1 files changed, 26 insertions, 44 deletions

diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
index 7846576c11..3a870b2d06 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
@@ -96,24 +96,12 @@ static void grpc_ares_request_ref(grpc_ares_request* r) {
   gpr_ref(&r->pending_queries);
 }
 
-static void grpc_ares_request_unref(grpc_exec_ctx* exec_ctx,
-                                    grpc_ares_request* r) {
+static void grpc_ares_request_unref(grpc_ares_request* r) {
   /* 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 RFC6724 before invoking on_done. */
-    if (exec_ctx == nullptr) {
-      /* 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
-         the newly created exec_ctx, since the caller has been warned not to
-         acquire locks in on_done. ares_dns_resolver is using combiner to
-         protect resources needed by on_done. */
-      grpc_exec_ctx new_exec_ctx = GRPC_EXEC_CTX_INIT;
-      GRPC_CLOSURE_SCHED(&new_exec_ctx, r->on_done, r->error);
-      grpc_exec_ctx_finish(&new_exec_ctx);
-    } else {
-      GRPC_CLOSURE_SCHED(exec_ctx, r->on_done, r->error);
-    }
+    GRPC_CLOSURE_SCHED(r->on_done, r->error);
     gpr_mu_destroy(&r->mu);
     grpc_ares_ev_driver_destroy(r->ev_driver);
     gpr_free(r);
@@ -133,9 +121,8 @@ static grpc_ares_hostbyname_request* create_hostbyname_request(
   return hr;
 }
 
-static void destroy_hostbyname_request(grpc_exec_ctx* exec_ctx,
-                                       grpc_ares_hostbyname_request* hr) {
-  grpc_ares_request_unref(exec_ctx, hr->parent_request);
+static void destroy_hostbyname_request(grpc_ares_hostbyname_request* hr) {
+  grpc_ares_request_unref(hr->parent_request);
   gpr_free(hr->host);
   gpr_free(hr);
 }
@@ -220,13 +207,13 @@ static void on_hostbyname_done_cb(void* arg, int status, int timeouts,
     }
   }
   gpr_mu_unlock(&r->mu);
-  destroy_hostbyname_request(nullptr, hr);
+  destroy_hostbyname_request(hr);
 }
 
 static void on_srv_query_done_cb(void* arg, int status, int timeouts,
                                  unsigned char* abuf, int alen) {
   grpc_ares_request* r = (grpc_ares_request*)arg;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_core::ExecCtx exec_ctx;
   gpr_log(GPR_DEBUG, "on_query_srv_done_cb");
   if (status == ARES_SUCCESS) {
     gpr_log(GPR_DEBUG, "on_query_srv_done_cb ARES_SUCCESS");
@@ -246,7 +233,7 @@ static void on_srv_query_done_cb(void* arg, int status, int timeouts,
             r, srv_it->host, htons(srv_it->port), true /* is_balancer */);
         ares_gethostbyname(*channel, hr->host, AF_INET, on_hostbyname_done_cb,
                            hr);
-        grpc_ares_ev_driver_start(&exec_ctx, r->ev_driver);
+        grpc_ares_ev_driver_start(r->ev_driver);
       }
     }
     if (reply != nullptr) {
@@ -264,8 +251,7 @@ static void on_srv_query_done_cb(void* arg, int status, int timeouts,
       r->error = grpc_error_add_child(error, r->error);
     }
   }
-  grpc_ares_request_unref(&exec_ctx, r);
-  grpc_exec_ctx_finish(&exec_ctx);
+  grpc_ares_request_unref(r);
 }
 
 static const char g_service_config_attribute_prefix[] = "grpc_config=";
@@ -323,14 +309,13 @@ fail:
   }
 done:
   gpr_mu_unlock(&r->mu);
-  grpc_ares_request_unref(nullptr, r);
+  grpc_ares_request_unref(r);
 }
 
 static grpc_ares_request* grpc_dns_lookup_ares_impl(
-    grpc_exec_ctx* exec_ctx, const char* dns_server, const char* name,
-    const char* default_port, grpc_pollset_set* interested_parties,
-    grpc_closure* on_done, grpc_lb_addresses** addrs, bool check_grpclb,
-    char** service_config_json) {
+    const char* dns_server, const char* name, const char* default_port,
+    grpc_pollset_set* interested_parties, grpc_closure* on_done,
+    grpc_lb_addresses** addrs, bool check_grpclb, char** service_config_json) {
   grpc_error* error = GRPC_ERROR_NONE;
   grpc_ares_hostbyname_request* hr = nullptr;
   grpc_ares_request* r = nullptr;
@@ -437,28 +422,28 @@ static grpc_ares_request* grpc_dns_lookup_ares_impl(
     gpr_free(config_name);
   }
   /* TODO(zyc): Handle CNAME records here. */
-  grpc_ares_ev_driver_start(exec_ctx, r->ev_driver);
-  grpc_ares_request_unref(exec_ctx, r);
+  grpc_ares_ev_driver_start(r->ev_driver);
+  grpc_ares_request_unref(r);
   gpr_free(host);
   gpr_free(port);
   return r;
 
 error_cleanup:
-  GRPC_CLOSURE_SCHED(exec_ctx, on_done, error);
+  GRPC_CLOSURE_SCHED(on_done, error);
   gpr_free(host);
   gpr_free(port);
   return nullptr;
 }
 
 grpc_ares_request* (*grpc_dns_lookup_ares)(
-    grpc_exec_ctx* exec_ctx, const char* dns_server, const char* name,
-    const char* default_port, grpc_pollset_set* interested_parties,
-    grpc_closure* on_done, grpc_lb_addresses** addrs, bool check_grpclb,
+    const char* dns_server, const char* name, const char* default_port,
+    grpc_pollset_set* interested_parties, grpc_closure* on_done,
+    grpc_lb_addresses** addrs, bool check_grpclb,
     char** service_config_json) = grpc_dns_lookup_ares_impl;
 
-void grpc_cancel_ares_request(grpc_exec_ctx* exec_ctx, grpc_ares_request* r) {
+void grpc_cancel_ares_request(grpc_ares_request* r) {
   if (grpc_dns_lookup_ares == grpc_dns_lookup_ares_impl) {
-    grpc_ares_ev_driver_shutdown(exec_ctx, r->ev_driver);
+    grpc_ares_ev_driver_shutdown(r->ev_driver);
   }
 }
 
@@ -501,8 +486,7 @@ typedef struct grpc_resolve_address_ares_request {
   grpc_closure on_dns_lookup_done;
 } grpc_resolve_address_ares_request;
 
-static void on_dns_lookup_done_cb(grpc_exec_ctx* exec_ctx, void* arg,
-                                  grpc_error* error) {
+static void on_dns_lookup_done_cb(void* arg, grpc_error* error) {
   grpc_resolve_address_ares_request* r =
       (grpc_resolve_address_ares_request*)arg;
   grpc_resolved_addresses** resolved_addresses = r->addrs_out;
@@ -520,14 +504,12 @@ static void on_dns_lookup_done_cb(grpc_exec_ctx* exec_ctx, void* arg,
              &r->lb_addrs->addresses[i].address, sizeof(grpc_resolved_address));
     }
   }
-  GRPC_CLOSURE_SCHED(exec_ctx, r->on_resolve_address_done,
-                     GRPC_ERROR_REF(error));
-  grpc_lb_addresses_destroy(exec_ctx, r->lb_addrs);
+  GRPC_CLOSURE_SCHED(r->on_resolve_address_done, GRPC_ERROR_REF(error));
+  grpc_lb_addresses_destroy(r->lb_addrs);
   gpr_free(r);
 }
 
-static void grpc_resolve_address_ares_impl(grpc_exec_ctx* exec_ctx,
-                                           const char* name,
+static void grpc_resolve_address_ares_impl(const char* name,
                                            const char* default_port,
                                            grpc_pollset_set* interested_parties,
                                            grpc_closure* on_done,
@@ -539,14 +521,14 @@ static void grpc_resolve_address_ares_impl(grpc_exec_ctx* exec_ctx,
   r->on_resolve_address_done = on_done;
   GRPC_CLOSURE_INIT(&r->on_dns_lookup_done, on_dns_lookup_done_cb, r,
                     grpc_schedule_on_exec_ctx);
-  grpc_dns_lookup_ares(exec_ctx, nullptr /* dns_server */, name, default_port,
+  grpc_dns_lookup_ares(nullptr /* dns_server */, name, default_port,
                        interested_parties, &r->on_dns_lookup_done, &r->lb_addrs,
                        false /* check_grpclb */,
                        nullptr /* service_config_json */);
 }
 
 void (*grpc_resolve_address_ares)(
-    grpc_exec_ctx* exec_ctx, const char* name, const char* default_port,
+    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;