@ TEST_P(AsyncEnd2endTest, ReconnectChannel) {
     return;
   }
   int poller_slowdown_factor = 1;
-#ifdef GRPC_POSIX_SOCKET
   // It needs 2 pollset_works to reconnect the channel with polling engine
   // "poll"
-  grpc_core::UniquePtr<char> poller = GPR_GLOBAL_CONFIG_GET(grpc_poll_strategy);
-  if (0 == strcmp(poller.get(), "poll")) {
+  char* s = gpr_getenv("GRPC_POLL_STRATEGY");
+  if (s != nullptr && 0 == strcmp(s, "poll")) {
     poller_slowdown_factor = 2;
   }
-#endif  // GRPC_POSIX_SOCKET
+  gpr_free(s);
   ResetStub();
   SendRpc(1);
   server_->Shutdown();

test/cpp/end2end/end2end_test.cc

@@ -35,6 +35,7 @@
 #include <grpcpp/server_context.h>
 
 #include "src/core/ext/filters/client_channel/backup_poller.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.h"
@@ -46,10 +47,6 @@
 #include "test/cpp/util/string_ref_helper.h"
 #include "test/cpp/util/test_credentials_provider.h"
 
-#ifdef GRPC_POSIX_SOCKET
-#include "src/core/lib/iomgr/ev_posix.h"
-#endif  // GRPC_POSIX_SOCKET
-
 #include <gtest/gtest.h>
 
 using grpc::testing::EchoRequest;
@@ -812,12 +809,11 @@ TEST_P(End2endTest, ReconnectChannel) {
   int poller_slowdown_factor = 1;
   // It needs 2 pollset_works to reconnect the channel with polling engine
   // "poll"
-#ifdef GRPC_POSIX_SOCKET
-  grpc_core::UniquePtr<char> poller = GPR_GLOBAL_CONFIG_GET(grpc_poll_strategy);
-  if (0 == strcmp(poller.get(), "poll")) {
+  char* s = gpr_getenv("GRPC_POLL_STRATEGY");
+  if (s != nullptr && 0 == strcmp(s, "poll")) {
     poller_slowdown_factor = 2;
   }
-#endif  // GRPC_POSIX_SOCKET
+  gpr_free(s);
   ResetStub();
   SendRpc(stub_.get(), 1, false);
   RestartServer(std::shared_ptr<AuthMetadataProcessor>());

test/cpp/naming/address_sorting_test.cc

@@ -36,10 +36,10 @@
 #include "src/core/ext/filters/client_channel/client_channel.h"
 #include "src/core/ext/filters/client_channel/resolver.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/filters/client_channel/server_address.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -829,13 +829,13 @@ TEST_F(AddressSortingTest, TestSorterKnowsIpv6LoopbackIsAvailable) {
 }  // namespace
 
 int main(int argc, char** argv) {
-  grpc_core::UniquePtr<char> resolver =
-      GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
-  if (strlen(resolver.get()) == 0) {
-    GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "ares");
-  } else if (strcmp("ares", resolver.get())) {
-    gpr_log(GPR_INFO, "GRPC_DNS_RESOLVER != ares: %s.", resolver.get());
+  char* resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver == nullptr || strlen(resolver) == 0) {
+    gpr_setenv("GRPC_DNS_RESOLVER", "ares");
+  } else if (strcmp("ares", resolver)) {
+    gpr_log(GPR_INFO, "GRPC_DNS_RESOLVER != ares: %s.", resolver);
   }
+  gpr_free(resolver);
   grpc::testing::TestEnvironment env(argc, argv);
   ::testing::InitGoogleTest(&argc, argv);
   auto result = RUN_ALL_TESTS();

test/cpp/naming/cancel_ares_query_test.cc

@@ -29,10 +29,10 @@
 #include <grpc/support/time.h>
 #include "include/grpc/support/string_util.h"
 #include "src/core/ext/filters/client_channel/resolver.h"
-#include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/orphanable.h"
@@ -374,7 +374,7 @@ TEST(
 int main(int argc, char** argv) {
   grpc::testing::TestEnvironment env(argc, argv);
   ::testing::InitGoogleTest(&argc, argv);
-  GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "ares");
+  gpr_setenv("GRPC_DNS_RESOLVER", "ares");
   // Sanity check the time that it takes to run the test
   // including the teardown time (the teardown
   // part of the test involves cancelling the DNS query,

test/cpp/naming/resolver_component_test.cc

@@ -46,6 +46,7 @@
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/filters/client_channel/server_address.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/orphanable.h"

tools/doxygen/Doxyfile.core.internal

@@ -953,8 +953,6 @@ src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
-src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc \
-src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h \
 src/core/ext/filters/client_channel/resolver/dns/native/README.md \
 src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
 src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc \

tools/run_tests/generated/sources_and_headers.json

@@ -9252,8 +9252,7 @@
     "deps": [
       "gpr", 
       "grpc_base", 
-      "grpc_client_channel", 
-      "grpc_resolver_dns_selection"
+      "grpc_client_channel"
     ], 
     "headers": [
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h", 
@@ -9286,8 +9285,7 @@
     "deps": [
       "gpr", 
       "grpc_base", 
-      "grpc_client_channel", 
-      "grpc_resolver_dns_selection"
+      "grpc_client_channel"
     ], 
     "headers": [], 
     "is_filegroup": true, 
@@ -9299,24 +9297,6 @@
     "third_party": false, 
     "type": "filegroup"
   }, 
-  {
-    "deps": [
-      "gpr", 
-      "grpc_base"
-    ], 
-    "headers": [
-      "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
-    ], 
-    "is_filegroup": true, 
-    "language": "c", 
-    "name": "grpc_resolver_dns_selection", 
-    "src": [
-      "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.cc", 
-      "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
-    ], 
-    "third_party": false, 
-    "type": "filegroup"
-  }, 
   {
     "deps": [
       "gpr", 

tools/run_tests/run_microbenchmark.py

@@ -96,7 +96,7 @@ def collect_latency(bm_name, args):
                     '--benchmark_filter=^%s$' % line,
                     '--benchmark_min_time=0.05'
                 ],
-                environ={'GRPC_LATENCY_TRACE': '%s.trace' % fnize(line)},
+                environ={'LATENCY_TRACE': '%s.trace' % fnize(line)},
                 shortname='profile-%s' % fnize(line)))
         profile_analysis.append(
             jobset.JobSpec(

tools/run_tests/sanity/core_banned_functions.py

@@ -45,6 +45,10 @@ BANNED_EXCEPT = {
     'grpc_closure_sched(': ['src/core/lib/iomgr/closure.cc'],
     'grpc_closure_run(': ['src/core/lib/iomgr/closure.cc'],
     'grpc_closure_list_sched(': ['src/core/lib/iomgr/closure.cc'],
+    'gpr_getenv_silent(': [
+        'src/core/lib/gpr/log.cc', 'src/core/lib/gpr/env_linux.cc',
+        'src/core/lib/gpr/env_posix.cc', 'src/core/lib/gpr/env_windows.cc'
+    ],
 }
 
 errors = 0