Merge branch 'master' of github.com:grpc/grpc into compression-interop

66 files changed, 1351 insertions, 437 deletions

diff --git a/test/build/zookeeper.c b/test/build/zookeeper.c
new file mode 100644
index 0000000000..7cd3d0da9e
--- /dev/null
+++ b/test/build/zookeeper.c
@@ -0,0 +1,43 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+/* This is just a compilation test, to see if we have Zookeeper C client
+   library installed. */
+
+#include <stdlib.h>
+#include <zookeeper/zookeeper.h>
+
+int main() {
+  zookeeper_init(NULL, NULL, 0, 0, 0, 0);
+  return 0;
+}
diff --git a/test/core/bad_client/bad_client.c b/test/core/bad_client/bad_client.c
index b050227b61..f7399770dd 100644
--- a/test/core/bad_client/bad_client.c
+++ b/test/core/bad_client/bad_client.c
@@ -102,11 +102,11 @@ void grpc_run_bad_client_test(grpc_bad_client_server_side_validator validator,
 
   /* Create server, completion events */
   a.server = grpc_server_create_from_filters(NULL, 0, NULL);
-  a.cq = grpc_completion_queue_create();
+  a.cq = grpc_completion_queue_create(NULL);
   gpr_event_init(&a.done_thd);
   gpr_event_init(&a.done_write);
   a.validator = validator;
-  grpc_server_register_completion_queue(a.server, a.cq);
+  grpc_server_register_completion_queue(a.server, a.cq, NULL);
   grpc_server_start(a.server);
   transport = grpc_create_chttp2_transport(NULL, sfd.server, mdctx, 0);
   server_setup_transport(&a, transport, mdctx);
@@ -151,7 +151,8 @@ void grpc_run_bad_client_test(grpc_bad_client_server_side_validator validator,
   }
   grpc_server_shutdown_and_notify(a.server, a.cq, NULL);
   GPR_ASSERT(grpc_completion_queue_pluck(a.cq, NULL,
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(a.server);
   grpc_completion_queue_destroy(a.cq);
diff --git a/test/core/bad_client/tests/connection_prefix.c b/test/core/bad_client/tests/connection_prefix.c
index 0bd86ecf55..de62e923f0 100644
--- a/test/core/bad_client/tests/connection_prefix.c
+++ b/test/core/bad_client/tests/connection_prefix.c
@@ -37,8 +37,8 @@
 static void verifier(grpc_server *server, grpc_completion_queue *cq) {
   while (grpc_server_has_open_connections(server)) {
     GPR_ASSERT(
-        grpc_completion_queue_next(cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(20))
-            .type == GRPC_QUEUE_TIMEOUT);
+        grpc_completion_queue_next(cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(20),
+                                   NULL).type == GRPC_QUEUE_TIMEOUT);
   }
 }
 
diff --git a/test/core/bad_client/tests/initial_settings_frame.c b/test/core/bad_client/tests/initial_settings_frame.c
index 2075602e27..28e9a39dff 100644
--- a/test/core/bad_client/tests/initial_settings_frame.c
+++ b/test/core/bad_client/tests/initial_settings_frame.c
@@ -39,8 +39,8 @@
 static void verifier(grpc_server *server, grpc_completion_queue *cq) {
   while (grpc_server_has_open_connections(server)) {
     GPR_ASSERT(
-        grpc_completion_queue_next(cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(20))
-            .type == GRPC_QUEUE_TIMEOUT);
+        grpc_completion_queue_next(cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(20),
+                                   NULL).type == GRPC_QUEUE_TIMEOUT);
   }
 }
 
diff --git a/test/core/compression/compression_test.c b/test/core/compression/compression_test.c
index 01349c22b5..810bcee8cc 100644
--- a/test/core/compression/compression_test.c
+++ b/test/core/compression/compression_test.c
@@ -42,7 +42,7 @@
 
 static void test_compression_algorithm_parse(void) {
   size_t i;
-  const char* valid_names[] = {"none", "gzip", "deflate"};
+  const char* valid_names[] = {"identity", "gzip", "deflate"};
   const grpc_compression_algorithm valid_algorithms[] = {
       GRPC_COMPRESS_NONE, GRPC_COMPRESS_GZIP, GRPC_COMPRESS_DEFLATE};
   const char* invalid_names[] = {"gzip2", "foo", "", "2gzip"};
diff --git a/test/core/end2end/cq_verifier.c b/test/core/end2end/cq_verifier.c
index c28932c52b..a9ba78dfdb 100644
--- a/test/core/end2end/cq_verifier.c
+++ b/test/core/end2end/cq_verifier.c
@@ -226,7 +226,7 @@ void cq_verify(cq_verifier *v) {
   gpr_strvec_init(&have_tags);
 
   while (v->expect.next != &v->expect) {
-    ev = grpc_completion_queue_next(v->cq, deadline);
+    ev = grpc_completion_queue_next(v->cq, deadline, NULL);
     if (ev.type == GRPC_QUEUE_TIMEOUT) {
       fail_no_event_received(v);
       break;
@@ -265,7 +265,7 @@ void cq_verify_empty(cq_verifier *v) {
 
   GPR_ASSERT(v->expect.next == &v->expect && "expectation queue must be empty");
 
-  ev = grpc_completion_queue_next(v->cq, deadline);
+  ev = grpc_completion_queue_next(v->cq, deadline, NULL);
   if (ev.type != GRPC_QUEUE_TIMEOUT) {
     char *s = grpc_event_string(&ev);
     gpr_log(GPR_ERROR, "unexpected event (expected nothing): %s", s);
diff --git a/test/core/end2end/dualstack_socket_test.c b/test/core/end2end/dualstack_socket_test.c
index 48a88be525..7b7dbc7472 100644
--- a/test/core/end2end/dualstack_socket_test.c
+++ b/test/core/end2end/dualstack_socket_test.c
@@ -53,7 +53,7 @@ static gpr_timespec ms_from_now(int ms) {
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, ms_from_now(5000));
+    ev = grpc_completion_queue_next(cq, ms_from_now(5000), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -75,6 +75,7 @@ void test_connect(const char *server_host, const char *client_host, int port,
   grpc_metadata_array trailing_metadata_recv;
   grpc_metadata_array request_metadata_recv;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -93,9 +94,9 @@ void test_connect(const char *server_host, const char *client_host, int port,
   grpc_call_details_init(&call_details);
 
   /* Create server. */
-  cq = grpc_completion_queue_create();
-  server = grpc_server_create(NULL);
-  grpc_server_register_completion_queue(server, cq);
+  cq = grpc_completion_queue_create(NULL);
+  server = grpc_server_create(NULL, NULL);
+  grpc_server_register_completion_queue(server, cq, NULL);
   GPR_ASSERT((got_port = grpc_server_add_insecure_http2_port(
                   server, server_hostport)) > 0);
   if (port == 0) {
@@ -113,7 +114,7 @@ void test_connect(const char *server_host, const char *client_host, int port,
   } else {
     gpr_join_host_port(&client_hostport, client_host, port);
   }
-  client = grpc_insecure_channel_create(client_hostport, NULL);
+  client = grpc_insecure_channel_create(client_hostport, NULL, NULL);
 
   gpr_log(GPR_INFO, "Testing with server=%s client=%s (expecting %s)",
           server_hostport, client_hostport, expect_ok ? "success" : "failure");
@@ -132,20 +133,23 @@ void test_connect(const char *server_host, const char *client_host, int port,
 
   /* Send a trivial request. */
   c = grpc_channel_create_call(client, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   op = ops;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -153,14 +157,16 @@ void test_connect(const char *server_host, const char *client_host, int port,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   if (expect_ok) {
     /* Check for a successful request. */
-    GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                   server, &s, &call_details,
-                                   &request_metadata_recv, cq, cq, tag(101)));
+    error = grpc_server_request_call(server, &s, &call_details,
+                                     &request_metadata_recv, cq, cq, tag(101));
+    GPR_ASSERT(GRPC_CALL_OK == error);
     cq_expect_completion(cqv, tag(101), 1);
     cq_verify(cqv);
 
@@ -179,8 +185,8 @@ void test_connect(const char *server_host, const char *client_host, int port,
     op->data.recv_close_on_server.cancelled = &was_cancelled;
     op->flags = 0;
     op++;
-    GPR_ASSERT(GRPC_CALL_OK ==
-               grpc_call_start_batch(s, ops, op - ops, tag(102)));
+    error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
 
     cq_expect_completion(cqv, tag(102), 1);
     cq_expect_completion(cqv, tag(1), 1);
@@ -215,7 +221,8 @@ void test_connect(const char *server_host, const char *client_host, int port,
   /* Destroy server. */
   grpc_server_shutdown_and_notify(server, cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(server);
   grpc_completion_queue_shutdown(cq);
diff --git a/test/core/end2end/fixtures/chttp2_fake_security.c b/test/core/end2end/fixtures/chttp2_fake_security.c
index 78b692a45d..27531ecbc3 100644
--- a/test/core/end2end/fixtures/chttp2_fake_security.c
+++ b/test/core/end2end/fixtures/chttp2_fake_security.c
@@ -60,7 +60,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -89,8 +89,8 @@ static void chttp2_init_server_secure_fullstack(
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_secure_http2_port(f->server, ffd->localaddr,
                                                server_creds));
   grpc_server_credentials_release(server_creds);
diff --git a/test/core/end2end/fixtures/chttp2_fullstack.c b/test/core/end2end/fixtures/chttp2_fullstack.c
index 53a6f0d7a5..0170dcf0e5 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack.c
@@ -64,7 +64,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -72,7 +72,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
 void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
                                   grpc_channel_args *client_args) {
   fullstack_fixture_data *ffd = f->fixture_data;
-  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args);
+  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args, NULL);
   GPR_ASSERT(f->client);
 }
 
@@ -82,8 +82,8 @@ void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(f->server, ffd->localaddr));
   grpc_server_start(f->server);
 }
diff --git a/test/core/end2end/fixtures/chttp2_fullstack_compression.c b/test/core/end2end/fixtures/chttp2_fullstack_compression.c
index a75075d1d4..6e7a1faf55 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack_compression.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack_compression.c
@@ -69,7 +69,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack_compression(
 
   memset(&f, 0, sizeof(f));
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -83,7 +83,7 @@ void chttp2_init_client_fullstack_compression(grpc_end2end_test_fixture *f,
   ffd->client_args_compression = grpc_channel_args_set_compression_algorithm(
       client_args, GRPC_COMPRESS_GZIP);
   f->client = grpc_insecure_channel_create(ffd->localaddr,
-                                           ffd->client_args_compression);
+                                           ffd->client_args_compression, NULL);
 }
 
 void chttp2_init_server_fullstack_compression(grpc_end2end_test_fixture *f,
@@ -97,8 +97,8 @@ void chttp2_init_server_fullstack_compression(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(ffd->server_args_compression);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(ffd->server_args_compression, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(f->server, ffd->localaddr));
   grpc_server_start(f->server);
 }
diff --git a/test/core/end2end/fixtures/chttp2_fullstack_uds_posix.c b/test/core/end2end/fixtures/chttp2_fullstack_uds_posix.c
index 20afdb868e..59d39bbb0f 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack_uds_posix.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack_uds_posix.c
@@ -70,7 +70,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
                unique++);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -78,7 +78,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
 void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
                                   grpc_channel_args *client_args) {
   fullstack_fixture_data *ffd = f->fixture_data;
-  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args);
+  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args, NULL);
 }
 
 void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
@@ -87,8 +87,8 @@ void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(f->server, ffd->localaddr));
   grpc_server_start(f->server);
 }
diff --git a/test/core/end2end/fixtures/chttp2_fullstack_uds_posix_with_poll.c b/test/core/end2end/fixtures/chttp2_fullstack_uds_posix_with_poll.c
index 8491ea6970..05b9ea0949 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack_uds_posix_with_poll.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack_uds_posix_with_poll.c
@@ -70,7 +70,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
                unique++);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -78,7 +78,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
 void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
                                   grpc_channel_args *client_args) {
   fullstack_fixture_data *ffd = f->fixture_data;
-  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args);
+  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args, NULL);
 }
 
 void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
@@ -87,8 +87,8 @@ void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(f->server, ffd->localaddr));
   grpc_server_start(f->server);
 }
diff --git a/test/core/end2end/fixtures/chttp2_fullstack_with_poll.c b/test/core/end2end/fixtures/chttp2_fullstack_with_poll.c
index 2a4835add1..48feefc931 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack_with_poll.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack_with_poll.c
@@ -64,7 +64,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -72,7 +72,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
 void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
                                   grpc_channel_args *client_args) {
   fullstack_fixture_data *ffd = f->fixture_data;
-  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args);
+  f->client = grpc_insecure_channel_create(ffd->localaddr, client_args, NULL);
 }
 
 void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
@@ -81,8 +81,8 @@ void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(f->server, ffd->localaddr));
   grpc_server_start(f->server);
 }
diff --git a/test/core/end2end/fixtures/chttp2_fullstack_with_proxy.c b/test/core/end2end/fixtures/chttp2_fullstack_with_proxy.c
index 248cc7d6e7..44083e2676 100644
--- a/test/core/end2end/fixtures/chttp2_fullstack_with_proxy.c
+++ b/test/core/end2end/fixtures/chttp2_fullstack_with_proxy.c
@@ -56,13 +56,13 @@ typedef struct fullstack_fixture_data {
 } fullstack_fixture_data;
 
 static grpc_server *create_proxy_server(const char *port) {
-  grpc_server *s = grpc_server_create(NULL);
+  grpc_server *s = grpc_server_create(NULL, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(s, port));
   return s;
 }
 
 static grpc_channel *create_proxy_client(const char *target) {
-  return grpc_insecure_channel_create(target, NULL);
+  return grpc_insecure_channel_create(target, NULL, NULL);
 }
 
 static const grpc_end2end_proxy_def proxy_def = {create_proxy_server,
@@ -77,7 +77,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
   ffd->proxy = grpc_end2end_proxy_create(&proxy_def);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -86,7 +86,7 @@ void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
                                   grpc_channel_args *client_args) {
   fullstack_fixture_data *ffd = f->fixture_data;
   f->client = grpc_insecure_channel_create(
-      grpc_end2end_proxy_get_client_target(ffd->proxy), client_args);
+      grpc_end2end_proxy_get_client_target(ffd->proxy), client_args, NULL);
   GPR_ASSERT(f->client);
 }
 
@@ -96,8 +96,8 @@ void chttp2_init_server_fullstack(grpc_end2end_test_fixture *f,
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_insecure_http2_port(
       f->server, grpc_end2end_proxy_get_server_port(ffd->proxy)));
   grpc_server_start(f->server);
diff --git a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack.c b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack.c
index 9850aac69b..491a293764 100644
--- a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack.c
+++ b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack.c
@@ -63,7 +63,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -92,8 +92,8 @@ static void chttp2_init_server_secure_fullstack(
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_secure_http2_port(f->server, ffd->localaddr,
                                                server_creds));
   grpc_server_credentials_release(server_creds);
diff --git a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_poll.c b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_poll.c
index 3df2acd296..f2736cc92f 100644
--- a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_poll.c
+++ b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_poll.c
@@ -63,7 +63,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -92,8 +92,8 @@ static void chttp2_init_server_secure_fullstack(
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_secure_http2_port(f->server, ffd->localaddr,
                                                server_creds));
   grpc_server_credentials_release(server_creds);
diff --git a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_proxy.c b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_proxy.c
index 4d77039cac..cc0b9dbbdd 100644
--- a/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_proxy.c
+++ b/test/core/end2end/fixtures/chttp2_simple_ssl_fullstack_with_proxy.c
@@ -54,7 +54,7 @@ typedef struct fullstack_secure_fixture_data {
 } fullstack_secure_fixture_data;
 
 static grpc_server *create_proxy_server(const char *port) {
-  grpc_server *s = grpc_server_create(NULL);
+  grpc_server *s = grpc_server_create(NULL, NULL);
   grpc_ssl_pem_key_cert_pair pem_cert_key_pair = {test_server1_key,
                                                   test_server1_cert};
   grpc_server_credentials *ssl_creds =
@@ -91,7 +91,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   ffd->proxy = grpc_end2end_proxy_create(&proxy_def);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -121,8 +121,8 @@ static void chttp2_init_server_secure_fullstack(
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_secure_http2_port(
       f->server, grpc_end2end_proxy_get_server_port(ffd->proxy), server_creds));
   grpc_server_credentials_release(server_creds);
diff --git a/test/core/end2end/fixtures/chttp2_simple_ssl_with_oauth2_fullstack.c b/test/core/end2end/fixtures/chttp2_simple_ssl_with_oauth2_fullstack.c
index 284d5f07ae..3c35baec6b 100644
--- a/test/core/end2end/fixtures/chttp2_simple_ssl_with_oauth2_fullstack.c
+++ b/test/core/end2end/fixtures/chttp2_simple_ssl_with_oauth2_fullstack.c
@@ -105,7 +105,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_secure_fullstack(
   gpr_join_host_port(&ffd->localaddr, "localhost", port);
 
   f.fixture_data = ffd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   return f;
 }
@@ -126,8 +126,8 @@ static void chttp2_init_server_secure_fullstack(
   if (f->server) {
     grpc_server_destroy(f->server);
   }
-  f->server = grpc_server_create(server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  f->server = grpc_server_create(server_args, NULL);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   GPR_ASSERT(grpc_server_add_secure_http2_port(f->server, ffd->localaddr,
                                                server_creds));
   grpc_server_credentials_release(server_creds);
diff --git a/test/core/end2end/fixtures/chttp2_socket_pair.c b/test/core/end2end/fixtures/chttp2_socket_pair.c
index 807fc8e7bc..16a04fbebf 100644
--- a/test/core/end2end/fixtures/chttp2_socket_pair.c
+++ b/test/core/end2end/fixtures/chttp2_socket_pair.c
@@ -95,7 +95,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_socketpair(
   grpc_end2end_test_fixture f;
   memset(&f, 0, sizeof(f));
   f.fixture_data = sfd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   *sfd = grpc_iomgr_create_endpoint_pair("fixture", 65536);
 
@@ -123,7 +123,7 @@ static void chttp2_init_server_socketpair(grpc_end2end_test_fixture *f,
   grpc_transport *transport;
   GPR_ASSERT(!f->server);
   f->server = grpc_server_create_from_filters(NULL, 0, server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   grpc_server_start(f->server);
   transport = grpc_create_chttp2_transport(server_args, sfd->server, mdctx, 0);
   server_setup_transport(f, transport, mdctx);
diff --git a/test/core/end2end/fixtures/chttp2_socket_pair_one_byte_at_a_time.c b/test/core/end2end/fixtures/chttp2_socket_pair_one_byte_at_a_time.c
index 21d4404237..94fc36f5ec 100644
--- a/test/core/end2end/fixtures/chttp2_socket_pair_one_byte_at_a_time.c
+++ b/test/core/end2end/fixtures/chttp2_socket_pair_one_byte_at_a_time.c
@@ -95,7 +95,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_socketpair(
   grpc_end2end_test_fixture f;
   memset(&f, 0, sizeof(f));
   f.fixture_data = sfd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   *sfd = grpc_iomgr_create_endpoint_pair("fixture", 1);
 
@@ -123,7 +123,7 @@ static void chttp2_init_server_socketpair(grpc_end2end_test_fixture *f,
   grpc_transport *transport;
   GPR_ASSERT(!f->server);
   f->server = grpc_server_create_from_filters(NULL, 0, server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   grpc_server_start(f->server);
   transport = grpc_create_chttp2_transport(server_args, sfd->server, mdctx, 0);
   server_setup_transport(f, transport, mdctx);
diff --git a/test/core/end2end/fixtures/chttp2_socket_pair_with_grpc_trace.c b/test/core/end2end/fixtures/chttp2_socket_pair_with_grpc_trace.c
index 9d798ad1d2..588c4b23e1 100644
--- a/test/core/end2end/fixtures/chttp2_socket_pair_with_grpc_trace.c
+++ b/test/core/end2end/fixtures/chttp2_socket_pair_with_grpc_trace.c
@@ -96,7 +96,7 @@ static grpc_end2end_test_fixture chttp2_create_fixture_socketpair(
   grpc_end2end_test_fixture f;
   memset(&f, 0, sizeof(f));
   f.fixture_data = sfd;
-  f.cq = grpc_completion_queue_create();
+  f.cq = grpc_completion_queue_create(NULL);
 
   *sfd = grpc_iomgr_create_endpoint_pair("fixture", 65536);
 
@@ -124,7 +124,7 @@ static void chttp2_init_server_socketpair(grpc_end2end_test_fixture *f,
   grpc_transport *transport;
   GPR_ASSERT(!f->server);
   f->server = grpc_server_create_from_filters(NULL, 0, server_args);
-  grpc_server_register_completion_queue(f->server, f->cq);
+  grpc_server_register_completion_queue(f->server, f->cq, NULL);
   grpc_server_start(f->server);
   transport = grpc_create_chttp2_transport(server_args, sfd->server, mdctx, 0);
   server_setup_transport(f, transport, mdctx);
diff --git a/test/core/end2end/fixtures/proxy.c b/test/core/end2end/fixtures/proxy.c
index e4f6263334..798d4e94d4 100644
--- a/test/core/end2end/fixtures/proxy.c
+++ b/test/core/end2end/fixtures/proxy.c
@@ -100,11 +100,11 @@ grpc_end2end_proxy *grpc_end2end_proxy_create(
 
   gpr_join_host_port(&proxy->proxy_port, "localhost", proxy_port);
   gpr_join_host_port(&proxy->server_port, "localhost", server_port);
-  proxy->cq = grpc_completion_queue_create();
+  proxy->cq = grpc_completion_queue_create(NULL);
   proxy->server = def->create_server(proxy->proxy_port);
   proxy->client = def->create_client(proxy->server_port);
 
-  grpc_server_register_completion_queue(proxy->server, proxy->cq);
+  grpc_server_register_completion_queue(proxy->server, proxy->cq, NULL);
   grpc_server_start(proxy->server);
 
   gpr_thd_options_set_joinable(&opt);
@@ -178,7 +178,8 @@ static void on_p2s_recv_initial_metadata(void *arg, int success) {
     op.data.send_initial_metadata.metadata = pc->p2s_initial_metadata.metadata;
     refpc(pc, "on_c2p_sent_initial_metadata");
     err = grpc_call_start_batch(pc->c2p, &op, 1,
-                                new_closure(on_c2p_sent_initial_metadata, pc));
+                                new_closure(on_c2p_sent_initial_metadata, pc),
+                                NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }
 
@@ -204,7 +205,7 @@ static void on_p2s_sent_message(void *arg, int success) {
     op.data.recv_message = &pc->c2p_msg;
     refpc(pc, "on_c2p_recv_msg");
     err = grpc_call_start_batch(pc->c2p, &op, 1,
-                                new_closure(on_c2p_recv_msg, pc));
+                                new_closure(on_c2p_recv_msg, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }
 
@@ -228,14 +229,14 @@ static void on_c2p_recv_msg(void *arg, int success) {
       op.data.send_message = pc->c2p_msg;
       refpc(pc, "on_p2s_sent_message");
       err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                  new_closure(on_p2s_sent_message, pc));
+                                  new_closure(on_p2s_sent_message, pc), NULL);
       GPR_ASSERT(err == GRPC_CALL_OK);
     } else {
       op.op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
       op.flags = 0;
       refpc(pc, "on_p2s_sent_close");
       err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                  new_closure(on_p2s_sent_close, pc));
+                                  new_closure(on_p2s_sent_close, pc), NULL);
       GPR_ASSERT(err == GRPC_CALL_OK);
     }
   }
@@ -257,7 +258,7 @@ static void on_c2p_sent_message(void *arg, int success) {
     op.data.recv_message = &pc->p2s_msg;
     refpc(pc, "on_p2s_recv_msg");
     err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                new_closure(on_p2s_recv_msg, pc));
+                                new_closure(on_p2s_recv_msg, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }
 
@@ -275,7 +276,7 @@ static void on_p2s_recv_msg(void *arg, int success) {
     op.data.send_message = pc->p2s_msg;
     refpc(pc, "on_c2p_sent_message");
     err = grpc_call_start_batch(pc->c2p, &op, 1,
-                                new_closure(on_c2p_sent_message, pc));
+                                new_closure(on_c2p_sent_message, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }
   unrefpc(pc, "on_p2s_recv_msg");
@@ -303,7 +304,7 @@ static void on_p2s_status(void *arg, int success) {
     op.data.send_status_from_server.status_details = pc->p2s_status_details;
     refpc(pc, "on_c2p_sent_status");
     err = grpc_call_start_batch(pc->c2p, &op, 1,
-                                new_closure(on_c2p_sent_status, pc));
+                                new_closure(on_c2p_sent_status, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }
 
@@ -330,7 +331,7 @@ static void on_new_call(void *arg, int success) {
     pc->p2s = grpc_channel_create_call(
         proxy->client, pc->c2p, GRPC_PROPAGATE_DEFAULTS, proxy->cq,
         proxy->new_call_details.method, proxy->new_call_details.host,
-        proxy->new_call_details.deadline);
+        proxy->new_call_details.deadline, NULL);
     gpr_ref_init(&pc->refs, 1);
 
     op.flags = 0;
@@ -339,7 +340,8 @@ static void on_new_call(void *arg, int success) {
     op.data.recv_initial_metadata = &pc->p2s_initial_metadata;
     refpc(pc, "on_p2s_recv_initial_metadata");
     err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                new_closure(on_p2s_recv_initial_metadata, pc));
+                                new_closure(on_p2s_recv_initial_metadata, pc),
+                                NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     op.op = GRPC_OP_SEND_INITIAL_METADATA;
@@ -347,21 +349,22 @@ static void on_new_call(void *arg, int success) {
     op.data.send_initial_metadata.metadata = pc->c2p_initial_metadata.metadata;
     refpc(pc, "on_p2s_sent_initial_metadata");
     err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                new_closure(on_p2s_sent_initial_metadata, pc));
+                                new_closure(on_p2s_sent_initial_metadata, pc),
+                                NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     op.op = GRPC_OP_RECV_MESSAGE;
     op.data.recv_message = &pc->c2p_msg;
     refpc(pc, "on_c2p_recv_msg");
     err = grpc_call_start_batch(pc->c2p, &op, 1,
-                                new_closure(on_c2p_recv_msg, pc));
+                                new_closure(on_c2p_recv_msg, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     op.op = GRPC_OP_RECV_MESSAGE;
     op.data.recv_message = &pc->p2s_msg;
     refpc(pc, "on_p2s_recv_msg");
     err = grpc_call_start_batch(pc->p2s, &op, 1,
-                                new_closure(on_p2s_recv_msg, pc));
+                                new_closure(on_p2s_recv_msg, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     op.op = GRPC_OP_RECV_STATUS_ON_CLIENT;
@@ -372,15 +375,15 @@ static void on_new_call(void *arg, int success) {
     op.data.recv_status_on_client.status_details_capacity =
         &pc->p2s_status_details_capacity;
     refpc(pc, "on_p2s_status");
-    err =
-        grpc_call_start_batch(pc->p2s, &op, 1, new_closure(on_p2s_status, pc));
+    err = grpc_call_start_batch(pc->p2s, &op, 1,
+                                new_closure(on_p2s_status, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     op.op = GRPC_OP_RECV_CLOSE_ON_SERVER;
     op.data.recv_close_on_server.cancelled = &pc->c2p_server_cancelled;
     refpc(pc, "on_c2p_closed");
-    err =
-        grpc_call_start_batch(pc->c2p, &op, 1, new_closure(on_c2p_closed, pc));
+    err = grpc_call_start_batch(pc->c2p, &op, 1,
+                                new_closure(on_c2p_closed, pc), NULL);
     GPR_ASSERT(err == GRPC_CALL_OK);
 
     request_call(proxy);
@@ -405,7 +408,7 @@ static void thread_main(void *arg) {
   closure *cl;
   for (;;) {
     grpc_event ev = grpc_completion_queue_next(
-        proxy->cq, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+        proxy->cq, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL);
     switch (ev.type) {
       case GRPC_QUEUE_TIMEOUT:
         gpr_log(GPR_ERROR, "Should never reach here");
diff --git a/test/core/end2end/multiple_server_queues_test.c b/test/core/end2end/multiple_server_queues_test.c
index 7772d14ba5..2befcd0124 100644
--- a/test/core/end2end/multiple_server_queues_test.c
+++ b/test/core/end2end/multiple_server_queues_test.c
@@ -41,20 +41,20 @@ int main(int argc, char **argv) {
 
   grpc_test_init(argc, argv);
   grpc_init();
-  cq1 = grpc_completion_queue_create();
-  cq2 = grpc_completion_queue_create();
-  server = grpc_server_create(NULL);
-  grpc_server_register_completion_queue(server, cq1);
+  cq1 = grpc_completion_queue_create(NULL);
+  cq2 = grpc_completion_queue_create(NULL);
+  server = grpc_server_create(NULL, NULL);
+  grpc_server_register_completion_queue(server, cq1, NULL);
   grpc_server_add_insecure_http2_port(server, "[::]:0");
-  grpc_server_register_completion_queue(server, cq2);
+  grpc_server_register_completion_queue(server, cq2, NULL);
   grpc_server_start(server);
   grpc_server_shutdown_and_notify(server, cq2, NULL);
   grpc_completion_queue_next(
-      cq2, gpr_inf_future(GPR_CLOCK_REALTIME)); /* cue queue hang */
+      cq2, gpr_inf_future(GPR_CLOCK_REALTIME), NULL); /* cue queue hang */
   grpc_completion_queue_shutdown(cq1);
   grpc_completion_queue_shutdown(cq2);
-  grpc_completion_queue_next(cq1, gpr_inf_future(GPR_CLOCK_REALTIME));
-  grpc_completion_queue_next(cq2, gpr_inf_future(GPR_CLOCK_REALTIME));
+  grpc_completion_queue_next(cq1, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
+  grpc_completion_queue_next(cq2, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   grpc_server_destroy(server);
   grpc_completion_queue_destroy(cq1);
   grpc_completion_queue_destroy(cq2);
diff --git a/test/core/end2end/no_server_test.c b/test/core/end2end/no_server_test.c
index 6a5e12325d..6ae87288f7 100644
--- a/test/core/end2end/no_server_test.c
+++ b/test/core/end2end/no_server_test.c
@@ -57,18 +57,19 @@ int main(int argc, char **argv) {
 
   grpc_metadata_array_init(&trailing_metadata_recv);
 
-  cq = grpc_completion_queue_create();
+  cq = grpc_completion_queue_create(NULL);
   cqv = cq_verifier_create(cq);
 
   /* create a call, channel to a non existant server */
-  chan = grpc_insecure_channel_create("nonexistant:54321", NULL);
+  chan = grpc_insecure_channel_create("nonexistant:54321", NULL, NULL);
   call = grpc_channel_create_call(chan, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
-                                  "/Foo", "nonexistant", deadline);
+                                  "/Foo", "nonexistant", deadline, NULL);
 
   op = ops;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -76,9 +77,10 @@ int main(int argc, char **argv) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, ops, op - ops, tag(1)));
+             grpc_call_start_batch(call, ops, op - ops, tag(1), NULL));
   /* verify that all tags get completed */
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
@@ -86,8 +88,8 @@ int main(int argc, char **argv) {
   GPR_ASSERT(status == GRPC_STATUS_DEADLINE_EXCEEDED);
 
   grpc_completion_queue_shutdown(cq);
-  while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME))
-             .type != GRPC_QUEUE_SHUTDOWN)
+  while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
+                                    NULL).type != GRPC_QUEUE_SHUTDOWN)
     ;
   grpc_completion_queue_destroy(cq);
   grpc_call_destroy(call);
diff --git a/test/core/end2end/tests/bad_hostname.c b/test/core/end2end/tests/bad_hostname.c
index 501db89b7b..61bbbe4855 100644
--- a/test/core/end2end/tests/bad_hostname.c
+++ b/test/core/end2end/tests/bad_hostname.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -110,11 +111,12 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "slartibartfast.local", deadline);
+                               "/foo", "slartibartfast.local", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -126,13 +128,16 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -140,8 +145,10 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
diff --git a/test/core/end2end/tests/cancel_after_accept.c b/test/core/end2end/tests/cancel_after_accept.c
index 2e166b8412..3715166348 100644
--- a/test/core/end2end/tests/cancel_after_accept.c
+++ b/test/core/end2end/tests/cancel_after_accept.c
@@ -69,7 +69,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -77,7 +77,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -114,6 +115,7 @@ static void test_cancel_after_accept(grpc_end2end_test_config config,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_byte_buffer *request_payload_recv = NULL;
@@ -127,7 +129,7 @@ static void test_cancel_after_accept(grpc_end2end_test_config config,
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -142,28 +144,34 @@ static void test_cancel_after_accept(grpc_end2end_test_config config,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(2)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq, tag(2));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(2), 1);
   cq_verify(cqv);
 
@@ -171,22 +179,27 @@ static void test_cancel_after_accept(grpc_end2end_test_config config,
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(3)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(3), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c));
+  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c, NULL));
 
   cq_expect_completion(cqv, tag(3), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/cancel_after_accept_and_writes_closed.c b/test/core/end2end/tests/cancel_after_accept_and_writes_closed.c
index 171c1874cc..ffb267c236 100644
--- a/test/core/end2end/tests/cancel_after_accept_and_writes_closed.c
+++ b/test/core/end2end/tests/cancel_after_accept_and_writes_closed.c
@@ -69,7 +69,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -77,7 +77,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -114,6 +115,7 @@ static void test_cancel_after_accept_and_writes_closed(
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_byte_buffer *request_payload_recv = NULL;
@@ -127,7 +129,7 @@ static void test_cancel_after_accept_and_writes_closed(
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -142,31 +144,38 @@ static void test_cancel_after_accept_and_writes_closed(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(2)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq, tag(2));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(2), 1);
   cq_verify(cqv);
 
@@ -174,22 +183,27 @@ static void test_cancel_after_accept_and_writes_closed(
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(3)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(3), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c));
+  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c, NULL));
 
   cq_expect_completion(cqv, tag(3), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/cancel_after_invoke.c b/test/core/end2end/tests/cancel_after_invoke.c
index 186cd44a43..7e984da591 100644
--- a/test/core/end2end/tests/cancel_after_invoke.c
+++ b/test/core/end2end/tests/cancel_after_invoke.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -114,6 +115,7 @@ static void test_cancel_after_invoke(grpc_end2end_test_config config,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_byte_buffer *response_payload_recv = NULL;
@@ -122,7 +124,7 @@ static void test_cancel_after_invoke(grpc_end2end_test_config config,
       grpc_raw_byte_buffer_create(&request_payload_slice, 1);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -137,29 +139,36 @@ static void test_cancel_after_invoke(grpc_end2end_test_config config,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, test_ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, test_ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c));
+  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c, NULL));
 
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
diff --git a/test/core/end2end/tests/cancel_before_invoke.c b/test/core/end2end/tests/cancel_before_invoke.c
index b511908b4f..06e6602681 100644
--- a/test/core/end2end/tests/cancel_before_invoke.c
+++ b/test/core/end2end/tests/cancel_before_invoke.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -112,6 +113,7 @@ static void test_cancel_before_invoke(grpc_end2end_test_config config,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_byte_buffer *response_payload_recv = NULL;
@@ -120,10 +122,10 @@ static void test_cancel_before_invoke(grpc_end2end_test_config config,
       grpc_raw_byte_buffer_create(&request_payload_slice, 1);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_cancel(c));
+  GPR_ASSERT(GRPC_CALL_OK == grpc_call_cancel(c, NULL));
 
   grpc_metadata_array_init(&initial_metadata_recv);
   grpc_metadata_array_init(&trailing_metadata_recv);
@@ -137,27 +139,34 @@ static void test_cancel_before_invoke(grpc_end2end_test_config config,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, test_ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, test_ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
diff --git a/test/core/end2end/tests/cancel_in_a_vacuum.c b/test/core/end2end/tests/cancel_in_a_vacuum.c
index 7645410184..f57a44caa4 100644
--- a/test/core/end2end/tests/cancel_in_a_vacuum.c
+++ b/test/core/end2end/tests/cancel_in_a_vacuum.c
@@ -69,7 +69,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -77,7 +77,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -108,10 +109,10 @@ static void test_cancel_in_a_vacuum(grpc_end2end_test_config config,
   cq_verifier *v_client = cq_verifier_create(f.cq);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
-  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c));
+  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c, NULL));
 
   grpc_call_destroy(c);
 
diff --git a/test/core/end2end/tests/cancel_test_helpers.h b/test/core/end2end/tests/cancel_test_helpers.h
index 8345c07904..6ea822fa9a 100644
--- a/test/core/end2end/tests/cancel_test_helpers.h
+++ b/test/core/end2end/tests/cancel_test_helpers.h
@@ -36,12 +36,13 @@
 
 typedef struct {
   const char *name;
-  grpc_call_error (*initiate_cancel)(grpc_call *call);
+  grpc_call_error (*initiate_cancel)(grpc_call *call, void *reserved);
   grpc_status_code expect_status;
   const char *expect_details;
 } cancellation_mode;
 
-static grpc_call_error wait_for_deadline(grpc_call *call) {
+static grpc_call_error wait_for_deadline(grpc_call *call, void *reserved) {
+  (void) reserved;
   return GRPC_CALL_OK;
 }
 
diff --git a/test/core/end2end/tests/census_simple_request.c b/test/core/end2end/tests/census_simple_request.c
index 2142dde921..8f615dec20 100644
--- a/test/core/end2end/tests/census_simple_request.c
+++ b/test/core/end2end/tests/census_simple_request.c
@@ -67,7 +67,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -82,7 +83,7 @@ static void shutdown_client(grpc_end2end_test_fixture *f) {
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, n_seconds_time(5));
+    ev = grpc_completion_queue_next(cq, n_seconds_time(5), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -107,12 +108,14 @@ static void test_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -124,13 +127,16 @@ static void test_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -138,12 +144,15 @@ static void test_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -151,18 +160,22 @@ static void test_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/default_host.c b/test/core/end2end/tests/default_host.c
index 920449f4fa..5cbf26b94f 100644
--- a/test/core/end2end/tests/default_host.c
+++ b/test/core/end2end/tests/default_host.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -111,13 +112,14 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
   char *peer;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", NULL, deadline);
+                               "/foo", NULL, deadline, NULL);
   GPR_ASSERT(c);
 
   peer = grpc_call_get_peer(c);
@@ -149,11 +151,13 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(error == GRPC_CALL_OK);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(error == GRPC_CALL_OK);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -181,7 +185,8 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(error == GRPC_CALL_OK);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/disappearing_server.c b/test/core/end2end/tests/disappearing_server.c
index 94bed336e8..0b98424c25 100644
--- a/test/core/end2end/tests/disappearing_server.c
+++ b/test/core/end2end/tests/disappearing_server.c
@@ -56,7 +56,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -93,12 +93,14 @@ static void do_request_and_shutdown_server(grpc_end2end_test_fixture *f,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f->client, NULL, GRPC_PROPAGATE_DEFAULTS, f->cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -110,13 +112,16 @@ static void do_request_and_shutdown_server(grpc_end2end_test_fixture *f,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -124,13 +129,15 @@ static void do_request_and_shutdown_server(grpc_end2end_test_fixture *f,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(f->server, &s,
-                                                      &call_details,
-                                                      &request_metadata_recv,
-                                                      f->cq, f->cq, tag(101)));
+  error = grpc_server_request_call(f->server, &s, &call_details,
+                                   &request_metadata_recv, f->cq, f->cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -142,18 +149,22 @@ static void do_request_and_shutdown_server(grpc_end2end_test_fixture *f,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/early_server_shutdown_finishes_inflight_calls.c b/test/core/end2end/tests/early_server_shutdown_finishes_inflight_calls.c
index 36cbe8067b..a5683129c1 100644
--- a/test/core/end2end/tests/early_server_shutdown_finishes_inflight_calls.c
+++ b/test/core/end2end/tests/early_server_shutdown_finishes_inflight_calls.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -101,12 +101,13 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -119,13 +120,16 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->data.send_initial_metadata.count = 0;
   op->data.send_initial_metadata.metadata = NULL;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -133,12 +137,15 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -146,8 +153,10 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   /* shutdown and destroy the server */
   grpc_server_shutdown_and_notify(f.server, f.cq, tag(1000));
diff --git a/test/core/end2end/tests/early_server_shutdown_finishes_tags.c b/test/core/end2end/tests/early_server_shutdown_finishes_tags.c
index fc03cb01a8..9b678a1754 100644
--- a/test/core/end2end/tests/early_server_shutdown_finishes_tags.c
+++ b/test/core/end2end/tests/early_server_shutdown_finishes_tags.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
diff --git a/test/core/end2end/tests/empty_batch.c b/test/core/end2end/tests/empty_batch.c
index 138c6b07c5..feb2f18166 100644
--- a/test/core/end2end/tests/empty_batch.c
+++ b/test/core/end2end/tests/empty_batch.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -103,13 +104,15 @@ static void empty_batch_body(grpc_end2end_test_fixture f) {
   grpc_call *c;
   gpr_timespec deadline = five_seconds_time();
   cq_verifier *cqv = cq_verifier_create(f.cq);
+  grpc_call_error error;
   grpc_op *op = NULL;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, op, 0, tag(1)));
+  error = grpc_call_start_batch(c, op, 0, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
 
diff --git a/test/core/end2end/tests/graceful_server_shutdown.c b/test/core/end2end/tests/graceful_server_shutdown.c
index 23efa0304f..9ec9430d47 100644
--- a/test/core/end2end/tests/graceful_server_shutdown.c
+++ b/test/core/end2end/tests/graceful_server_shutdown.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -108,12 +108,13 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -126,13 +127,16 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->data.send_initial_metadata.count = 0;
   op->data.send_initial_metadata.metadata = NULL;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -140,12 +144,15 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -157,18 +164,22 @@ static void test_early_server_shutdown_finishes_inflight_calls(
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(0xdead), 1);
diff --git a/test/core/end2end/tests/invoke_large_request.c b/test/core/end2end/tests/invoke_large_request.c
index e32645e2ba..5fe369ea45 100644
--- a/test/core/end2end/tests/invoke_large_request.c
+++ b/test/core/end2end/tests/invoke_large_request.c
@@ -66,7 +66,7 @@ static gpr_timespec n_seconds_time(int n) {
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, n_seconds_time(5));
+    ev = grpc_completion_queue_next(cq, n_seconds_time(5), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -74,7 +74,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -124,12 +125,13 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -141,21 +143,26 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -163,12 +170,15 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -176,12 +186,15 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -190,18 +203,22 @@ static void test_invoke_large_request(grpc_end2end_test_config config) {
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/max_concurrent_streams.c b/test/core/end2end/tests/max_concurrent_streams.c
index 049c028835..203d98d100 100644
--- a/test/core/end2end/tests/max_concurrent_streams.c
+++ b/test/core/end2end/tests/max_concurrent_streams.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -109,12 +110,14 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -126,13 +129,16 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -140,12 +146,15 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -153,18 +162,22 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
@@ -207,6 +220,7 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   grpc_metadata_array initial_metadata_recv2;
   grpc_metadata_array trailing_metadata_recv2;
   grpc_status_code status1;
+  grpc_call_error error;
   char *details1 = NULL;
   size_t details_capacity1 = 0;
   grpc_status_code status2;
@@ -245,10 +259,12 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
      the first completes */
   deadline = n_seconds_time(1000);
   c1 = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                                "/alpha", "foo.test.google.fr:1234", deadline);
+                                "/alpha", "foo.test.google.fr:1234", deadline,
+                                NULL);
   GPR_ASSERT(c1);
   c2 = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                                "/beta", "foo.test.google.fr:1234", deadline);
+                                "/beta", "foo.test.google.fr:1234", deadline,
+                                NULL);
   GPR_ASSERT(c2);
 
   GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
@@ -259,12 +275,14 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(c1, ops, op - ops, tag(301)));
+  error = grpc_call_start_batch(c1, ops, op - ops, tag(301), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   op = ops;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
@@ -273,24 +291,28 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details1;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity1;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv1;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(c1, ops, op - ops, tag(302)));
+  error = grpc_call_start_batch(c1, ops, op - ops, tag(302), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   op = ops;
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(c2, ops, op - ops, tag(401)));
+  error = grpc_call_start_batch(c2, ops, op - ops, tag(401), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   op = ops;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
@@ -299,19 +321,22 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details2;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity2;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv1;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(c2, ops, op - ops, tag(402)));
+  error = grpc_call_start_batch(c2, ops, op - ops, tag(402), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   got_client_start = 0;
   got_server_start = 0;
   live_call = -1;
   while (!got_client_start || !got_server_start) {
-    ev = grpc_completion_queue_next(f.cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(3));
+    ev = grpc_completion_queue_next(f.cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(3),
+                                    NULL);
     GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
     GPR_ASSERT(ev.success);
     if (ev.tag == tag(101)) {
@@ -334,19 +359,22 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(s1, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s1, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(live_call + 2), 1);
@@ -365,19 +393,22 @@ static void test_max_concurrent_streams(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(s2, ops, op - ops, tag(202)));
+  error = grpc_call_start_batch(s2, ops, op - ops, tag(202), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(live_call + 2), 1);
   cq_expect_completion(cqv, tag(202), 1);
diff --git a/test/core/end2end/tests/max_message_length.c b/test/core/end2end/tests/max_message_length.c
index feea49c68f..dd30e68f42 100644
--- a/test/core/end2end/tests/max_message_length.c
+++ b/test/core/end2end/tests/max_message_length.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -114,6 +115,7 @@ static void test_max_message_length(grpc_end2end_test_config config) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -130,7 +132,7 @@ static void test_max_message_length(grpc_end2end_test_config config) {
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
                                "/foo", "foo.test.google.fr:1234",
-                               gpr_inf_future(GPR_CLOCK_REALTIME));
+                               gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -142,17 +144,21 @@ static void test_max_message_length(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -160,12 +166,15 @@ static void test_max_message_length(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -173,8 +182,10 @@ static void test_max_message_length(grpc_end2end_test_config config) {
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/no_op.c b/test/core/end2end/tests/no_op.c
index 8ead664758..565d4ea280 100644
--- a/test/core/end2end/tests/no_op.c
+++ b/test/core/end2end/tests/no_op.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
diff --git a/test/core/end2end/tests/ping_pong_streaming.c b/test/core/end2end/tests/ping_pong_streaming.c
index 0ae611b518..e19f115e40 100644
--- a/test/core/end2end/tests/ping_pong_streaming.c
+++ b/test/core/end2end/tests/ping_pong_streaming.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -113,6 +114,7 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -125,7 +127,8 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   gpr_slice response_payload_slice = gpr_slice_from_copied_string("hello you");
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -137,10 +140,12 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -148,12 +153,15 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(100)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(100));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(100), 1);
   cq_verify(cqv);
 
@@ -161,12 +169,15 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(101)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(101), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   for (i = 0; i < messages; i++) {
     request_payload = grpc_raw_byte_buffer_create(&request_payload_slice, 1);
@@ -176,20 +187,24 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
     op->op = GRPC_OP_SEND_MESSAGE;
     op->data.send_message = request_payload;
     op->flags = 0;
+    op->reserved = NULL;
     op++;
     op->op = GRPC_OP_RECV_MESSAGE;
     op->data.recv_message = &response_payload_recv;
     op->flags = 0;
+    op->reserved = NULL;
     op++;
-    GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(2)));
+    error = grpc_call_start_batch(c, ops, op - ops, tag(2), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
 
     op = ops;
     op->op = GRPC_OP_RECV_MESSAGE;
     op->data.recv_message = &request_payload_recv;
     op->flags = 0;
+    op->reserved = NULL;
     op++;
-    GPR_ASSERT(GRPC_CALL_OK ==
-               grpc_call_start_batch(s, ops, op - ops, tag(102)));
+    error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
     cq_expect_completion(cqv, tag(102), 1);
     cq_verify(cqv);
 
@@ -197,9 +212,10 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
     op->op = GRPC_OP_SEND_MESSAGE;
     op->data.send_message = response_payload;
     op->flags = 0;
+    op->reserved = NULL;
     op++;
-    GPR_ASSERT(GRPC_CALL_OK ==
-               grpc_call_start_batch(s, ops, op - ops, tag(103)));
+    error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
     cq_expect_completion(cqv, tag(103), 1);
     cq_expect_completion(cqv, tag(2), 1);
     cq_verify(cqv);
@@ -216,8 +232,10 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   op = ops;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(3)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(3), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   op = ops;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
@@ -225,8 +243,10 @@ static void test_pingpong_streaming(grpc_end2end_test_config config,
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(104)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(104), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(1), 1);
   cq_expect_completion(cqv, tag(3), 1);
diff --git a/test/core/end2end/tests/registered_call.c b/test/core/end2end/tests/registered_call.c
index ffc4cd40a0..1ef595ee56 100644
--- a/test/core/end2end/tests/registered_call.c
+++ b/test/core/end2end/tests/registered_call.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -111,12 +112,13 @@ static void simple_request_body(grpc_end2end_test_fixture f, void *rc) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_registered_call(
-      f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq, rc, deadline);
+      f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq, rc, deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -128,13 +130,16 @@ static void simple_request_body(grpc_end2end_test_fixture f, void *rc) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -142,12 +147,15 @@ static void simple_request_body(grpc_end2end_test_fixture f, void *rc) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -155,18 +163,22 @@ static void simple_request_body(grpc_end2end_test_fixture f, void *rc) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
@@ -194,7 +206,8 @@ static void test_invoke_simple_request(grpc_end2end_test_config config) {
   grpc_end2end_test_fixture f =
       begin_test(config, "test_invoke_simple_request", NULL, NULL);
   void *rc =
-      grpc_channel_register_call(f.client, "/foo", "foo.test.google.fr:1234");
+      grpc_channel_register_call(f.client, "/foo", "foo.test.google.fr:1234",
+                                 NULL);
 
   simple_request_body(f, rc);
   end_test(&f);
@@ -206,7 +219,8 @@ static void test_invoke_10_simple_requests(grpc_end2end_test_config config) {
   grpc_end2end_test_fixture f =
       begin_test(config, "test_invoke_10_simple_requests", NULL, NULL);
   void *rc =
-      grpc_channel_register_call(f.client, "/foo", "foo.test.google.fr:1234");
+      grpc_channel_register_call(f.client, "/foo", "foo.test.google.fr:1234",
+                                 NULL);
 
   for (i = 0; i < 10; i++) {
     simple_request_body(f, rc);
diff --git a/test/core/end2end/tests/request_response_with_binary_metadata_and_payload.c b/test/core/end2end/tests/request_response_with_binary_metadata_and_payload.c
index 600642e6a7..de6f460795 100644
--- a/test/core/end2end/tests/request_response_with_binary_metadata_and_payload.c
+++ b/test/core/end2end/tests/request_response_with_binary_metadata_and_payload.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -113,20 +114,24 @@ static void test_request_response_with_metadata_and_payload(
       {"key1-bin",
        "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc",
        13,
-       {{NULL, NULL, NULL}}},
+       0,
+       {{NULL, NULL, NULL, NULL}}},
       {"key2-bin",
        "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d",
        14,
-       {{NULL, NULL, NULL}}}};
+       0,
+       {{NULL, NULL, NULL, NULL}}}};
   grpc_metadata meta_s[2] = {
       {"key3-bin",
        "\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee",
        15,
-       {{NULL, NULL, NULL}}},
+       0,
+       {{NULL, NULL, NULL, NULL}}},
       {"key4-bin",
        "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff",
        16,
-       {{NULL, NULL, NULL}}}};
+       0,
+       {{NULL, NULL, NULL, NULL}}}};
   grpc_end2end_test_fixture f = begin_test(
       config, "test_request_response_with_metadata_and_payload", NULL, NULL);
   cq_verifier *cqv = cq_verifier_create(f.cq);
@@ -139,12 +144,13 @@ static void test_request_response_with_metadata_and_payload(
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -157,21 +163,26 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_c;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -179,12 +190,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -193,12 +207,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_s;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -207,18 +224,22 @@ static void test_request_response_with_metadata_and_payload(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_response_with_metadata_and_payload.c b/test/core/end2end/tests/request_response_with_metadata_and_payload.c
index 7e8cce10f4..b6196ab46e 100644
--- a/test/core/end2end/tests/request_response_with_metadata_and_payload.c
+++ b/test/core/end2end/tests/request_response_with_metadata_and_payload.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -109,10 +110,10 @@ static void test_request_response_with_metadata_and_payload(
   grpc_byte_buffer *response_payload =
       grpc_raw_byte_buffer_create(&response_payload_slice, 1);
   gpr_timespec deadline = five_seconds_time();
-  grpc_metadata meta_c[2] = {{"key1", "val1", 4, {{NULL, NULL, NULL}}},
-                             {"key2", "val2", 4, {{NULL, NULL, NULL}}}};
-  grpc_metadata meta_s[2] = {{"KeY3", "val3", 4, {{NULL, NULL, NULL}}},
-                             {"KeY4", "val4", 4, {{NULL, NULL, NULL}}}};
+  grpc_metadata meta_c[2] = {{"key1", "val1", 4, 0, {{NULL, NULL, NULL, NULL}}},
+                             {"key2", "val2", 4, 0, {{NULL, NULL, NULL, NULL}}}};
+  grpc_metadata meta_s[2] = {{"KeY3", "val3", 4, 0, {{NULL, NULL, NULL, NULL}}},
+                             {"KeY4", "val4", 4, 0, {{NULL, NULL, NULL, NULL}}}};
   grpc_end2end_test_fixture f = begin_test(
       config, "test_request_response_with_metadata_and_payload", NULL, NULL);
   cq_verifier *cqv = cq_verifier_create(f.cq);
@@ -125,12 +126,13 @@ static void test_request_response_with_metadata_and_payload(
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -143,21 +145,26 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_c;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -165,12 +172,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -179,12 +189,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_s;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -193,18 +206,22 @@ static void test_request_response_with_metadata_and_payload(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_response_with_payload.c b/test/core/end2end/tests/request_response_with_payload.c
index 55323895fb..0a45a482a3 100644
--- a/test/core/end2end/tests/request_response_with_payload.c
+++ b/test/core/end2end/tests/request_response_with_payload.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -117,12 +118,13 @@ static void request_response_with_payload(grpc_end2end_test_fixture f) {
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -134,21 +136,26 @@ static void request_response_with_payload(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -156,12 +163,15 @@ static void request_response_with_payload(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -169,12 +179,15 @@ static void request_response_with_payload(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -183,18 +196,22 @@ static void request_response_with_payload(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_response_with_payload_and_call_creds.c b/test/core/end2end/tests/request_response_with_payload_and_call_creds.c
index 342dfa03f6..8e0bc4e2ae 100644
--- a/test/core/end2end/tests/request_response_with_payload_and_call_creds.c
+++ b/test/core/end2end/tests/request_response_with_payload_and_call_creds.c
@@ -86,7 +86,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -94,7 +94,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -139,7 +140,7 @@ static void test_call_creds_failure(grpc_end2end_test_config config) {
       begin_test(config, "test_call_creds_failure", 0);
   gpr_timespec deadline = five_seconds_time();
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   /* Try with credentials unfit to be set on a call (channel creds). */
@@ -176,6 +177,7 @@ static void request_response_with_payload_and_call_creds(
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -187,7 +189,7 @@ static void request_response_with_payload_and_call_creds(
   cqv = cq_verifier_create(f.cq);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
   creds = grpc_iam_credentials_create(iam_token, iam_selector);
   GPR_ASSERT(creds != NULL);
@@ -217,21 +219,26 @@ static void request_response_with_payload_and_call_creds(
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -239,12 +246,15 @@ static void request_response_with_payload_and_call_creds(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
   s_auth_context = grpc_call_auth_context(s);
@@ -264,12 +274,15 @@ static void request_response_with_payload_and_call_creds(
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -278,18 +291,22 @@ static void request_response_with_payload_and_call_creds(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
@@ -389,6 +406,7 @@ static void test_request_with_server_rejecting_client_creds(
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_byte_buffer *response_payload_recv = NULL;
@@ -401,7 +419,7 @@ static void test_request_with_server_rejecting_client_creds(
   cqv = cq_verifier_create(f.cq);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   creds = grpc_iam_credentials_create(iam_token, iam_selector);
@@ -441,7 +459,8 @@ static void test_request_with_server_rejecting_client_creds(
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(error == GRPC_CALL_OK);
 
   cq_expect_completion(cqv, tag(1), 1);
   cq_verify(cqv);
diff --git a/test/core/end2end/tests/request_response_with_trailing_metadata_and_payload.c b/test/core/end2end/tests/request_response_with_trailing_metadata_and_payload.c
index 26be4ef643..83744a8e24 100644
--- a/test/core/end2end/tests/request_response_with_trailing_metadata_and_payload.c
+++ b/test/core/end2end/tests/request_response_with_trailing_metadata_and_payload.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -109,12 +110,12 @@ static void test_request_response_with_metadata_and_payload(
   grpc_byte_buffer *response_payload =
       grpc_raw_byte_buffer_create(&response_payload_slice, 1);
   gpr_timespec deadline = five_seconds_time();
-  grpc_metadata meta_c[2] = {{"key1", "val1", 4, {{NULL, NULL, NULL}}},
-                             {"key2", "val2", 4, {{NULL, NULL, NULL}}}};
-  grpc_metadata meta_s[2] = {{"key3", "val3", 4, {{NULL, NULL, NULL}}},
-                             {"key4", "val4", 4, {{NULL, NULL, NULL}}}};
-  grpc_metadata meta_t[2] = {{"key5", "val5", 4, {{NULL, NULL, NULL}}},
-                             {"key6", "val6", 4, {{NULL, NULL, NULL}}}};
+  grpc_metadata meta_c[2] = {{"key1", "val1", 4, 0, {{NULL, NULL, NULL, NULL}}},
+                             {"key2", "val2", 4, 0, {{NULL, NULL, NULL, NULL}}}};
+  grpc_metadata meta_s[2] = {{"key3", "val3", 4, 0, {{NULL, NULL, NULL, NULL}}},
+                             {"key4", "val4", 4, 0, {{NULL, NULL, NULL, NULL}}}};
+  grpc_metadata meta_t[2] = {{"key5", "val5", 4, 0, {{NULL, NULL, NULL, NULL}}},
+                             {"key6", "val6", 4, 0, {{NULL, NULL, NULL, NULL}}}};
   grpc_end2end_test_fixture f = begin_test(
       config, "test_request_response_with_metadata_and_payload", NULL, NULL);
   cq_verifier *cqv = cq_verifier_create(f.cq);
@@ -127,12 +128,13 @@ static void test_request_response_with_metadata_and_payload(
   grpc_byte_buffer *response_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -145,21 +147,26 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_c;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &response_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -167,12 +174,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -181,12 +191,15 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_initial_metadata.count = 2;
   op->data.send_initial_metadata.metadata = meta_s;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -195,10 +208,12 @@ static void test_request_response_with_metadata_and_payload(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = response_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 2;
@@ -206,8 +221,10 @@ static void test_request_response_with_metadata_and_payload(
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_with_compressed_payload.c b/test/core/end2end/tests/request_with_compressed_payload.c
index fe6014a42a..cb8b3381d6 100644
--- a/test/core/end2end/tests/request_with_compressed_payload.c
+++ b/test/core/end2end/tests/request_with_compressed_payload.c
@@ -73,7 +73,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -81,7 +81,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -124,6 +125,7 @@ static void request_with_payload_template(
   grpc_byte_buffer *request_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -143,7 +145,7 @@ static void request_with_payload_template(
   cqv = cq_verifier_create(f.cq);
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -160,17 +162,21 @@ static void request_with_payload_template(
     op->data.send_initial_metadata.count = 0;
   }
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = send_flags_bitmask;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -178,13 +184,15 @@ static void request_with_payload_template(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_server_request_call(f.server, &s, &call_details,
-                                      &request_metadata_recv, f.cq,
-                                      f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq,
+                                   f.cq, tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -200,12 +208,15 @@ static void request_with_payload_template(
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -214,14 +225,17 @@ static void request_with_payload_template(
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
@@ -295,12 +309,12 @@ static void test_invoke_request_with_compressed_payload_md_override(
          sizeof(gzip_compression_override.internal_data));
 
   none_compression_override.key = GRPC_COMPRESS_REQUEST_ALGORITHM_KEY;
-  none_compression_override.value = "none";
+  none_compression_override.value = "identity";
   none_compression_override.value_length = 4;
   memset(&none_compression_override.internal_data, 0,
          sizeof(none_compression_override.internal_data));
 
-  /* Channel default NONE, call override to GZIP */
+  /* Channel default NONE (aka IDENTITY), call override to GZIP */
   request_with_payload_template(
       config, "test_invoke_request_with_compressed_payload_md_override_1", 0,
       GRPC_COMPRESS_NONE, GRPC_COMPRESS_GZIP, &gzip_compression_override);
@@ -310,7 +324,7 @@ static void test_invoke_request_with_compressed_payload_md_override(
       config, "test_invoke_request_with_compressed_payload_md_override_2", 0,
       GRPC_COMPRESS_DEFLATE, GRPC_COMPRESS_GZIP, &gzip_compression_override);
 
-  /* Channel default DEFLATE, call override to NONE */
+  /* Channel default DEFLATE, call override to NONE (aka IDENTITY) */
   request_with_payload_template(
       config, "test_invoke_request_with_compressed_payload_md_override_3", 0,
       GRPC_COMPRESS_DEFLATE, GRPC_COMPRESS_NONE, &none_compression_override);
diff --git a/test/core/end2end/tests/request_with_flags.c b/test/core/end2end/tests/request_with_flags.c
index 37c4825c8b..3255f14457 100644
--- a/test/core/end2end/tests/request_with_flags.c
+++ b/test/core/end2end/tests/request_with_flags.c
@@ -69,7 +69,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -77,7 +77,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -117,12 +118,13 @@ static void test_invoke_request_with_flags(
   grpc_byte_buffer *request_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   grpc_call_error expectation;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -134,17 +136,21 @@ static void test_invoke_request_with_flags(
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = flags_for_op[op->op];
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = flags_for_op[op->op];
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = flags_for_op[op->op];
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = flags_for_op[op->op];
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -152,9 +158,11 @@ static void test_invoke_request_with_flags(
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = flags_for_op[op->op];
+  op->reserved = NULL;
   op++;
   expectation = call_start_batch_expected_result;
-  GPR_ASSERT(expectation == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(expectation == error);
 
   if (expectation == GRPC_CALL_OK) {
     cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_with_large_metadata.c b/test/core/end2end/tests/request_with_large_metadata.c
index 9ea8273ab0..5b43caf18c 100644
--- a/test/core/end2end/tests/request_with_large_metadata.c
+++ b/test/core/end2end/tests/request_with_large_metadata.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -117,13 +118,14 @@ static void test_request_with_large_metadata(grpc_end2end_test_config config) {
   grpc_byte_buffer *request_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
   const int large_size = 64 * 1024;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   meta.key = "key";
@@ -142,17 +144,21 @@ static void test_request_with_large_metadata(grpc_end2end_test_config config) {
   op->data.send_initial_metadata.count = 1;
   op->data.send_initial_metadata.metadata = &meta;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -160,12 +166,15 @@ static void test_request_with_large_metadata(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -173,12 +182,15 @@ static void test_request_with_large_metadata(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -187,14 +199,17 @@ static void test_request_with_large_metadata(grpc_end2end_test_config config) {
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/request_with_payload.c b/test/core/end2end/tests/request_with_payload.c
index 6b5f173f01..c0013fb60f 100644
--- a/test/core/end2end/tests/request_with_payload.c
+++ b/test/core/end2end/tests/request_with_payload.c
@@ -68,7 +68,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -76,7 +76,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -116,12 +117,13 @@ static void test_invoke_request_with_payload(grpc_end2end_test_config config) {
   grpc_byte_buffer *request_payload_recv = NULL;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -133,17 +135,21 @@ static void test_invoke_request_with_payload(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_MESSAGE;
   op->data.send_message = request_payload;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -151,8 +157,10 @@ static void test_invoke_request_with_payload(grpc_end2end_test_config config) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
                                  f.server, &s, &call_details,
@@ -164,12 +172,15 @@ static void test_invoke_request_with_payload(grpc_end2end_test_config config) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_MESSAGE;
   op->data.recv_message = &request_payload_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_verify(cqv);
@@ -178,14 +189,17 @@ static void test_invoke_request_with_payload(grpc_end2end_test_config config) {
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_OK;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(103)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(103), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(103), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/server_finishes_request.c b/test/core/end2end/tests/server_finishes_request.c
index 661c099d93..ab2f575263 100644
--- a/test/core/end2end/tests/server_finishes_request.c
+++ b/test/core/end2end/tests/server_finishes_request.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -111,12 +112,14 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -128,10 +131,12 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -139,12 +144,15 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -152,18 +160,22 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/simple_delayed_request.c b/test/core/end2end/tests/simple_delayed_request.c
index 82d2bf9657..277aa2596e 100644
--- a/test/core/end2end/tests/simple_delayed_request.c
+++ b/test/core/end2end/tests/simple_delayed_request.c
@@ -56,7 +56,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -64,7 +64,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -101,6 +102,7 @@ static void simple_delayed_request_body(grpc_end2end_test_config config,
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
@@ -108,7 +110,7 @@ static void simple_delayed_request_body(grpc_end2end_test_config config,
   config.init_client(f, client_args);
 
   c = grpc_channel_create_call(f->client, NULL, GRPC_PROPAGATE_DEFAULTS, f->cq,
-                               "/foo", "foo.test.google.fr", deadline);
+                               "/foo", "foo.test.google.fr", deadline, NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -120,13 +122,16 @@ static void simple_delayed_request_body(grpc_end2end_test_config config,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -134,15 +139,17 @@ static void simple_delayed_request_body(grpc_end2end_test_config config,
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   config.init_server(f, server_args);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(f->server, &s,
-                                                      &call_details,
-                                                      &request_metadata_recv,
-                                                      f->cq, f->cq, tag(101)));
+  error = grpc_server_request_call(f->server, &s, &call_details,
+                                   &request_metadata_recv, f->cq, f->cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -150,18 +157,22 @@ static void simple_delayed_request_body(grpc_end2end_test_config config,
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/simple_request.c b/test/core/end2end/tests/simple_request.c
index d60a63e682..d3d2f27560 100644
--- a/test/core/end2end/tests/simple_request.c
+++ b/test/core/end2end/tests/simple_request.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -111,13 +112,15 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
   char *peer;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   peer = grpc_call_get_peer(c);
@@ -134,13 +137,16 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -148,12 +154,15 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -170,18 +179,22 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/end2end/tests/simple_request_with_high_initial_sequence_number.c b/test/core/end2end/tests/simple_request_with_high_initial_sequence_number.c
index 2244e22416..4fc206cbfc 100644
--- a/test/core/end2end/tests/simple_request_with_high_initial_sequence_number.c
+++ b/test/core/end2end/tests/simple_request_with_high_initial_sequence_number.c
@@ -70,7 +70,7 @@ static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
 static void drain_cq(grpc_completion_queue *cq) {
   grpc_event ev;
   do {
-    ev = grpc_completion_queue_next(cq, five_seconds_time());
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
   } while (ev.type != GRPC_QUEUE_SHUTDOWN);
 }
 
@@ -78,7 +78,8 @@ static void shutdown_server(grpc_end2end_test_fixture *f) {
   if (!f->server) return;
   grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->cq, tag(1000),
-                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                                         GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                         NULL)
                  .type == GRPC_OP_COMPLETE);
   grpc_server_destroy(f->server);
   f->server = NULL;
@@ -111,12 +112,14 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   grpc_metadata_array request_metadata_recv;
   grpc_call_details call_details;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
   int was_cancelled = 2;
 
   c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
-                               "/foo", "foo.test.google.fr:1234", deadline);
+                               "/foo", "foo.test.google.fr:1234", deadline,
+                               NULL);
   GPR_ASSERT(c);
 
   grpc_metadata_array_init(&initial_metadata_recv);
@@ -128,13 +131,16 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
   op->data.recv_initial_metadata = &initial_metadata_recv;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -142,12 +148,15 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(c, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(c, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
-                                 f.server, &s, &call_details,
-                                 &request_metadata_recv, f.cq, f.cq, tag(101)));
+  error = grpc_server_request_call(f.server, &s, &call_details,
+                                   &request_metadata_recv, f.cq, f.cq,
+                                   tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
   cq_expect_completion(cqv, tag(101), 1);
   cq_verify(cqv);
 
@@ -155,18 +164,22 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   op->data.send_status_from_server.trailing_metadata_count = 0;
   op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
   op->data.send_status_from_server.status_details = "xyz";
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(s, ops, op - ops, tag(102)));
+  error = grpc_call_start_batch(s, ops, op - ops, tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   cq_expect_completion(cqv, tag(102), 1);
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/core/fling/client.c b/test/core/fling/client.c
index 17b737c9dd..54c9274510 100644
--- a/test/core/fling/client.c
+++ b/test/core/fling/client.c
@@ -91,24 +91,25 @@ static void init_ping_pong_request(void) {
 static void step_ping_pong_request(void) {
   call = grpc_channel_create_call(channel, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
                                   "/Reflector/reflectUnary", "localhost",
-                                  gpr_inf_future(GPR_CLOCK_REALTIME));
+                                  gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, ops, op - ops, (void *)1));
-  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME));
+             grpc_call_start_batch(call, ops, op - ops, (void *)1, NULL));
+  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   grpc_call_destroy(call);
   grpc_byte_buffer_destroy(response_payload_recv);
   call = NULL;
 }
 
 static void init_ping_pong_stream(void) {
+  grpc_call_error error;
   call = grpc_channel_create_call(channel, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
                                   "/Reflector/reflectStream", "localhost",
-                                  gpr_inf_future(GPR_CLOCK_REALTIME));
+                                  gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   stream_init_op.op = GRPC_OP_SEND_INITIAL_METADATA;
   stream_init_op.data.send_initial_metadata.count = 0;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, &stream_init_op, 1, (void *)1));
-  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME));
+  error = grpc_call_start_batch(call, &stream_init_op, 1, (void *)1, NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
 
   grpc_metadata_array_init(&initial_metadata_recv);
 
@@ -119,9 +120,10 @@ static void init_ping_pong_stream(void) {
 }
 
 static void step_ping_pong_stream(void) {
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, stream_step_ops, 2, (void *)1));
-  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME));
+  grpc_call_error error;
+  error = grpc_call_start_batch(call, stream_step_ops, 2, (void *)1, NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+  grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
   grpc_byte_buffer_destroy(response_payload_recv);
 }
 
@@ -152,6 +154,7 @@ int main(int argc, char **argv) {
   int secure = 0;
   char *target = "localhost:443";
   gpr_cmdline *cl;
+  grpc_event event;
   char *scenario_name = "ping-pong-request";
   scenario sc = {NULL, NULL, NULL};
 
@@ -183,8 +186,8 @@ int main(int argc, char **argv) {
     return 1;
   }
 
-  channel = grpc_insecure_channel_create(target, NULL);
-  cq = grpc_completion_queue_create();
+  channel = grpc_insecure_channel_create(target, NULL, NULL);
+  cq = grpc_completion_queue_create(NULL);
   the_buffer = grpc_raw_byte_buffer_create(&slice, payload_size);
   histogram = gpr_histogram_create(0.01, 60e9);
 
@@ -210,9 +213,10 @@ int main(int argc, char **argv) {
 
   grpc_channel_destroy(channel);
   grpc_completion_queue_shutdown(cq);
-  while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME))
-             .type != GRPC_QUEUE_SHUTDOWN)
-    ;
+  do {
+    event = grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
+                                       NULL);
+  } while (event.type != GRPC_QUEUE_SHUTDOWN);
   grpc_completion_queue_destroy(cq);
   grpc_byte_buffer_destroy(the_buffer);
   gpr_slice_unref(slice);
diff --git a/test/core/fling/server.c b/test/core/fling/server.c
index f445c68178..2873e4af4b 100644
--- a/test/core/fling/server.c
+++ b/test/core/fling/server.c
@@ -97,6 +97,7 @@ static void request_call(void) {
 
 static void handle_unary_method(void) {
   grpc_op *op;
+  grpc_call_error error;
 
   grpc_metadata_array_init(&initial_metadata_send);
 
@@ -122,41 +123,47 @@ static void handle_unary_method(void) {
   op->data.recv_close_on_server.cancelled = &was_cancelled;
   op++;
 
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, unary_ops, op - unary_ops,
-                                   tag(FLING_SERVER_BATCH_OPS_FOR_UNARY)));
+  error = grpc_call_start_batch(call, unary_ops, op - unary_ops,
+                                tag(FLING_SERVER_BATCH_OPS_FOR_UNARY), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 }
 
 static void send_initial_metadata(void) {
+  grpc_call_error error;
+  void *tagarg = tag(FLING_SERVER_SEND_INIT_METADATA_FOR_STREAMING);
   grpc_metadata_array_init(&initial_metadata_send);
   metadata_send_op.op = GRPC_OP_SEND_INITIAL_METADATA;
   metadata_send_op.data.send_initial_metadata.count = 0;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(
-                 call, &metadata_send_op, 1,
-                 tag(FLING_SERVER_SEND_INIT_METADATA_FOR_STREAMING)));
+  error = grpc_call_start_batch(call, &metadata_send_op, 1, tagarg, NULL);
+
+  GPR_ASSERT(GRPC_CALL_OK == error);
 }
 
 static void start_read_op(int t) {
+  grpc_call_error error;
   /* Starting read at server */
   read_op.op = GRPC_OP_RECV_MESSAGE;
   read_op.data.recv_message = &payload_buffer;
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(call, &read_op, 1, tag(t)));
+  error = grpc_call_start_batch(call, &read_op, 1, tag(t), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 }
 
 static void start_write_op(void) {
+  grpc_call_error error;
+  void *tagarg = tag(FLING_SERVER_WRITE_FOR_STREAMING);
   /* Starting write at server */
   write_op.op = GRPC_OP_SEND_MESSAGE;
   if (payload_buffer == NULL) {
     gpr_log(GPR_INFO, "NULL payload buffer !!!");
   }
   write_op.data.send_message = payload_buffer;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, &write_op, 1,
-                                   tag(FLING_SERVER_WRITE_FOR_STREAMING)));
+  error = grpc_call_start_batch(call, &write_op, 1, tagarg, NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 }
 
 static void start_send_status(void) {
+  grpc_call_error error;
+  void *tagarg = tag(FLING_SERVER_SEND_STATUS_FOR_STREAMING);
   status_op[0].op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   status_op[0].data.send_status_from_server.status = GRPC_STATUS_OK;
   status_op[0].data.send_status_from_server.trailing_metadata_count = 0;
@@ -164,9 +171,8 @@ static void start_send_status(void) {
   status_op[1].op = GRPC_OP_RECV_CLOSE_ON_SERVER;
   status_op[1].data.recv_close_on_server.cancelled = &was_cancelled;
 
-  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(
-                                 call, status_op, 2,
-                                 tag(FLING_SERVER_SEND_STATUS_FOR_STREAMING)));
+  error = grpc_call_start_batch(call, status_op, 2, tagarg, NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 }
 
 /* We have some sort of deadlock, so let's not exit gracefully for now.
@@ -205,20 +211,20 @@ int main(int argc, char **argv) {
   }
   gpr_log(GPR_INFO, "creating server on: %s", addr);
 
-  cq = grpc_completion_queue_create();
+  cq = grpc_completion_queue_create(NULL);
   if (secure) {
     grpc_ssl_pem_key_cert_pair pem_key_cert_pair = {test_server1_key,
                                                     test_server1_cert};
     grpc_server_credentials *ssl_creds =
         grpc_ssl_server_credentials_create(NULL, &pem_key_cert_pair, 1, 0);
-    server = grpc_server_create(NULL);
+    server = grpc_server_create(NULL, NULL);
     GPR_ASSERT(grpc_server_add_secure_http2_port(server, addr, ssl_creds));
     grpc_server_credentials_release(ssl_creds);
   } else {
-    server = grpc_server_create(NULL);
+    server = grpc_server_create(NULL, NULL);
     GPR_ASSERT(grpc_server_add_insecure_http2_port(server, addr));
   }
-  grpc_server_register_completion_queue(server, cq);
+  grpc_server_register_completion_queue(server, cq, NULL);
   grpc_server_start(server);
 
   gpr_free(addr_buf);
@@ -235,14 +241,14 @@ int main(int argc, char **argv) {
       gpr_log(GPR_INFO, "Shutting down due to SIGINT");
       grpc_server_shutdown_and_notify(server, cq, tag(1000));
       GPR_ASSERT(grpc_completion_queue_pluck(
-                     cq, tag(1000), GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5))
+                     cq, tag(1000), GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5), NULL)
                      .type == GRPC_OP_COMPLETE);
       grpc_completion_queue_shutdown(cq);
       shutdown_started = 1;
     }
     ev = grpc_completion_queue_next(
         cq, gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                         gpr_time_from_micros(1000000, GPR_TIMESPAN)));
+                         gpr_time_from_micros(1000000, GPR_TIMESPAN)), NULL);
     s = ev.tag;
     switch (ev.type) {
       case GRPC_OP_COMPLETE:
diff --git a/test/core/iomgr/udp_server_test.c b/test/core/iomgr/udp_server_test.c
new file mode 100644
index 0000000000..74b78958b0
--- /dev/null
+++ b/test/core/iomgr/udp_server_test.c
@@ -0,0 +1,178 @@
+/*
+ *
+ * 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 "src/core/iomgr/udp_server.h"
+#include "src/core/iomgr/iomgr.h"
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+#include "test/core/util/test_config.h"
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <unistd.h>
+
+#define LOG_TEST(x) gpr_log(GPR_INFO, "%s", #x)
+
+static grpc_pollset g_pollset;
+static int g_number_of_reads = 0;
+static int g_number_of_bytes_read = 0;
+
+static void on_connect(void *arg, grpc_endpoint *udp) {
+}
+
+static void on_read(int fd, grpc_udp_server_cb new_transport_cb, void *cb_arg) {
+  char read_buffer[512];
+  int byte_count;
+
+  gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
+  byte_count = recv(fd, read_buffer, sizeof(read_buffer), 0);
+
+  g_number_of_reads++;
+  g_number_of_bytes_read += byte_count;
+
+  grpc_pollset_kick(&g_pollset, NULL);
+  gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
+}
+
+static void test_no_op(void) {
+  grpc_udp_server *s = grpc_udp_server_create();
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_start(void) {
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_start");
+  grpc_udp_server_start(s, NULL, 0, on_connect, NULL);
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_port(void) {
+  struct sockaddr_in addr;
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_port");
+
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, sizeof(addr),
+                                      on_read));
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_port_and_start(void) {
+  struct sockaddr_in addr;
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_port_and_start");
+
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, sizeof(addr),
+                                      on_read));
+
+  grpc_udp_server_start(s, NULL, 0, on_connect, NULL);
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_receive(int number_of_clients) {
+  struct sockaddr_storage addr;
+  socklen_t addr_len = sizeof(addr);
+  int clifd, svrfd;
+  grpc_udp_server *s = grpc_udp_server_create();
+  int i;
+  int number_of_reads_before;
+  gpr_timespec deadline;
+  grpc_pollset *pollsets[1];
+  LOG_TEST("test_receive");
+  gpr_log(GPR_INFO, "clients=%d", number_of_clients);
+
+  g_number_of_bytes_read = 0;
+
+  memset(&addr, 0, sizeof(addr));
+  addr.ss_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, addr_len, on_read));
+
+  svrfd = grpc_udp_server_get_fd(s, 0);
+  GPR_ASSERT(svrfd >= 0);
+  GPR_ASSERT(getsockname(svrfd, (struct sockaddr *)&addr, &addr_len) == 0);
+  GPR_ASSERT(addr_len <= sizeof(addr));
+
+  pollsets[0] = &g_pollset;
+  grpc_udp_server_start(s, pollsets, 1, on_connect, NULL);
+
+  gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
+
+  for (i = 0; i < number_of_clients; i++) {
+    deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(4000);
+
+    number_of_reads_before = g_number_of_reads;
+    /* Create a socket, send a packet to the UDP server. */
+    clifd = socket(addr.ss_family, SOCK_DGRAM, 0);
+    GPR_ASSERT(clifd >= 0);
+    GPR_ASSERT(connect(clifd, (struct sockaddr *)&addr, addr_len) == 0);
+    GPR_ASSERT(5 == write(clifd, "hello", 5));
+    while (g_number_of_reads == number_of_reads_before &&
+           gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0) {
+      grpc_pollset_worker worker;
+      grpc_pollset_work(&g_pollset, &worker, deadline);
+    }
+    GPR_ASSERT(g_number_of_reads == number_of_reads_before + 1);
+    close(clifd);
+  }
+  GPR_ASSERT(g_number_of_bytes_read == 5 * number_of_clients);
+
+  gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void destroy_pollset(void *p) { grpc_pollset_destroy(p); }
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  grpc_iomgr_init();
+  grpc_pollset_init(&g_pollset);
+
+  test_no_op();
+  test_no_op_with_start();
+  test_no_op_with_port();
+  test_no_op_with_port_and_start();
+  test_receive(1);
+  test_receive(10);
+
+  grpc_pollset_shutdown(&g_pollset, destroy_pollset, &g_pollset);
+  grpc_iomgr_shutdown();
+  return 0;
+}
diff --git a/test/core/surface/completion_queue_test.c b/test/core/surface/completion_queue_test.c
index 0e59ea4b22..0741ab920d 100644
--- a/test/core/surface/completion_queue_test.c
+++ b/test/core/surface/completion_queue_test.c
@@ -52,7 +52,7 @@ static void *create_test_tag(void) {
 static void shutdown_and_destroy(grpc_completion_queue *cc) {
   grpc_event ev;
   grpc_completion_queue_shutdown(cc);
-  ev = grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME));
+  ev = grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
   GPR_ASSERT(ev.type == GRPC_QUEUE_SHUTDOWN);
   grpc_completion_queue_destroy(cc);
 }
@@ -60,17 +60,18 @@ static void shutdown_and_destroy(grpc_completion_queue *cc) {
 /* ensure we can create and destroy a completion channel */
 static void test_no_op(void) {
   LOG_TEST("test_no_op");
-  shutdown_and_destroy(grpc_completion_queue_create());
+  shutdown_and_destroy(grpc_completion_queue_create(NULL));
 }
 
 static void test_wait_empty(void) {
   grpc_completion_queue *cc;
+  grpc_event event;
 
   LOG_TEST("test_wait_empty");
 
-  cc = grpc_completion_queue_create();
-  GPR_ASSERT(grpc_completion_queue_next(cc, gpr_now(GPR_CLOCK_REALTIME)).type ==
-             GRPC_QUEUE_TIMEOUT);
+  cc = grpc_completion_queue_create(NULL);
+  event = grpc_completion_queue_next(cc, gpr_now(GPR_CLOCK_REALTIME), NULL);
+  GPR_ASSERT(event.type == GRPC_QUEUE_TIMEOUT);
   shutdown_and_destroy(cc);
 }
 
@@ -84,12 +85,12 @@ static void test_cq_end_op(void) {
 
   LOG_TEST("test_cq_end_op");
 
-  cc = grpc_completion_queue_create();
+  cc = grpc_completion_queue_create(NULL);
 
   grpc_cq_begin_op(cc);
   grpc_cq_end_op(cc, tag, 1, do_nothing_end_completion, NULL, &completion);
 
-  ev = grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME));
+  ev = grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
   GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
   GPR_ASSERT(ev.tag == tag);
   GPR_ASSERT(ev.success);
@@ -99,23 +100,27 @@ static void test_cq_end_op(void) {
 
 static void test_shutdown_then_next_polling(void) {
   grpc_completion_queue *cc;
+  grpc_event event;
   LOG_TEST("test_shutdown_then_next_polling");
 
-  cc = grpc_completion_queue_create();
+  cc = grpc_completion_queue_create(NULL);
   grpc_completion_queue_shutdown(cc);
-  GPR_ASSERT(grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME))
-                 .type == GRPC_QUEUE_SHUTDOWN);
+  event = grpc_completion_queue_next(cc, gpr_inf_past(GPR_CLOCK_REALTIME),
+                                     NULL);
+  GPR_ASSERT(event.type == GRPC_QUEUE_SHUTDOWN);
   grpc_completion_queue_destroy(cc);
 }
 
 static void test_shutdown_then_next_with_timeout(void) {
   grpc_completion_queue *cc;
+  grpc_event event;
   LOG_TEST("test_shutdown_then_next_with_timeout");
 
-  cc = grpc_completion_queue_create();
+  cc = grpc_completion_queue_create(NULL);
   grpc_completion_queue_shutdown(cc);
-  GPR_ASSERT(grpc_completion_queue_next(cc, gpr_inf_future(GPR_CLOCK_REALTIME))
-                 .type == GRPC_QUEUE_SHUTDOWN);
+  event = grpc_completion_queue_next(cc, gpr_inf_future(GPR_CLOCK_REALTIME),
+                                     NULL);
+  GPR_ASSERT(event.type == GRPC_QUEUE_SHUTDOWN);
   grpc_completion_queue_destroy(cc);
 }
 
@@ -135,7 +140,7 @@ static void test_pluck(void) {
     }
   }
 
-  cc = grpc_completion_queue_create();
+  cc = grpc_completion_queue_create(NULL);
 
   for (i = 0; i < GPR_ARRAY_SIZE(tags); i++) {
     grpc_cq_begin_op(cc);
@@ -145,7 +150,7 @@ static void test_pluck(void) {
 
   for (i = 0; i < GPR_ARRAY_SIZE(tags); i++) {
     ev = grpc_completion_queue_pluck(cc, tags[i],
-                                     gpr_inf_past(GPR_CLOCK_REALTIME));
+                                     gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
     GPR_ASSERT(ev.tag == tags[i]);
   }
 
@@ -157,7 +162,7 @@ static void test_pluck(void) {
 
   for (i = 0; i < GPR_ARRAY_SIZE(tags); i++) {
     ev = grpc_completion_queue_pluck(cc, tags[GPR_ARRAY_SIZE(tags) - i - 1],
-                                     gpr_inf_past(GPR_CLOCK_REALTIME));
+                                     gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
     GPR_ASSERT(ev.tag == tags[GPR_ARRAY_SIZE(tags) - i - 1]);
   }
 
@@ -229,7 +234,7 @@ static void consumer_thread(void *arg) {
 
   gpr_log(GPR_INFO, "consumer %d phase 2", opt->id);
   for (;;) {
-    ev = grpc_completion_queue_next(opt->cc, ten_seconds_time());
+    ev = grpc_completion_queue_next(opt->cc, ten_seconds_time(), NULL);
     switch (ev.type) {
       case GRPC_OP_COMPLETE:
         GPR_ASSERT(ev.success);
@@ -251,7 +256,7 @@ static void test_threading(int producers, int consumers) {
       gpr_malloc((producers + consumers) * sizeof(test_thread_options));
   gpr_event phase1 = GPR_EVENT_INIT;
   gpr_event phase2 = GPR_EVENT_INIT;
-  grpc_completion_queue *cc = grpc_completion_queue_create();
+  grpc_completion_queue *cc = grpc_completion_queue_create(NULL);
   int i;
   int total_consumed = 0;
   static int optid = 101;
diff --git a/test/core/surface/lame_client_test.c b/test/core/surface/lame_client_test.c
index 5e6c9ae15c..216eeca8e1 100644
--- a/test/core/surface/lame_client_test.c
+++ b/test/core/surface/lame_client_test.c
@@ -49,6 +49,7 @@ int main(int argc, char **argv) {
   grpc_op *op;
   grpc_metadata_array trailing_metadata_recv;
   grpc_status_code status;
+  grpc_call_error error;
   char *details = NULL;
   size_t details_capacity = 0;
 
@@ -59,10 +60,11 @@ int main(int argc, char **argv) {
 
   chan = grpc_lame_client_channel_create("lampoon:national");
   GPR_ASSERT(chan);
-  cq = grpc_completion_queue_create();
+  cq = grpc_completion_queue_create(NULL);
   call = grpc_channel_create_call(chan, NULL, GRPC_PROPAGATE_DEFAULTS, cq,
                                   "/Foo", "anywhere",
-                                  GRPC_TIMEOUT_SECONDS_TO_DEADLINE(100));
+                                  GRPC_TIMEOUT_SECONDS_TO_DEADLINE(100),
+                                  NULL);
   GPR_ASSERT(call);
   cqv = cq_verifier_create(cq);
 
@@ -70,6 +72,7 @@ int main(int argc, char **argv) {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = 0;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
@@ -77,9 +80,10 @@ int main(int argc, char **argv) {
   op->data.recv_status_on_client.status_details = &details;
   op->data.recv_status_on_client.status_details_capacity = &details_capacity;
   op->flags = 0;
+  op->reserved = NULL;
   op++;
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call, ops, op - ops, tag(1)));
+  error = grpc_call_start_batch(call, ops, op - ops, tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
 
   /* the call should immediately fail */
   cq_expect_completion(cqv, tag(1), 1);
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 9b53bdc999..f00d19ed6c 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -666,6 +666,28 @@ TEST_F(AsyncEnd2endTest, ServerCheckDone) {
   EXPECT_TRUE(recv_status.ok());
 }
 
+TEST_F(AsyncEnd2endTest, UnimplementedRpc) {
+  std::shared_ptr<ChannelInterface> channel = CreateChannel(
+      server_address_.str(), InsecureCredentials(), ChannelArguments());
+  std::unique_ptr<grpc::cpp::test::util::UnimplementedService::Stub> stub;
+  stub =
+      std::move(grpc::cpp::test::util::UnimplementedService::NewStub(channel));
+  EchoRequest send_request;
+  EchoResponse recv_response;
+  Status recv_status;
+
+  ClientContext cli_ctx;
+  send_request.set_message("Hello");
+  std::unique_ptr<ClientAsyncResponseReader<EchoResponse> > response_reader(
+      stub->AsyncUnimplemented(&cli_ctx, send_request, cq_.get()));
+
+  response_reader->Finish(&recv_response, &recv_status, tag(4));
+  Verifier().Expect(4, false).Verify(cq_.get());
+
+  EXPECT_EQ(StatusCode::UNIMPLEMENTED, recv_status.error_code());
+  EXPECT_EQ("", recv_status.error_message());
+}
+
 }  // namespace
 }  // namespace testing
 }  // namespace grpc
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 37669815c6..3827cdf730 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -290,13 +290,17 @@ class End2endTest : public ::testing::TestWithParam<bool> {
     if (proxy_server_) proxy_server_->Shutdown();
   }
 
-  void ResetStub(bool use_proxy) {
+  void ResetChannel() {
     SslCredentialsOptions ssl_opts = {test_root_cert, "", ""};
     ChannelArguments args;
     args.SetSslTargetNameOverride("foo.test.google.fr");
     args.SetString(GRPC_ARG_SECONDARY_USER_AGENT_STRING, "end2end_test");
     channel_ = CreateChannel(server_address_.str(), SslCredentials(ssl_opts),
                              args);
+  }
+
+  void ResetStub(bool use_proxy) {
+    ResetChannel();
     if (use_proxy) {
       proxy_service_.reset(new Proxy(channel_));
       int port = grpc_pick_unused_port_or_die();
@@ -930,6 +934,23 @@ TEST_F(End2endTest, ChannelState) {
   EXPECT_EQ(GRPC_CHANNEL_CONNECTING, channel_->GetState(false));
 }
 
+// Talking to a non-existing service.
+TEST_F(End2endTest, NonExistingService) {
+  ResetChannel();
+  std::unique_ptr<grpc::cpp::test::util::UnimplementedService::Stub> stub;
+  stub =
+      std::move(grpc::cpp::test::util::UnimplementedService::NewStub(channel_));
+
+  EchoRequest request;
+  EchoResponse response;
+  request.set_message("Hello");
+
+  ClientContext context;
+  Status s = stub->Unimplemented(&context, request, &response);
+  EXPECT_EQ(StatusCode::UNIMPLEMENTED, s.error_code());
+  EXPECT_EQ("", s.error_message());
+}
+
 INSTANTIATE_TEST_CASE_P(End2end, End2endTest, ::testing::Values(false, true));
 
 }  // namespace testing
diff --git a/test/cpp/end2end/zookeeper_test.cc b/test/cpp/end2end/zookeeper_test.cc
new file mode 100644
index 0000000000..a48c497d9a
--- /dev/null
+++ b/test/cpp/end2end/zookeeper_test.cc
@@ -0,0 +1,223 @@
+/*
+ *
+ * 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 "test/core/util/test_config.h"
+#include "test/core/util/port.h"
+#include "test/cpp/util/echo.grpc.pb.h"
+#include "src/core/support/env.h"
+#include <grpc++/channel_arguments.h>
+#include <grpc++/channel_interface.h>
+#include <grpc++/client_context.h>
+#include <grpc++/create_channel.h>
+#include <grpc++/credentials.h>
+#include <grpc++/server.h>
+#include <grpc++/server_builder.h>
+#include <grpc++/server_context.h>
+#include <grpc++/server_credentials.h>
+#include <grpc++/status.h>
+#include <gtest/gtest.h>
+#include <grpc/grpc.h>
+#include <grpc/grpc_zookeeper.h>
+#include <zookeeper/zookeeper.h>
+
+using grpc::cpp::test::util::EchoRequest;
+using grpc::cpp::test::util::EchoResponse;
+
+namespace grpc {
+namespace testing {
+
+class ZookeeperTestServiceImpl
+    : public ::grpc::cpp::test::util::TestService::Service {
+ public:
+  Status Echo(ServerContext* context, const EchoRequest* request,
+              EchoResponse* response) GRPC_OVERRIDE {
+    response->set_message(request->message());
+    return Status::OK;
+  }
+};
+
+class ZookeeperTest : public ::testing::Test {
+ protected:
+  ZookeeperTest() {}
+
+  void SetUp() GRPC_OVERRIDE {
+    SetUpZookeeper();
+
+    // Sets up two servers
+    int port1 = grpc_pick_unused_port_or_die();
+    server1_ = SetUpServer(port1);
+
+    int port2 = grpc_pick_unused_port_or_die();
+    server2_ = SetUpServer(port2);
+
+    // Registers service /test in zookeeper
+    RegisterService("/test", "test");
+
+    // Registers service instance /test/1 in zookeeper
+    string value =
+        "{\"host\":\"localhost\",\"port\":\"" + to_string(port1) + "\"}";
+    RegisterService("/test/1", value);
+
+    // Registers service instance /test/2 in zookeeper
+    value =
+        "{\"host\":\"localhost\",\"port\":\"" + to_string(port2) + "\"}";
+    RegisterService("/test/2", value);
+  }
+
+  // Requires zookeeper server running
+  void SetUpZookeeper() {
+    // Finds zookeeper server address in environment
+    // Default is localhost:2181
+    zookeeper_address_ = "localhost:2181";
+    char* addr = gpr_getenv("GRPC_ZOOKEEPER_SERVER_TEST");
+    if (addr != NULL) {
+      string addr_str(addr);
+      zookeeper_address_ = addr_str;
+      gpr_free(addr);
+    }
+    gpr_log(GPR_DEBUG, zookeeper_address_.c_str());
+
+    // Connects to zookeeper server
+    zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
+    zookeeper_handle_ =
+        zookeeper_init(zookeeper_address_.c_str(), NULL, 15000, 0, 0, 0);
+    GPR_ASSERT(zookeeper_handle_ != NULL);
+
+    // Registers zookeeper name resolver in grpc
+    grpc_zookeeper_register();
+  }
+
+  std::unique_ptr<Server> SetUpServer(const int port) {
+    string server_address = "localhost:" + to_string(port);
+
+    ServerBuilder builder;
+    builder.AddListeningPort(server_address, InsecureServerCredentials());
+    builder.RegisterService(&service_);
+    std::unique_ptr<Server> server = builder.BuildAndStart();
+    return server;
+  }
+
+  void RegisterService(const string& name, const string& value) {
+    char* path = (char*)gpr_malloc(name.size());
+
+    int status = zoo_exists(zookeeper_handle_, name.c_str(), 0, NULL);
+    if (status == ZNONODE) {
+      status =
+          zoo_create(zookeeper_handle_, name.c_str(), value.c_str(),
+                     value.size(), &ZOO_OPEN_ACL_UNSAFE, 0, path, name.size());
+    } else {
+      status = zoo_set(zookeeper_handle_, name.c_str(), value.c_str(),
+                       value.size(), -1);
+    }
+    gpr_free(path);
+    GPR_ASSERT(status == 0);
+  }
+
+  void DeleteService(const string& name) {
+    int status = zoo_delete(zookeeper_handle_, name.c_str(), -1);
+    GPR_ASSERT(status == 0);
+  }
+
+  void ChangeZookeeperState() {
+    server1_->Shutdown();
+    DeleteService("/test/1");
+  }
+
+  void TearDown() GRPC_OVERRIDE {
+    server1_->Shutdown();
+    server2_->Shutdown();
+    zookeeper_close(zookeeper_handle_);
+  }
+
+  void ResetStub() {
+    string target = "zookeeper://" + zookeeper_address_ + "/test";
+    channel_ = CreateChannel(target, InsecureCredentials(), ChannelArguments());
+    stub_ = std::move(grpc::cpp::test::util::TestService::NewStub(channel_));
+  }
+
+  string to_string(const int number) {
+    std::stringstream strs;
+    strs << number;
+    return strs.str();
+  }
+
+  std::shared_ptr<ChannelInterface> channel_;
+  std::unique_ptr<grpc::cpp::test::util::TestService::Stub> stub_;
+  std::unique_ptr<Server> server1_;
+  std::unique_ptr<Server> server2_;
+  ZookeeperTestServiceImpl service_;
+  zhandle_t* zookeeper_handle_;
+  string zookeeper_address_;
+};
+
+// Tests zookeeper state change between two RPCs
+// TODO(ctiller): leaked objects in this test
+TEST_F(ZookeeperTest, ZookeeperStateChangeTwoRpc) {
+  ResetStub();
+
+  // First RPC
+  EchoRequest request1;
+  EchoResponse response1;
+  ClientContext context1;
+  context1.set_authority("test");
+  request1.set_message("Hello");
+  Status s1 = stub_->Echo(&context1, request1, &response1);
+  EXPECT_EQ(response1.message(), request1.message());
+  EXPECT_TRUE(s1.ok());
+
+  // Zookeeper state changes
+  gpr_log(GPR_DEBUG, "Zookeeper state change"); 
+  ChangeZookeeperState();
+  // Waits for re-resolving addresses
+  // TODO(ctiller): RPC will probably fail if not waiting
+  sleep(1);
+
+  // Second RPC
+  EchoRequest request2;
+  EchoResponse response2;
+  ClientContext context2;
+  context2.set_authority("test");
+  request2.set_message("World");
+  Status s2 = stub_->Echo(&context2, request2, &response2);
+  EXPECT_EQ(response2.message(), request2.message());
+  EXPECT_TRUE(s2.ok());
+}
+
+}  // namespace testing
+}  // namespace grpc
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/test/cpp/util/echo.proto b/test/cpp/util/echo.proto
index 6bb09316b4..8ea2f59897 100644
--- a/test/cpp/util/echo.proto
+++ b/test/cpp/util/echo.proto
@@ -41,3 +41,7 @@ service TestService {
   rpc BidiStream(stream EchoRequest) returns (stream EchoResponse);
   rpc Unimplemented(EchoRequest) returns (EchoResponse);
 }
+
+service UnimplementedService {
+  rpc Unimplemented(EchoRequest) returns (EchoResponse);
+}