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

3 files changed, 700 insertions, 13 deletions

diff --git a/test/cpp/end2end/server_builder_plugin_test.cc b/test/cpp/end2end/server_builder_plugin_test.cc
index 778a2be573..b967a5d1e9 100644
--- a/test/cpp/end2end/server_builder_plugin_test.cc
+++ b/test/cpp/end2end/server_builder_plugin_test.cc
@@ -191,7 +191,7 @@ class ServerBuilderPluginTest : public ::testing::TestWithParam<bool> {
     // we run some tests without a service, and for those we need to supply a
     // frequently polled completion queue
     cq_ = builder_->AddCompletionQueue();
-    cq_thread_ = grpc::thread(std::bind(&ServerBuilderPluginTest::RunCQ, this));
+    cq_thread_ = new grpc::thread(&ServerBuilderPluginTest::RunCQ, this);
     server_ = builder_->BuildAndStart();
     EXPECT_TRUE(CheckPresent());
   }
@@ -209,7 +209,8 @@ class ServerBuilderPluginTest : public ::testing::TestWithParam<bool> {
     EXPECT_TRUE(plugin->finish_is_called());
     server_->Shutdown();
     cq_->Shutdown();
-    cq_thread_.join();
+    cq_thread_->join();
+    delete cq_thread_;
   }
 
   string to_string(const int number) {
@@ -224,7 +225,7 @@ class ServerBuilderPluginTest : public ::testing::TestWithParam<bool> {
   std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
   std::unique_ptr<ServerCompletionQueue> cq_;
   std::unique_ptr<Server> server_;
-  grpc::thread cq_thread_;
+  grpc::thread* cq_thread_;
   TestServiceImpl service_;
   int port_;
 
diff --git a/test/cpp/grpclb/grpclb_api_test.cc b/test/cpp/grpclb/grpclb_api_test.cc
index bf77878e0a..33de1ee93c 100644
--- a/test/cpp/grpclb/grpclb_api_test.cc
+++ b/test/cpp/grpclb/grpclb_api_test.cc
@@ -58,26 +58,24 @@ TEST_F(GrpclbTest, CreateRequest) {
   grpc_grpclb_request_destroy(c_req);
 }
 
-TEST_F(GrpclbTest, ParseResponse) {
+TEST_F(GrpclbTest, ParseInitialResponse) {
   LoadBalanceResponse response;
   auto* initial_response = response.mutable_initial_response();
   auto* client_stats_report_interval =
       initial_response->mutable_client_stats_report_interval();
   client_stats_report_interval->set_seconds(123);
   client_stats_report_interval->set_nanos(456);
-
   const std::string encoded_response = response.SerializeAsString();
   gpr_slice encoded_slice =
       gpr_slice_from_copied_string(encoded_response.c_str());
-  grpc_grpclb_response* c_response = grpc_grpclb_response_parse(encoded_slice);
-  EXPECT_TRUE(c_response->has_initial_response);
-  EXPECT_FALSE(c_response->initial_response.has_load_balancer_delegate);
-  EXPECT_EQ(c_response->initial_response.client_stats_report_interval.seconds,
-            123);
-  EXPECT_EQ(c_response->initial_response.client_stats_report_interval.nanos,
-            456);
+
+  grpc_grpclb_initial_response* c_initial_response =
+      grpc_grpclb_initial_response_parse(encoded_slice);
+  EXPECT_FALSE(c_initial_response->has_load_balancer_delegate);
+  EXPECT_EQ(c_initial_response->client_stats_report_interval.seconds, 123);
+  EXPECT_EQ(c_initial_response->client_stats_report_interval.nanos, 456);
   gpr_slice_unref(encoded_slice);
-  grpc_grpclb_response_destroy(c_response);
+  grpc_grpclb_initial_response_destroy(c_initial_response);
 }
 
 TEST_F(GrpclbTest, ParseResponseServerList) {
diff --git a/test/cpp/grpclb/grpclb_test.cc b/test/cpp/grpclb/grpclb_test.cc
new file mode 100644
index 0000000000..1430f9de58
--- /dev/null
+++ b/test/cpp/grpclb/grpclb_test.cc
@@ -0,0 +1,688 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <cinttypes>
+#include <cstdarg>
+#include <cstdint>
+#include <cstring>
+#include <string>
+
+extern "C" {
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/thd.h>
+#include <grpc/support/time.h>
+
+#include "src/core/ext/client_config/client_channel.h"
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/support/tmpfile.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/server.h"
+#include "test/core/end2end/cq_verifier.h"
+#include "test/core/util/port.h"
+#include "test/core/util/test_config.h"
+}
+
+#include "src/proto/grpc/lb/v1/load_balancer.pb.h"
+
+#define NUM_BACKENDS 4
+
+// TODO(dgq): Other scenarios in need of testing:
+// - Send an empty serverlist update and verify that the client request blocks
+//   until a new serverlist with actual contents is available.
+// - Send identical serverlist update
+// - Test reception of invalid serverlist
+// - Test pinging
+// - Test against a non-LB server. That server should return UNIMPLEMENTED and
+//   the call should fail.
+// - Random LB server closing the stream unexpectedly.
+
+namespace grpc {
+namespace {
+
+typedef struct client_fixture {
+  grpc_channel *client;
+  char *server_uri;
+  grpc_completion_queue *cq;
+} client_fixture;
+
+typedef struct server_fixture {
+  grpc_server *server;
+  grpc_call *server_call;
+  grpc_completion_queue *cq;
+  char *servers_hostport;
+  int port;
+  gpr_thd_id tid;
+  int num_calls_serviced;
+} server_fixture;
+
+typedef struct test_fixture {
+  server_fixture lb_server;
+  server_fixture lb_backends[NUM_BACKENDS];
+  client_fixture client;
+  int lb_server_update_delay_ms;
+} test_fixture;
+
+static void *tag(intptr_t t) { return (void *)t; }
+
+static gpr_slice build_response_payload_slice(
+    const char *host, int *ports, size_t nports,
+    int64_t expiration_interval_secs, int32_t expiration_interval_nanos) {
+  // server_list {
+  //   servers {
+  //     ip_address: "127.0.0.1"
+  //     port: ...
+  //     load_balance_token: "token..."
+  //   }
+  //   ...
+  // }
+  grpc::lb::v1::LoadBalanceResponse response;
+  auto *serverlist = response.mutable_server_list();
+
+  if (expiration_interval_secs > 0 || expiration_interval_nanos > 0) {
+    auto *expiration_interval = serverlist->mutable_expiration_interval();
+    if (expiration_interval_secs > 0) {
+      expiration_interval->set_seconds(expiration_interval_secs);
+    }
+    if (expiration_interval_nanos > 0) {
+      expiration_interval->set_nanos(expiration_interval_nanos);
+    }
+  }
+  for (size_t i = 0; i < nports; i++) {
+    auto *server = serverlist->add_servers();
+    server->set_ip_address(host);
+    server->set_port(ports[i]);
+    // The following long long int cast is meant to work around the
+    // disfunctional implementation of std::to_string in gcc 4.4, which doesn't
+    // have a version for int but does have one for long long int.
+    server->set_load_balance_token("token" +
+                                   std::to_string((long long int)ports[i]));
+  }
+
+  gpr_log(GPR_INFO, "generating response: %s",
+          response.ShortDebugString().c_str());
+
+  const gpr_slice response_slice =
+      gpr_slice_from_copied_string(response.SerializeAsString().c_str());
+  return response_slice;
+}
+
+static void drain_cq(grpc_completion_queue *cq) {
+  grpc_event ev;
+  do {
+    ev = grpc_completion_queue_next(cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5),
+                                    NULL);
+  } while (ev.type != GRPC_QUEUE_SHUTDOWN);
+}
+
+static void sleep_ms(int delay_ms) {
+  gpr_sleep_until(gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                               gpr_time_from_millis(delay_ms, GPR_TIMESPAN)));
+}
+
+static void start_lb_server(server_fixture *sf, int *ports, size_t nports,
+                            int update_delay_ms) {
+  grpc_call *s;
+  cq_verifier *cqv = cq_verifier_create(sf->cq);
+  grpc_op ops[6];
+  grpc_op *op;
+  grpc_metadata_array request_metadata_recv;
+  grpc_call_details call_details;
+  grpc_call_error error;
+  int was_cancelled = 2;
+  grpc_byte_buffer *request_payload_recv;
+  grpc_byte_buffer *response_payload;
+
+  memset(ops, 0, sizeof(ops));
+  grpc_metadata_array_init(&request_metadata_recv);
+  grpc_call_details_init(&call_details);
+
+  error = grpc_server_request_call(sf->server, &s, &call_details,
+                                   &request_metadata_recv, sf->cq, sf->cq,
+                                   tag(200));
+  GPR_ASSERT(GRPC_CALL_OK == error);
+  gpr_log(GPR_INFO, "LB Server[%s] up", sf->servers_hostport);
+  cq_expect_completion(cqv, tag(200), 1);
+  cq_verify(cqv);
+  gpr_log(GPR_INFO, "LB Server[%s] after tag 200", sf->servers_hostport);
+
+  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_CLOSE_ON_SERVER;
+  op->data.recv_close_on_server.cancelled = &was_cancelled;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(201), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+  gpr_log(GPR_INFO, "LB Server[%s] after tag 201", sf->servers_hostport);
+
+  // receive request for backends
+  op = ops;
+  op->op = GRPC_OP_RECV_MESSAGE;
+  op->data.recv_message = &request_payload_recv;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(202), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+  cq_expect_completion(cqv, tag(202), 1);
+  cq_verify(cqv);
+  gpr_log(GPR_INFO, "LB Server[%s] after RECV_MSG", sf->servers_hostport);
+  // TODO(dgq): validate request.
+  grpc_byte_buffer_destroy(request_payload_recv);
+  gpr_slice response_payload_slice;
+  for (int i = 0; i < 2; i++) {
+    if (i == 0) {
+      // First half of the ports.
+      response_payload_slice =
+          build_response_payload_slice("127.0.0.1", ports, nports / 2, -1, -1);
+    } else {
+      // Second half of the ports.
+      sleep_ms(update_delay_ms);
+      response_payload_slice =
+          build_response_payload_slice("127.0.0.1", ports + (nports / 2),
+                                       (nports + 1) / 2 /* ceil */, -1, -1);
+    }
+
+    response_payload = grpc_raw_byte_buffer_create(&response_payload_slice, 1);
+    op = ops;
+    op->op = GRPC_OP_SEND_MESSAGE;
+    op->data.send_message = response_payload;
+    op->flags = 0;
+    op->reserved = NULL;
+    op++;
+    error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(203), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
+    cq_expect_completion(cqv, tag(203), 1);
+    cq_verify(cqv);
+    gpr_log(GPR_INFO, "LB Server[%s] after SEND_MESSAGE, iter %d",
+            sf->servers_hostport, i);
+
+    grpc_byte_buffer_destroy(response_payload);
+    gpr_slice_unref(response_payload_slice);
+  }
+  gpr_log(GPR_INFO, "LB Server[%s] shutting down", sf->servers_hostport);
+
+  op = ops;
+  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++;
+  error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(204), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  cq_expect_completion(cqv, tag(201), 1);
+  cq_expect_completion(cqv, tag(204), 1);
+  cq_verify(cqv);
+  gpr_log(GPR_INFO, "LB Server[%s] after tag 204. All done. LB server out",
+          sf->servers_hostport);
+
+  grpc_call_destroy(s);
+
+  cq_verifier_destroy(cqv);
+
+  grpc_metadata_array_destroy(&request_metadata_recv);
+  grpc_call_details_destroy(&call_details);
+}
+
+static void start_backend_server(server_fixture *sf) {
+  grpc_call *s;
+  cq_verifier *cqv;
+  grpc_op ops[6];
+  grpc_op *op;
+  grpc_metadata_array request_metadata_recv;
+  grpc_call_details call_details;
+  grpc_call_error error;
+  int was_cancelled;
+  grpc_byte_buffer *request_payload_recv;
+  grpc_byte_buffer *response_payload;
+  grpc_event ev;
+
+  while (true) {
+    memset(ops, 0, sizeof(ops));
+    cqv = cq_verifier_create(sf->cq);
+    was_cancelled = 2;
+    grpc_metadata_array_init(&request_metadata_recv);
+    grpc_call_details_init(&call_details);
+
+    error = grpc_server_request_call(sf->server, &s, &call_details,
+                                     &request_metadata_recv, sf->cq, sf->cq,
+                                     tag(100));
+    GPR_ASSERT(GRPC_CALL_OK == error);
+    gpr_log(GPR_INFO, "Server[%s] up", sf->servers_hostport);
+    ev = grpc_completion_queue_next(sf->cq,
+                                    GRPC_TIMEOUT_SECONDS_TO_DEADLINE(60), NULL);
+    if (!ev.success) {
+      gpr_log(GPR_INFO, "Server[%s] being torn down", sf->servers_hostport);
+      cq_verifier_destroy(cqv);
+      grpc_metadata_array_destroy(&request_metadata_recv);
+      grpc_call_details_destroy(&call_details);
+      return;
+    }
+    GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
+    gpr_log(GPR_INFO, "Server[%s] after tag 100", sf->servers_hostport);
+
+    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_CLOSE_ON_SERVER;
+    op->data.recv_close_on_server.cancelled = &was_cancelled;
+    op->flags = 0;
+    op->reserved = NULL;
+    op++;
+    error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(101), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
+    gpr_log(GPR_INFO, "Server[%s] after tag 101", sf->servers_hostport);
+
+    bool exit = false;
+    gpr_slice response_payload_slice =
+        gpr_slice_from_copied_string("hello you");
+    while (!exit) {
+      op = ops;
+      op->op = GRPC_OP_RECV_MESSAGE;
+      op->data.recv_message = &request_payload_recv;
+      op->flags = 0;
+      op->reserved = NULL;
+      op++;
+      error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(102), NULL);
+      GPR_ASSERT(GRPC_CALL_OK == error);
+      ev = grpc_completion_queue_next(
+          sf->cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(3), NULL);
+      if (ev.type == GRPC_OP_COMPLETE && ev.success) {
+        GPR_ASSERT(ev.tag = tag(102));
+        if (request_payload_recv == NULL) {
+          exit = true;
+          gpr_log(GPR_INFO,
+                  "Server[%s] recv \"close\" from client, exiting. Call #%d",
+                  sf->servers_hostport, sf->num_calls_serviced);
+        }
+      } else {
+        gpr_log(GPR_INFO, "Server[%s] forced to shutdown. Call #%d",
+                sf->servers_hostport, sf->num_calls_serviced);
+        exit = true;
+      }
+      gpr_log(GPR_INFO, "Server[%s] after tag 102. Call #%d",
+              sf->servers_hostport, sf->num_calls_serviced);
+
+      if (!exit) {
+        response_payload =
+            grpc_raw_byte_buffer_create(&response_payload_slice, 1);
+        op = ops;
+        op->op = GRPC_OP_SEND_MESSAGE;
+        op->data.send_message = response_payload;
+        op->flags = 0;
+        op->reserved = NULL;
+        op++;
+        error =
+            grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(103), NULL);
+        GPR_ASSERT(GRPC_CALL_OK == error);
+        ev = grpc_completion_queue_next(
+            sf->cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(3), NULL);
+        if (ev.type == GRPC_OP_COMPLETE && ev.success) {
+          GPR_ASSERT(ev.tag = tag(103));
+        } else {
+          gpr_log(GPR_INFO, "Server[%s] forced to shutdown. Call #%d",
+                  sf->servers_hostport, sf->num_calls_serviced);
+          exit = true;
+        }
+        gpr_log(GPR_INFO, "Server[%s] after tag 103. Call #%d",
+                sf->servers_hostport, sf->num_calls_serviced);
+        grpc_byte_buffer_destroy(response_payload);
+      }
+
+      grpc_byte_buffer_destroy(request_payload_recv);
+    }
+    ++sf->num_calls_serviced;
+
+    gpr_log(GPR_INFO, "Server[%s] OUT OF THE LOOP", sf->servers_hostport);
+    gpr_slice_unref(response_payload_slice);
+
+    op = ops;
+    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 = "Backend server out a-ok";
+    op->flags = 0;
+    op->reserved = NULL;
+    op++;
+    error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(104), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
+
+    cq_expect_completion(cqv, tag(101), 1);
+    cq_expect_completion(cqv, tag(104), 1);
+    cq_verify(cqv);
+    gpr_log(GPR_INFO, "Server[%s] DONE. After servicing %d calls",
+            sf->servers_hostport, sf->num_calls_serviced);
+
+    grpc_call_destroy(s);
+    cq_verifier_destroy(cqv);
+    grpc_metadata_array_destroy(&request_metadata_recv);
+    grpc_call_details_destroy(&call_details);
+  }
+}
+
+static void perform_request(client_fixture *cf) {
+  grpc_call *c;
+  cq_verifier *cqv = cq_verifier_create(cf->cq);
+  grpc_op ops[6];
+  grpc_op *op;
+  grpc_metadata_array initial_metadata_recv;
+  grpc_metadata_array trailing_metadata_recv;
+  grpc_status_code status;
+  grpc_call_error error;
+  char *details = NULL;
+  size_t details_capacity = 0;
+  grpc_byte_buffer *request_payload;
+  grpc_byte_buffer *response_payload_recv;
+  int i;
+
+  memset(ops, 0, sizeof(ops));
+  gpr_slice request_payload_slice = gpr_slice_from_copied_string("hello world");
+
+  c = grpc_channel_create_call(cf->client, NULL, GRPC_PROPAGATE_DEFAULTS,
+                               cf->cq, "/foo", "foo.test.google.fr:1234",
+                               GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1000), NULL);
+  gpr_log(GPR_INFO, "Call 0x%" PRIxPTR " created", (intptr_t)c);
+  GPR_ASSERT(c);
+  char *peer;
+
+  grpc_metadata_array_init(&initial_metadata_recv);
+  grpc_metadata_array_init(&trailing_metadata_recv);
+
+  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_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;
+  op->data.recv_status_on_client.status = &status;
+  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++;
+  error = grpc_call_start_batch(c, ops, (size_t)(op - ops), tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  for (i = 0; i < 4; i++) {
+    request_payload = grpc_raw_byte_buffer_create(&request_payload_slice, 1);
+
+    op = ops;
+    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++;
+    error = grpc_call_start_batch(c, ops, (size_t)(op - ops), tag(2), NULL);
+    GPR_ASSERT(GRPC_CALL_OK == error);
+
+    peer = grpc_call_get_peer(c);
+    cq_expect_completion(cqv, tag(2), 1);
+    cq_verify(cqv);
+    gpr_free(peer);
+
+    grpc_byte_buffer_destroy(request_payload);
+    grpc_byte_buffer_destroy(response_payload_recv);
+  }
+
+  gpr_slice_unref(request_payload_slice);
+
+  op = ops;
+  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  error = grpc_call_start_batch(c, ops, (size_t)(op - ops), tag(3), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  cq_expect_completion(cqv, tag(1), 1);
+  cq_expect_completion(cqv, tag(3), 1);
+  cq_verify(cqv);
+  peer = grpc_call_get_peer(c);
+  gpr_log(GPR_INFO, "Client DONE WITH SERVER %s ", peer);
+  gpr_free(peer);
+
+  grpc_call_destroy(c);
+
+  cq_verify_empty_timeout(cqv, 1);
+  cq_verifier_destroy(cqv);
+
+  grpc_metadata_array_destroy(&initial_metadata_recv);
+  grpc_metadata_array_destroy(&trailing_metadata_recv);
+  gpr_free(details);
+}
+
+static void setup_client(const char *server_hostport, client_fixture *cf) {
+  cf->cq = grpc_completion_queue_create(NULL);
+  cf->server_uri = gpr_strdup(server_hostport);
+  cf->client = grpc_insecure_channel_create(cf->server_uri, NULL, NULL);
+}
+
+static void teardown_client(client_fixture *cf) {
+  grpc_completion_queue_shutdown(cf->cq);
+  drain_cq(cf->cq);
+  grpc_completion_queue_destroy(cf->cq);
+  cf->cq = NULL;
+  grpc_channel_destroy(cf->client);
+  cf->client = NULL;
+  gpr_free(cf->server_uri);
+}
+
+static void setup_server(const char *host, server_fixture *sf) {
+  int assigned_port;
+
+  sf->cq = grpc_completion_queue_create(NULL);
+  const char *colon_idx = strchr(host, ':');
+  if (colon_idx) {
+    const char *port_str = colon_idx + 1;
+    sf->port = atoi(port_str);
+    sf->servers_hostport = gpr_strdup(host);
+  } else {
+    sf->port = grpc_pick_unused_port_or_die();
+    gpr_join_host_port(&sf->servers_hostport, host, sf->port);
+  }
+
+  sf->server = grpc_server_create(NULL, NULL);
+  grpc_server_register_completion_queue(sf->server, sf->cq, NULL);
+  GPR_ASSERT((assigned_port = grpc_server_add_insecure_http2_port(
+                  sf->server, sf->servers_hostport)) > 0);
+  GPR_ASSERT(sf->port == assigned_port);
+  grpc_server_start(sf->server);
+}
+
+static void teardown_server(server_fixture *sf) {
+  if (!sf->server) return;
+
+  gpr_log(GPR_INFO, "Server[%s] shutting down", sf->servers_hostport);
+  grpc_server_shutdown_and_notify(sf->server, sf->cq, tag(1000));
+  GPR_ASSERT(grpc_completion_queue_pluck(
+                 sf->cq, tag(1000), GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5), NULL)
+                 .type == GRPC_OP_COMPLETE);
+  grpc_server_destroy(sf->server);
+  gpr_thd_join(sf->tid);
+
+  sf->server = NULL;
+  grpc_completion_queue_shutdown(sf->cq);
+  drain_cq(sf->cq);
+  grpc_completion_queue_destroy(sf->cq);
+
+  gpr_log(GPR_INFO, "Server[%s] bye bye", sf->servers_hostport);
+  gpr_free(sf->servers_hostport);
+}
+
+static void fork_backend_server(void *arg) {
+  server_fixture *sf = static_cast<server_fixture *>(arg);
+  start_backend_server(sf);
+}
+
+static void fork_lb_server(void *arg) {
+  test_fixture *tf = static_cast<test_fixture *>(arg);
+  int ports[NUM_BACKENDS];
+  for (int i = 0; i < NUM_BACKENDS; i++) {
+    ports[i] = tf->lb_backends[i].port;
+  }
+  start_lb_server(&tf->lb_server, ports, NUM_BACKENDS,
+                  tf->lb_server_update_delay_ms);
+}
+
+static void setup_test_fixture(test_fixture *tf,
+                               int lb_server_update_delay_ms) {
+  tf->lb_server_update_delay_ms = lb_server_update_delay_ms;
+
+  gpr_thd_options options = gpr_thd_options_default();
+  gpr_thd_options_set_joinable(&options);
+
+  for (int i = 0; i < NUM_BACKENDS; ++i) {
+    setup_server("127.0.0.1", &tf->lb_backends[i]);
+    gpr_thd_new(&tf->lb_backends[i].tid, fork_backend_server,
+                &tf->lb_backends[i], &options);
+  }
+
+  setup_server("127.0.0.1", &tf->lb_server);
+  gpr_thd_new(&tf->lb_server.tid, fork_lb_server, &tf->lb_server, &options);
+
+  char *server_uri;
+  gpr_asprintf(&server_uri, "ipv4:%s?lb_policy=grpclb&lb_enabled=1",
+               tf->lb_server.servers_hostport);
+  setup_client(server_uri, &tf->client);
+  gpr_free(server_uri);
+}
+
+static void teardown_test_fixture(test_fixture *tf) {
+  teardown_client(&tf->client);
+  for (int i = 0; i < NUM_BACKENDS; ++i) {
+    teardown_server(&tf->lb_backends[i]);
+  }
+  teardown_server(&tf->lb_server);
+}
+
+// The LB server will send two updates: batch 1 and batch 2. Each batch
+// contains
+// two addresses, both of a valid and running backend server. Batch 1 is
+// readily
+// available and provided as soon as the client establishes the streaming
+// call.
+// Batch 2 is sent after a delay of \a lb_server_update_delay_ms
+// milliseconds.
+static test_fixture test_update(int lb_server_update_delay_ms) {
+  gpr_log(GPR_INFO, "start %s(%d)", __func__, lb_server_update_delay_ms);
+  test_fixture tf;
+  memset(&tf, 0, sizeof(tf));
+  setup_test_fixture(&tf, lb_server_update_delay_ms);
+  perform_request(
+      &tf.client);  // "consumes" 1st backend server of 1st serverlist
+  perform_request(
+      &tf.client);  // "consumes" 2nd backend server of 1st serverlist
+
+  perform_request(
+      &tf.client);  // "consumes" 1st backend server of 2nd serverlist
+  perform_request(
+      &tf.client);  // "consumes" 2nd backend server of 2nd serverlist
+
+  teardown_test_fixture(&tf);
+  gpr_log(GPR_INFO, "end %s(%d)", __func__, lb_server_update_delay_ms);
+  return tf;
+}
+
+}  // namespace
+}  // namespace grpc
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  grpc_init();
+
+  grpc::test_fixture tf_result;
+  // Clients take a bit over one second to complete a call (the last part of the
+  // call sleeps for 1 second while verifying the client's completion queue is
+  // empty). Therefore:
+  //
+  // If the LB server waits 800ms before sending an update, it will arrive
+  // before the first client request is done, skipping the second server from
+  // batch 1 altogether: the 2nd client request will go to the 1st server of
+  // batch 2 (ie, the third one out of the four total servers).
+  tf_result = grpc::test_update(800);
+  GPR_ASSERT(tf_result.lb_backends[0].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[1].num_calls_serviced == 0);
+  GPR_ASSERT(tf_result.lb_backends[2].num_calls_serviced == 2);
+  GPR_ASSERT(tf_result.lb_backends[3].num_calls_serviced == 1);
+
+  // If the LB server waits 1500ms, the update arrives after having picked the
+  // 2nd server from batch 1 but before the next pick for the first server of
+  // batch 2. All server are used.
+  tf_result = grpc::test_update(1500);
+  GPR_ASSERT(tf_result.lb_backends[0].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[1].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[2].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[3].num_calls_serviced == 1);
+
+  // If the LB server waits > 2000ms, the update arrives after the first two
+  // request are done and the third pick is performed, which returns, in RR
+  // fashion, the 1st server of the 1st update. Therefore, the second server of
+  // batch 1 is hit twice, whereas the first server of batch 2 is never hit.
+  tf_result = grpc::test_update(2100);
+  GPR_ASSERT(tf_result.lb_backends[0].num_calls_serviced == 2);
+  GPR_ASSERT(tf_result.lb_backends[1].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[2].num_calls_serviced == 1);
+  GPR_ASSERT(tf_result.lb_backends[3].num_calls_serviced == 0);
+
+  grpc_shutdown();
+  return 0;
+}