merge conflict fix

31 files changed, 420 insertions, 148 deletions

diff --git a/test/core/end2end/fuzzers/hpack.dictionary b/test/core/end2end/fuzzers/hpack.dictionary
index a79fe5ad95..0469421c97 100644
--- a/test/core/end2end/fuzzers/hpack.dictionary
+++ b/test/core/end2end/fuzzers/hpack.dictionary
@@ -35,6 +35,7 @@
 "\x1Fgrpc.max_response_message_bytes"
 "$/grpc.lb.v1.LoadBalancer/BalanceLoad"
 "\x1C/grpc.health.v1.Health/Watch"
+"P/envoy.service.discovery.v2.AggregatedDiscoveryService/StreamAggregatedResources"
 "\x07deflate"
 "\x04gzip"
 "\x0Bstream/gzip"
diff --git a/test/core/gprpp/ref_counted_test.cc b/test/core/gprpp/ref_counted_test.cc
index f85a2e4675..62a3ea4d53 100644
--- a/test/core/gprpp/ref_counted_test.cc
+++ b/test/core/gprpp/ref_counted_test.cc
@@ -29,7 +29,10 @@ namespace {
 
 class Foo : public RefCounted<Foo> {
  public:
-  Foo() {}
+  Foo() {
+    static_assert(std::has_virtual_destructor<Foo>::value,
+                  "PolymorphicRefCount doesn't have a virtual dtor");
+  }
 };
 
 TEST(RefCounted, Basic) {
@@ -45,6 +48,28 @@ TEST(RefCounted, ExtraRef) {
   foo->Unref();
 }
 
+class FooNonPolymorphic
+    : public RefCounted<FooNonPolymorphic, NonPolymorphicRefCount> {
+ public:
+  FooNonPolymorphic() {
+    static_assert(!std::has_virtual_destructor<FooNonPolymorphic>::value,
+                  "NonPolymorphicRefCount has a virtual dtor");
+  }
+};
+
+TEST(RefCountedNonPolymorphic, Basic) {
+  FooNonPolymorphic* foo = New<FooNonPolymorphic>();
+  foo->Unref();
+}
+
+TEST(RefCountedNonPolymorphic, ExtraRef) {
+  FooNonPolymorphic* foo = New<FooNonPolymorphic>();
+  RefCountedPtr<FooNonPolymorphic> foop = foo->Ref();
+  foop.release();
+  foo->Unref();
+  foo->Unref();
+}
+
 // Note: We use DebugOnlyTraceFlag instead of TraceFlag to ensure that
 // things build properly in both debug and non-debug cases.
 DebugOnlyTraceFlag foo_tracer(true, "foo");
@@ -66,6 +91,26 @@ TEST(RefCountedWithTracing, Basic) {
   foo->Unref(DEBUG_LOCATION, "original_ref");
 }
 
+class FooNonPolymorphicWithTracing
+    : public RefCountedWithTracing<FooNonPolymorphicWithTracing,
+                                   NonPolymorphicRefCount> {
+ public:
+  FooNonPolymorphicWithTracing() : RefCountedWithTracing(&foo_tracer) {}
+};
+
+TEST(RefCountedNonPolymorphicWithTracing, Basic) {
+  FooNonPolymorphicWithTracing* foo = New<FooNonPolymorphicWithTracing>();
+  RefCountedPtr<FooNonPolymorphicWithTracing> foop =
+      foo->Ref(DEBUG_LOCATION, "extra_ref");
+  foop.release();
+  foo->Unref(DEBUG_LOCATION, "extra_ref");
+  // Can use the no-argument methods, too.
+  foop = foo->Ref();
+  foop.release();
+  foo->Unref();
+  foo->Unref(DEBUG_LOCATION, "original_ref");
+}
+
 }  // namespace
 }  // namespace testing
 }  // namespace grpc_core
diff --git a/test/core/iomgr/buffer_list_test.cc b/test/core/iomgr/buffer_list_test.cc
index c7f30fa092..e104e8e91a 100644
--- a/test/core/iomgr/buffer_list_test.cc
+++ b/test/core/iomgr/buffer_list_test.cc
@@ -50,7 +50,7 @@ static void TestShutdownFlushesList() {
     grpc_core::TracedBuffer::AddNewEntry(
         &list, i, static_cast<void*>(&verifier_called[i]));
   }
-  grpc_core::TracedBuffer::Shutdown(&list, GRPC_ERROR_NONE);
+  grpc_core::TracedBuffer::Shutdown(&list, nullptr, GRPC_ERROR_NONE);
   GPR_ASSERT(list == nullptr);
   for (auto i = 0; i < NUM_ELEM; i++) {
     GPR_ASSERT(gpr_atm_acq_load(&verifier_called[i]) ==
@@ -88,7 +88,7 @@ static void TestVerifierCalledOnAck() {
   grpc_core::TracedBuffer::ProcessTimestamp(&list, &serr, &tss);
   GPR_ASSERT(gpr_atm_acq_load(&verifier_called) == static_cast<gpr_atm>(1));
   GPR_ASSERT(list == nullptr);
-  grpc_core::TracedBuffer::Shutdown(&list, GRPC_ERROR_NONE);
+  grpc_core::TracedBuffer::Shutdown(&list, nullptr, GRPC_ERROR_NONE);
 }
 
 static void TestTcpBufferList() {
diff --git a/test/core/transport/chttp2/BUILD b/test/core/transport/chttp2/BUILD
index 6eff716b01..33437373e4 100644
--- a/test/core/transport/chttp2/BUILD
+++ b/test/core/transport/chttp2/BUILD
@@ -67,6 +67,22 @@ grpc_cc_test(
 )
 
 grpc_cc_test(
+    name = "context_list_test",
+    srcs = ["context_list_test.cc"],
+    external_deps = [
+        "gtest",
+    ],
+    language = "C++",
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+
+grpc_cc_test(
     name = "hpack_encoder_test",
     srcs = ["hpack_encoder_test.cc"],
     language = "C++",
diff --git a/test/core/transport/chttp2/context_list_test.cc b/test/core/transport/chttp2/context_list_test.cc
new file mode 100644
index 0000000000..e2100899d3
--- /dev/null
+++ b/test/core/transport/chttp2/context_list_test.cc
@@ -0,0 +1,98 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#include <gtest/gtest.h>
+#include <new>
+#include <vector>
+
+#include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
+#include "src/core/ext/transport/chttp2/transport/context_list.h"
+#include "src/core/lib/transport/transport.h"
+#include "test/core/util/mock_endpoint.h"
+#include "test/core/util/test_config.h"
+
+#include <grpc/grpc.h>
+
+namespace grpc_core {
+namespace testing {
+namespace {
+void TestExecuteFlushesListVerifier(void* arg, grpc_core::Timestamps* ts) {
+  GPR_ASSERT(arg != nullptr);
+  gpr_atm* done = reinterpret_cast<gpr_atm*>(arg);
+  gpr_atm_rel_store(done, static_cast<gpr_atm>(1));
+}
+
+void discard_write(grpc_slice slice) {}
+
+/** Tests that all ContextList elements in the list are flushed out on
+ * execute.
+ * Also tests that arg is passed correctly.
+ */
+TEST(ContextList, ExecuteFlushesList) {
+  grpc_core::ContextList* list = nullptr;
+  grpc_http2_set_write_timestamps_callback(TestExecuteFlushesListVerifier);
+  const int kNumElems = 5;
+  grpc_core::ExecCtx exec_ctx;
+  grpc_stream_refcount ref;
+  GRPC_STREAM_REF_INIT(&ref, 1, nullptr, nullptr, "dummy ref");
+  grpc_resource_quota* resource_quota =
+      grpc_resource_quota_create("context_list_test");
+  grpc_endpoint* mock_endpoint =
+      grpc_mock_endpoint_create(discard_write, resource_quota);
+  grpc_transport* t =
+      grpc_create_chttp2_transport(nullptr, mock_endpoint, true);
+  std::vector<grpc_chttp2_stream*> s;
+  s.reserve(kNumElems);
+  gpr_atm verifier_called[kNumElems];
+  for (auto i = 0; i < kNumElems; i++) {
+    s.push_back(static_cast<grpc_chttp2_stream*>(
+        gpr_malloc(grpc_transport_stream_size(t))));
+    grpc_transport_init_stream(reinterpret_cast<grpc_transport*>(t),
+                               reinterpret_cast<grpc_stream*>(s[i]), &ref,
+                               nullptr, nullptr);
+    s[i]->context = &verifier_called[i];
+    gpr_atm_rel_store(&verifier_called[i], static_cast<gpr_atm>(0));
+    grpc_core::ContextList::Append(&list, s[i]);
+  }
+  grpc_core::Timestamps ts;
+  grpc_core::ContextList::Execute(list, &ts, GRPC_ERROR_NONE);
+  for (auto i = 0; i < kNumElems; i++) {
+    GPR_ASSERT(gpr_atm_acq_load(&verifier_called[i]) ==
+               static_cast<gpr_atm>(1));
+    grpc_transport_destroy_stream(reinterpret_cast<grpc_transport*>(t),
+                                  reinterpret_cast<grpc_stream*>(s[i]),
+                                  nullptr);
+    exec_ctx.Flush();
+    gpr_free(s[i]);
+  }
+  grpc_transport_destroy(t);
+  grpc_resource_quota_unref(resource_quota);
+  exec_ctx.Flush();
+}
+}  // namespace
+}  // namespace testing
+}  // namespace grpc_core
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  grpc_init();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/test/core/util/mock_endpoint.cc b/test/core/util/mock_endpoint.cc
index ef6fd62b51..e5867cd526 100644
--- a/test/core/util/mock_endpoint.cc
+++ b/test/core/util/mock_endpoint.cc
@@ -103,18 +103,19 @@ static grpc_resource_user* me_get_resource_user(grpc_endpoint* ep) {
 
 static int me_get_fd(grpc_endpoint* ep) { return -1; }
 
-static const grpc_endpoint_vtable vtable = {
-    me_read,
-    me_write,
-    me_add_to_pollset,
-    me_add_to_pollset_set,
-    me_delete_from_pollset_set,
-    me_shutdown,
-    me_destroy,
-    me_get_resource_user,
-    me_get_peer,
-    me_get_fd,
-};
+static bool me_can_track_err(grpc_endpoint* ep) { return false; }
+
+static const grpc_endpoint_vtable vtable = {me_read,
+                                            me_write,
+                                            me_add_to_pollset,
+                                            me_add_to_pollset_set,
+                                            me_delete_from_pollset_set,
+                                            me_shutdown,
+                                            me_destroy,
+                                            me_get_resource_user,
+                                            me_get_peer,
+                                            me_get_fd,
+                                            me_can_track_err};
 
 grpc_endpoint* grpc_mock_endpoint_create(void (*on_write)(grpc_slice slice),
                                          grpc_resource_quota* resource_quota) {
diff --git a/test/core/util/passthru_endpoint.cc b/test/core/util/passthru_endpoint.cc
index 3cc8ad6fe1..51b6de4695 100644
--- a/test/core/util/passthru_endpoint.cc
+++ b/test/core/util/passthru_endpoint.cc
@@ -155,6 +155,8 @@ static char* me_get_peer(grpc_endpoint* ep) {
 
 static int me_get_fd(grpc_endpoint* ep) { return -1; }
 
+static bool me_can_track_err(grpc_endpoint* ep) { return false; }
+
 static grpc_resource_user* me_get_resource_user(grpc_endpoint* ep) {
   half* m = reinterpret_cast<half*>(ep);
   return m->resource_user;
@@ -171,6 +173,7 @@ static const grpc_endpoint_vtable vtable = {
     me_get_resource_user,
     me_get_peer,
     me_get_fd,
+    me_can_track_err,
 };
 
 static void half_init(half* m, passthru_endpoint* parent,
diff --git a/test/core/util/trickle_endpoint.cc b/test/core/util/trickle_endpoint.cc
index 62ed72a629..b0da735e57 100644
--- a/test/core/util/trickle_endpoint.cc
+++ b/test/core/util/trickle_endpoint.cc
@@ -131,6 +131,8 @@ static int te_get_fd(grpc_endpoint* ep) {
   return grpc_endpoint_get_fd(te->wrapped);
 }
 
+static bool te_can_track_err(grpc_endpoint* ep) { return false; }
+
 static void te_finish_write(void* arg, grpc_error* error) {
   trickle_endpoint* te = static_cast<trickle_endpoint*>(arg);
   gpr_mu_lock(&te->mu);
@@ -148,7 +150,8 @@ static const grpc_endpoint_vtable vtable = {te_read,
                                             te_destroy,
                                             te_get_resource_user,
                                             te_get_peer,
-                                            te_get_fd};
+                                            te_get_fd,
+                                            te_can_track_err};
 
 grpc_endpoint* grpc_trickle_endpoint_create(grpc_endpoint* wrap,
                                             double bytes_per_second) {
diff --git a/test/cpp/end2end/client_callback_end2end_test.cc b/test/cpp/end2end/client_callback_end2end_test.cc
index 7ffc610ce2..a35991396a 100644
--- a/test/cpp/end2end/client_callback_end2end_test.cc
+++ b/test/cpp/end2end/client_callback_end2end_test.cc
@@ -34,6 +34,7 @@
 #include "test/core/util/test_config.h"
 #include "test/cpp/end2end/test_service_impl.h"
 #include "test/cpp/util/byte_buffer_proto_helper.h"
+#include "test/cpp/util/string_ref_helper.h"
 
 #include <gtest/gtest.h>
 
@@ -100,11 +101,13 @@ class ClientCallbackEnd2endTest
 
       test_string += "Hello world. ";
       request.set_message(test_string);
-
+      grpc::string val;
       if (with_binary_metadata) {
+        request.mutable_param()->set_echo_metadata(true);
         char bytes[8] = {'\0', '\1', '\2', '\3',
                          '\4', '\5', '\6', static_cast<char>(i)};
-        cli_ctx.AddMetadata("custom-bin", grpc::string(bytes, 8));
+        val = grpc::string(bytes, 8);
+        cli_ctx.AddMetadata("custom-bin", val);
       }
 
       cli_ctx.set_compression_algorithm(GRPC_COMPRESS_GZIP);
@@ -114,10 +117,18 @@ class ClientCallbackEnd2endTest
       bool done = false;
       stub_->experimental_async()->Echo(
           &cli_ctx, &request, &response,
-          [&request, &response, &done, &mu, &cv](Status s) {
+          [&cli_ctx, &request, &response, &done, &mu, &cv, val,
+           with_binary_metadata](Status s) {
             GPR_ASSERT(s.ok());
 
             EXPECT_EQ(request.message(), response.message());
+            if (with_binary_metadata) {
+              EXPECT_EQ(
+                  1u, cli_ctx.GetServerTrailingMetadata().count("custom-bin"));
+              EXPECT_EQ(val, ToString(cli_ctx.GetServerTrailingMetadata()
+                                          .find("custom-bin")
+                                          ->second));
+            }
             std::lock_guard<std::mutex> l(mu);
             done = true;
             cv.notify_one();
diff --git a/test/cpp/end2end/client_interceptors_end2end_test.cc b/test/cpp/end2end/client_interceptors_end2end_test.cc
index 0b34ec93ae..60e8b051ab 100644
--- a/test/cpp/end2end/client_interceptors_end2end_test.cc
+++ b/test/cpp/end2end/client_interceptors_end2end_test.cc
@@ -361,15 +361,13 @@ class ClientInterceptorsEnd2endTest : public ::testing::Test {
 TEST_F(ClientInterceptorsEnd2endTest, ClientInterceptorLoggingTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -382,20 +380,18 @@ TEST_F(ClientInterceptorsEnd2endTest, ClientInterceptorLoggingTest) {
 TEST_F(ClientInterceptorsEnd2endTest, ClientInterceptorHijackingTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 20 dummy interceptors before hijacking interceptor
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
-  creators->push_back(std::unique_ptr<HijackingInterceptorFactory>(
+  creators.push_back(std::unique_ptr<HijackingInterceptorFactory>(
       new HijackingInterceptorFactory()));
   // Add 20 dummy interceptors after hijacking interceptor
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -408,13 +404,11 @@ TEST_F(ClientInterceptorsEnd2endTest, ClientInterceptorHijackingTest) {
 
 TEST_F(ClientInterceptorsEnd2endTest, ClientInterceptorLogThenHijackTest) {
   ChannelArguments args;
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
-  creators->push_back(std::unique_ptr<HijackingInterceptorFactory>(
+  creators.push_back(std::unique_ptr<HijackingInterceptorFactory>(
       new HijackingInterceptorFactory()));
   auto channel = experimental::CreateCustomChannelWithInterceptors(
       server_address_, InsecureChannelCredentials(), args, std::move(creators));
@@ -426,21 +420,19 @@ TEST_F(ClientInterceptorsEnd2endTest,
        ClientInterceptorHijackingMakesAnotherCallTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 5 dummy interceptors before hijacking interceptor
   for (auto i = 0; i < 5; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
-  creators->push_back(
+  creators.push_back(
       std::unique_ptr<experimental::ClientInterceptorFactoryInterface>(
           new HijackingInterceptorMakesAnotherCallFactory()));
   // Add 7 dummy interceptors after hijacking interceptor
   for (auto i = 0; i < 7; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = server_->experimental().InProcessChannelWithInterceptors(
@@ -456,15 +448,13 @@ TEST_F(ClientInterceptorsEnd2endTest,
        ClientInterceptorLoggingTestWithCallback) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = server_->experimental().InProcessChannelWithInterceptors(
@@ -496,15 +486,13 @@ class ClientInterceptorsStreamingEnd2endTest : public ::testing::Test {
 TEST_F(ClientInterceptorsStreamingEnd2endTest, ClientStreamingTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -517,15 +505,13 @@ TEST_F(ClientInterceptorsStreamingEnd2endTest, ClientStreamingTest) {
 TEST_F(ClientInterceptorsStreamingEnd2endTest, ServerStreamingTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -538,15 +524,13 @@ TEST_F(ClientInterceptorsStreamingEnd2endTest, ServerStreamingTest) {
 TEST_F(ClientInterceptorsStreamingEnd2endTest, BidiStreamingTest) {
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
-  creators->push_back(std::unique_ptr<LoggingInterceptorFactory>(
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
+  creators.push_back(std::unique_ptr<LoggingInterceptorFactory>(
       new LoggingInterceptorFactory()));
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -583,13 +567,11 @@ TEST_F(ClientGlobalInterceptorEnd2endTest, DummyGlobalInterceptor) {
   experimental::RegisterGlobalClientInterceptorFactory(&global_factory);
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -610,13 +592,11 @@ TEST_F(ClientGlobalInterceptorEnd2endTest, LoggingGlobalInterceptor) {
   experimental::RegisterGlobalClientInterceptorFactory(&global_factory);
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
@@ -637,13 +617,11 @@ TEST_F(ClientGlobalInterceptorEnd2endTest, HijackingGlobalInterceptor) {
   experimental::RegisterGlobalClientInterceptorFactory(&global_factory);
   ChannelArguments args;
   DummyInterceptor::Reset();
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 20 dummy interceptors
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   auto channel = experimental::CreateCustomChannelWithInterceptors(
diff --git a/test/cpp/end2end/client_lb_end2end_test.cc b/test/cpp/end2end/client_lb_end2end_test.cc
index 9218c85717..312065a2df 100644
--- a/test/cpp/end2end/client_lb_end2end_test.cc
+++ b/test/cpp/end2end/client_lb_end2end_test.cc
@@ -149,7 +149,7 @@ class ClientLbEnd2endTest : public ::testing::Test {
 
   void StartServers(size_t num_servers,
                     std::vector<int> ports = std::vector<int>()) {
-    CreateServers(num_servers, ports);
+    CreateServers(num_servers, std::move(ports));
     for (size_t i = 0; i < num_servers; ++i) {
       StartServer(i);
     }
@@ -191,6 +191,11 @@ class ClientLbEnd2endTest : public ::testing::Test {
     grpc_channel_args_destroy(fake_results);
   }
 
+  void SetFailureOnReresolution() {
+    grpc_core::ExecCtx exec_ctx;
+    response_generator_->SetFailureOnReresolution();
+  }
+
   std::vector<int> GetServersPorts() {
     std::vector<int> ports;
     for (const auto& server : servers_) ports.push_back(server->port_);
@@ -728,6 +733,23 @@ TEST_F(ClientLbEnd2endTest, PickFirstCheckStateBeforeStartWatch) {
   EXPECT_EQ("pick_first", channel_2->GetLoadBalancingPolicyName());
 }
 
+TEST_F(ClientLbEnd2endTest, PickFirstIdleOnDisconnect) {
+  // Start server, send RPC, and make sure channel is READY.
+  const int kNumServers = 1;
+  StartServers(kNumServers);
+  auto channel = BuildChannel("");  // pick_first is the default.
+  auto stub = BuildStub(channel);
+  SetNextResolution(GetServersPorts());
+  CheckRpcSendOk(stub, DEBUG_LOCATION);
+  EXPECT_EQ(channel->GetState(false), GRPC_CHANNEL_READY);
+  // Stop server.  Channel should go into state IDLE.
+  SetFailureOnReresolution();
+  servers_[0]->Shutdown();
+  EXPECT_TRUE(WaitForChannelNotReady(channel.get()));
+  EXPECT_EQ(channel->GetState(false), GRPC_CHANNEL_IDLE);
+  servers_.clear();
+}
+
 TEST_F(ClientLbEnd2endTest, RoundRobin) {
   // Start servers and send one RPC per server.
   const int kNumServers = 3;
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 4558437102..03291e1785 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -272,6 +272,7 @@ class End2endTest : public ::testing::TestWithParam<TestScenario> {
           std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
           creators;
       // Add 20 dummy server interceptors
+      creators.reserve(20);
       for (auto i = 0; i < 20; i++) {
         creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
             new DummyInterceptorFactory()));
diff --git a/test/cpp/end2end/interceptors_util.cc b/test/cpp/end2end/interceptors_util.cc
index 602d1695a3..5d59c1a4b7 100644
--- a/test/cpp/end2end/interceptors_util.cc
+++ b/test/cpp/end2end/interceptors_util.cc
@@ -132,16 +132,13 @@ bool CheckMetadata(const std::multimap<grpc::string_ref, grpc::string_ref>& map,
   return false;
 }
 
-std::unique_ptr<std::vector<
-    std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>
+std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
 CreateDummyClientInterceptors() {
-  auto creators = std::unique_ptr<std::vector<
-      std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>(
-      new std::vector<
-          std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>());
+  std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
+      creators;
   // Add 20 dummy interceptors before hijacking interceptor
   for (auto i = 0; i < 20; i++) {
-    creators->push_back(std::unique_ptr<DummyInterceptorFactory>(
+    creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
   }
   return creators;
diff --git a/test/cpp/end2end/interceptors_util.h b/test/cpp/end2end/interceptors_util.h
index b4c4791fca..d886e32494 100644
--- a/test/cpp/end2end/interceptors_util.h
+++ b/test/cpp/end2end/interceptors_util.h
@@ -149,8 +149,7 @@ void MakeCallbackCall(const std::shared_ptr<Channel>& channel);
 bool CheckMetadata(const std::multimap<grpc::string_ref, grpc::string_ref>& map,
                    const string& key, const string& value);
 
-std::unique_ptr<std::vector<
-    std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>>
+std::vector<std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
 CreateDummyClientInterceptors();
 
 inline void* tag(int i) { return (void*)static_cast<intptr_t>(i); }
diff --git a/test/cpp/end2end/server_interceptors_end2end_test.cc b/test/cpp/end2end/server_interceptors_end2end_test.cc
index 4ae086ea76..295d63516b 100644
--- a/test/cpp/end2end/server_interceptors_end2end_test.cc
+++ b/test/cpp/end2end/server_interceptors_end2end_test.cc
@@ -391,6 +391,7 @@ TEST_F(ServerInterceptorsAsyncEnd2endTest, GenericRPCTest) {
   builder.RegisterAsyncGenericService(&service);
   std::vector<std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
       creators;
+  creators.reserve(20);
   for (auto i = 0; i < 20; i++) {
     creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
@@ -486,6 +487,7 @@ TEST_F(ServerInterceptorsAsyncEnd2endTest, UnimplementedRpcTest) {
   builder.AddListeningPort(server_address, InsecureServerCredentials());
   std::vector<std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
       creators;
+  creators.reserve(20);
   for (auto i = 0; i < 20; i++) {
     creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
@@ -539,6 +541,7 @@ TEST_F(ServerInterceptorsSyncUnimplementedEnd2endTest, UnimplementedRpcTest) {
   builder.AddListeningPort(server_address, InsecureServerCredentials());
   std::vector<std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
       creators;
+  creators.reserve(20);
   for (auto i = 0; i < 20; i++) {
     creators.push_back(std::unique_ptr<DummyInterceptorFactory>(
         new DummyInterceptorFactory()));
diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index a99cf8122f..4ff153f980 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -76,7 +76,7 @@ void UnaryCompressionChecks(const InteropClientContextInspector& inspector,
 
 InteropClient::ServiceStub::ServiceStub(
     ChannelCreationFunc channel_creation_func, bool new_stub_every_call)
-    : channel_creation_func_(channel_creation_func),
+    : channel_creation_func_(std::move(channel_creation_func)),
       channel_(channel_creation_func_()),
       new_stub_every_call_(new_stub_every_call) {
   // If new_stub_every_call is false, then this is our chance to initialize
@@ -112,7 +112,7 @@ void InteropClient::ServiceStub::ResetChannel() {
 InteropClient::InteropClient(ChannelCreationFunc channel_creation_func,
                              bool new_stub_every_test_case,
                              bool do_not_abort_on_transient_failures)
-    : serviceStub_(channel_creation_func, new_stub_every_test_case),
+    : serviceStub_(std::move(channel_creation_func), new_stub_every_test_case),
       do_not_abort_on_transient_failures_(do_not_abort_on_transient_failures) {}
 
 bool InteropClient::AssertStatusOk(const Status& s,
diff --git a/test/cpp/interop/stress_interop_client.cc b/test/cpp/interop/stress_interop_client.cc
index 7dc1956f78..5bbe913365 100644
--- a/test/cpp/interop/stress_interop_client.cc
+++ b/test/cpp/interop/stress_interop_client.cc
@@ -73,7 +73,7 @@ StressTestInteropClient::StressTestInteropClient(
     long sleep_duration_ms, bool do_not_abort_on_transient_failures)
     : test_id_(test_id),
       server_address_(server_address),
-      channel_creation_func_(channel_creation_func),
+      channel_creation_func_(std::move(channel_creation_func)),
       interop_client_(new InteropClient(channel_creation_func_, false,
                                         do_not_abort_on_transient_failures)),
       test_selector_(test_selector),
diff --git a/test/cpp/microbenchmarks/bm_call_create.cc b/test/cpp/microbenchmarks/bm_call_create.cc
index 446dc93edb..8d12606434 100644
--- a/test/cpp/microbenchmarks/bm_call_create.cc
+++ b/test/cpp/microbenchmarks/bm_call_create.cc
@@ -135,7 +135,8 @@ static void BM_LameChannelCallCreateCpp(benchmark::State& state) {
           "",
           grpc_lame_client_channel_create("localhost:1234",
                                           GRPC_STATUS_UNAUTHENTICATED, "blah"),
-          nullptr));
+          std::vector<std::unique_ptr<
+              grpc::experimental::ClientInterceptorFactoryInterface>>()));
   grpc::CompletionQueue cq;
   grpc::testing::EchoRequest send_request;
   grpc::testing::EchoResponse recv_response;
diff --git a/test/cpp/microbenchmarks/bm_chttp2_transport.cc b/test/cpp/microbenchmarks/bm_chttp2_transport.cc
index f7ae16e61d..650152ecc0 100644
--- a/test/cpp/microbenchmarks/bm_chttp2_transport.cc
+++ b/test/cpp/microbenchmarks/bm_chttp2_transport.cc
@@ -54,7 +54,8 @@ class DummyEndpoint : public grpc_endpoint {
                                                    destroy,
                                                    get_resource_user,
                                                    get_peer,
-                                                   get_fd};
+                                                   get_fd,
+                                                   can_track_err};
     grpc_endpoint::vtable = &my_vtable;
     ru_ = grpc_resource_user_create(Library::get().rq(), "dummy_endpoint");
   }
@@ -125,6 +126,7 @@ class DummyEndpoint : public grpc_endpoint {
   }
   static char* get_peer(grpc_endpoint* ep) { return gpr_strdup("test"); }
   static int get_fd(grpc_endpoint* ep) { return 0; }
+  static bool can_track_err(grpc_endpoint* ep) { return false; }
 };
 
 class Fixture {
diff --git a/test/cpp/microbenchmarks/fullstack_fixtures.h b/test/cpp/microbenchmarks/fullstack_fixtures.h
index e57eb6ddd1..71e8d9972b 100644
--- a/test/cpp/microbenchmarks/fullstack_fixtures.h
+++ b/test/cpp/microbenchmarks/fullstack_fixtures.h
@@ -218,7 +218,10 @@ class EndpointPairFixture : public BaseFixture {
           "target", &c_args, GRPC_CLIENT_DIRECT_CHANNEL, client_transport_);
       grpc_chttp2_transport_start_reading(client_transport_, nullptr, nullptr);
 
-      channel_ = CreateChannelInternal("", channel, nullptr);
+      channel_ = CreateChannelInternal(
+          "", channel,
+          std::vector<std::unique_ptr<
+              experimental::ClientInterceptorFactoryInterface>>());
     }
   }
 
diff --git a/test/cpp/performance/writes_per_rpc_test.cc b/test/cpp/performance/writes_per_rpc_test.cc
index 32eab1fc44..baeede34ea 100644
--- a/test/cpp/performance/writes_per_rpc_test.cc
+++ b/test/cpp/performance/writes_per_rpc_test.cc
@@ -118,7 +118,10 @@ class EndpointPairFixture {
           "target", &c_args, GRPC_CLIENT_DIRECT_CHANNEL, transport);
       grpc_chttp2_transport_start_reading(transport, nullptr, nullptr);
 
-      channel_ = CreateChannelInternal("", channel, nullptr);
+      channel_ = CreateChannelInternal(
+          "", channel,
+          std::vector<std::unique_ptr<
+              experimental::ClientInterceptorFactoryInterface>>());
     }
   }
 
diff --git a/test/cpp/qps/client.h b/test/cpp/qps/client.h
index 4ed34e0405..668d941916 100644
--- a/test/cpp/qps/client.h
+++ b/test/cpp/qps/client.h
@@ -94,9 +94,11 @@ class ClientRequestCreator<ByteBuffer> {
  public:
   ClientRequestCreator(ByteBuffer* req, const PayloadConfig& payload_config) {
     if (payload_config.has_bytebuf_params()) {
-      std::unique_ptr<char[]> buf(
-          new char[payload_config.bytebuf_params().req_size()]);
-      Slice slice(buf.get(), payload_config.bytebuf_params().req_size());
+      size_t req_sz =
+          static_cast<size_t>(payload_config.bytebuf_params().req_size());
+      std::unique_ptr<char[]> buf(new char[req_sz]);
+      memset(buf.get(), 0, req_sz);
+      Slice slice(buf.get(), req_sz);
       *req = ByteBuffer(&slice, 1);
     } else {
       GPR_ASSERT(false);  // not appropriate for this specialization
diff --git a/test/cpp/qps/driver.cc b/test/cpp/qps/driver.cc
index 11cfb4aa05..181e11f12b 100644
--- a/test/cpp/qps/driver.cc
+++ b/test/cpp/qps/driver.cc
@@ -95,6 +95,17 @@ static deque<string> get_workers(const string& env_name) {
   return out;
 }
 
+std::string GetCredType(
+    const std::string& worker_addr,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    const std::string& credential_type) {
+  auto it = per_worker_credential_types.find(worker_addr);
+  if (it != per_worker_credential_types.end()) {
+    return it->second;
+  }
+  return credential_type;
+}
+
 // helpers for postprocess_scenario_result
 static double WallTime(const ClientStats& s) { return s.time_elapsed(); }
 static double SystemTime(const ClientStats& s) { return s.time_system(); }
@@ -198,8 +209,9 @@ std::unique_ptr<ScenarioResult> RunScenario(
     const ServerConfig& initial_server_config, size_t num_servers,
     int warmup_seconds, int benchmark_seconds, int spawn_local_worker_count,
     const grpc::string& qps_server_target_override,
-    const grpc::string& credential_type, bool run_inproc,
-    int32_t median_latency_collection_interval_millis) {
+    const grpc::string& credential_type,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool run_inproc, int32_t median_latency_collection_interval_millis) {
   if (run_inproc) {
     g_inproc_servers = new std::vector<grpc::testing::Server*>;
   }
@@ -278,7 +290,9 @@ std::unique_ptr<ScenarioResult> RunScenario(
     if (!run_inproc) {
       servers[i].stub = WorkerService::NewStub(CreateChannel(
           workers[i], GetCredentialsProvider()->GetChannelCredentials(
-                          credential_type, &channel_args)));
+                          GetCredType(workers[i], per_worker_credential_types,
+                                      credential_type),
+                          &channel_args)));
     } else {
       servers[i].stub = WorkerService::NewStub(
           local_workers[i]->InProcessChannel(channel_args));
@@ -335,9 +349,11 @@ std::unique_ptr<ScenarioResult> RunScenario(
     gpr_log(GPR_INFO, "Starting client on %s (worker #%" PRIuPTR ")",
             worker.c_str(), i + num_servers);
     if (!run_inproc) {
-      clients[i].stub = WorkerService::NewStub(
-          CreateChannel(worker, GetCredentialsProvider()->GetChannelCredentials(
-                                    credential_type, &channel_args)));
+      clients[i].stub = WorkerService::NewStub(CreateChannel(
+          worker,
+          GetCredentialsProvider()->GetChannelCredentials(
+              GetCredType(worker, per_worker_credential_types, credential_type),
+              &channel_args)));
     } else {
       clients[i].stub = WorkerService::NewStub(
           local_workers[i + num_servers]->InProcessChannel(channel_args));
@@ -529,7 +545,9 @@ std::unique_ptr<ScenarioResult> RunScenario(
   return result;
 }
 
-bool RunQuit(const grpc::string& credential_type) {
+bool RunQuit(
+    const grpc::string& credential_type,
+    const std::map<std::string, std::string>& per_worker_credential_types) {
   // Get client, server lists
   bool result = true;
   auto workers = get_workers("QPS_WORKERS");
@@ -541,7 +559,9 @@ bool RunQuit(const grpc::string& credential_type) {
   for (size_t i = 0; i < workers.size(); i++) {
     auto stub = WorkerService::NewStub(CreateChannel(
         workers[i], GetCredentialsProvider()->GetChannelCredentials(
-                        credential_type, &channel_args)));
+                        GetCredType(workers[i], per_worker_credential_types,
+                                    credential_type),
+                        &channel_args)));
     Void dummy;
     grpc::ClientContext ctx;
     ctx.set_wait_for_ready(true);
diff --git a/test/cpp/qps/driver.h b/test/cpp/qps/driver.h
index cda89f7ddf..568871d2da 100644
--- a/test/cpp/qps/driver.h
+++ b/test/cpp/qps/driver.h
@@ -32,10 +32,13 @@ std::unique_ptr<ScenarioResult> RunScenario(
     const grpc::testing::ServerConfig& server_config, size_t num_servers,
     int warmup_seconds, int benchmark_seconds, int spawn_local_worker_count,
     const grpc::string& qps_server_target_override,
-    const grpc::string& credential_type, bool run_inproc,
-    int32_t median_latency_collection_interval_millis);
+    const grpc::string& credential_type,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool run_inproc, int32_t median_latency_collection_interval_millis);
 
-bool RunQuit(const grpc::string& credential_type);
+bool RunQuit(
+    const grpc::string& credential_type,
+    const std::map<std::string, std::string>& per_worker_credential_types);
 }  // namespace testing
 }  // namespace grpc
 
diff --git a/test/cpp/qps/inproc_sync_unary_ping_pong_test.cc b/test/cpp/qps/inproc_sync_unary_ping_pong_test.cc
index 56d1730252..6257e42ebf 100644
--- a/test/cpp/qps/inproc_sync_unary_ping_pong_test.cc
+++ b/test/cpp/qps/inproc_sync_unary_ping_pong_test.cc
@@ -48,7 +48,7 @@ static void RunSynchronousUnaryPingPong() {
 
   const auto result =
       RunScenario(client_config, 1, server_config, 1, WARMUP, BENCHMARK, -2, "",
-                  kInsecureCredentialsType, true, 0);
+                  kInsecureCredentialsType, {}, true, 0);
 
   GetReporter()->ReportQPS(*result);
   GetReporter()->ReportLatency(*result);
diff --git a/test/cpp/qps/qps_json_driver.cc b/test/cpp/qps/qps_json_driver.cc
index eaa0dd992c..2b81cca2d6 100644
--- a/test/cpp/qps/qps_json_driver.cc
+++ b/test/cpp/qps/qps_json_driver.cc
@@ -65,6 +65,16 @@ DEFINE_string(json_file_out, "", "File to write the JSON output to.");
 
 DEFINE_string(credential_type, grpc::testing::kInsecureCredentialsType,
               "Credential type for communication with workers");
+DEFINE_string(
+    per_worker_credential_types, "",
+    "A map of QPS worker addresses to credential types. When creating a "
+    "channel to a QPS worker's driver port, the qps_json_driver first checks "
+    "if the 'name:port' string is in the map, and it uses the corresponding "
+    "credential type if so. If the QPS worker's 'name:port' string is not "
+    "in the map, then the driver -> worker channel will be created with "
+    "the credentials specified in --credential_type. The value of this flag "
+    "is a semicolon-separated list of map entries, where each map entry is "
+    "a comma-separated pair.");
 DEFINE_bool(run_inproc, false, "Perform an in-process transport test");
 DEFINE_int32(
     median_latency_collection_interval_millis, 0,
@@ -75,16 +85,53 @@ DEFINE_int32(
 namespace grpc {
 namespace testing {
 
-static std::unique_ptr<ScenarioResult> RunAndReport(const Scenario& scenario,
-                                                    bool* success) {
+static std::map<std::string, std::string>
+ConstructPerWorkerCredentialTypesMap() {
+  // Parse a list of the form: "addr1,cred_type1;addr2,cred_type2;..." into
+  // a map.
+  std::string remaining = FLAGS_per_worker_credential_types;
+  std::map<std::string, std::string> out;
+  while (remaining.size() > 0) {
+    size_t next_semicolon = remaining.find(';');
+    std::string next_entry = remaining.substr(0, next_semicolon);
+    if (next_semicolon == std::string::npos) {
+      remaining = "";
+    } else {
+      remaining = remaining.substr(next_semicolon + 1, std::string::npos);
+    }
+    size_t comma = next_entry.find(',');
+    if (comma == std::string::npos) {
+      gpr_log(GPR_ERROR,
+              "Expectd --per_worker_credential_types to be a list "
+              "of the form: 'addr1,cred_type1;addr2,cred_type2;...' "
+              "into.");
+      abort();
+    }
+    std::string addr = next_entry.substr(0, comma);
+    std::string cred_type = next_entry.substr(comma + 1, std::string::npos);
+    if (out.find(addr) != out.end()) {
+      gpr_log(GPR_ERROR,
+              "Found duplicate addr in per_worker_credential_types.");
+      abort();
+    }
+    out[addr] = cred_type;
+  }
+  return out;
+}
+
+static std::unique_ptr<ScenarioResult> RunAndReport(
+    const Scenario& scenario,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool* success) {
   std::cerr << "RUNNING SCENARIO: " << scenario.name() << "\n";
-  auto result = RunScenario(
-      scenario.client_config(), scenario.num_clients(),
-      scenario.server_config(), scenario.num_servers(),
-      scenario.warmup_seconds(), scenario.benchmark_seconds(),
-      !FLAGS_run_inproc ? scenario.spawn_local_worker_count() : -2,
-      FLAGS_qps_server_target_override, FLAGS_credential_type, FLAGS_run_inproc,
-      FLAGS_median_latency_collection_interval_millis);
+  auto result =
+      RunScenario(scenario.client_config(), scenario.num_clients(),
+                  scenario.server_config(), scenario.num_servers(),
+                  scenario.warmup_seconds(), scenario.benchmark_seconds(),
+                  !FLAGS_run_inproc ? scenario.spawn_local_worker_count() : -2,
+                  FLAGS_qps_server_target_override, FLAGS_credential_type,
+                  per_worker_credential_types, FLAGS_run_inproc,
+                  FLAGS_median_latency_collection_interval_millis);
 
   // Amend the result with scenario config. Eventually we should adjust
   // RunScenario contract so we don't need to touch the result here.
@@ -115,21 +162,26 @@ static std::unique_ptr<ScenarioResult> RunAndReport(const Scenario& scenario,
   return result;
 }
 
-static double GetCpuLoad(Scenario* scenario, double offered_load,
-                         bool* success) {
+static double GetCpuLoad(
+    Scenario* scenario, double offered_load,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool* success) {
   scenario->mutable_client_config()
       ->mutable_load_params()
       ->mutable_poisson()
       ->set_offered_load(offered_load);
-  auto result = RunAndReport(*scenario, success);
+  auto result = RunAndReport(*scenario, per_worker_credential_types, success);
   return result->summary().server_cpu_usage();
 }
 
-static double BinarySearch(Scenario* scenario, double targeted_cpu_load,
-                           double low, double high, bool* success) {
+static double BinarySearch(
+    Scenario* scenario, double targeted_cpu_load, double low, double high,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool* success) {
   while (low <= high * (1 - FLAGS_error_tolerance)) {
     double mid = low + (high - low) / 2;
-    double current_cpu_load = GetCpuLoad(scenario, mid, success);
+    double current_cpu_load =
+        GetCpuLoad(scenario, mid, per_worker_credential_types, success);
     gpr_log(GPR_DEBUG, "Binary Search: current_offered_load %.0f", mid);
     if (!*success) {
       gpr_log(GPR_ERROR, "Client/Server Failure");
@@ -145,12 +197,14 @@ static double BinarySearch(Scenario* scenario, double targeted_cpu_load,
   return low;
 }
 
-static double SearchOfferedLoad(double initial_offered_load,
-                                double targeted_cpu_load, Scenario* scenario,
-                                bool* success) {
+static double SearchOfferedLoad(
+    double initial_offered_load, double targeted_cpu_load, Scenario* scenario,
+    const std::map<std::string, std::string>& per_worker_credential_types,
+    bool* success) {
   std::cerr << "RUNNING SCENARIO: " << scenario->name() << "\n";
   double current_offered_load = initial_offered_load;
-  double current_cpu_load = GetCpuLoad(scenario, current_offered_load, success);
+  double current_cpu_load = GetCpuLoad(scenario, current_offered_load,
+                                       per_worker_credential_types, success);
   if (current_cpu_load > targeted_cpu_load) {
     gpr_log(GPR_ERROR, "Initial offered load too high");
     return -1;
@@ -158,14 +212,15 @@ static double SearchOfferedLoad(double initial_offered_load,
 
   while (*success && (current_cpu_load < targeted_cpu_load)) {
     current_offered_load *= 2;
-    current_cpu_load = GetCpuLoad(scenario, current_offered_load, success);
+    current_cpu_load = GetCpuLoad(scenario, current_offered_load,
+                                  per_worker_credential_types, success);
     gpr_log(GPR_DEBUG, "Binary Search: current_offered_load  %.0f",
             current_offered_load);
   }
 
   double targeted_offered_load =
       BinarySearch(scenario, targeted_cpu_load, current_offered_load / 2,
-                   current_offered_load, success);
+                   current_offered_load, per_worker_credential_types, success);
 
   return targeted_offered_load;
 }
@@ -183,6 +238,7 @@ static bool QpsDriver() {
     abort();
   }
 
+  auto per_worker_credential_types = ConstructPerWorkerCredentialTypesMap();
   if (scfile) {
     // Read the json data from disk
     FILE* json_file = fopen(FLAGS_scenarios_file.c_str(), "r");
@@ -198,7 +254,7 @@ static bool QpsDriver() {
   } else if (scjson) {
     json = FLAGS_scenarios_json.c_str();
   } else if (FLAGS_quit) {
-    return RunQuit(FLAGS_credential_type);
+    return RunQuit(FLAGS_credential_type, per_worker_credential_types);
   }
 
   // Parse into an array of scenarios
@@ -212,15 +268,16 @@ static bool QpsDriver() {
   for (int i = 0; i < scenarios.scenarios_size(); i++) {
     if (FLAGS_search_param == "") {
       const Scenario& scenario = scenarios.scenarios(i);
-      RunAndReport(scenario, &success);
+      RunAndReport(scenario, per_worker_credential_types, &success);
     } else {
       if (FLAGS_search_param == "offered_load") {
         Scenario* scenario = scenarios.mutable_scenarios(i);
-        double targeted_offered_load =
-            SearchOfferedLoad(FLAGS_initial_search_value,
-                              FLAGS_targeted_cpu_load, scenario, &success);
+        double targeted_offered_load = SearchOfferedLoad(
+            FLAGS_initial_search_value, FLAGS_targeted_cpu_load, scenario,
+            per_worker_credential_types, &success);
         gpr_log(GPR_INFO, "targeted_offered_load %f", targeted_offered_load);
-        GetCpuLoad(scenario, targeted_offered_load, &success);
+        GetCpuLoad(scenario, targeted_offered_load, per_worker_credential_types,
+                   &success);
       } else {
         gpr_log(GPR_ERROR, "Unimplemented search param");
       }
diff --git a/test/cpp/qps/qps_openloop_test.cc b/test/cpp/qps/qps_openloop_test.cc
index 6044f4265a..68062e66f2 100644
--- a/test/cpp/qps/qps_openloop_test.cc
+++ b/test/cpp/qps/qps_openloop_test.cc
@@ -52,7 +52,7 @@ static void RunQPS() {
 
   const auto result =
       RunScenario(client_config, 1, server_config, 1, WARMUP, BENCHMARK, -2, "",
-                  kInsecureCredentialsType, false, 0);
+                  kInsecureCredentialsType, {}, false, 0);
 
   GetReporter()->ReportQPSPerCore(*result);
   GetReporter()->ReportLatency(*result);
diff --git a/test/cpp/qps/secure_sync_unary_ping_pong_test.cc b/test/cpp/qps/secure_sync_unary_ping_pong_test.cc
index a559c82cc8..422bd617eb 100644
--- a/test/cpp/qps/secure_sync_unary_ping_pong_test.cc
+++ b/test/cpp/qps/secure_sync_unary_ping_pong_test.cc
@@ -55,7 +55,7 @@ static void RunSynchronousUnaryPingPong() {
 
   const auto result =
       RunScenario(client_config, 1, server_config, 1, WARMUP, BENCHMARK, -2, "",
-                  kInsecureCredentialsType, false, 0);
+                  kInsecureCredentialsType, {}, false, 0);
 
   GetReporter()->ReportQPS(*result);
   GetReporter()->ReportLatency(*result);
diff --git a/test/cpp/qps/server_async.cc b/test/cpp/qps/server_async.cc
index 5cd975cf74..a5f8347c26 100644
--- a/test/cpp/qps/server_async.cc
+++ b/test/cpp/qps/server_async.cc
@@ -562,6 +562,7 @@ static Status ProcessGenericRPC(const PayloadConfig& payload_config,
   request->Clear();
   int resp_size = payload_config.bytebuf_params().resp_size();
   std::unique_ptr<char[]> buf(new char[resp_size]);
+  memset(buf.get(), 0, static_cast<size_t>(resp_size));
   Slice slice(buf.get(), resp_size);
   *response = ByteBuffer(&slice, 1);
   return Status::OK;
diff --git a/test/cpp/util/BUILD b/test/cpp/util/BUILD
index c8d4333ef0..57eaf3baf2 100644
--- a/test/cpp/util/BUILD
+++ b/test/cpp/util/BUILD
@@ -185,6 +185,7 @@ grpc_cc_test(
     external_deps = [
         "gtest",
     ],
+    tags = ["nomsan"],  # death tests seem to be incompatible with msan
     deps = [
         ":grpc_cli_libs",
         ":test_util",
diff --git a/test/cpp/util/byte_buffer_proto_helper.h b/test/cpp/util/byte_buffer_proto_helper.h
index eb923eccb5..3d01fb2468 100644
--- a/test/cpp/util/byte_buffer_proto_helper.h
+++ b/test/cpp/util/byte_buffer_proto_helper.h
@@ -27,12 +27,13 @@
 namespace grpc {
 namespace testing {
 
-bool ParseFromByteBuffer(ByteBuffer* buffer, grpc::protobuf::Message* message);
+bool ParseFromByteBuffer(ByteBuffer* buffer,
+                         ::grpc::protobuf::Message* message);
 
 std::unique_ptr<ByteBuffer> SerializeToByteBuffer(
-    grpc::protobuf::Message* message);
+    ::grpc::protobuf::Message* message);
 
-bool SerializeToByteBufferInPlace(grpc::protobuf::Message* message,
+bool SerializeToByteBufferInPlace(::grpc::protobuf::Message* message,
                                   ByteBuffer* buffer);
 
 }  // namespace testing