Add cares glue for libuv event loop

BUILD

@@ -1552,10 +1552,12 @@ grpc_cc_library(
     srcs = [
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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",
     ],

BUILD.gn

@@ -309,11 +309,13 @@ config("grpc_config") {
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
         "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_ev_driver_libuv.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
         "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_fallback.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc",

CMakeLists.txt

@@ -1281,10 +1281,12 @@ add_library(grpc
   src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc
@@ -2650,10 +2652,12 @@ add_library(grpc_unsecure
   src/core/ext/transport/inproc/inproc_transport.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc

Makefile

@@ -3736,10 +3736,12 @@ LIBGRPC_SRC = \
     src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc \
@@ -5053,10 +5055,12 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/transport/inproc/inproc_transport.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc \

build.yaml

@@ -781,10 +781,12 @@ filegroups:
   src:
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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
   plugin: grpc_resolver_dns_ares

config.m4

@@ -396,10 +396,12 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc \

config.w32

@@ -371,10 +371,12 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\client_channel\\lb_policy\\round_robin\\round_robin.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\dns_resolver_ares.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_libuv.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_posix.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_fallback.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_libuv.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\\native\\dns_resolver.cc " +

gRPC-Core.podspec

@@ -843,10 +843,12 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc',

grpc.gemspec

@@ -780,10 +780,12 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc )

grpc.gyp

@@ -578,10 +578,12 @@
         'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc',
@@ -1317,10 +1319,12 @@
         'src/core/ext/transport/inproc/inproc_transport.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc',

package.xml

@@ -785,10 +785,12 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc" role="src" />

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

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include <limits.h>
 #include <stdio.h>
@@ -464,10 +464,10 @@ void grpc_resolver_dns_ares_shutdown() {
   gpr_free(resolver_env);
 }
 
-#else /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#else /* GRPC_ARES == 1 */
 
 void grpc_resolver_dns_ares_init(void) {}
 
 void grpc_resolver_dns_ares_shutdown(void) {}
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

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

@@ -18,7 +18,7 @@
 #include <grpc/support/port_platform.h>
 
 #include "src/core/lib/iomgr/port.h"
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include <ares.h>
 #include <string.h>
@@ -218,6 +218,7 @@ static void on_timeout_locked(void* arg, grpc_error* error) {
 
 static void on_readable_locked(void* arg, grpc_error* error) {
   fd_node* fdn = static_cast<fd_node*>(arg);
+  GPR_ASSERT(fdn->readable_registered);
   grpc_ares_ev_driver* ev_driver = fdn->ev_driver;
   const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked();
   fdn->readable_registered = false;
@@ -242,6 +243,7 @@ static void on_readable_locked(void* arg, grpc_error* error) {
 
 static void on_writable_locked(void* arg, grpc_error* error) {
   fd_node* fdn = static_cast<fd_node*>(arg);
+  GPR_ASSERT(fdn->writable_registered);
   grpc_ares_ev_driver* ev_driver = fdn->ev_driver;
   const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked();
   fdn->writable_registered = false;
@@ -365,4 +367,4 @@ void grpc_ares_ev_driver_start_locked(grpc_ares_ev_driver* ev_driver) {
   }
 }
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

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

@@ -0,0 +1,134 @@
+/*
+ *
+ * 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.
+ *
+ */
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GRPC_UV)
+
+#include <ares.h>
+#include <uv.h>
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/gpr/string.h"
+
+namespace grpc_core {
+
+void ares_uv_poll_cb(uv_poll_t* handle, int status, int events);
+
+void ares_uv_poll_close_cb(uv_handle_t *handle) {
+  delete handle;
+}
+
+class GrpcPolledFdLibuv : public GrpcPolledFd {
+ public:
+  GrpcPolledFdLibuv(ares_socket_t as): as_(as) {
+    gpr_asprintf(&name_, "c-ares socket: %" PRIdPTR, (intptr_t)as);
+    handle_ = new uv_poll_t;
+    uv_poll_init_socket(uv_default_loop(), handle_, as);
+    handle_->data = this;
+  }
+
+  ~GrpcPolledFdLibuv() {
+    gpr_free(name_);
+  }
+
+  void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
+    GPR_ASSERT(read_closure_ == nullptr);
+    GPR_ASSERT((poll_events_ & UV_READABLE) == 0);
+    read_closure_ = read_closure;
+    poll_events_ |= UV_READABLE;
+    uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
+  }
+
+  void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
+    GPR_ASSERT(write_closure_ == nullptr);
+    GPR_ASSERT((poll_events_ & UV_WRITABLE) == 0);
+    write_closure_ = write_closure;
+    poll_events_ |= UV_WRITABLE;
+    uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
+  }
+
+  bool IsFdStillReadableLocked() override {
+    /* uv_poll_t is based on poll, which is level triggered. So, if cares
+     * leaves some data unread, the event will trigger again. */
+    return false;
+  }
+
+  void ShutdownLocked(grpc_error* error) override {
+    uv_poll_stop(handle_);
+    uv_close(reinterpret_cast<uv_handle_t*>(handle_), ares_uv_poll_close_cb);
+  }
+
+  ares_socket_t GetWrappedAresSocketLocked() override { return as_; }
+
+  const char* GetName() override { return name_; }
+
+  char* name_;
+  ares_socket_t as_;
+  uv_poll_t* handle_;
+  grpc_closure* read_closure_ = nullptr;
+  grpc_closure* write_closure_ = nullptr;
+  int poll_events_ = 0;
+};
+
+void ares_uv_poll_cb(uv_poll_t* handle, int status, int events) {
+  grpc_core::ExecCtx exec_ctx;
+  GrpcPolledFdLibuv* polled_fd = reinterpret_cast<GrpcPolledFdLibuv*>(handle->data);
+  grpc_error *error = GRPC_ERROR_NONE;
+  if (status < 0) {
+    error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("cares polling error");
+    error = grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR,
+                               grpc_slice_from_static_string(uv_strerror(status)));
+  }
+  if ((events & UV_READABLE) && polled_fd->read_closure_) {
+    GRPC_CLOSURE_SCHED(polled_fd->read_closure_, error);
+    polled_fd->read_closure_ = nullptr;
+    polled_fd->poll_events_ &= ~UV_READABLE;
+  }
+  if ((events & UV_WRITABLE) && polled_fd->write_closure_) {
+    GRPC_CLOSURE_SCHED(polled_fd->write_closure_, error);
+    polled_fd->write_closure_ = nullptr;
+    polled_fd->poll_events_ &= ~UV_WRITABLE;
+  }
+  uv_poll_start(handle, polled_fd->poll_events_, ares_uv_poll_cb);
+}
+
+class GrpcPolledFdFactoryLibuv : public GrpcPolledFdFactory {
+ public:
+  GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
+                                      grpc_pollset_set* driver_pollset_set,
+                                      grpc_combiner* combiner) override {
+    return New<GrpcPolledFdLibuv>(as);
+  }
+
+  void ConfigureAresChannelLocked(ares_channel channel) override {}
+};
+
+UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner) {
+  return UniquePtr<GrpcPolledFdFactory>(New<GrpcPolledFdFactoryLibuv>());
+}
+
+} // namespace grpc_core
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_UV) */

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

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/iomgr/sockaddr.h"
@@ -687,4 +687,4 @@ void (*grpc_resolve_address_ares)(
     grpc_pollset_set* interested_parties, grpc_closure* on_done,
     grpc_resolved_addresses** addrs) = grpc_resolve_address_ares_impl;
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

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

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES != 1 || defined(GRPC_UV)
+#if GRPC_ARES != 1
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 
@@ -62,4 +62,4 @@ void (*grpc_resolve_address_ares)(
     grpc_pollset_set* interested_parties, grpc_closure* on_done,
     grpc_resolved_addresses** addrs) = grpc_resolve_address_ares_impl;
 
-#endif /* GRPC_ARES != 1 || defined(GRPC_UV) */
+#endif /* GRPC_ARES != 1 */

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

@@ -0,0 +1,103 @@
+/*
+ *
+ * Copyright 2016 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GRPC_UV)
+
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/server_address.h"
+#include "src/core/lib/gpr/host_port.h"
+#include "src/core/lib/gpr/string.h"
+
+bool grpc_ares_query_ipv6() { 
+  /* The libuv grpc code currently does not have the code to probe for this,
+   * so we assume for nowthat IPv6 is always available in contexts where this
+   * code will be used. */
+  return true; 
+}
+
+/* The following two functions were copied entirely from the Windows file. This
+ * code can run on Windows so it can have the same problem. */
+static bool inner_maybe_resolve_localhost_manually_locked(
+    const char* name, const char* default_port,
+    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, char** host,
+    char** port) {
+  gpr_split_host_port(name, host, port);
+  if (*host == nullptr) {
+    gpr_log(GPR_ERROR,
+            "Failed to parse %s into host:port during Windows localhost "
+            "resolution check.",
+            name);
+    return false;
+  }
+  if (*port == nullptr) {
+    if (default_port == nullptr) {
+      gpr_log(GPR_ERROR,
+              "No port or default port for %s during Windows localhost "
+              "resolution check.",
+              name);
+      return false;
+    }
+    *port = gpr_strdup(default_port);
+  }
+  if (gpr_stricmp(*host, "localhost") == 0) {
+    GPR_ASSERT(*addrs == nullptr);
+    *addrs = grpc_core::MakeUnique<grpc_core::ServerAddressList>();
+    uint16_t numeric_port = grpc_strhtons(*port);
+    // Append the ipv6 loopback address.
+    struct sockaddr_in6 ipv6_loopback_addr;
+    memset(&ipv6_loopback_addr, 0, sizeof(ipv6_loopback_addr));
+    ((char*)&ipv6_loopback_addr.sin6_addr)[15] = 1;
+    ipv6_loopback_addr.sin6_family = AF_INET6;
+    ipv6_loopback_addr.sin6_port = numeric_port;
+    (*addrs)->emplace_back(&ipv6_loopback_addr, sizeof(ipv6_loopback_addr),
+                           nullptr /* args */);
+    // Append the ipv4 loopback address.
+    struct sockaddr_in ipv4_loopback_addr;
+    memset(&ipv4_loopback_addr, 0, sizeof(ipv4_loopback_addr));
+    ((char*)&ipv4_loopback_addr.sin_addr)[0] = 0x7f;
+    ((char*)&ipv4_loopback_addr.sin_addr)[3] = 0x01;
+    ipv4_loopback_addr.sin_family = AF_INET;
+    ipv4_loopback_addr.sin_port = numeric_port;
+    (*addrs)->emplace_back(&ipv4_loopback_addr, sizeof(ipv4_loopback_addr),
+                           nullptr /* args */);
+    // Let the address sorter figure out which one should be tried first.
+    grpc_cares_wrapper_address_sorting_sort(addrs->get());
+    return true;
+  }
+  return false;
+}
+
+bool grpc_ares_maybe_resolve_localhost_manually_locked(
+    const char* name, const char* default_port,
+    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs) {
+  char* host = nullptr;
+  char* port = nullptr;
+  bool out = inner_maybe_resolve_localhost_manually_locked(name, default_port,
+                                                           addrs, &host, &port);
+  gpr_free(host);
+  gpr_free(port);
+  return out;
+}
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_UV) */

src/python/grpcio/grpc_core_dependencies.py

@@ -370,10 +370,12 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+    'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+    'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/dns_resolver.cc',

tools/doxygen/Doxyfile.core.internal

@@ -942,11 +942,13 @@ src/core/ext/filters/client_channel/resolver/README.md \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
 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_ev_driver_libuv.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
 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_fallback.cc \
+src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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/native/README.md \

tools/run_tests/generated/sources_and_headers.json

@@ -9084,11 +9084,13 @@
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc", 
       "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_ev_driver_libuv.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc", 
       "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_fallback.cc", 
+      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.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"
     ],