Turn off c_ares resolver by default

doc/environment_variables.md

@@ -74,6 +74,6 @@ some configuration as environment variables that can be set.
   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.
   Available DNS resolver include:
-  - ares (default) - a DNS resolver based around the c-ares library
+  - native (default)- a DNS resolver based around getaddrinfo(), creates a new thread to
-  - native - a DNS resolver based around getaddrinfo(), creates a new thread to
     perform name resolution
+  - ares - a DNS resolver based around the c-ares library

src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c

@@ -369,7 +369,9 @@ static grpc_resolver_factory *dns_ares_resolver_factory_create() {
 
 void grpc_resolver_dns_ares_init(void) {
   char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
-  if (resolver == NULL || gpr_stricmp(resolver, "ares") == 0) {
+  /* TODO(zyc): Turn on c-ares based resolver by default after the address
+     sorter is added. */
+  if (resolver != NULL && gpr_stricmp(resolver, "ares") == 0) {
     grpc_error *error = grpc_ares_init();
     if (error != GRPC_ERROR_NONE) {
       GRPC_LOG_IF_ERROR("ares_library_init() failed", error);

src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_fallback.c

@@ -1,58 +0,0 @@
-/*
- *
- * 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 <grpc/support/port_platform.h>
-#include "src/core/lib/iomgr/port.h"
-#if !(GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET))
-
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
-
-struct grpc_ares_ev_driver {
-  char unused_member;  // unused member to prevent undefined behaviour
-};
-
-void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx,
-                               grpc_ares_ev_driver *ev_driver) {}
-
-ares_channel *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver) {
-  return NULL;
-}
-
-grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver,
-                                       grpc_pollset_set *pollset_set) {
-  return GRPC_ERROR_NONE;
-}
-
-void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver) {}
-
-#endif /* !(GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET)) */

src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c

@@ -98,7 +98,7 @@ static void grpc_ares_request_unref(grpc_exec_ctx *exec_ctx,
   /* If there are no pending queries, invoke on_done callback and destroy the
      request */
   if (gpr_unref(&r->pending_queries)) {
-    /* TODO(zyc): Sort results with RPC6724 before invoking on_done. */
+    /* TODO(zyc): Sort results with RFC6724 before invoking on_done. */
     if (exec_ctx == NULL) {
       /* A new exec_ctx is created here, as the c-ares interface does not
          provide one in ares_host_callback. It's safe to schedule on_done with

src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c

@@ -1,60 +0,0 @@
-/*
- *
- * 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.
- *
- */
-
-/* TODO(zyc): remove this fallback after we can build c-ares on windows */
-
-#include <grpc/support/port_platform.h>
-#if !(GRPC_ARES == 1)
-
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
-
-void grpc_resolve_address_ares_impl(grpc_exec_ctx *exec_ctx, const char *name,
-                                    const char *default_port,
-                                    grpc_pollset_set *interested_parties,
-                                    grpc_closure *on_done,
-                                    grpc_resolved_addresses **addrs) {
-  grpc_resolve_address(exec_ctx, name, default_port, interested_parties,
-                       on_done, addrs);
-}
-
-void (*grpc_resolve_address_ares)(
-    grpc_exec_ctx *exec_ctx, const char *name, const char *default_port,
-    grpc_pollset_set *interested_parties, grpc_closure *on_done,
-    grpc_resolved_addresses **addrs) = grpc_resolve_address_ares_impl;
-
-grpc_error *grpc_ares_init(void) { return GRPC_ERROR_NONE; }
-
-void grpc_ares_cleanup(void) {}
-
-#endif /* GRPC_NATIVE_ADDRESS_RESOLVE */

src/core/lib/iomgr/exec_ctx.c

@@ -64,7 +64,6 @@ bool grpc_always_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored) {
 
 bool grpc_exec_ctx_flush(grpc_exec_ctx *exec_ctx) {
   bool did_something = 0;
-  gpr_log(GPR_DEBUG, "grpc_exec_ctx_flush");
   GPR_TIMER_BEGIN("grpc_exec_ctx_flush", 0);
   for (;;) {
     if (!grpc_closure_list_empty(exec_ctx->closure_list)) {

src/core/lib/iomgr/tcp_client_posix.c

@@ -35,9 +35,6 @@
 
 #ifdef GRPC_POSIX_SOCKET
 
-#include "src/core/lib/iomgr/sockaddr.h"
-#include "src/core/lib/iomgr/socket_utils_posix.h"
-
 #include "src/core/lib/iomgr/tcp_client_posix.h"
 
 #include <errno.h>
@@ -290,24 +287,6 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
 
   *ep = NULL;
 
-  struct sockaddr_in *addr4 = (struct sockaddr_in *)addr->addr;
-  if (addr4->sin_family == AF_INET) {
-    char output[INET_ADDRSTRLEN];
-    inet_ntop(AF_INET, &addr4->sin_addr, output, INET_ADDRSTRLEN);
-    gpr_log(GPR_DEBUG,
-            "native resolver gets a AF_INET result: \n"
-            "  addr: %s\n",
-            output);
-  } else {
-    struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr->addr;
-    char output[INET6_ADDRSTRLEN];
-    inet_ntop(AF_INET6, &addr6->sin6_addr, output, INET6_ADDRSTRLEN);
-    gpr_log(GPR_DEBUG,
-            "native resolver gets a AF_INET6 result: \n"
-            "  addr: %s\n, sin6_scope_id: %d\n",
-            output, addr6->sin6_scope_id);
-  }
-
   /* Use dualstack sockets where available. */
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
     addr = &addr6_v4mapped;

tools/run_tests/run_tests_matrix.py

@@ -221,19 +221,20 @@ def _create_portability_test_jobs(extra_args=[], inner_jobs=_DEFAULT_INNER_JOBS)
                                   extra_args=extra_args,
                                   inner_jobs=inner_jobs)
 
-  # C and C++ with the native DNS resolver on Linux
+  # C and C++ with the c-ares DNS resolver on Linux
   test_jobs += _generate_jobs(languages=['c', 'c++'],
                               configs=['dbg'], platforms=['linux'],
                               labels=['portability'],
                               extra_args=extra_args,
-                              extra_envs={'GRPC_DNS_RESOLVER': 'native'})
+                              extra_envs={'GRPC_DNS_RESOLVER': 'ares'})
-
+
-  # C with the native DNS resolver on Windonws
+  # TODO(zyc): Turn on this test after adding c-ares support on windows.
-  test_jobs += _generate_jobs(languages=['c'],
+  # C with the c-ares DNS resolver on Windonws
-                              configs=['dbg'], platforms=['windows'],
+  # test_jobs += _generate_jobs(languages=['c'],
-                              labels=['portability'],
+  #                             configs=['dbg'], platforms=['windows'],
-                              extra_args=extra_args,
+  #                             labels=['portability'],
-                              extra_envs={'GRPC_DNS_RESOLVER': 'native'})
+  #                             extra_args=extra_args,
+  #                             extra_envs={'GRPC_DNS_RESOLVER': 'ares'})
 
   # cmake build for C and C++
   # TODO(jtattermusch): some of the tests are failing, so we force --build_only