Merge branch 'master' of https://github.com/grpc/grpc into cpp_bazelness

29 files changed, 1374 insertions, 235 deletions

diff --git a/src/core/ext/client_channel/channel_connectivity.c b/src/core/ext/client_channel/channel_connectivity.c
index dd70bc2c6c..f6cb3b9115 100644
--- a/src/core/ext/client_channel/channel_connectivity.c
+++ b/src/core/ext/client_channel/channel_connectivity.c
@@ -139,8 +139,8 @@ static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
     error = GRPC_ERROR_NONE;
   } else {
     if (error == GRPC_ERROR_NONE) {
-      error =
-          GRPC_ERROR_CREATE("Timed out waiting for connection state change");
+      error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "Timed out waiting for connection state change");
     } else if (error == GRPC_ERROR_CANCELLED) {
       error = GRPC_ERROR_NONE;
     }
diff --git a/src/core/ext/client_channel/client_channel.c b/src/core/ext/client_channel/client_channel.c
index 00c20913b0..435a3ab0fe 100644
--- a/src/core/ext/client_channel/client_channel.c
+++ b/src/core/ext/client_channel/client_channel.c
@@ -355,7 +355,8 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   grpc_slice_hash_table *method_params_table = NULL;
   grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE;
   bool exit_idle = false;
-  grpc_error *state_error = GRPC_ERROR_CREATE("No load balancing policy");
+  grpc_error *state_error =
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("No load balancing policy");
   char *service_config_json = NULL;
   service_config_parsing_state parsing_state;
   memset(&parsing_state, 0, sizeof(parsing_state));
@@ -475,9 +476,9 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   if (lb_policy != NULL) {
     grpc_closure_list_sched(exec_ctx, &chand->waiting_for_config_closures);
   } else if (chand->resolver == NULL /* disconnected */) {
-    grpc_closure_list_fail_all(
-        &chand->waiting_for_config_closures,
-        GRPC_ERROR_CREATE_REFERENCING("Channel disconnected", &error, 1));
+    grpc_closure_list_fail_all(&chand->waiting_for_config_closures,
+                               GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                                   "Channel disconnected", &error, 1));
     grpc_closure_list_sched(exec_ctx, &chand->waiting_for_config_closures);
   }
   if (lb_policy != NULL && chand->exit_idle_when_lb_policy_arrives) {
@@ -505,8 +506,8 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     grpc_error *refs[] = {error, state_error};
     set_channel_connectivity_state_locked(
         exec_ctx, chand, GRPC_CHANNEL_SHUTDOWN,
-        GRPC_ERROR_CREATE_REFERENCING("Got config after disconnection", refs,
-                                      GPR_ARRAY_SIZE(refs)),
+        GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+            "Got config after disconnection", refs, GPR_ARRAY_SIZE(refs)),
         "resolver_gone");
   }
 
@@ -545,8 +546,9 @@ static void start_transport_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
 
   if (op->send_ping != NULL) {
     if (chand->lb_policy == NULL) {
-      grpc_closure_sched(exec_ctx, op->send_ping,
-                         GRPC_ERROR_CREATE("Ping with no load balancing"));
+      grpc_closure_sched(
+          exec_ctx, op->send_ping,
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Ping with no load balancing"));
     } else {
       grpc_lb_policy_ping_one_locked(exec_ctx, chand->lb_policy, op->send_ping);
       op->bind_pollset = NULL;
@@ -661,7 +663,7 @@ static grpc_error *cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
   if (proxy_name != NULL) gpr_free(proxy_name);
   if (new_args != NULL) grpc_channel_args_destroy(exec_ctx, new_args);
   if (chand->resolver == NULL) {
-    return GRPC_ERROR_CREATE("resolver creation failed");
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING("resolver creation failed");
   }
   return GRPC_ERROR_NONE;
 }
@@ -874,12 +876,14 @@ static void subchannel_ready_locked(grpc_exec_ctx *exec_ctx, void *arg,
   calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
   if (calld->connected_subchannel == NULL) {
     gpr_atm_no_barrier_store(&calld->subchannel_call, 1);
-    fail_locked(exec_ctx, calld, GRPC_ERROR_CREATE_REFERENCING(
-                                     "Failed to create subchannel", &error, 1));
+    fail_locked(exec_ctx, calld,
+                GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                    "Failed to create subchannel", &error, 1));
   } else if (GET_CALL(calld) == CANCELLED_CALL) {
     /* already cancelled before subchannel became ready */
-    grpc_error *cancellation_error = GRPC_ERROR_CREATE_REFERENCING(
-        "Cancelled before creating subchannel", &error, 1);
+    grpc_error *cancellation_error =
+        GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+            "Cancelled before creating subchannel", &error, 1);
     /* if due to deadline, attach the deadline exceeded status to the error */
     if (gpr_time_cmp(calld->deadline, gpr_now(GPR_CLOCK_MONOTONIC)) < 0) {
       cancellation_error =
@@ -981,9 +985,9 @@ static bool pick_subchannel_locked(
       cpa = closure->cb_arg;
       if (cpa->connected_subchannel == connected_subchannel) {
         cpa->connected_subchannel = NULL;
-        grpc_closure_sched(
-            exec_ctx, cpa->on_ready,
-            GRPC_ERROR_CREATE_REFERENCING("Pick cancelled", &error, 1));
+        grpc_closure_sched(exec_ctx, cpa->on_ready,
+                           GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                               "Pick cancelled", &error, 1));
       }
     }
     GPR_TIMER_END("pick_subchannel", 0);
@@ -1040,7 +1044,8 @@ static bool pick_subchannel_locked(
     grpc_closure_list_append(&chand->waiting_for_config_closures, &cpa->closure,
                              GRPC_ERROR_NONE);
   } else {
-    grpc_closure_sched(exec_ctx, on_ready, GRPC_ERROR_CREATE("Disconnected"));
+    grpc_closure_sched(exec_ctx, on_ready,
+                       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Disconnected"));
   }
 
   GPR_TIMER_END("pick_subchannel", 0);
diff --git a/src/core/ext/client_channel/http_connect_handshaker.c b/src/core/ext/client_channel/http_connect_handshaker.c
index 58ab233f1b..778d76c39f 100644
--- a/src/core/ext/client_channel/http_connect_handshaker.c
+++ b/src/core/ext/client_channel/http_connect_handshaker.c
@@ -116,7 +116,7 @@ static void handshake_failed_locked(grpc_exec_ctx* exec_ctx,
     // If we were shut down after an endpoint operation succeeded but
     // before the endpoint callback was invoked, we need to generate our
     // own error.
-    error = GRPC_ERROR_CREATE("Handshaker shutdown");
+    error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshaker shutdown");
   }
   if (!handshaker->shutdown) {
     // TODO(ctiller): It is currently necessary to shutdown endpoints
@@ -226,7 +226,7 @@ static void on_read_done(grpc_exec_ctx* exec_ctx, void* arg,
     char* msg;
     gpr_asprintf(&msg, "HTTP proxy returned response code %d",
                  handshaker->http_response.status);
-    error = GRPC_ERROR_CREATE(msg);
+    error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     handshake_failed_locked(exec_ctx, handshaker, error);
     goto done;
diff --git a/src/core/ext/client_channel/resolver_registry.c b/src/core/ext/client_channel/resolver_registry.c
index 3c5a6fb3ff..0f074a3386 100644
--- a/src/core/ext/client_channel/resolver_registry.c
+++ b/src/core/ext/client_channel/resolver_registry.c
@@ -93,7 +93,6 @@ static grpc_resolver_factory *lookup_factory(const char *name) {
       return g_all_of_the_resolvers[i];
     }
   }
-
   return NULL;
 }
 
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/client_channel/subchannel.c
index e886fbc0cc..063c0badff 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -269,8 +269,9 @@ static void disconnect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
   gpr_mu_lock(&c->mu);
   GPR_ASSERT(!c->disconnected);
   c->disconnected = true;
-  grpc_connector_shutdown(exec_ctx, c->connector,
-                          GRPC_ERROR_CREATE("Subchannel disconnected"));
+  grpc_connector_shutdown(
+      exec_ctx, c->connector,
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Subchannel disconnected"));
   con = GET_CONNECTED_SUBCHANNEL(c, no_barrier);
   if (con != NULL) {
     GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, con, "connection");
@@ -437,7 +438,8 @@ static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   gpr_mu_lock(&c->mu);
   c->have_alarm = false;
   if (c->disconnected) {
-    error = GRPC_ERROR_CREATE_REFERENCING("Disconnected", &error, 1);
+    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING("Disconnected",
+                                                             &error, 1);
   } else {
     GRPC_ERROR_REF(error);
   }
@@ -688,9 +690,9 @@ static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg,
   } else {
     grpc_connectivity_state_set(
         exec_ctx, &c->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE,
-        grpc_error_set_int(
-            GRPC_ERROR_CREATE_REFERENCING("Connect Failed", &error, 1),
-            GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE),
+        grpc_error_set_int(GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                               "Connect Failed", &error, 1),
+                           GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE),
         "connect_failed");
 
     const char *errmsg = grpc_error_string(error);
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index d612591f2e..601b0e643b 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -925,7 +925,7 @@ static void glb_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
   grpc_connectivity_state_set(
       exec_ctx, &glb_policy->state_tracker, GRPC_CHANNEL_SHUTDOWN,
-      GRPC_ERROR_CREATE("Channel Shutdown"), "glb_shutdown");
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown"), "glb_shutdown");
   /* We need a copy of the lb_call pointer because we can't cancell the call
    * while holding glb_policy->mu: lb_on_server_status_received, invoked due to
    * the cancel, needs to acquire that same lock */
@@ -965,9 +965,9 @@ static void glb_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if (pp->target == target) {
       *target = NULL;
-      grpc_closure_sched(
-          exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
-          GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick Cancelled", &error, 1));
     } else {
       pp->next = glb_policy->pending_picks;
       glb_policy->pending_picks = pp;
@@ -989,9 +989,9 @@ static void glb_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
     pending_pick *next = pp->next;
     if ((pp->pick_args.initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_closure_sched(
-          exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
-          GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick Cancelled", &error, 1));
     } else {
       pp->next = glb_policy->pending_picks;
       glb_policy->pending_picks = pp;
@@ -1023,10 +1023,10 @@ static int glb_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
                            grpc_closure *on_complete) {
   if (pick_args->lb_token_mdelem_storage == NULL) {
     *target = NULL;
-    grpc_closure_sched(
-        exec_ctx, on_complete,
-        GRPC_ERROR_CREATE("No mdelem storage for the LB token. Load reporting "
-                          "won't work without it. Failing"));
+    grpc_closure_sched(exec_ctx, on_complete,
+                       GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                           "No mdelem storage for the LB token. Load reporting "
+                           "won't work without it. Failing"));
     return 0;
   }
 
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index e2a66d16bd..fc65dfdcb9 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -101,7 +101,7 @@ static void pf_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   p->pending_picks = NULL;
   grpc_connectivity_state_set(
       exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
-      GRPC_ERROR_CREATE("Channel shutdown"), "shutdown");
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown"), "shutdown");
   /* cancel subscription */
   if (p->selected != NULL) {
     grpc_connected_subchannel_notify_on_state_change(
@@ -131,9 +131,9 @@ static void pf_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if (pp->target == target) {
       *target = NULL;
-      grpc_closure_sched(
-          exec_ctx, pp->on_complete,
-          GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, pp->on_complete,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick Cancelled", &error, 1));
       gpr_free(pp);
     } else {
       pp->next = p->pending_picks;
@@ -156,9 +156,9 @@ static void pf_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_closure_sched(
-          exec_ctx, pp->on_complete,
-          GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, pp->on_complete,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick Cancelled", &error, 1));
       gpr_free(pp);
     } else {
       pp->next = p->pending_picks;
@@ -325,8 +325,8 @@ static void pf_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg,
         if (p->num_subchannels == 0) {
           grpc_connectivity_state_set(
               exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
-              GRPC_ERROR_CREATE_REFERENCING("Pick first exhausted channels",
-                                            &error, 1),
+              GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                  "Pick first exhausted channels", &error, 1),
               "no_more_channels");
           while ((pp = p->pending_picks)) {
             p->pending_picks = pp->next;
@@ -373,7 +373,8 @@ static void pf_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   if (p->selected) {
     grpc_connected_subchannel_ping(exec_ctx, p->selected, closure);
   } else {
-    grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_CREATE("Not connected"));
+    grpc_closure_sched(exec_ctx, closure,
+                       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected"));
   }
 }
 
@@ -423,11 +424,13 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
               "This LB policy doesn't support user data. It will be ignored");
     }
 
+    static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS};
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
     grpc_arg addr_arg =
         grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
-    grpc_channel_args *new_args =
-        grpc_channel_args_copy_and_add(args->args, &addr_arg, 1);
+    grpc_channel_args *new_args = grpc_channel_args_copy_and_add_and_remove(
+        args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg,
+        1);
     gpr_free(addr_arg.value.string);
     sc_args.args = new_args;
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index f2d1d46179..a62082a2ff 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -320,13 +320,14 @@ static void rr_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   while ((pp = p->pending_picks)) {
     p->pending_picks = pp->next;
     *pp->target = NULL;
-    grpc_closure_sched(exec_ctx, pp->on_complete,
-                       GRPC_ERROR_CREATE("Channel Shutdown"));
+    grpc_closure_sched(
+        exec_ctx, pp->on_complete,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown"));
     gpr_free(pp);
   }
   grpc_connectivity_state_set(
       exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
-      GRPC_ERROR_CREATE("Channel Shutdown"), "rr_shutdown");
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown"), "rr_shutdown");
   for (i = 0; i < p->num_subchannels; i++) {
     subchannel_data *sd = p->subchannels[i];
     grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
@@ -345,9 +346,9 @@ static void rr_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if (pp->target == target) {
       *target = NULL;
-      grpc_closure_sched(
-          exec_ctx, pp->on_complete,
-          GRPC_ERROR_CREATE_REFERENCING("Pick cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, pp->on_complete,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick cancelled", &error, 1));
       gpr_free(pp);
     } else {
       pp->next = p->pending_picks;
@@ -371,9 +372,9 @@ static void rr_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
       *pp->target = NULL;
-      grpc_closure_sched(
-          exec_ctx, pp->on_complete,
-          GRPC_ERROR_CREATE_REFERENCING("Pick cancelled", &error, 1));
+      grpc_closure_sched(exec_ctx, pp->on_complete,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick cancelled", &error, 1));
       gpr_free(pp);
     } else {
       pp->next = p->pending_picks;
@@ -661,8 +662,8 @@ static void rr_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     grpc_connected_subchannel_ping(exec_ctx, target, closure);
     GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, target, "rr_picked");
   } else {
-    grpc_closure_sched(exec_ctx, closure,
-                       GRPC_ERROR_CREATE("Round Robin not connected"));
+    grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                              "Round Robin not connected"));
   }
 }
 
@@ -709,11 +710,13 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
     /* Skip balancer addresses, since we only know how to handle backends. */
     if (addresses->addresses[i].is_balancer) continue;
 
+    static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS};
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
     grpc_arg addr_arg =
         grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
-    grpc_channel_args *new_args =
-        grpc_channel_args_copy_and_add(args->args, &addr_arg, 1);
+    grpc_channel_args *new_args = grpc_channel_args_copy_and_add_and_remove(
+        args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg,
+        1);
     gpr_free(addr_arg.value.string);
     sc_args.args = new_args;
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 4ed832671d..ea57c85c3a 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -78,8 +78,8 @@ static void on_initial_md_ready(grpc_exec_ctx *exec_ctx, void *user_data,
           GRPC_MDVALUE(calld->recv_initial_metadata->idx.named.path->md));
       calld->have_service_method = true;
     } else {
-      err =
-          grpc_error_add_child(err, GRPC_ERROR_CREATE("Missing :path header"));
+      err = grpc_error_add_child(
+          err, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Missing :path header"));
     }
     if (calld->recv_initial_metadata->idx.named.lb_token != NULL) {
       calld->initial_md_string = grpc_slice_ref_internal(
diff --git a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
new file mode 100644
index 0000000000..f27da231f5
--- /dev/null
+++ b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
@@ -0,0 +1,350 @@
+/*
+ *
+ * Copyright 2015, 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>
+#if GRPC_ARES == 1 && !defined(GRPC_UV)
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/support/backoff.h"
+#include "src/core/lib/support/env.h"
+#include "src/core/lib/support/string.h"
+
+#define GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS 1
+#define GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS 1
+#define GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER 1.6
+#define GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS 120
+#define GRPC_DNS_RECONNECT_JITTER 0.2
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** name to resolve (usually the same as target_name) */
+  char *name_to_resolve;
+  /** default port to use */
+  char *default_port;
+  /** channel args. */
+  grpc_channel_args *channel_args;
+  /** pollset_set to drive the name resolution process */
+  grpc_pollset_set *interested_parties;
+
+  /** Closures used by the combiner */
+  grpc_closure dns_ares_on_retry_timer_locked;
+  grpc_closure dns_ares_on_resolved_locked;
+
+  /** Combiner guarding the rest of the state */
+  grpc_combiner *combiner;
+  /** are we currently resolving? */
+  bool resolving;
+  /** which version of the result have we published? */
+  int published_version;
+  /** which version of the result is current? */
+  int resolved_version;
+  /** pending next completion, or NULL */
+  grpc_closure *next_completion;
+  /** target result address for next completion */
+  grpc_channel_args **target_result;
+  /** current (fully resolved) result */
+  grpc_channel_args *resolved_result;
+  /** retry timer */
+  bool have_retry_timer;
+  grpc_timer retry_timer;
+  /** retry backoff state */
+  gpr_backoff backoff_state;
+
+  /** currently resolving addresses */
+  grpc_resolved_addresses *addresses;
+} ares_dns_resolver;
+
+static void dns_ares_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void dns_ares_start_resolving_locked(grpc_exec_ctx *exec_ctx,
+                                            ares_dns_resolver *r);
+static void dns_ares_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                              ares_dns_resolver *r);
+
+static void dns_ares_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
+                                              grpc_resolver *r);
+static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+                                 grpc_channel_args **target_result,
+                                 grpc_closure *on_complete);
+
+static const grpc_resolver_vtable dns_ares_resolver_vtable = {
+    dns_ares_destroy, dns_ares_shutdown_locked,
+    dns_ares_channel_saw_error_locked, dns_ares_next_locked};
+
+static void dns_ares_shutdown_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_resolver *resolver) {
+  ares_dns_resolver *r = (ares_dns_resolver *)resolver;
+  if (r->have_retry_timer) {
+    grpc_timer_cancel(exec_ctx, &r->retry_timer);
+  }
+  if (r->next_completion != NULL) {
+    *r->target_result = NULL;
+    grpc_closure_sched(
+        exec_ctx, r->next_completion,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Resolver Shutdown"));
+    r->next_completion = NULL;
+  }
+}
+
+static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
+                                              grpc_resolver *resolver) {
+  ares_dns_resolver *r = (ares_dns_resolver *)resolver;
+  if (!r->resolving) {
+    gpr_backoff_reset(&r->backoff_state);
+    dns_ares_start_resolving_locked(exec_ctx, r);
+  }
+}
+
+static void dns_ares_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                           grpc_error *error) {
+  ares_dns_resolver *r = arg;
+  r->have_retry_timer = false;
+  if (error == GRPC_ERROR_NONE) {
+    if (!r->resolving) {
+      dns_ares_start_resolving_locked(exec_ctx, r);
+    }
+  }
+  GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "retry-timer");
+}
+
+static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error) {
+  ares_dns_resolver *r = arg;
+  grpc_channel_args *result = NULL;
+  GPR_ASSERT(r->resolving);
+  r->resolving = false;
+  if (r->addresses != NULL) {
+    grpc_lb_addresses *addresses = grpc_lb_addresses_create(
+        r->addresses->naddrs, NULL /* user_data_vtable */);
+    for (size_t i = 0; i < r->addresses->naddrs; ++i) {
+      grpc_lb_addresses_set_address(
+          addresses, i, &r->addresses->addrs[i].addr,
+          r->addresses->addrs[i].len, false /* is_balancer */,
+          NULL /* balancer_name */, NULL /* user_data */);
+    }
+    grpc_arg new_arg = grpc_lb_addresses_create_channel_arg(addresses);
+    result = grpc_channel_args_copy_and_add(r->channel_args, &new_arg, 1);
+    grpc_resolved_addresses_destroy(r->addresses);
+    grpc_lb_addresses_destroy(exec_ctx, addresses);
+  } else {
+    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
+    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
+            grpc_error_string(error));
+    GPR_ASSERT(!r->have_retry_timer);
+    r->have_retry_timer = true;
+    GRPC_RESOLVER_REF(&r->base, "retry-timer");
+    if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
+      gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
+              timeout.tv_nsec);
+    } else {
+      gpr_log(GPR_DEBUG, "retrying immediately");
+    }
+    grpc_timer_init(exec_ctx, &r->retry_timer, next_try,
+                    &r->dns_ares_on_retry_timer_locked, now);
+  }
+  if (r->resolved_result != NULL) {
+    grpc_channel_args_destroy(exec_ctx, r->resolved_result);
+  }
+  r->resolved_result = result;
+  r->resolved_version++;
+  dns_ares_maybe_finish_next_locked(exec_ctx, r);
+  GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
+}
+
+static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx,
+                                 grpc_resolver *resolver,
+                                 grpc_channel_args **target_result,
+                                 grpc_closure *on_complete) {
+  gpr_log(GPR_DEBUG, "dns_ares_next is called.");
+  ares_dns_resolver *r = (ares_dns_resolver *)resolver;
+  GPR_ASSERT(!r->next_completion);
+  r->next_completion = on_complete;
+  r->target_result = target_result;
+  if (r->resolved_version == 0 && !r->resolving) {
+    gpr_backoff_reset(&r->backoff_state);
+    dns_ares_start_resolving_locked(exec_ctx, r);
+  } else {
+    dns_ares_maybe_finish_next_locked(exec_ctx, r);
+  }
+}
+
+static void dns_ares_start_resolving_locked(grpc_exec_ctx *exec_ctx,
+                                            ares_dns_resolver *r) {
+  GRPC_RESOLVER_REF(&r->base, "dns-resolving");
+  GPR_ASSERT(!r->resolving);
+  r->resolving = true;
+  r->addresses = NULL;
+  grpc_resolve_address(exec_ctx, r->name_to_resolve, r->default_port,
+                       r->interested_parties, &r->dns_ares_on_resolved_locked,
+                       &r->addresses);
+}
+
+static void dns_ares_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                              ares_dns_resolver *r) {
+  if (r->next_completion != NULL &&
+      r->resolved_version != r->published_version) {
+    *r->target_result = r->resolved_result == NULL
+                            ? NULL
+                            : grpc_channel_args_copy(r->resolved_result);
+    grpc_closure_sched(exec_ctx, r->next_completion, GRPC_ERROR_NONE);
+    r->next_completion = NULL;
+    r->published_version = r->resolved_version;
+  }
+}
+
+static void dns_ares_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+  gpr_log(GPR_DEBUG, "dns_ares_destroy");
+  ares_dns_resolver *r = (ares_dns_resolver *)gr;
+  if (r->resolved_result != NULL) {
+    grpc_channel_args_destroy(exec_ctx, r->resolved_result);
+  }
+  grpc_pollset_set_destroy(exec_ctx, r->interested_parties);
+  gpr_free(r->name_to_resolve);
+  gpr_free(r->default_port);
+  grpc_channel_args_destroy(exec_ctx, r->channel_args);
+  gpr_free(r);
+}
+
+static grpc_resolver *dns_ares_create(grpc_exec_ctx *exec_ctx,
+                                      grpc_resolver_args *args,
+                                      const char *default_port) {
+  // Get name from args.
+  const char *path = args->uri->path;
+  if (0 != strcmp(args->uri->authority, "")) {
+    gpr_log(GPR_ERROR, "authority based dns uri's not supported");
+    return NULL;
+  }
+  if (path[0] == '/') ++path;
+  // Create resolver.
+  ares_dns_resolver *r = gpr_zalloc(sizeof(ares_dns_resolver));
+  grpc_resolver_init(&r->base, &dns_ares_resolver_vtable, args->combiner);
+  r->name_to_resolve = gpr_strdup(path);
+  r->default_port = gpr_strdup(default_port);
+  r->channel_args = grpc_channel_args_copy(args->args);
+  r->interested_parties = grpc_pollset_set_create();
+  if (args->pollset_set != NULL) {
+    grpc_pollset_set_add_pollset_set(exec_ctx, r->interested_parties,
+                                     args->pollset_set);
+  }
+  gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
+                   GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
+                   GRPC_DNS_RECONNECT_JITTER,
+                   GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                   GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_closure_init(&r->dns_ares_on_retry_timer_locked,
+                    dns_ares_on_retry_timer_locked, r,
+                    grpc_combiner_scheduler(r->base.combiner, false));
+  grpc_closure_init(&r->dns_ares_on_resolved_locked,
+                    dns_ares_on_resolved_locked, r,
+                    grpc_combiner_scheduler(r->base.combiner, false));
+  return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void dns_ares_factory_ref(grpc_resolver_factory *factory) {}
+
+static void dns_ares_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *dns_factory_create_resolver(
+    grpc_exec_ctx *exec_ctx, grpc_resolver_factory *factory,
+    grpc_resolver_args *args) {
+  return dns_ares_create(exec_ctx, args, "https");
+}
+
+static char *dns_ares_factory_get_default_host_name(
+    grpc_resolver_factory *factory, grpc_uri *uri) {
+  const char *path = uri->path;
+  if (path[0] == '/') ++path;
+  return gpr_strdup(path);
+}
+
+static const grpc_resolver_factory_vtable dns_ares_factory_vtable = {
+    dns_ares_factory_ref, dns_ares_factory_unref, dns_factory_create_resolver,
+    dns_ares_factory_get_default_host_name, "dns"};
+static grpc_resolver_factory dns_resolver_factory = {&dns_ares_factory_vtable};
+
+static grpc_resolver_factory *dns_ares_resolver_factory_create() {
+  return &dns_resolver_factory;
+}
+
+void grpc_resolver_dns_ares_init(void) {
+  char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  /* TODO(zyc): Turn on c-ares based resolver by default after the address
+     sorter and the CNAME support are 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);
+      return;
+    }
+    grpc_resolve_address = grpc_resolve_address_ares;
+    grpc_register_resolver_type(dns_ares_resolver_factory_create());
+  }
+  gpr_free(resolver);
+}
+
+void grpc_resolver_dns_ares_shutdown(void) {
+  char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver != NULL && gpr_stricmp(resolver, "ares") == 0) {
+    grpc_ares_cleanup();
+  }
+  gpr_free(resolver);
+}
+
+#else /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+
+void grpc_resolver_dns_ares_init(void) {}
+
+void grpc_resolver_dns_ares_shutdown(void) {}
+
+#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h
new file mode 100644
index 0000000000..334feaa2ab
--- /dev/null
+++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
+#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
+
+#include <ares.h>
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/pollset_set.h"
+
+typedef struct grpc_ares_ev_driver grpc_ares_ev_driver;
+
+/* Start \a ev_driver. It will keep working until all IO on its ares_channel is
+   done, or grpc_ares_ev_driver_destroy() is called. It may notify the callbacks
+   bound to its ares_channel when necessary. */
+void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx,
+                               grpc_ares_ev_driver *ev_driver);
+
+/* Returns the ares_channel owned by \a ev_driver. To bind a c-ares query to
+   \a ev_driver, use the ares_channel owned by \a ev_driver as the arg of the
+   query. */
+ares_channel *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver);
+
+/* Creates a new grpc_ares_ev_driver. Returns GRPC_ERROR_NONE if \a ev_driver is
+   created successfully. */
+grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver,
+                                       grpc_pollset_set *pollset_set);
+
+/* Destroys \a ev_driver asynchronously. Pending lookups made on \a ev_driver
+   will be cancelled and their on_done callbacks will be invoked with a status
+   of ARES_ECANCELLED. */
+void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver);
+
+#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H */
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
new file mode 100644
index 0000000000..fab4f0c977
--- /dev/null
+++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
@@ -0,0 +1,319 @@
+/*
+ *
+ * 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"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+#include <grpc/support/useful.h>
+#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/support/string.h"
+
+typedef struct fd_node {
+  /** the owner of this fd node */
+  grpc_ares_ev_driver *ev_driver;
+  /** the grpc_fd owned by this fd node */
+  grpc_fd *grpc_fd;
+  /** a closure wrapping on_readable_cb, which should be invoked when the
+      grpc_fd in this node becomes readable. */
+  grpc_closure read_closure;
+  /** a closure wrapping on_writable_cb, which should be invoked when the
+      grpc_fd in this node becomes writable. */
+  grpc_closure write_closure;
+  /** next fd node in the list */
+  struct fd_node *next;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** if the readable closure has been registered */
+  bool readable_registered;
+  /** if the writable closure has been registered */
+  bool writable_registered;
+} fd_node;
+
+struct grpc_ares_ev_driver {
+  /** the ares_channel owned by this event driver */
+  ares_channel channel;
+  /** pollset set for driving the IO events of the channel */
+  grpc_pollset_set *pollset_set;
+  /** refcount of the event driver */
+  gpr_refcount refs;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** a list of grpc_fd that this event driver is currently using. */
+  fd_node *fds;
+  /** is this event driver currently working? */
+  bool working;
+  /** is this event driver being shut down */
+  bool shutting_down;
+};
+
+static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
+                                             grpc_ares_ev_driver *ev_driver);
+
+static grpc_ares_ev_driver *grpc_ares_ev_driver_ref(
+    grpc_ares_ev_driver *ev_driver) {
+  gpr_log(GPR_DEBUG, "Ref ev_driver %" PRIuPTR, (uintptr_t)ev_driver);
+  gpr_ref(&ev_driver->refs);
+  return ev_driver;
+}
+
+static void grpc_ares_ev_driver_unref(grpc_ares_ev_driver *ev_driver) {
+  gpr_log(GPR_DEBUG, "Unref ev_driver %" PRIuPTR, (uintptr_t)ev_driver);
+  if (gpr_unref(&ev_driver->refs)) {
+    gpr_log(GPR_DEBUG, "destroy ev_driver %" PRIuPTR, (uintptr_t)ev_driver);
+    GPR_ASSERT(ev_driver->fds == NULL);
+    gpr_mu_destroy(&ev_driver->mu);
+    ares_destroy(ev_driver->channel);
+    gpr_free(ev_driver);
+  }
+}
+
+static void fd_node_destroy(grpc_exec_ctx *exec_ctx, fd_node *fdn) {
+  gpr_log(GPR_DEBUG, "delete fd: %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  GPR_ASSERT(!fdn->readable_registered);
+  GPR_ASSERT(!fdn->writable_registered);
+  gpr_mu_destroy(&fdn->mu);
+  grpc_pollset_set_del_fd(exec_ctx, fdn->ev_driver->pollset_set, fdn->grpc_fd);
+  grpc_fd_shutdown(exec_ctx, fdn->grpc_fd,
+                   GRPC_ERROR_CREATE_FROM_STATIC_STRING("fd node destroyed"));
+  grpc_fd_orphan(exec_ctx, fdn->grpc_fd, NULL, NULL, "c-ares query finished");
+  gpr_free(fdn);
+}
+
+grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver,
+                                       grpc_pollset_set *pollset_set) {
+  *ev_driver = gpr_malloc(sizeof(grpc_ares_ev_driver));
+  int status = ares_init(&(*ev_driver)->channel);
+  gpr_log(GPR_DEBUG, "grpc_ares_ev_driver_create");
+  if (status != ARES_SUCCESS) {
+    char *err_msg;
+    gpr_asprintf(&err_msg, "Failed to init ares channel. C-ares error: %s",
+                 ares_strerror(status));
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(err_msg);
+    gpr_free(err_msg);
+    gpr_free(*ev_driver);
+    return err;
+  }
+  gpr_mu_init(&(*ev_driver)->mu);
+  gpr_ref_init(&(*ev_driver)->refs, 1);
+  (*ev_driver)->pollset_set = pollset_set;
+  (*ev_driver)->fds = NULL;
+  (*ev_driver)->working = false;
+  (*ev_driver)->shutting_down = false;
+  return GRPC_ERROR_NONE;
+}
+
+void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver) {
+  // It's not safe to shut down remaining fds here directly, becauses
+  // ares_host_callback does not provide an exec_ctx. We mark the event driver
+  // as being shut down. If the event driver is working,
+  // grpc_ares_notify_on_event_locked will shut down the fds; if it's not
+  // working, there are no fds to shut down.
+  gpr_mu_lock(&ev_driver->mu);
+  ev_driver->shutting_down = true;
+  gpr_mu_unlock(&ev_driver->mu);
+  grpc_ares_ev_driver_unref(ev_driver);
+}
+
+// Search fd in the fd_node list head. This is an O(n) search, the max possible
+// value of n is ARES_GETSOCK_MAXNUM (16). n is typically 1 - 2 in our tests.
+static fd_node *pop_fd_node(fd_node **head, int fd) {
+  fd_node dummy_head;
+  dummy_head.next = *head;
+  fd_node *node = &dummy_head;
+  while (node->next != NULL) {
+    if (grpc_fd_wrapped_fd(node->next->grpc_fd) == fd) {
+      fd_node *ret = node->next;
+      node->next = node->next->next;
+      *head = dummy_head.next;
+      return ret;
+    }
+    node = node->next;
+  }
+  return NULL;
+}
+
+static void on_readable_cb(grpc_exec_ctx *exec_ctx, void *arg,
+                           grpc_error *error) {
+  fd_node *fdn = arg;
+  grpc_ares_ev_driver *ev_driver = fdn->ev_driver;
+  gpr_mu_lock(&fdn->mu);
+  fdn->readable_registered = false;
+  gpr_mu_unlock(&fdn->mu);
+
+  gpr_log(GPR_DEBUG, "readable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  if (error == GRPC_ERROR_NONE) {
+    ares_process_fd(ev_driver->channel, grpc_fd_wrapped_fd(fdn->grpc_fd),
+                    ARES_SOCKET_BAD);
+  } else {
+    // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or
+    // timed out. The pending lookups made on this ev_driver will be cancelled
+    // by the following ares_cancel() and the on_done callbacks will be invoked
+    // with a status of ARES_ECANCELLED. The remaining file descriptors in this
+    // ev_driver will be cleaned up in the follwing
+    // grpc_ares_notify_on_event_locked().
+    ares_cancel(ev_driver->channel);
+  }
+  gpr_mu_lock(&ev_driver->mu);
+  grpc_ares_notify_on_event_locked(exec_ctx, ev_driver);
+  gpr_mu_unlock(&ev_driver->mu);
+  grpc_ares_ev_driver_unref(ev_driver);
+}
+
+static void on_writable_cb(grpc_exec_ctx *exec_ctx, void *arg,
+                           grpc_error *error) {
+  fd_node *fdn = arg;
+  grpc_ares_ev_driver *ev_driver = fdn->ev_driver;
+  gpr_mu_lock(&fdn->mu);
+  fdn->writable_registered = false;
+  gpr_mu_unlock(&fdn->mu);
+
+  gpr_log(GPR_DEBUG, "writable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  if (error == GRPC_ERROR_NONE) {
+    ares_process_fd(ev_driver->channel, ARES_SOCKET_BAD,
+                    grpc_fd_wrapped_fd(fdn->grpc_fd));
+  } else {
+    // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or
+    // timed out. The pending lookups made on this ev_driver will be cancelled
+    // by the following ares_cancel() and the on_done callbacks will be invoked
+    // with a status of ARES_ECANCELLED. The remaining file descriptors in this
+    // ev_driver will be cleaned up in the follwing
+    // grpc_ares_notify_on_event_locked().
+    ares_cancel(ev_driver->channel);
+  }
+  gpr_mu_lock(&ev_driver->mu);
+  grpc_ares_notify_on_event_locked(exec_ctx, ev_driver);
+  gpr_mu_unlock(&ev_driver->mu);
+  grpc_ares_ev_driver_unref(ev_driver);
+}
+
+ares_channel *grpc_ares_ev_driver_get_channel(grpc_ares_ev_driver *ev_driver) {
+  return &ev_driver->channel;
+}
+
+// Get the file descriptors used by the ev_driver's ares channel, register
+// driver_closure with these filedescriptors.
+static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
+                                             grpc_ares_ev_driver *ev_driver) {
+  fd_node *new_list = NULL;
+  if (!ev_driver->shutting_down) {
+    ares_socket_t socks[ARES_GETSOCK_MAXNUM];
+    int socks_bitmask =
+        ares_getsock(ev_driver->channel, socks, ARES_GETSOCK_MAXNUM);
+    for (size_t i = 0; i < ARES_GETSOCK_MAXNUM; i++) {
+      if (ARES_GETSOCK_READABLE(socks_bitmask, i) ||
+          ARES_GETSOCK_WRITABLE(socks_bitmask, i)) {
+        fd_node *fdn = pop_fd_node(&ev_driver->fds, socks[i]);
+        // Create a new fd_node if sock[i] is not in the fd_node list.
+        if (fdn == NULL) {
+          char *fd_name;
+          gpr_asprintf(&fd_name, "ares_ev_driver-%" PRIuPTR, i);
+          fdn = gpr_malloc(sizeof(fd_node));
+          gpr_log(GPR_DEBUG, "new fd: %d", socks[i]);
+          fdn->grpc_fd = grpc_fd_create(socks[i], fd_name);
+          fdn->ev_driver = ev_driver;
+          fdn->readable_registered = false;
+          fdn->writable_registered = false;
+          gpr_mu_init(&fdn->mu);
+          grpc_closure_init(&fdn->read_closure, on_readable_cb, fdn,
+                            grpc_schedule_on_exec_ctx);
+          grpc_closure_init(&fdn->write_closure, on_writable_cb, fdn,
+                            grpc_schedule_on_exec_ctx);
+          grpc_pollset_set_add_fd(exec_ctx, ev_driver->pollset_set,
+                                  fdn->grpc_fd);
+          gpr_free(fd_name);
+        }
+        fdn->next = new_list;
+        new_list = fdn;
+        gpr_mu_lock(&fdn->mu);
+        // Register read_closure if the socket is readable and read_closure has
+        // not been registered with this socket.
+        if (ARES_GETSOCK_READABLE(socks_bitmask, i) &&
+            !fdn->readable_registered) {
+          grpc_ares_ev_driver_ref(ev_driver);
+          gpr_log(GPR_DEBUG, "notify read on: %d",
+                  grpc_fd_wrapped_fd(fdn->grpc_fd));
+          grpc_fd_notify_on_read(exec_ctx, fdn->grpc_fd, &fdn->read_closure);
+          fdn->readable_registered = true;
+        }
+        // Register write_closure if the socket is writable and write_closure
+        // has not been registered with this socket.
+        if (ARES_GETSOCK_WRITABLE(socks_bitmask, i) &&
+            !fdn->writable_registered) {
+          gpr_log(GPR_DEBUG, "notify write on: %d",
+                  grpc_fd_wrapped_fd(fdn->grpc_fd));
+          grpc_ares_ev_driver_ref(ev_driver);
+          grpc_fd_notify_on_write(exec_ctx, fdn->grpc_fd, &fdn->write_closure);
+          fdn->writable_registered = true;
+        }
+        gpr_mu_unlock(&fdn->mu);
+      }
+    }
+  }
+  // Any remaining fds in ev_driver->fds were not returned by ares_getsock() and
+  // are therefore no longer in use, so they can be shut down and removed from
+  // the list.
+  while (ev_driver->fds != NULL) {
+    fd_node *cur = ev_driver->fds;
+    ev_driver->fds = ev_driver->fds->next;
+    fd_node_destroy(exec_ctx, cur);
+  }
+  ev_driver->fds = new_list;
+  // If the ev driver has no working fd, all the tasks are done.
+  if (new_list == NULL) {
+    ev_driver->working = false;
+    gpr_log(GPR_DEBUG, "ev driver stop working");
+  }
+}
+
+void grpc_ares_ev_driver_start(grpc_exec_ctx *exec_ctx,
+                               grpc_ares_ev_driver *ev_driver) {
+  gpr_mu_lock(&ev_driver->mu);
+  if (!ev_driver->working) {
+    ev_driver->working = true;
+    grpc_ares_notify_on_event_locked(exec_ctx, ev_driver);
+  }
+  gpr_mu_unlock(&ev_driver->mu);
+}
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET) */
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c
new file mode 100644
index 0000000000..3eee8e3513
--- /dev/null
+++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c
@@ -0,0 +1,289 @@
+/*
+ *
+ * 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>
+#if GRPC_ARES == 1 && !defined(GRPC_UV)
+
+#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/socket_utils_posix.h"
+
+#include <string.h>
+#include <sys/types.h>
+
+#include <ares.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+#include <grpc/support/useful.h>
+#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+#include "src/core/lib/iomgr/executor.h"
+#include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/support/string.h"
+
+static gpr_once g_basic_init = GPR_ONCE_INIT;
+static gpr_mu g_init_mu;
+
+typedef struct grpc_ares_request {
+  /** following members are set in grpc_resolve_address_ares_impl */
+  /** host to resolve, parsed from the name to resolve */
+  char *host;
+  /** port to fill in sockaddr_in, parsed from the name to resolve */
+  char *port;
+  /** default port to use */
+  char *default_port;
+  /** closure to call when the request completes */
+  grpc_closure *on_done;
+  /** the pointer to receive the resolved addresses */
+  grpc_resolved_addresses **addrs_out;
+  /** the evernt driver used by this request */
+  grpc_ares_ev_driver *ev_driver;
+  /** number of ongoing queries */
+  gpr_refcount pending_queries;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** is there at least one successful query, set in on_done_cb */
+  bool success;
+  /** the errors explaining the request failure, set in on_done_cb */
+  grpc_error *error;
+} grpc_ares_request;
+
+static void do_basic_init(void) { gpr_mu_init(&g_init_mu); }
+
+static uint16_t strhtons(const char *port) {
+  if (strcmp(port, "http") == 0) {
+    return htons(80);
+  } else if (strcmp(port, "https") == 0) {
+    return htons(443);
+  }
+  return htons((unsigned short)atoi(port));
+}
+
+static void grpc_ares_request_unref(grpc_exec_ctx *exec_ctx,
+                                    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 == 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
+         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);
+    }
+    gpr_mu_destroy(&r->mu);
+    grpc_ares_ev_driver_destroy(r->ev_driver);
+    gpr_free(r->host);
+    gpr_free(r->port);
+    gpr_free(r->default_port);
+    gpr_free(r);
+  }
+}
+
+static void on_done_cb(void *arg, int status, int timeouts,
+                       struct hostent *hostent) {
+  grpc_ares_request *r = (grpc_ares_request *)arg;
+  gpr_mu_lock(&r->mu);
+  if (status == ARES_SUCCESS) {
+    GRPC_ERROR_UNREF(r->error);
+    r->error = GRPC_ERROR_NONE;
+    r->success = true;
+    grpc_resolved_addresses **addresses = r->addrs_out;
+    if (*addresses == NULL) {
+      *addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
+      (*addresses)->naddrs = 0;
+      (*addresses)->addrs = NULL;
+    }
+    size_t prev_naddr = (*addresses)->naddrs;
+    size_t i;
+    for (i = 0; hostent->h_addr_list[i] != NULL; i++) {
+    }
+    (*addresses)->naddrs += i;
+    (*addresses)->addrs =
+        gpr_realloc((*addresses)->addrs,
+                    sizeof(grpc_resolved_address) * (*addresses)->naddrs);
+    for (i = prev_naddr; i < (*addresses)->naddrs; i++) {
+      memset(&(*addresses)->addrs[i], 0, sizeof(grpc_resolved_address));
+      if (hostent->h_addrtype == AF_INET6) {
+        (*addresses)->addrs[i].len = sizeof(struct sockaddr_in6);
+        struct sockaddr_in6 *addr =
+            (struct sockaddr_in6 *)&(*addresses)->addrs[i].addr;
+        addr->sin6_family = (sa_family_t)hostent->h_addrtype;
+        addr->sin6_port = strhtons(r->port);
+
+        char output[INET6_ADDRSTRLEN];
+        memcpy(&addr->sin6_addr, hostent->h_addr_list[i - prev_naddr],
+               sizeof(struct in6_addr));
+        ares_inet_ntop(AF_INET6, &addr->sin6_addr, output, INET6_ADDRSTRLEN);
+        gpr_log(GPR_DEBUG,
+                "c-ares resolver gets a AF_INET6 result: \n"
+                "  addr: %s\n  port: %s\n  sin6_scope_id: %d\n",
+                output, r->port, addr->sin6_scope_id);
+      } else {
+        (*addresses)->addrs[i].len = sizeof(struct sockaddr_in);
+        struct sockaddr_in *addr =
+            (struct sockaddr_in *)&(*addresses)->addrs[i].addr;
+        memcpy(&addr->sin_addr, hostent->h_addr_list[i - prev_naddr],
+               sizeof(struct in_addr));
+        addr->sin_family = (sa_family_t)hostent->h_addrtype;
+        addr->sin_port = strhtons(r->port);
+
+        char output[INET_ADDRSTRLEN];
+        ares_inet_ntop(AF_INET, &addr->sin_addr, output, INET_ADDRSTRLEN);
+        gpr_log(GPR_DEBUG,
+                "c-ares resolver gets a AF_INET result: \n"
+                "  addr: %s\n  port: %s\n",
+                output, r->port);
+      }
+    }
+  } else if (!r->success) {
+    char *error_msg;
+    gpr_asprintf(&error_msg, "C-ares status is not ARES_SUCCESS: %s",
+                 ares_strerror(status));
+    grpc_error *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+    gpr_free(error_msg);
+    if (r->error == GRPC_ERROR_NONE) {
+      r->error = error;
+    } else {
+      r->error = grpc_error_add_child(error, r->error);
+    }
+  }
+  gpr_mu_unlock(&r->mu);
+  grpc_ares_request_unref(NULL, r);
+}
+
+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) {
+  /* TODO(zyc): Enable tracing after #9603 is checked in */
+  /* if (grpc_dns_trace) {
+      gpr_log(GPR_DEBUG, "resolve_address (blocking): name=%s, default_port=%s",
+              name, default_port);
+     } */
+
+  /* parse name, splitting it into host and port parts */
+  char *host;
+  char *port;
+  gpr_split_host_port(name, &host, &port);
+  if (host == NULL) {
+    grpc_error *err = grpc_error_set_str(
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("unparseable host:port"),
+        GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name));
+    grpc_closure_sched(exec_ctx, on_done, err);
+    goto error_cleanup;
+  } else if (port == NULL) {
+    if (default_port == NULL) {
+      grpc_error *err = grpc_error_set_str(
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("no port in name"),
+          GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(name));
+      grpc_closure_sched(exec_ctx, on_done, err);
+      goto error_cleanup;
+    }
+    port = gpr_strdup(default_port);
+  }
+
+  grpc_ares_ev_driver *ev_driver;
+  grpc_error *err = grpc_ares_ev_driver_create(&ev_driver, interested_parties);
+  if (err != GRPC_ERROR_NONE) {
+    GRPC_LOG_IF_ERROR("grpc_ares_ev_driver_create() failed", err);
+    goto error_cleanup;
+  }
+
+  grpc_ares_request *r = gpr_malloc(sizeof(grpc_ares_request));
+  gpr_mu_init(&r->mu);
+  r->ev_driver = ev_driver;
+  r->on_done = on_done;
+  r->addrs_out = addrs;
+  r->default_port = gpr_strdup(default_port);
+  r->port = port;
+  r->host = host;
+  r->success = false;
+  r->error = GRPC_ERROR_NONE;
+  ares_channel *channel = grpc_ares_ev_driver_get_channel(r->ev_driver);
+  gpr_ref_init(&r->pending_queries, 2);
+  if (grpc_ipv6_loopback_available()) {
+    gpr_ref(&r->pending_queries);
+    ares_gethostbyname(*channel, r->host, AF_INET6, on_done_cb, r);
+  }
+  ares_gethostbyname(*channel, r->host, AF_INET, on_done_cb, r);
+  /* TODO(zyc): Handle CNAME records here. */
+  grpc_ares_ev_driver_start(exec_ctx, r->ev_driver);
+  grpc_ares_request_unref(exec_ctx, r);
+  return;
+
+error_cleanup:
+  gpr_free(host);
+  gpr_free(port);
+}
+
+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) {
+  gpr_once_init(&g_basic_init, do_basic_init);
+  gpr_mu_lock(&g_init_mu);
+  int status = ares_library_init(ARES_LIB_INIT_ALL);
+  gpr_mu_unlock(&g_init_mu);
+
+  if (status != ARES_SUCCESS) {
+    char *error_msg;
+    gpr_asprintf(&error_msg, "ares_library_init failed: %s",
+                 ares_strerror(status));
+    grpc_error *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+    gpr_free(error_msg);
+    return error;
+  }
+  return GRPC_ERROR_NONE;
+}
+
+void grpc_ares_cleanup(void) {
+  gpr_mu_lock(&g_init_mu);
+  ares_library_cleanup();
+  gpr_mu_unlock(&g_init_mu);
+}
+
+#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h
new file mode 100644
index 0000000000..ab00a26b36
--- /dev/null
+++ b/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h
@@ -0,0 +1,63 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
+#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/iomgr.h"
+#include "src/core/lib/iomgr/polling_entity.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+
+/* Asynchronously resolve addr. Use \a default_port if a port isn't designated
+   in addr, otherwise use the port in addr. grpc_ares_init() must be called at
+   least once before this function. \a on_done may be called directly in this
+   function without being scheduled with \a exec_ctx, it must not try to acquire
+   locks that are being held by the caller. */
+extern void (*grpc_resolve_address_ares)(grpc_exec_ctx *exec_ctx,
+                                         const char *addr,
+                                         const char *default_port,
+                                         grpc_pollset_set *interested_parties,
+                                         grpc_closure *on_done,
+                                         grpc_resolved_addresses **addresses);
+
+/* Initialize gRPC ares wrapper. Must be called at least once before
+   grpc_resolve_address_ares(). */
+grpc_error *grpc_ares_init(void);
+
+/* Uninitialized gRPC ares wrapper. If there was more than one previous call to
+   grpc_ares_init(), this function uninitializes the gRPC ares wrapper only if
+   it has been called the same number of times as grpc_ares_init(). */
+void grpc_ares_cleanup(void);
+
+#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H */
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index d227c19c43..97cd0486a9 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -44,6 +44,7 @@
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/support/backoff.h"
+#include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 
 #define GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS 1
@@ -113,8 +114,9 @@ static void dns_shutdown_locked(grpc_exec_ctx *exec_ctx,
   }
   if (r->next_completion != NULL) {
     *r->target_result = NULL;
-    grpc_closure_sched(exec_ctx, r->next_completion,
-                       GRPC_ERROR_CREATE("Resolver Shutdown"));
+    grpc_closure_sched(
+        exec_ctx, r->next_completion,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Resolver Shutdown"));
     r->next_completion = NULL;
   }
 }
@@ -303,7 +305,21 @@ static grpc_resolver_factory *dns_resolver_factory_create() {
 }
 
 void grpc_resolver_dns_native_init(void) {
-  grpc_register_resolver_type(dns_resolver_factory_create());
+  char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
+  if (resolver != NULL && gpr_stricmp(resolver, "native") == 0) {
+    gpr_log(GPR_DEBUG, "Using native dns resolver");
+    grpc_register_resolver_type(dns_resolver_factory_create());
+  } else {
+    grpc_resolver_factory *existing_factory =
+        grpc_resolver_factory_lookup("dns");
+    if (existing_factory == NULL) {
+      gpr_log(GPR_DEBUG, "Using native dns resolver");
+      grpc_register_resolver_type(dns_resolver_factory_create());
+    } else {
+      grpc_resolver_factory_unref(existing_factory);
+    }
+  }
+  gpr_free(resolver);
 }
 
 void grpc_resolver_dns_native_shutdown(void) {}
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.c b/src/core/ext/transport/chttp2/client/chttp2_connector.c
index d49c32b671..2b226c1bf7 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.c
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.c
@@ -113,7 +113,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_lock(&c->mu);
   if (error != GRPC_ERROR_NONE || c->shutdown) {
     if (error == GRPC_ERROR_NONE) {
-      error = GRPC_ERROR_CREATE("connector shutdown");
+      error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("connector shutdown");
       // We were shut down after handshaking completed successfully, so
       // destroy the endpoint here.
       // TODO(ctiller): It is currently necessary to shutdown endpoints
@@ -164,7 +164,7 @@ static void connected(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   c->connecting = false;
   if (error != GRPC_ERROR_NONE || c->shutdown) {
     if (error == GRPC_ERROR_NONE) {
-      error = GRPC_ERROR_CREATE("connector shutdown");
+      error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("connector shutdown");
     } else {
       error = GRPC_ERROR_REF(error);
     }
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.c
index 837b9fd03d..6433968ca5 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.c
@@ -256,7 +256,7 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
     char *msg;
     gpr_asprintf(&msg, "No address added out of total %" PRIuPTR " resolved",
                  naddrs);
-    err = GRPC_ERROR_CREATE_REFERENCING(msg, errors, naddrs);
+    err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
     gpr_free(msg);
     goto error;
   } else if (count != naddrs) {
@@ -264,7 +264,7 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
     gpr_asprintf(&msg, "Only %" PRIuPTR
                        " addresses added out of total %" PRIuPTR " resolved",
                  count, naddrs);
-    err = GRPC_ERROR_CREATE_REFERENCING(msg, errors, naddrs);
+    err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
     gpr_free(msg);
 
     const char *warning_message = grpc_error_string(err);
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
index cb2b3f5502..88c813f3be 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
@@ -61,7 +61,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
       3, (server, addr, creds));
   // Create security context.
   if (creds == NULL) {
-    err = GRPC_ERROR_CREATE(
+    err = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
         "No credentials specified for secure server port (creds==NULL)");
     goto done;
   }
@@ -72,7 +72,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
     gpr_asprintf(&msg,
                  "Unable to create secure server with credentials of type %s.",
                  creds->type);
-    err = grpc_error_set_int(GRPC_ERROR_CREATE(msg),
+    err = grpc_error_set_int(GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg),
                              GRPC_ERROR_INT_SECURITY_STATUS, status);
     gpr_free(msg);
     goto done;
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 89659e7464..8676a3752e 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -187,7 +187,8 @@ static void destruct_transport(grpc_exec_ctx *exec_ctx,
 
   GRPC_COMBINER_UNREF(exec_ctx, t->combiner, "chttp2_transport");
 
-  cancel_pings(exec_ctx, t, GRPC_ERROR_CREATE("Transport destroyed"));
+  cancel_pings(exec_ctx, t,
+               GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport destroyed"));
 
   while (t->write_cb_pool) {
     grpc_chttp2_write_cb *next = t->write_cb_pool->next;
@@ -494,8 +495,9 @@ static void destroy_transport_locked(grpc_exec_ctx *exec_ctx, void *tp,
   t->destroying = 1;
   close_transport_locked(
       exec_ctx, t,
-      grpc_error_set_int(GRPC_ERROR_CREATE("Transport destroyed"),
-                         GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state));
+      grpc_error_set_int(
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport destroyed"),
+          GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state));
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "destroy");
 }
 
@@ -518,7 +520,8 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
     if (t->write_state != GRPC_CHTTP2_WRITE_STATE_IDLE) {
       if (t->close_transport_on_writes_finished == NULL) {
         t->close_transport_on_writes_finished =
-            GRPC_ERROR_CREATE("Delayed close due to in-progress write");
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                "Delayed close due to in-progress write");
       }
       t->close_transport_on_writes_finished =
           grpc_error_add_child(t->close_transport_on_writes_finished, error);
@@ -834,7 +837,8 @@ static void write_action_end_locked(grpc_exec_ctx *exec_ctx, void *tp,
   if (t->sent_goaway_state == GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED) {
     t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SENT;
     if (grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
-      close_transport_locked(exec_ctx, t, GRPC_ERROR_CREATE("goaway sent"));
+      close_transport_locked(
+          exec_ctx, t, GRPC_ERROR_CREATE_FROM_STATIC_STRING("goaway sent"));
     }
   }
 
@@ -898,22 +902,19 @@ void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
                                      grpc_chttp2_transport *t,
                                      uint32_t goaway_error,
                                      grpc_slice goaway_text) {
-  char *msg = grpc_dump_slice(goaway_text, GPR_DUMP_HEX | GPR_DUMP_ASCII);
-  GRPC_CHTTP2_IF_TRACING(
-      gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg));
-  grpc_slice_unref_internal(exec_ctx, goaway_text);
+  // GRPC_CHTTP2_IF_TRACING(
+  //     gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg));
   t->seen_goaway = 1;
   /* lie: use transient failure from the transport to indicate goaway has been
    * received */
   connectivity_state_set(
       exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE,
       grpc_error_set_str(
-          grpc_error_set_int(GRPC_ERROR_CREATE("GOAWAY received"),
-                             GRPC_ERROR_INT_HTTP2_ERROR,
-                             (intptr_t)goaway_error),
-          GRPC_ERROR_STR_RAW_BYTES, msg),
+          grpc_error_set_int(
+              GRPC_ERROR_CREATE_FROM_STATIC_STRING("GOAWAY received"),
+              GRPC_ERROR_INT_HTTP2_ERROR, (intptr_t)goaway_error),
+          GRPC_ERROR_STR_RAW_BYTES, goaway_text),
       "got_goaway");
-  gpr_free(msg);
 }
 
 static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
@@ -936,9 +937,10 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
     t->next_stream_id += 2;
 
     if (t->next_stream_id >= MAX_CLIENT_STREAM_ID) {
-      connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE,
-                             GRPC_ERROR_CREATE("Stream IDs exhausted"),
-                             "no_more_stream_ids");
+      connectivity_state_set(
+          exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE,
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Stream IDs exhausted"),
+          "no_more_stream_ids");
     }
 
     grpc_chttp2_stream_map_add(&t->stream_map, s->id, s);
@@ -952,9 +954,9 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
          grpc_chttp2_list_pop_waiting_for_concurrency(t, &s)) {
     grpc_chttp2_cancel_stream(
         exec_ctx, t, s,
-        grpc_error_set_int(GRPC_ERROR_CREATE("Stream IDs exhausted"),
-                           GRPC_ERROR_INT_GRPC_STATUS,
-                           GRPC_STATUS_UNAVAILABLE));
+        grpc_error_set_int(
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING("Stream IDs exhausted"),
+            GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE));
   }
 }
 
@@ -1003,11 +1005,11 @@ void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
   }
   if (error != GRPC_ERROR_NONE) {
     if (closure->error_data.error == GRPC_ERROR_NONE) {
-      closure->error_data.error =
-          GRPC_ERROR_CREATE("Error in HTTP transport completing operation");
-      closure->error_data.error =
-          grpc_error_set_str(closure->error_data.error,
-                             GRPC_ERROR_STR_TARGET_ADDRESS, t->peer_string);
+      closure->error_data.error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "Error in HTTP transport completing operation");
+      closure->error_data.error = grpc_error_set_str(
+          closure->error_data.error, GRPC_ERROR_STR_TARGET_ADDRESS,
+          grpc_slice_from_copied_string(t->peer_string));
     }
     closure->error_data.error =
         grpc_error_add_child(closure->error_data.error, error);
@@ -1182,10 +1184,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           exec_ctx, t, s,
           grpc_error_set_int(
               grpc_error_set_int(
-                  grpc_error_set_int(
-                      GRPC_ERROR_CREATE("to-be-sent initial metadata size "
-                                        "exceeds peer limit"),
-                      GRPC_ERROR_INT_SIZE, (intptr_t)metadata_size),
+                  grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                         "to-be-sent initial metadata size "
+                                         "exceeds peer limit"),
+                                     GRPC_ERROR_INT_SIZE,
+                                     (intptr_t)metadata_size),
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
@@ -1201,9 +1204,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           } else {
             grpc_chttp2_cancel_stream(
                 exec_ctx, t, s,
-                grpc_error_set_int(GRPC_ERROR_CREATE("Transport closed"),
-                                   GRPC_ERROR_INT_GRPC_STATUS,
-                                   GRPC_STATUS_UNAVAILABLE));
+                grpc_error_set_int(
+                    GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport closed"),
+                    GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE));
           }
         } else {
           GPR_ASSERT(s->id != 0);
@@ -1215,7 +1218,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
         s->send_initial_metadata = NULL;
         grpc_chttp2_complete_closure_step(
             exec_ctx, t, s, &s->send_initial_metadata_finished,
-            GRPC_ERROR_CREATE_REFERENCING(
+            GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
                 "Attempt to send initial metadata after stream was closed",
                 &s->write_closed_error, 1),
             "send_initial_metadata_finished");
@@ -1229,7 +1232,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     if (s->write_closed) {
       grpc_chttp2_complete_closure_step(
           exec_ctx, t, s, &s->fetching_send_message_finished,
-          GRPC_ERROR_CREATE_REFERENCING(
+          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
               "Attempt to send message after stream was closed",
               &s->write_closed_error, 1),
           "fetching_send_message_finished");
@@ -1277,10 +1280,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           exec_ctx, t, s,
           grpc_error_set_int(
               grpc_error_set_int(
-                  grpc_error_set_int(
-                      GRPC_ERROR_CREATE("to-be-sent trailing metadata size "
-                                        "exceeds peer limit"),
-                      GRPC_ERROR_INT_SIZE, (intptr_t)metadata_size),
+                  grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                         "to-be-sent trailing metadata size "
+                                         "exceeds peer limit"),
+                                     GRPC_ERROR_INT_SIZE,
+                                     (intptr_t)metadata_size),
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
@@ -1293,8 +1297,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
             exec_ctx, t, s, &s->send_trailing_metadata_finished,
             grpc_metadata_batch_is_empty(op->send_trailing_metadata)
                 ? GRPC_ERROR_NONE
-                : GRPC_ERROR_CREATE("Attempt to send trailing metadata after "
-                                    "stream was closed"),
+                : GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                      "Attempt to send trailing metadata after "
+                      "stream was closed"),
             "send_trailing_metadata_finished");
       } else if (s->id != 0) {
         /* TODO(ctiller): check if there's flow control for any outstanding
@@ -1409,11 +1414,11 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                         grpc_error *error) {
   t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED;
   grpc_http2_error_code http_error;
-  const char *msg;
-  grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL, &msg,
-                        &http_error);
+  grpc_slice slice;
+  grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL,
+                        &slice, &http_error);
   grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
-                            grpc_slice_from_copied_string(msg), &t->qbuf);
+                            grpc_slice_ref_internal(slice), &t->qbuf);
   grpc_chttp2_initiate_write(exec_ctx, t, false, "goaway_sent");
   GRPC_ERROR_UNREF(error);
 }
@@ -1573,7 +1578,7 @@ static void remove_stream(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     if (t->sent_goaway_state == GRPC_CHTTP2_GOAWAY_SENT) {
       close_transport_locked(
           exec_ctx, t,
-          GRPC_ERROR_CREATE_REFERENCING(
+          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
               "Last stream closed after sending GOAWAY", &error, 1));
     }
   }
@@ -1614,8 +1619,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
 void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              grpc_chttp2_stream *s, grpc_error *error) {
   grpc_status_code status;
-  const char *msg;
-  grpc_error_get_status(error, s->deadline, &status, &msg, NULL);
+  grpc_slice slice;
+  grpc_error_get_status(error, s->deadline, &status, &slice, NULL);
 
   if (status != GRPC_STATUS_OK) {
     s->seen_error = true;
@@ -1636,13 +1641,13 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           grpc_mdelem_from_slices(
                               exec_ctx, GRPC_MDSTR_GRPC_STATUS,
                               grpc_slice_from_copied_string(status_string))));
-    if (msg != NULL) {
+    if (!GRPC_SLICE_IS_EMPTY(slice)) {
       GRPC_LOG_IF_ERROR(
           "add_status_message",
           grpc_chttp2_incoming_metadata_buffer_replace_or_add(
               exec_ctx, &s->metadata_buffer[1],
               grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
-                                      grpc_slice_from_copied_string(msg))));
+                                      grpc_slice_ref_internal(slice))));
     }
     s->published_metadata[1] = GRPC_METADATA_SYNTHESIZED_FROM_FAKE;
     grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
@@ -1671,7 +1676,8 @@ static grpc_error *removal_error(grpc_error *extra_error, grpc_chttp2_stream *s,
   add_error(extra_error, refs, &nrefs);
   grpc_error *error = GRPC_ERROR_NONE;
   if (nrefs > 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING(master_error_msg, refs, nrefs);
+    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(master_error_msg,
+                                                             refs, nrefs);
   }
   GRPC_ERROR_UNREF(extra_error);
   return error;
@@ -1770,8 +1776,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   uint8_t *p;
   uint32_t len = 0;
   grpc_status_code grpc_status;
-  const char *msg;
-  grpc_error_get_status(error, s->deadline, &grpc_status, &msg, NULL);
+  grpc_slice slice;
+  grpc_error_get_status(error, s->deadline, &grpc_status, &slice, NULL);
 
   GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100);
 
@@ -1827,32 +1833,30 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   GPR_ASSERT(p == GRPC_SLICE_END_PTR(status_hdr));
   len += (uint32_t)GRPC_SLICE_LENGTH(status_hdr);
 
-  if (msg != NULL) {
-    size_t msg_len = strlen(msg);
-    GPR_ASSERT(msg_len <= UINT32_MAX);
-    uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 0);
-    message_pfx = grpc_slice_malloc(14 + msg_len_len);
-    p = GRPC_SLICE_START_PTR(message_pfx);
-    *p++ = 0x00; /* literal header, not indexed */
-    *p++ = 12;   /* len(grpc-message) */
-    *p++ = 'g';
-    *p++ = 'r';
-    *p++ = 'p';
-    *p++ = 'c';
-    *p++ = '-';
-    *p++ = 'm';
-    *p++ = 'e';
-    *p++ = 's';
-    *p++ = 's';
-    *p++ = 'a';
-    *p++ = 'g';
-    *p++ = 'e';
-    GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 0, 0, p, (uint32_t)msg_len_len);
-    p += msg_len_len;
-    GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx));
-    len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx);
-    len += (uint32_t)msg_len;
-  }
+  size_t msg_len = GRPC_SLICE_LENGTH(slice);
+  GPR_ASSERT(msg_len <= UINT32_MAX);
+  uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 1);
+  message_pfx = grpc_slice_malloc(14 + msg_len_len);
+  p = GRPC_SLICE_START_PTR(message_pfx);
+  *p++ = 0x00; /* literal header, not indexed */
+  *p++ = 12;   /* len(grpc-message) */
+  *p++ = 'g';
+  *p++ = 'r';
+  *p++ = 'p';
+  *p++ = 'c';
+  *p++ = '-';
+  *p++ = 'm';
+  *p++ = 'e';
+  *p++ = 's';
+  *p++ = 's';
+  *p++ = 'a';
+  *p++ = 'g';
+  *p++ = 'e';
+  GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 1, 0, p, (uint32_t)msg_len_len);
+  p += msg_len_len;
+  GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx));
+  len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx);
+  len += (uint32_t)msg_len;
 
   hdr = grpc_slice_malloc(9);
   p = GRPC_SLICE_START_PTR(hdr);
@@ -1872,10 +1876,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     grpc_slice_buffer_add(&t->qbuf, http_status_hdr);
   }
   grpc_slice_buffer_add(&t->qbuf, status_hdr);
-  if (msg != NULL) {
-    grpc_slice_buffer_add(&t->qbuf, message_pfx);
-    grpc_slice_buffer_add(&t->qbuf, grpc_slice_from_copied_string(msg));
-  }
+  grpc_slice_buffer_add(&t->qbuf, message_pfx);
+  grpc_slice_buffer_add(&t->qbuf, grpc_slice_ref_internal(slice));
   grpc_slice_buffer_add(
       &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR,
                                               &s->stats.outgoing));
@@ -1950,9 +1952,9 @@ static grpc_error *try_http_parsing(grpc_exec_ctx *exec_ctx,
   if (parse_error == GRPC_ERROR_NONE &&
       (parse_error = grpc_http_parser_eof(&parser)) == GRPC_ERROR_NONE) {
     error = grpc_error_set_int(
-        grpc_error_set_int(
-            GRPC_ERROR_CREATE("Trying to connect an http1.x server"),
-            GRPC_ERROR_INT_HTTP_STATUS, response.status),
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                               "Trying to connect an http1.x server"),
+                           GRPC_ERROR_INT_HTTP_STATUS, response.status),
         GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE);
   }
   GRPC_ERROR_UNREF(parse_error);
@@ -1973,9 +1975,10 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
   grpc_error *err = error;
   if (err != GRPC_ERROR_NONE) {
-    err = grpc_error_set_int(
-        GRPC_ERROR_CREATE_REFERENCING("Endpoint read failed", &err, 1),
-        GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state);
+    err = grpc_error_set_int(GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                                 "Endpoint read failed", &err, 1),
+                             GRPC_ERROR_INT_OCCURRED_DURING_WRITE,
+                             t->write_state);
   }
   GPR_SWAP(grpc_error *, err, error);
   GRPC_ERROR_UNREF(err);
@@ -1996,8 +1999,8 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
     if (errors[1] != GRPC_ERROR_NONE) {
       errors[2] = try_http_parsing(exec_ctx, t);
       GRPC_ERROR_UNREF(error);
-      error = GRPC_ERROR_CREATE_REFERENCING("Failed parsing HTTP/2", errors,
-                                            GPR_ARRAY_SIZE(errors));
+      error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+          "Failed parsing HTTP/2", errors, GPR_ARRAY_SIZE(errors));
     }
     for (i = 0; i < GPR_ARRAY_SIZE(errors); i++) {
       GRPC_ERROR_UNREF(errors[i]);
@@ -2022,7 +2025,7 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
   GPR_TIMER_BEGIN("post_reading_action_locked", 0);
   bool keep_reading = false;
   if (error == GRPC_ERROR_NONE && t->closed) {
-    error = GRPC_ERROR_CREATE("Transport closed");
+    error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport closed");
   }
   if (error != GRPC_ERROR_NONE) {
     close_transport_locked(exec_ctx, t, GRPC_ERROR_REF(error));
@@ -2157,8 +2160,8 @@ static void keepalive_watchdog_fired_locked(grpc_exec_ctx *exec_ctx, void *arg,
   if (t->keepalive_state == GRPC_CHTTP2_KEEPALIVE_STATE_PINGING) {
     if (error == GRPC_ERROR_NONE) {
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DYING;
-      close_transport_locked(exec_ctx, t,
-                             GRPC_ERROR_CREATE("keepalive watchdog timeout"));
+      close_transport_locked(exec_ctx, t, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                              "keepalive watchdog timeout"));
     }
   } else {
     /** The watchdog timer should have been cancelled by
@@ -2357,7 +2360,8 @@ void grpc_chttp2_incoming_byte_stream_push(grpc_exec_ctx *exec_ctx,
   gpr_mu_lock(&bs->slice_mu);
   if (bs->remaining_bytes < GRPC_SLICE_LENGTH(slice)) {
     incoming_byte_stream_publish_error(
-        exec_ctx, bs, GRPC_ERROR_CREATE("Too many bytes in stream"));
+        exec_ctx, bs,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Too many bytes in stream"));
   } else {
     bs->remaining_bytes -= (uint32_t)GRPC_SLICE_LENGTH(slice);
     if (bs->on_next != NULL) {
@@ -2377,7 +2381,7 @@ void grpc_chttp2_incoming_byte_stream_finished(
   if (error == GRPC_ERROR_NONE) {
     gpr_mu_lock(&bs->slice_mu);
     if (bs->remaining_bytes != 0) {
-      error = GRPC_ERROR_CREATE("Truncated message");
+      error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Truncated message");
     }
     gpr_mu_unlock(&bs->slice_mu);
   }
@@ -2457,9 +2461,9 @@ static void benign_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
               t->peer_string);
     }
     send_goaway(exec_ctx, t,
-                grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"),
-                                   GRPC_ERROR_INT_HTTP2_ERROR,
-                                   GRPC_HTTP2_ENHANCE_YOUR_CALM));
+                grpc_error_set_int(
+                    GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"),
+                    GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_ENHANCE_YOUR_CALM));
   } else if (error == GRPC_ERROR_NONE && grpc_resource_quota_trace) {
     gpr_log(GPR_DEBUG,
             "HTTP2: %s - skip benign reclamation, there are still %" PRIdPTR
@@ -2486,9 +2490,10 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
               s->id);
     }
     grpc_chttp2_cancel_stream(
-        exec_ctx, t, s, grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"),
-                                           GRPC_ERROR_INT_HTTP2_ERROR,
-                                           GRPC_HTTP2_ENHANCE_YOUR_CALM));
+        exec_ctx, t, s,
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"),
+                           GRPC_ERROR_INT_HTTP2_ERROR,
+                           GRPC_HTTP2_ENHANCE_YOUR_CALM));
     if (n > 1) {
       /* Since we cancel one stream per destructive reclamation, if
          there are more streams left, we can immediately post a new
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.c b/src/core/ext/transport/chttp2/transport/frame_data.c
index f9b9e1b309..6e9258ee7e 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.c
+++ b/src/core/ext/transport/chttp2/transport/frame_data.c
@@ -54,7 +54,8 @@ void grpc_chttp2_data_parser_destroy(grpc_exec_ctx *exec_ctx,
                                      grpc_chttp2_data_parser *parser) {
   if (parser->parsing_frame != NULL) {
     grpc_chttp2_incoming_byte_stream_finished(
-        exec_ctx, parser->parsing_frame, GRPC_ERROR_CREATE("Parser destroyed"));
+        exec_ctx, parser->parsing_frame,
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Parser destroyed"));
   }
   GRPC_ERROR_UNREF(parser->error);
 }
@@ -65,8 +66,9 @@ grpc_error *grpc_chttp2_data_parser_begin_frame(grpc_chttp2_data_parser *parser,
   if (flags & ~GRPC_CHTTP2_DATA_FLAG_END_STREAM) {
     char *msg;
     gpr_asprintf(&msg, "unsupported data flags: 0x%02x", flags);
-    grpc_error *err = grpc_error_set_int(
-        GRPC_ERROR_CREATE(msg), GRPC_ERROR_INT_STREAM_ID, (intptr_t)stream_id);
+    grpc_error *err =
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg),
+                           GRPC_ERROR_INT_STREAM_ID, (intptr_t)stream_id);
     gpr_free(msg);
     return err;
   }
@@ -173,13 +175,13 @@ static grpc_error *parse_inner(grpc_exec_ctx *exec_ctx,
           break;
         default:
           gpr_asprintf(&msg, "Bad GRPC frame type 0x%02x", p->frame_type);
-          p->error = GRPC_ERROR_CREATE(msg);
+          p->error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
           p->error = grpc_error_set_int(p->error, GRPC_ERROR_INT_STREAM_ID,
                                         (intptr_t)s->id);
           gpr_free(msg);
           msg = grpc_dump_slice(slice, GPR_DUMP_HEX | GPR_DUMP_ASCII);
-          p->error =
-              grpc_error_set_str(p->error, GRPC_ERROR_STR_RAW_BYTES, msg);
+          p->error = grpc_error_set_str(p->error, GRPC_ERROR_STR_RAW_BYTES,
+                                        grpc_slice_from_copied_string(msg));
           gpr_free(msg);
           p->error =
               grpc_error_set_int(p->error, GRPC_ERROR_INT_OFFSET, cur - beg);
@@ -265,7 +267,8 @@ static grpc_error *parse_inner(grpc_exec_ctx *exec_ctx,
       }
   }
 
-  GPR_UNREACHABLE_CODE(return GRPC_ERROR_CREATE("Should never reach here"));
+  GPR_UNREACHABLE_CODE(
+      return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Should never reach here"));
 }
 
 grpc_error *grpc_chttp2_data_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.c b/src/core/ext/transport/chttp2/transport/frame_goaway.c
index d99d486c1b..001271dd22 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.c
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.c
@@ -54,7 +54,7 @@ grpc_error *grpc_chttp2_goaway_parser_begin_frame(grpc_chttp2_goaway_parser *p,
   if (length < 8) {
     char *msg;
     gpr_asprintf(&msg, "goaway frame too short (%d bytes)", length);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -156,7 +156,8 @@ grpc_error *grpc_chttp2_goaway_parser_parse(grpc_exec_ctx *exec_ctx,
       }
       return GRPC_ERROR_NONE;
   }
-  GPR_UNREACHABLE_CODE(return GRPC_ERROR_CREATE("Should never reach here"));
+  GPR_UNREACHABLE_CODE(
+      return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Should never reach here"));
 }
 
 void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.c
index 9b4b1a7b84..de8462a17e 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.c
@@ -71,7 +71,7 @@ grpc_error *grpc_chttp2_ping_parser_begin_frame(grpc_chttp2_ping_parser *parser,
   if (flags & 0xfe || length != 8) {
     char *msg;
     gpr_asprintf(&msg, "invalid ping: length=%d, flags=%02x", length, flags);
-    grpc_error *error = GRPC_ERROR_CREATE(msg);
+    grpc_error *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return error;
   }
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
index cb017e75f0..225f15c77c 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
@@ -76,7 +76,7 @@ grpc_error *grpc_chttp2_rst_stream_parser_begin_frame(
     char *msg;
     gpr_asprintf(&msg, "invalid rst_stream: length=%d, flags=%02x", length,
                  flags);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -112,8 +112,9 @@ grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
       char *message;
       gpr_asprintf(&message, "Received RST_STREAM with error code %d", reason);
       error = grpc_error_set_int(
-          grpc_error_set_str(GRPC_ERROR_CREATE("RST_STREAM"),
-                             GRPC_ERROR_STR_GRPC_MESSAGE, message),
+          grpc_error_set_str(GRPC_ERROR_CREATE_FROM_STATIC_STRING("RST_STREAM"),
+                             GRPC_ERROR_STR_GRPC_MESSAGE,
+                             grpc_slice_from_copied_string(message)),
           GRPC_ERROR_INT_HTTP2_ERROR, (intptr_t)reason);
       gpr_free(message);
     }
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.c b/src/core/ext/transport/chttp2/transport/frame_settings.c
index 82290e34cd..16881c0707 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.c
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.c
@@ -131,13 +131,16 @@ grpc_error *grpc_chttp2_settings_parser_begin_frame(
   if (flags == GRPC_CHTTP2_FLAG_ACK) {
     parser->is_ack = 1;
     if (length != 0) {
-      return GRPC_ERROR_CREATE("non-empty settings ack frame received");
+      return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "non-empty settings ack frame received");
     }
     return GRPC_ERROR_NONE;
   } else if (flags != 0) {
-    return GRPC_ERROR_CREATE("invalid flags on settings frame");
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "invalid flags on settings frame");
   } else if (length % 6 != 0) {
-    return GRPC_ERROR_CREATE("settings frames must be a multiple of six bytes");
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "settings frames must be a multiple of six bytes");
   } else {
     return GRPC_ERROR_NONE;
   }
@@ -229,7 +232,7 @@ grpc_error *grpc_chttp2_settings_parser_parse(grpc_exec_ctx *exec_ctx, void *p,
                     &t->qbuf);
                 gpr_asprintf(&msg, "invalid value %u passed for %s",
                              parser->value, sp->name);
-                grpc_error *err = GRPC_ERROR_CREATE(msg);
+                grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
                 gpr_free(msg);
                 return err;
             }
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.c b/src/core/ext/transport/chttp2/transport/frame_window_update.c
index 8fa0bb471a..b76b6f6f47 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.c
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.c
@@ -70,7 +70,7 @@ grpc_error *grpc_chttp2_window_update_parser_begin_frame(
     char *msg;
     gpr_asprintf(&msg, "invalid window update: length=%d, flags=%02x", length,
                  flags);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -102,7 +102,7 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
     if (received_update == 0 || (received_update & 0x80000000u)) {
       char *msg;
       gpr_asprintf(&msg, "invalid window update bytes: %d", p->amount);
-      grpc_error *err = GRPC_ERROR_CREATE(msg);
+      grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
       gpr_free(msg);
       return err;
     }
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.c
index 1865b997b7..5099d736bf 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.c
@@ -693,7 +693,7 @@ static grpc_error *on_hdr(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p,
   }
   if (p->on_header == NULL) {
     GRPC_MDELEM_UNREF(exec_ctx, md);
-    return GRPC_ERROR_CREATE("on_header callback not set");
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING("on_header callback not set");
   }
   p->on_header(exec_ctx, p->on_header_user_data, md);
   return GRPC_ERROR_NONE;
@@ -810,7 +810,8 @@ static grpc_error *finish_indexed_field(grpc_exec_ctx *exec_ctx,
   grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   if (GRPC_MDISNULL(md)) {
     return grpc_error_set_int(
-        grpc_error_set_int(GRPC_ERROR_CREATE("Invalid HPACK index received"),
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                               "Invalid HPACK index received"),
                            GRPC_ERROR_INT_INDEX, (intptr_t)p->index),
         GRPC_ERROR_INT_SIZE, (intptr_t)p->table.num_ents);
   }
@@ -1074,7 +1075,7 @@ static grpc_error *parse_max_tbl_size(grpc_exec_ctx *exec_ctx,
   if (p->dynamic_table_update_allowed == 0) {
     return parse_error(
         exec_ctx, p, cur, end,
-        GRPC_ERROR_CREATE(
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING(
             "More than two max table size changes in a single frame"));
   }
   p->dynamic_table_update_allowed--;
@@ -1092,7 +1093,7 @@ static grpc_error *parse_max_tbl_size_x(grpc_exec_ctx *exec_ctx,
   if (p->dynamic_table_update_allowed == 0) {
     return parse_error(
         exec_ctx, p, cur, end,
-        GRPC_ERROR_CREATE(
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING(
             "More than two max table size changes in a single frame"));
   }
   p->dynamic_table_update_allowed--;
@@ -1126,7 +1127,7 @@ static grpc_error *parse_illegal_op(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(cur != end);
   char *msg;
   gpr_asprintf(&msg, "Illegal hpack op code %d", *cur);
-  grpc_error *err = GRPC_ERROR_CREATE(msg);
+  grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
   gpr_free(msg);
   return parse_error(exec_ctx, p, cur, end, err);
 }
@@ -1246,7 +1247,7 @@ error:
                "integer overflow in hpack integer decoding: have 0x%08x, "
                "got byte 0x%02x on byte 5",
                *p->parsing.value, *cur);
-  grpc_error *err = GRPC_ERROR_CREATE(msg);
+  grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
   gpr_free(msg);
   return parse_error(exec_ctx, p, cur, end, err);
 }
@@ -1275,7 +1276,7 @@ static grpc_error *parse_value5up(grpc_exec_ctx *exec_ctx,
                "integer overflow in hpack integer decoding: have 0x%08x, "
                "got byte 0x%02x sometime after byte 5",
                *p->parsing.value, *cur);
-  grpc_error *err = GRPC_ERROR_CREATE(msg);
+  grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
   gpr_free(msg);
   return parse_error(exec_ctx, p, cur, end, err);
 }
@@ -1333,8 +1334,9 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(exec_ctx, p, cur, end,
-                           GRPC_ERROR_CREATE("Illegal base64 character"));
+        return parse_error(
+            exec_ctx, p, cur, end,
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte0;
       p->base64_buffer = bits << 18;
@@ -1348,8 +1350,9 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(exec_ctx, p, cur, end,
-                           GRPC_ERROR_CREATE("Illegal base64 character"));
+        return parse_error(
+            exec_ctx, p, cur, end,
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte1;
       p->base64_buffer |= bits << 12;
@@ -1363,8 +1366,9 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(exec_ctx, p, cur, end,
-                           GRPC_ERROR_CREATE("Illegal base64 character"));
+        return parse_error(
+            exec_ctx, p, cur, end,
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte2;
       p->base64_buffer |= bits << 6;
@@ -1378,8 +1382,9 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(exec_ctx, p, cur, end,
-                           GRPC_ERROR_CREATE("Illegal base64 character"));
+        return parse_error(
+            exec_ctx, p, cur, end,
+            GRPC_ERROR_CREATE_FROM_STATIC_STRING("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte3;
       p->base64_buffer |= bits;
@@ -1391,7 +1396,8 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       goto b64_byte0;
   }
   GPR_UNREACHABLE_CODE(return parse_error(
-      exec_ctx, p, cur, end, GRPC_ERROR_CREATE("Should never reach here")));
+      exec_ctx, p, cur, end,
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Should never reach here")));
 }
 
 static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
@@ -1406,16 +1412,16 @@ static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
     case B64_BYTE0:
       break;
     case B64_BYTE1:
-      return parse_error(
-          exec_ctx, p, cur, end,
-          GRPC_ERROR_CREATE("illegal base64 encoding")); /* illegal encoding */
+      return parse_error(exec_ctx, p, cur, end,
+                         GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                             "illegal base64 encoding")); /* illegal encoding */
     case B64_BYTE2:
       bits = p->base64_buffer;
       if (bits & 0xffff) {
         char *msg;
         gpr_asprintf(&msg, "trailing bits in base64 encoding: 0x%04x",
                      bits & 0xffff);
-        grpc_error *err = GRPC_ERROR_CREATE(msg);
+        grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
         gpr_free(msg);
         return parse_error(exec_ctx, p, cur, end, err);
       }
@@ -1428,7 +1434,7 @@ static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
         char *msg;
         gpr_asprintf(&msg, "trailing bits in base64 encoding: 0x%02x",
                      bits & 0xff);
-        grpc_error *err = GRPC_ERROR_CREATE(msg);
+        grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
         gpr_free(msg);
         return parse_error(exec_ctx, p, cur, end, err);
       }
@@ -1550,7 +1556,8 @@ static grpc_error *is_binary_indexed_header(grpc_chttp2_hpack_parser *p,
   grpc_mdelem elem = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   if (GRPC_MDISNULL(elem)) {
     return grpc_error_set_int(
-        grpc_error_set_int(GRPC_ERROR_CREATE("Invalid HPACK index received"),
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                               "Invalid HPACK index received"),
                            GRPC_ERROR_INT_INDEX, (intptr_t)p->index),
         GRPC_ERROR_INT_SIZE, (intptr_t)p->table.num_ents);
   }
@@ -1675,7 +1682,7 @@ grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
   if (is_last) {
     if (parser->is_boundary && parser->state != parse_begin) {
       GPR_TIMER_END("grpc_chttp2_hpack_parser_parse", 0);
-      return GRPC_ERROR_CREATE(
+      return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
           "end of header frame not aligned with a hpack record boundary");
     }
     /* need to check for null stream: this can occur if we receive an invalid
@@ -1683,7 +1690,8 @@ grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
     if (s != NULL) {
       if (parser->is_boundary) {
         if (s->header_frames_received == GPR_ARRAY_SIZE(s->metadata_buffer)) {
-          return GRPC_ERROR_CREATE("Too many trailer frames");
+          return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+              "Too many trailer frames");
         }
         s->published_metadata[s->header_frames_received] =
             GRPC_METADATA_PUBLISHED_FROM_WIRE;
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.c b/src/core/ext/transport/chttp2/transport/hpack_table.c
index 62dd1b8cab..9dd41fdbe1 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.c
@@ -280,7 +280,7 @@ grpc_error *grpc_chttp2_hptbl_set_current_table_size(grpc_exec_ctx *exec_ctx,
     gpr_asprintf(&msg,
                  "Attempt to make hpack table %d bytes when max is %d bytes",
                  bytes, tbl->max_bytes);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -317,7 +317,7 @@ grpc_error *grpc_chttp2_hptbl_add(grpc_exec_ctx *exec_ctx,
         "HPACK max table size reduced to %d but not reflected by hpack "
         "stream (still at %d)",
         tbl->max_bytes, tbl->current_table_bytes);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
diff --git a/src/core/ext/transport/chttp2/transport/parsing.c b/src/core/ext/transport/chttp2/transport/parsing.c
index 7efc8c63c9..7e457ced27 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.c
@@ -116,7 +116,7 @@ grpc_error *grpc_chttp2_perform_read(grpc_exec_ctx *exec_ctx,
               GRPC_CHTTP2_CLIENT_CONNECT_STRING[t->deframe_state],
               (int)(uint8_t)GRPC_CHTTP2_CLIENT_CONNECT_STRING[t->deframe_state],
               *cur, (int)*cur, t->deframe_state);
-          err = GRPC_ERROR_CREATE(msg);
+          err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
           gpr_free(msg);
           return err;
         }
@@ -219,7 +219,7 @@ grpc_error *grpc_chttp2_perform_read(grpc_exec_ctx *exec_ctx,
                      t->incoming_frame_size,
                      t->settings[GRPC_ACKED_SETTINGS]
                                 [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE]);
-        err = GRPC_ERROR_CREATE(msg);
+        err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
         gpr_free(msg);
         return err;
       }
@@ -278,7 +278,7 @@ static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
     gpr_asprintf(
         &msg, "Expected SETTINGS frame as the first frame, got frame type %d",
         t->incoming_frame_type);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -288,7 +288,7 @@ static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
       char *msg;
       gpr_asprintf(&msg, "Expected CONTINUATION frame, got frame type %02x",
                    t->incoming_frame_type);
-      grpc_error *err = GRPC_ERROR_CREATE(msg);
+      grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
       gpr_free(msg);
       return err;
     }
@@ -299,7 +299,7 @@ static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
           "Expected CONTINUATION frame for grpc_chttp2_stream %08x, got "
           "grpc_chttp2_stream %08x",
           t->expect_continuation_stream_id, t->incoming_stream_id);
-      grpc_error *err = GRPC_ERROR_CREATE(msg);
+      grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
       gpr_free(msg);
       return err;
     }
@@ -311,7 +311,8 @@ static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
     case GRPC_CHTTP2_FRAME_HEADER:
       return init_header_frame_parser(exec_ctx, t, 0);
     case GRPC_CHTTP2_FRAME_CONTINUATION:
-      return GRPC_ERROR_CREATE("Unexpected CONTINUATION frame");
+      return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "Unexpected CONTINUATION frame");
     case GRPC_CHTTP2_FRAME_RST_STREAM:
       return init_rst_stream_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_SETTINGS:
@@ -371,7 +372,7 @@ static grpc_error *update_incoming_window(grpc_exec_ctx *exec_ctx,
     char *msg;
     gpr_asprintf(&msg, "frame of size %d overflows incoming window of %" PRId64,
                  t->incoming_frame_size, t->incoming_window);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
+    grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
   }
@@ -409,7 +410,7 @@ static grpc_error *update_incoming_window(grpc_exec_ctx *exec_ctx,
                      s->incoming_window_delta +
                          t->settings[GRPC_ACKED_SETTINGS]
                                     [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]);
-        grpc_error *err = GRPC_ERROR_CREATE(msg);
+        grpc_error *err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
         gpr_free(msg);
         return err;
       }
@@ -542,7 +543,8 @@ static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
       grpc_chttp2_cancel_stream(
           exec_ctx, t, s,
           grpc_error_set_int(
-              GRPC_ERROR_CREATE("received initial metadata size exceeds limit"),
+              GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                  "received initial metadata size exceeds limit"),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
       grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
       s->seen_error = true;
@@ -598,9 +600,10 @@ static void on_trailing_header(grpc_exec_ctx *exec_ctx, void *tp,
             new_size, metadata_size_limit);
     grpc_chttp2_cancel_stream(
         exec_ctx, t, s,
-        grpc_error_set_int(
-            GRPC_ERROR_CREATE("received trailing metadata size exceeds limit"),
-            GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                               "received trailing metadata size exceeds limit"),
+                           GRPC_ERROR_INT_GRPC_STATUS,
+                           GRPC_STATUS_RESOURCE_EXHAUSTED));
     grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
     s->seen_error = true;
     GRPC_MDELEM_UNREF(exec_ctx, md);
@@ -771,7 +774,8 @@ static grpc_error *init_goaway_parser(grpc_exec_ctx *exec_ctx,
 static grpc_error *init_settings_frame_parser(grpc_exec_ctx *exec_ctx,
                                               grpc_chttp2_transport *t) {
   if (t->incoming_stream_id != 0) {
-    return GRPC_ERROR_CREATE("Settings frame received for grpc_chttp2_stream");
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Settings frame received for grpc_chttp2_stream");
   }
 
   grpc_error *err = grpc_chttp2_settings_parser_begin_frame(
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index 36bb67869c..952690eba7 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -290,7 +290,7 @@ static void maybe_flush_read(stream_obj *s) {
 }
 
 static grpc_error *make_error_with_desc(int error_code, const char *desc) {
-  grpc_error *error = GRPC_ERROR_CREATE(desc);
+  grpc_error *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(desc);
   error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS, error_code);
   return error;
 }