Merge branch 'master' into gpr_review3

25 files changed, 728 insertions, 360 deletions

diff --git a/test/core/bad_client/bad_client.cc b/test/core/bad_client/bad_client.cc
index dd8d88170e..df803d16a2 100644
--- a/test/core/bad_client/bad_client.cc
+++ b/test/core/bad_client/bad_client.cc
@@ -34,25 +34,32 @@
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/completion_queue.h"
 #include "src/core/lib/surface/server.h"
+#include "test/core/end2end/cq_verifier.h"
 
+#define MIN_HTTP2_FRAME_SIZE 9
+
+/* Args to provide to thread running server side validator */
 typedef struct {
   grpc_server* server;
   grpc_completion_queue* cq;
   grpc_bad_client_server_side_validator validator;
   void* registered_method;
   gpr_event done_thd;
-  gpr_event done_write;
 } thd_args;
 
+/* Run the server side validator and set done_thd once done */
 static void thd_func(void* arg) {
   thd_args* a = (thd_args*)arg;
-  a->validator(a->server, a->cq, a->registered_method);
+  if (a->validator != nullptr) {
+    a->validator(a->server, a->cq, a->registered_method);
+  }
   gpr_event_set(&a->done_thd, (void*)1);
 }
 
-static void done_write(void* arg, grpc_error* error) {
-  thd_args* a = (thd_args*)arg;
-  gpr_event_set(&a->done_write, (void*)1);
+/* Sets the done_write event */
+static void set_done_write(void* arg, grpc_error* error) {
+  gpr_event* done_write = (gpr_event*)arg;
+  gpr_event_set(done_write, (void*)1);
 }
 
 static void server_setup_transport(void* ts, grpc_transport* transport) {
@@ -62,136 +69,172 @@ static void server_setup_transport(void* ts, grpc_transport* transport) {
                               grpc_server_get_channel_args(a->server));
 }
 
-static void read_done(void* arg, grpc_error* error) {
+/* Sets the read_done event */
+static void set_read_done(void* arg, grpc_error* error) {
   gpr_event* read_done = (gpr_event*)arg;
   gpr_event_set(read_done, (void*)1);
 }
 
-void grpc_run_bad_client_test(
-    grpc_bad_client_server_side_validator server_validator,
-    grpc_bad_client_client_stream_validator client_validator,
-    const char* client_payload, size_t client_payload_length, uint32_t flags) {
-  grpc_endpoint_pair sfd;
-  thd_args a;
-  gpr_thd_id id;
-  char* hex;
-  grpc_transport* transport;
-  grpc_slice slice =
-      grpc_slice_from_copied_buffer(client_payload, client_payload_length);
-  grpc_slice_buffer outgoing;
-  grpc_closure done_write_closure;
-  grpc_core::ExecCtx exec_ctx;
-  grpc_completion_queue* shutdown_cq;
+/* shutdown client */
+static void shutdown_client(grpc_endpoint** client_fd) {
+  if (*client_fd != nullptr) {
+    grpc_endpoint_shutdown(
+        *client_fd, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Forced Disconnect"));
+    grpc_endpoint_destroy(*client_fd);
+    grpc_core::ExecCtx::Get()->Flush();
+    *client_fd = nullptr;
+  }
+}
 
-  if (client_payload_length < 4 * 1024) {
-    hex = gpr_dump(client_payload, client_payload_length,
+/* Runs client side validator */
+void grpc_run_client_side_validator(grpc_bad_client_arg* arg, uint32_t flags,
+                                    grpc_endpoint_pair* sfd,
+                                    grpc_completion_queue* client_cq) {
+  char* hex;
+  gpr_event done_write;
+  if (arg->client_payload_length < 4 * 1024) {
+    hex = gpr_dump(arg->client_payload, arg->client_payload_length,
                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
-
     /* Add a debug log */
     gpr_log(GPR_INFO, "TEST: %s", hex);
-
     gpr_free(hex);
   } else {
     gpr_log(GPR_INFO, "TEST: (%" PRIdPTR " byte long string)",
-            client_payload_length);
+            arg->client_payload_length);
   }
 
-  /* Init grpc */
-  grpc_init();
-
-  /* Create endpoints */
-  sfd = grpc_iomgr_create_endpoint_pair("fixture", nullptr);
-
-  /* Create server, completion events */
-  a.server = grpc_server_create(nullptr, nullptr);
-  a.cq = grpc_completion_queue_create_for_next(nullptr);
-  gpr_event_init(&a.done_thd);
-  gpr_event_init(&a.done_write);
-  a.validator = server_validator;
-  grpc_server_register_completion_queue(a.server, a.cq, nullptr);
-  a.registered_method =
-      grpc_server_register_method(a.server, GRPC_BAD_CLIENT_REGISTERED_METHOD,
-                                  GRPC_BAD_CLIENT_REGISTERED_HOST,
-                                  GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER, 0);
-  grpc_server_start(a.server);
-  transport = grpc_create_chttp2_transport(nullptr, sfd.server, false);
-  server_setup_transport(&a, transport);
-  grpc_chttp2_transport_start_reading(transport, nullptr, nullptr);
-
-  /* Bind everything into the same pollset */
-  grpc_endpoint_add_to_pollset(sfd.client, grpc_cq_pollset(a.cq));
-  grpc_endpoint_add_to_pollset(sfd.server, grpc_cq_pollset(a.cq));
-
-  /* Check a ground truth */
-  GPR_ASSERT(grpc_server_has_open_connections(a.server));
-
-  /* Start validator */
-  gpr_thd_new(&id, "grpc_bad_client", thd_func, &a, nullptr);
+  grpc_slice slice = grpc_slice_from_copied_buffer(arg->client_payload,
+                                                   arg->client_payload_length);
+  grpc_slice_buffer outgoing;
+  grpc_closure done_write_closure;
+  gpr_event_init(&done_write);
 
   grpc_slice_buffer_init(&outgoing);
   grpc_slice_buffer_add(&outgoing, slice);
-  GRPC_CLOSURE_INIT(&done_write_closure, done_write, &a,
+  GRPC_CLOSURE_INIT(&done_write_closure, set_done_write, &done_write,
                     grpc_schedule_on_exec_ctx);
 
   /* Write data */
-  grpc_endpoint_write(sfd.client, &outgoing, &done_write_closure);
+  grpc_endpoint_write(sfd->client, &outgoing, &done_write_closure);
   grpc_core::ExecCtx::Get()->Flush();
 
   /* Await completion, unless the request is large and write may not finish
    * before the peer shuts down. */
   if (!(flags & GRPC_BAD_CLIENT_LARGE_REQUEST)) {
     GPR_ASSERT(
-        gpr_event_wait(&a.done_write, grpc_timeout_seconds_to_deadline(5)));
+        gpr_event_wait(&done_write, grpc_timeout_seconds_to_deadline(5)));
   }
 
   if (flags & GRPC_BAD_CLIENT_DISCONNECT) {
-    grpc_endpoint_shutdown(
-        sfd.client, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Forced Disconnect"));
-    grpc_endpoint_destroy(sfd.client);
-    grpc_core::ExecCtx::Get()->Flush();
-    sfd.client = nullptr;
+    shutdown_client(&sfd->client);
   }
 
-  GPR_ASSERT(gpr_event_wait(&a.done_thd, grpc_timeout_seconds_to_deadline(5)));
-
-  if (sfd.client != nullptr) {
-    // Validate client stream, if requested.
-    if (client_validator != nullptr) {
+  if (sfd->client != nullptr) {
+    /* Validate client stream, if requested. */
+    if (arg->client_validator != nullptr) {
       gpr_timespec deadline = grpc_timeout_seconds_to_deadline(5);
       grpc_slice_buffer incoming;
       grpc_slice_buffer_init(&incoming);
-      // We may need to do multiple reads to read the complete server response.
+      /* We may need to do multiple reads to read the complete server
+       * response. */
       while (true) {
         gpr_event read_done_event;
         gpr_event_init(&read_done_event);
         grpc_closure read_done_closure;
-        GRPC_CLOSURE_INIT(&read_done_closure, read_done, &read_done_event,
+        GRPC_CLOSURE_INIT(&read_done_closure, set_read_done, &read_done_event,
                           grpc_schedule_on_exec_ctx);
-        grpc_endpoint_read(sfd.client, &incoming, &read_done_closure);
+        grpc_endpoint_read(sfd->client, &incoming, &read_done_closure);
         grpc_core::ExecCtx::Get()->Flush();
         do {
           GPR_ASSERT(gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0);
-          GPR_ASSERT(
-              grpc_completion_queue_next(
-                  a.cq, grpc_timeout_milliseconds_to_deadline(100), nullptr)
-                  .type == GRPC_QUEUE_TIMEOUT);
+          /* Perform a cq next just to provide a thread that can read incoming
+           bytes on the client fd */
+          GPR_ASSERT(grpc_completion_queue_next(
+                         client_cq, grpc_timeout_milliseconds_to_deadline(100),
+                         nullptr)
+                         .type == GRPC_QUEUE_TIMEOUT);
         } while (!gpr_event_get(&read_done_event));
-        if (client_validator(&incoming)) break;
+        if (arg->client_validator(&incoming, arg->client_validator_arg)) break;
         gpr_log(GPR_INFO,
                 "client validator failed; trying additional read "
                 "in case we didn't get all the data");
       }
       grpc_slice_buffer_destroy_internal(&incoming);
     }
-    // Shutdown.
-    grpc_endpoint_shutdown(
-        sfd.client, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Test Shutdown"));
-    grpc_endpoint_destroy(sfd.client);
     grpc_core::ExecCtx::Get()->Flush();
   }
 
-  GPR_ASSERT(
-      gpr_event_wait(&a.done_write, grpc_timeout_seconds_to_deadline(1)));
+  /* If the request was too large, then we need to forcefully shut down the
+   * client, so that the write can be considered completed */
+  if (flags & GRPC_BAD_CLIENT_LARGE_REQUEST) {
+    shutdown_client(&sfd->client);
+  }
+
+  /* Make sure that the client is done writing */
+  while (!gpr_event_get(&done_write)) {
+    GPR_ASSERT(
+        grpc_completion_queue_next(
+            client_cq, grpc_timeout_milliseconds_to_deadline(100), nullptr)
+            .type == GRPC_QUEUE_TIMEOUT);
+  }
+
+  grpc_slice_buffer_destroy_internal(&outgoing);
+  grpc_core::ExecCtx::Get()->Flush();
+}
+
+void grpc_run_bad_client_test(
+    grpc_bad_client_server_side_validator server_validator,
+    grpc_bad_client_arg args[], int num_args, uint32_t flags) {
+  grpc_endpoint_pair sfd;
+  thd_args a;
+  grpc_transport* transport;
+  grpc_core::ExecCtx exec_ctx;
+  grpc_completion_queue* shutdown_cq;
+  grpc_completion_queue* client_cq;
+
+  /* Init grpc */
+  grpc_init();
+
+  /* Create endpoints */
+  sfd = grpc_iomgr_create_endpoint_pair("fixture", nullptr);
+
+  /* Create server, completion events */
+  a.server = grpc_server_create(nullptr, nullptr);
+  a.cq = grpc_completion_queue_create_for_next(nullptr);
+  client_cq = grpc_completion_queue_create_for_next(nullptr);
+
+  grpc_server_register_completion_queue(a.server, a.cq, nullptr);
+  a.registered_method =
+      grpc_server_register_method(a.server, GRPC_BAD_CLIENT_REGISTERED_METHOD,
+                                  GRPC_BAD_CLIENT_REGISTERED_HOST,
+                                  GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER, 0);
+  grpc_server_start(a.server);
+  transport = grpc_create_chttp2_transport(nullptr, sfd.server, false);
+  server_setup_transport(&a, transport);
+  grpc_chttp2_transport_start_reading(transport, nullptr, nullptr);
+
+  /* Bind fds to pollsets */
+  grpc_endpoint_add_to_pollset(sfd.client, grpc_cq_pollset(client_cq));
+  grpc_endpoint_add_to_pollset(sfd.server, grpc_cq_pollset(a.cq));
+
+  /* Check a ground truth */
+  GPR_ASSERT(grpc_server_has_open_connections(a.server));
+
+  gpr_thd_id id;
+  gpr_event_init(&a.done_thd);
+  a.validator = server_validator;
+  /* Start validator */
+  gpr_thd_new(&id, "grpc_bad_client", thd_func, &a, nullptr);
+  for (int i = 0; i < num_args; i++) {
+    grpc_run_client_side_validator(&args[i], i == (num_args - 1) ? flags : 0,
+                                   &sfd, client_cq);
+  }
+  /* Wait for server thread to finish */
+  GPR_ASSERT(gpr_event_wait(&a.done_thd, grpc_timeout_seconds_to_deadline(1)));
+
+  /* Shutdown. */
+  shutdown_client(&sfd.client);
+
   shutdown_cq = grpc_completion_queue_create_for_pluck(nullptr);
   grpc_server_shutdown_and_notify(a.server, shutdown_cq, nullptr);
   GPR_ASSERT(grpc_completion_queue_pluck(shutdown_cq, nullptr,
@@ -201,7 +244,91 @@ void grpc_run_bad_client_test(
   grpc_completion_queue_destroy(shutdown_cq);
   grpc_server_destroy(a.server);
   grpc_completion_queue_destroy(a.cq);
-  grpc_slice_buffer_destroy_internal(&outgoing);
-
+  grpc_completion_queue_destroy(client_cq);
   grpc_shutdown();
 }
+
+bool client_connection_preface_validator(grpc_slice_buffer* incoming,
+                                         void* arg) {
+  if (incoming->count < 1) {
+    return false;
+  }
+  grpc_slice slice = incoming->slices[0];
+  /* There should be atleast a settings frame present */
+  if (GRPC_SLICE_LENGTH(slice) < MIN_HTTP2_FRAME_SIZE) {
+    return false;
+  }
+  const uint8_t* p = GRPC_SLICE_START_PTR(slice);
+  /* Check the frame type (SETTINGS) */
+  if (*(p + 3) != 4) {
+    return false;
+  }
+  return true;
+}
+
+/* connection preface and settings frame to be sent by the client */
+#define CONNECTION_PREFACE_FROM_CLIENT \
+  "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"   \
+  "\x00\x00\x00\x04\x00\x00\x00\x00\x00"
+
+grpc_bad_client_arg connection_preface_arg = {
+    client_connection_preface_validator, nullptr,
+    CONNECTION_PREFACE_FROM_CLIENT, sizeof(CONNECTION_PREFACE_FROM_CLIENT) - 1};
+
+bool rst_stream_client_validator(grpc_slice_buffer* incoming, void* arg) {
+  // Get last frame from incoming slice buffer.
+  grpc_slice_buffer last_frame_buffer;
+  grpc_slice_buffer_init(&last_frame_buffer);
+  grpc_slice_buffer_trim_end(incoming, 13, &last_frame_buffer);
+  GPR_ASSERT(last_frame_buffer.count == 1);
+  grpc_slice last_frame = last_frame_buffer.slices[0];
+
+  const uint8_t* p = GRPC_SLICE_START_PTR(last_frame);
+  bool success =
+      // Length == 4
+      *p++ != 0 || *p++ != 0 || *p++ != 4 ||
+      // Frame type (RST_STREAM)
+      *p++ != 3 ||
+      // Flags
+      *p++ != 0 ||
+      // Stream ID.
+      *p++ != 0 || *p++ != 0 || *p++ != 0 || *p++ != 1 ||
+      // Payload (error code)
+      *p++ == 0 || *p++ == 0 || *p++ == 0 || *p == 0 || *p == 11;
+
+  if (!success) {
+    gpr_log(GPR_INFO, "client expected RST_STREAM frame, not found");
+  }
+
+  grpc_slice_buffer_destroy(&last_frame_buffer);
+  return success;
+}
+
+static void* tag(intptr_t t) { return (void*)t; }
+
+void server_verifier_request_call(grpc_server* server,
+                                  grpc_completion_queue* cq,
+                                  void* registered_method) {
+  grpc_call_error error;
+  grpc_call* s;
+  grpc_call_details call_details;
+  cq_verifier* cqv = cq_verifier_create(cq);
+  grpc_metadata_array request_metadata_recv;
+
+  grpc_call_details_init(&call_details);
+  grpc_metadata_array_init(&request_metadata_recv);
+
+  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);
+
+  GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.host, "localhost"));
+  GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.method, "/foo/bar"));
+
+  grpc_metadata_array_destroy(&request_metadata_recv);
+  grpc_call_details_destroy(&call_details);
+  grpc_call_unref(s);
+  cq_verifier_destroy(cqv);
+}
diff --git a/test/core/bad_client/bad_client.h b/test/core/bad_client/bad_client.h
index d3abfac2aa..de7d830cd7 100644
--- a/test/core/bad_client/bad_client.h
+++ b/test/core/bad_client/bad_client.h
@@ -28,30 +28,69 @@
 #define GRPC_BAD_CLIENT_REGISTERED_METHOD "/registered/bar"
 #define GRPC_BAD_CLIENT_REGISTERED_HOST "localhost"
 
+/* The server side validator function to run */
 typedef void (*grpc_bad_client_server_side_validator)(grpc_server* server,
                                                       grpc_completion_queue* cq,
                                                       void* registered_method);
 
-// Returns false if we need to read more data.
+/* Returns false if we need to read more data. */
 typedef bool (*grpc_bad_client_client_stream_validator)(
-    grpc_slice_buffer* incoming);
+    grpc_slice_buffer* incoming, void* arg);
 
+struct grpc_bad_client_arg {
+  grpc_bad_client_client_stream_validator client_validator;
+  void* client_validator_arg;
+  const char* client_payload;
+  size_t client_payload_length;
+};
+
+/* Flags for grpc_run_bad_client_test */
 #define GRPC_BAD_CLIENT_DISCONNECT 1
 #define GRPC_BAD_CLIENT_LARGE_REQUEST 2
 
 /* Test runner.
-
-   Create a server, and send client_payload to it as bytes from a client.
-   Execute server_validator in a separate thread to assert that the bytes are
-   handled as expected. */
+ *
+ * Create a server, and for each arg in \a args send client_payload. For each
+ * payload, run client_validator to make sure that the response is as expected.
+ * Also execute \a server_validator in a separate thread to assert that the
+ * bytes are handled as expected.
+ *
+ * The flags are only applicable to the last validator in the array. (This can
+ * be changed in the future if necessary)
+ */
 void grpc_run_bad_client_test(
     grpc_bad_client_server_side_validator server_validator,
-    grpc_bad_client_client_stream_validator client_validator,
-    const char* client_payload, size_t client_payload_length, uint32_t flags);
+    grpc_bad_client_arg args[], int num_args, uint32_t flags);
+
+/* A hack to let old tests work as before. In these tests, instead of an array,
+ * the tests provide a single client_validator and payload
+ */
+#define COMBINE1(X, Y) X##Y
+#define COMBINE(X, Y) COMBINE1(X, Y)
+
+#define GRPC_RUN_BAD_CLIENT_TEST(server_validator, client_validator, payload,  \
+                                 flags)                                        \
+  grpc_bad_client_arg COMBINE(bca, __LINE__) = {client_validator, nullptr,     \
+                                                payload, sizeof(payload) - 1}; \
+  grpc_run_bad_client_test(server_validator, &COMBINE(bca, __LINE__), 1, flags)
+
+/* Helper validator functions */
+/* Client side validator for connection preface from server. \a arg is unused */
+bool client_connection_preface_validator(grpc_slice_buffer* incoming,
+                                         void* arg);
+
+/* Client side validator for checking if reset stream is present at the end
+ * of the buffer. \a arg is unused.
+ */
+bool rst_stream_client_validator(grpc_slice_buffer* incoming, void* arg);
 
-#define GRPC_RUN_BAD_CLIENT_TEST(server_validator, client_validator, payload, \
-                                 flags)                                       \
-  grpc_run_bad_client_test(server_validator, client_validator, payload,       \
-                           sizeof(payload) - 1, flags)
+/* Helper grpc_bad_client_arg arguments for direct use */
+/* Sends a connection preface from the client with an empty settings frame */
+extern grpc_bad_client_arg connection_preface_arg;
 
+/* Server side verifier function that performs a
+ *  single grpc_server_request_call */
+void server_verifier_request_call(grpc_server* server,
+                                  grpc_completion_queue* cq,
+                                  void* registered_method);
 #endif /* GRPC_TEST_CORE_BAD_CLIENT_BAD_CLIENT_H */
diff --git a/test/core/bad_client/gen_build_yaml.py b/test/core/bad_client/gen_build_yaml.py
index 14c8a27334..a8fd777216 100755
--- a/test/core/bad_client/gen_build_yaml.py
+++ b/test/core/bad_client/gen_build_yaml.py
@@ -30,7 +30,7 @@ BAD_CLIENT_TESTS = {
     'headers': default_test_options._replace(cpu_cost=0.2),
     'initial_settings_frame': default_test_options._replace(cpu_cost=0.2),
     'head_of_line_blocking': default_test_options,
-    # 'large_metadata': default_test_options, #disabling as per issue #11745
+    'large_metadata': default_test_options,
     'server_registered_method': default_test_options,
     'simple_request': default_test_options,
     'window_overflow': default_test_options,
diff --git a/test/core/bad_client/generate_tests.bzl b/test/core/bad_client/generate_tests.bzl
index 022edf3ff3..b595defb8c 100755
--- a/test/core/bad_client/generate_tests.bzl
+++ b/test/core/bad_client/generate_tests.bzl
@@ -28,7 +28,7 @@ BAD_CLIENT_TESTS = {
     'headers': test_options(),
     'initial_settings_frame': test_options(),
     'head_of_line_blocking': test_options(),
-    # 'large_metadata': test_options(), # disabling as per issue #11745
+    'large_metadata': test_options(),
     'server_registered_method': test_options(),
     'simple_request': test_options(),
     'window_overflow': test_options(),
diff --git a/test/core/bad_client/tests/head_of_line_blocking.cc b/test/core/bad_client/tests/head_of_line_blocking.cc
index f56c4d71dd..8668e091b6 100644
--- a/test/core/bad_client/tests/head_of_line_blocking.cc
+++ b/test/core/bad_client/tests/head_of_line_blocking.cc
@@ -131,7 +131,8 @@ int main(int argc, char** argv) {
     addbuf(hdr, sizeof(hdr));
     addbuf(msg, FRAME_SIZE);
   }
-  grpc_run_bad_client_test(verifier, nullptr, g_buffer, g_count, 0);
+  grpc_bad_client_arg bca = {nullptr, nullptr, g_buffer, g_count};
+  grpc_run_bad_client_test(verifier, &bca, 1, 0);
   gpr_free(g_buffer);
   grpc_shutdown();
 
diff --git a/test/core/bad_client/tests/large_metadata.cc b/test/core/bad_client/tests/large_metadata.cc
index ff3e9eb932..d534753f53 100644
--- a/test/core/bad_client/tests/large_metadata.cc
+++ b/test/core/bad_client/tests/large_metadata.cc
@@ -31,23 +31,20 @@
 // be longer than the C99 string literal limit.  Instead, we dynamically
 // construct it by adding the large headers one at a time.
 
-#define PFX_TOO_MUCH_METADATA_FROM_CLIENT_PREFIX_STR                       \
-  "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"     /* settings frame */              \
-  "\x00\x00\x00\x04\x00\x00\x00\x00\x00" /* headers: generated from        \
-                                            large_metadata.headers in this \
-                                            directory */                   \
-  "\x00\x00\x00\x04\x01\x00\x00\x00\x00"                                   \
-  "\x00"                                                                   \
-  "5{\x01\x05\x00\x00\x00\x01"                                             \
-  "\x10\x05:path\x08/foo/bar"                                              \
-  "\x10\x07:scheme\x04http"                                                \
-  "\x10\x07:method\x04POST"                                                \
-  "\x10\x0a:authority\x09localhost"                                        \
-  "\x10\x0c"                                                               \
-  "content-type\x10"                                                       \
-  "application/grpc"                                                       \
-  "\x10\x14grpc-accept-encoding\x15identity,deflate,gzip"                  \
-  "\x10\x02te\x08trailers"                                                 \
+/* headers: generated from  large_metadata.headers in this directory */
+#define PFX_TOO_MUCH_METADATA_FROM_CLIENT_REQUEST         \
+  "\x00\x00\x00\x04\x01\x00\x00\x00\x00"                  \
+  "\x00"                                                  \
+  "5{\x01\x05\x00\x00\x00\x01"                            \
+  "\x10\x05:path\x08/foo/bar"                             \
+  "\x10\x07:scheme\x04http"                               \
+  "\x10\x07:method\x04POST"                               \
+  "\x10\x0a:authority\x09localhost"                       \
+  "\x10\x0c"                                              \
+  "content-type\x10"                                      \
+  "application/grpc"                                      \
+  "\x10\x14grpc-accept-encoding\x15identity,deflate,gzip" \
+  "\x10\x02te\x08trailers"                                \
   "\x10\x0auser-agent\"bad-client grpc-c/0.12.0.0 (linux)"
 
 // Each large-metadata header is constructed from these start and end
@@ -65,8 +62,8 @@
 // The number of headers we're adding and the total size of the client
 // payload.
 #define NUM_HEADERS 46
-#define PFX_TOO_MUCH_METADATA_FROM_CLIENT_PAYLOAD_SIZE          \
-  ((sizeof(PFX_TOO_MUCH_METADATA_FROM_CLIENT_PREFIX_STR) - 1) + \
+#define TOO_MUCH_METADATA_FROM_CLIENT_REQUEST_SIZE           \
+  ((sizeof(PFX_TOO_MUCH_METADATA_FROM_CLIENT_REQUEST) - 1) + \
    (NUM_HEADERS * PFX_TOO_MUCH_METADATA_FROM_CLIENT_HEADER_SIZE) + 1)
 
 #define PFX_TOO_MUCH_METADATA_FROM_SERVER_STR                                              \
@@ -95,32 +92,6 @@
 
 static void* tag(intptr_t t) { return (void*)t; }
 
-static void server_verifier(grpc_server* server, grpc_completion_queue* cq,
-                            void* registered_method) {
-  grpc_call_error error;
-  grpc_call* s;
-  grpc_call_details call_details;
-  cq_verifier* cqv = cq_verifier_create(cq);
-  grpc_metadata_array request_metadata_recv;
-
-  grpc_call_details_init(&call_details);
-  grpc_metadata_array_init(&request_metadata_recv);
-
-  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);
-
-  GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.host, "localhost"));
-  GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.method, "/foo/bar"));
-
-  grpc_metadata_array_destroy(&request_metadata_recv);
-  grpc_call_details_destroy(&call_details);
-  grpc_call_unref(s);
-  cq_verifier_destroy(cqv);
-}
-
 static void server_verifier_sends_too_much_metadata(grpc_server* server,
                                                     grpc_completion_queue* cq,
                                                     void* registered_method) {
@@ -167,43 +138,6 @@ static void server_verifier_sends_too_much_metadata(grpc_server* server,
   cq_verifier_destroy(cqv);
 }
 
-static bool client_validator(grpc_slice_buffer* incoming) {
-  for (size_t i = 0; i < incoming->count; ++i) {
-    const char* s = (const char*)GRPC_SLICE_START_PTR(incoming->slices[i]);
-    char* hex = gpr_dump(s, GRPC_SLICE_LENGTH(incoming->slices[i]),
-                         GPR_DUMP_HEX | GPR_DUMP_ASCII);
-    gpr_log(GPR_INFO, "RESPONSE SLICE %" PRIdPTR ": %s", i, hex);
-    gpr_free(hex);
-  }
-
-  // Get last frame from incoming slice buffer.
-  grpc_slice_buffer last_frame_buffer;
-  grpc_slice_buffer_init(&last_frame_buffer);
-  grpc_slice_buffer_trim_end(incoming, 13, &last_frame_buffer);
-  GPR_ASSERT(last_frame_buffer.count == 1);
-  grpc_slice last_frame = last_frame_buffer.slices[0];
-
-  const uint8_t* p = GRPC_SLICE_START_PTR(last_frame);
-  bool success =
-      // Length == 4
-      *p++ != 0 || *p++ != 0 || *p++ != 4 ||
-      // Frame type (RST_STREAM)
-      *p++ != 3 ||
-      // Flags
-      *p++ != 0 ||
-      // Stream ID.
-      *p++ != 0 || *p++ != 0 || *p++ != 0 || *p++ != 1 ||
-      // Payload (error code)
-      *p++ == 0 || *p++ == 0 || *p++ == 0 || *p == 0 || *p == 11;
-
-  if (!success) {
-    gpr_log(GPR_INFO, "client expected RST_STREAM frame, not found");
-  }
-
-  grpc_slice_buffer_destroy(&last_frame_buffer);
-  return success;
-}
-
 int main(int argc, char** argv) {
   int i;
 
@@ -222,19 +156,22 @@ int main(int argc, char** argv) {
   size_t headers_len;
   const char* client_headers = gpr_strvec_flatten(&headers, &headers_len);
   gpr_strvec_destroy(&headers);
-  char client_payload[PFX_TOO_MUCH_METADATA_FROM_CLIENT_PAYLOAD_SIZE] =
-      PFX_TOO_MUCH_METADATA_FROM_CLIENT_PREFIX_STR;
-  memcpy(
-      client_payload + sizeof(PFX_TOO_MUCH_METADATA_FROM_CLIENT_PREFIX_STR) - 1,
-      client_headers, headers_len);
-  GRPC_RUN_BAD_CLIENT_TEST(server_verifier, client_validator, client_payload,
-                           0);
+  char client_payload[TOO_MUCH_METADATA_FROM_CLIENT_REQUEST_SIZE] =
+      PFX_TOO_MUCH_METADATA_FROM_CLIENT_REQUEST;
+  memcpy(client_payload + sizeof(PFX_TOO_MUCH_METADATA_FROM_CLIENT_REQUEST) - 1,
+         client_headers, headers_len);
+  grpc_bad_client_arg args[2];
+  args[0] = connection_preface_arg;
+  args[1].client_validator = rst_stream_client_validator;
+  args[1].client_payload = client_payload;
+  args[1].client_payload_length = sizeof(client_payload) - 1;
+
+  grpc_run_bad_client_test(server_verifier_request_call, args, 2, 0);
   gpr_free((void*)client_headers);
 
   // Test sending more metadata than the client will accept.
   GRPC_RUN_BAD_CLIENT_TEST(server_verifier_sends_too_much_metadata,
-                           client_validator,
+                           rst_stream_client_validator,
                            PFX_TOO_MUCH_METADATA_FROM_SERVER_STR, 0);
-
   return 0;
 }
diff --git a/test/core/bad_client/tests/window_overflow.cc b/test/core/bad_client/tests/window_overflow.cc
index ed8279c951..fe6b05d03a 100644
--- a/test/core/bad_client/tests/window_overflow.cc
+++ b/test/core/bad_client/tests/window_overflow.cc
@@ -26,8 +26,7 @@
 #include "src/core/lib/surface/server.h"
 
 #define PFX_STR                                                            \
-  "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"                                       \
-  "\x00\x00\x00\x04\x00\x00\x00\x00\x00" /* settings frame */              \
+  "\x00\x00\x00\x04\x01\x00\x00\x00\x00"                                   \
   "\x00\x00\xc9\x01\x04\x00\x00\x00\x01" /* headers: generated from        \
                                             simple_request.headers in this \
                                             directory */                   \
@@ -70,7 +69,7 @@ int main(int argc, char** argv) {
 #define MAX_FRAME_SIZE 16384
 #define MESSAGES_PER_FRAME (MAX_FRAME_SIZE / 5)
 #define FRAME_SIZE (MESSAGES_PER_FRAME * 5)
-#define SEND_SIZE (6 * 1024 * 1024)
+#define SEND_SIZE (4 * 1024 * 1024)
 #define NUM_FRAMES (SEND_SIZE / FRAME_SIZE + 1)
   grpc_test_init(argc, argv);
   grpc_init();
@@ -92,8 +91,10 @@ int main(int argc, char** argv) {
       addbuf(message, sizeof(message));
     }
   }
-  grpc_run_bad_client_test(verifier, nullptr, g_buffer, g_count,
-                           GRPC_BAD_CLIENT_LARGE_REQUEST);
+  grpc_bad_client_arg bca[2];
+  bca[0] = connection_preface_arg;
+  bca[1] = {rst_stream_client_validator, nullptr, g_buffer, g_count};
+  grpc_run_bad_client_test(verifier, bca, 2, GRPC_BAD_CLIENT_LARGE_REQUEST);
   gpr_free(g_buffer);
   grpc_shutdown();
 
diff --git a/test/core/client_channel/resolvers/BUILD b/test/core/client_channel/resolvers/BUILD
index b5269c7ef0..d8b0395846 100644
--- a/test/core/client_channel/resolvers/BUILD
+++ b/test/core/client_channel/resolvers/BUILD
@@ -43,6 +43,18 @@ grpc_cc_test(
 )
 
 grpc_cc_test(
+    name = "dns_resolver_cooldown_test",
+    srcs = ["dns_resolver_cooldown_test.cc"],
+    language = "C++",
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+grpc_cc_test(
     name = "sockaddr_resolver_test",
     srcs = ["sockaddr_resolver_test.cc"],
     language = "C++",
diff --git a/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc b/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc
new file mode 100644
index 0000000000..64342b48c8
--- /dev/null
+++ b/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc
@@ -0,0 +1,304 @@
+/*
+ *
+ * Copyright 2015 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 <cstring>
+
+#include <grpc/support/log.h>
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "test/core/util/test_config.h"
+
+static grpc_combiner* g_combiner;
+
+static void (*g_default_grpc_resolve_address)(
+    const char* name, const char* default_port,
+    grpc_pollset_set* interested_parties, grpc_closure* on_done,
+    grpc_resolved_addresses** addrs);
+
+grpc_ares_request* (*g_default_dns_lookup_ares)(
+    const char* dns_server, const char* name, const char* default_port,
+    grpc_pollset_set* interested_parties, grpc_closure* on_done,
+    grpc_lb_addresses** addrs, bool check_grpclb, char** service_config_json);
+
+// Counter incremented by test_resolve_address_impl indicating the number of
+// times a system-level resolution has happened.
+static int g_resolution_count;
+
+struct iomgr_args {
+  gpr_event ev;
+  gpr_atm done_atm;
+  gpr_mu* mu;
+  grpc_pollset* pollset;
+  grpc_pollset_set* pollset_set;
+} g_iomgr_args;
+
+// Wrapper around g_default_grpc_resolve_address in order to count the number of
+// times we incur in a system-level name resolution.
+static void test_resolve_address_impl(const char* name,
+                                      const char* default_port,
+                                      grpc_pollset_set* interested_parties,
+                                      grpc_closure* on_done,
+                                      grpc_resolved_addresses** addrs) {
+  g_default_grpc_resolve_address(name, default_port, g_iomgr_args.pollset_set,
+                                 on_done, addrs);
+  ++g_resolution_count;
+}
+
+grpc_ares_request* test_dns_lookup_ares(
+    const char* dns_server, const char* name, const char* default_port,
+    grpc_pollset_set* interested_parties, grpc_closure* on_done,
+    grpc_lb_addresses** addrs, bool check_grpclb, char** service_config_json) {
+  grpc_ares_request* result = g_default_dns_lookup_ares(
+      dns_server, name, default_port, g_iomgr_args.pollset_set, on_done, addrs,
+      check_grpclb, service_config_json);
+  ++g_resolution_count;
+  return result;
+}
+
+static gpr_timespec test_deadline(void) {
+  return grpc_timeout_seconds_to_deadline(100);
+}
+
+static void do_nothing(void* arg, grpc_error* error) {}
+
+void iomgr_args_init(iomgr_args* args) {
+  gpr_event_init(&args->ev);
+  args->pollset = static_cast<grpc_pollset*>(gpr_zalloc(grpc_pollset_size()));
+  grpc_pollset_init(args->pollset, &args->mu);
+  args->pollset_set = grpc_pollset_set_create();
+  grpc_pollset_set_add_pollset(args->pollset_set, args->pollset);
+  gpr_atm_rel_store(&args->done_atm, 0);
+}
+
+void iomgr_args_finish(iomgr_args* args) {
+  GPR_ASSERT(gpr_event_wait(&args->ev, test_deadline()));
+  grpc_pollset_set_del_pollset(args->pollset_set, args->pollset);
+  grpc_pollset_set_destroy(args->pollset_set);
+  grpc_closure do_nothing_cb;
+  GRPC_CLOSURE_INIT(&do_nothing_cb, do_nothing, nullptr,
+                    grpc_schedule_on_exec_ctx);
+  gpr_mu_lock(args->mu);
+  grpc_pollset_shutdown(args->pollset, &do_nothing_cb);
+  gpr_mu_unlock(args->mu);
+  // exec_ctx needs to be flushed before calling grpc_pollset_destroy()
+  grpc_core::ExecCtx::Get()->Flush();
+  grpc_pollset_destroy(args->pollset);
+  gpr_free(args->pollset);
+}
+
+static grpc_millis n_sec_deadline(int seconds) {
+  return grpc_timespec_to_millis_round_up(
+      grpc_timeout_seconds_to_deadline(seconds));
+}
+
+static void poll_pollset_until_request_done(iomgr_args* args) {
+  grpc_core::ExecCtx exec_ctx;
+  grpc_millis deadline = n_sec_deadline(10);
+  while (true) {
+    bool done = gpr_atm_acq_load(&args->done_atm) != 0;
+    if (done) {
+      break;
+    }
+    grpc_millis time_left = deadline - grpc_core::ExecCtx::Get()->Now();
+    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRIdPTR, done, time_left);
+    GPR_ASSERT(time_left >= 0);
+    grpc_pollset_worker* worker = nullptr;
+    gpr_mu_lock(args->mu);
+    GRPC_LOG_IF_ERROR("pollset_work", grpc_pollset_work(args->pollset, &worker,
+                                                        n_sec_deadline(1)));
+    gpr_mu_unlock(args->mu);
+    grpc_core::ExecCtx::Get()->Flush();
+  }
+  gpr_event_set(&args->ev, (void*)1);
+}
+
+typedef struct on_resolution_cb_arg {
+  const char* uri_str;
+  grpc_resolver* resolver;
+  grpc_channel_args* result;
+  grpc_millis delay_before_second_resolution;
+  bool using_cares;
+} on_resolution_cb_arg;
+
+// Counter for the number of times a resolution notification callback has been
+// invoked.
+static int g_on_resolution_invocations_count;
+
+// Set to true by the last callback in the resolution chain.
+bool g_all_callbacks_invoked;
+
+void on_third_resolution(void* arg, grpc_error* error) {
+  on_resolution_cb_arg* cb_arg = static_cast<on_resolution_cb_arg*>(arg);
+  GPR_ASSERT(error == GRPC_ERROR_NONE);
+  ++g_on_resolution_invocations_count;
+  grpc_channel_args_destroy(cb_arg->result);
+  gpr_log(GPR_INFO,
+          "3rd: g_on_resolution_invocations_count: %d, g_resolution_count: %d",
+          g_on_resolution_invocations_count, g_resolution_count);
+  // In this case we expect to have incurred in another system-level resolution
+  // because on_second_resolution slept for longer than the min resolution
+  // period.
+  GPR_ASSERT(g_on_resolution_invocations_count == 3);
+  GPR_ASSERT(g_resolution_count == 2);
+  grpc_resolver_shutdown_locked(cb_arg->resolver);
+  GRPC_RESOLVER_UNREF(cb_arg->resolver, "on_third_resolution");
+  if (cb_arg->using_cares) {
+    gpr_atm_rel_store(&g_iomgr_args.done_atm, 1);
+    gpr_mu_lock(g_iomgr_args.mu);
+    GRPC_LOG_IF_ERROR("pollset_kick",
+                      grpc_pollset_kick(g_iomgr_args.pollset, nullptr));
+    gpr_mu_unlock(g_iomgr_args.mu);
+  }
+  gpr_free(cb_arg);
+  g_all_callbacks_invoked = true;
+}
+
+void on_second_resolution(void* arg, grpc_error* error) {
+  on_resolution_cb_arg* cb_arg = static_cast<on_resolution_cb_arg*>(arg);
+  ++g_on_resolution_invocations_count;
+  grpc_channel_args_destroy(cb_arg->result);
+
+  gpr_log(GPR_INFO,
+          "2nd: g_on_resolution_invocations_count: %d, g_resolution_count: %d",
+          g_on_resolution_invocations_count, g_resolution_count);
+  // The resolution request for which this function is the callback happened
+  // before the min resolution period. Therefore, no new system-level
+  // resolutions happened, as indicated by g_resolution_count.
+  GPR_ASSERT(g_on_resolution_invocations_count == 2);
+  GPR_ASSERT(g_resolution_count == 1);
+  grpc_core::ExecCtx::Get()->TestOnlySetNow(
+      cb_arg->delay_before_second_resolution * 2);
+  grpc_resolver_next_locked(
+      cb_arg->resolver, &cb_arg->result,
+      GRPC_CLOSURE_CREATE(on_third_resolution, arg,
+                          grpc_combiner_scheduler(g_combiner)));
+  grpc_resolver_channel_saw_error_locked(cb_arg->resolver);
+  if (cb_arg->using_cares) {
+    gpr_mu_lock(g_iomgr_args.mu);
+    GRPC_LOG_IF_ERROR("pollset_kick",
+                      grpc_pollset_kick(g_iomgr_args.pollset, nullptr));
+    gpr_mu_unlock(g_iomgr_args.mu);
+  }
+}
+
+void on_first_resolution(void* arg, grpc_error* error) {
+  on_resolution_cb_arg* cb_arg = static_cast<on_resolution_cb_arg*>(arg);
+  ++g_on_resolution_invocations_count;
+  grpc_channel_args_destroy(cb_arg->result);
+  grpc_resolver_next_locked(
+      cb_arg->resolver, &cb_arg->result,
+      GRPC_CLOSURE_CREATE(on_second_resolution, arg,
+                          grpc_combiner_scheduler(g_combiner)));
+  grpc_resolver_channel_saw_error_locked(cb_arg->resolver);
+  gpr_log(GPR_INFO,
+          "1st: g_on_resolution_invocations_count: %d, g_resolution_count: %d",
+          g_on_resolution_invocations_count, g_resolution_count);
+  // Theres one initial system-level resolution and one invocation of a
+  // notification callback (the current function).
+  GPR_ASSERT(g_on_resolution_invocations_count == 1);
+  GPR_ASSERT(g_resolution_count == 1);
+  if (cb_arg->using_cares) {
+    gpr_mu_lock(g_iomgr_args.mu);
+    GRPC_LOG_IF_ERROR("pollset_kick",
+                      grpc_pollset_kick(g_iomgr_args.pollset, nullptr));
+    gpr_mu_unlock(g_iomgr_args.mu);
+  }
+}
+
+static void start_test_under_combiner(void* arg, grpc_error* error) {
+  on_resolution_cb_arg* res_cb_arg = static_cast<on_resolution_cb_arg*>(arg);
+  grpc_resolver* resolver;
+  grpc_resolver_factory* factory = grpc_resolver_factory_lookup("dns");
+  grpc_uri* uri = grpc_uri_parse(res_cb_arg->uri_str, 0);
+  grpc_resolver_args args;
+  gpr_log(GPR_DEBUG, "test: '%s' should be valid for '%s'", res_cb_arg->uri_str,
+          factory->vtable->scheme);
+  GPR_ASSERT(uri);
+  memset(&args, 0, sizeof(args));
+  args.uri = uri;
+  args.combiner = g_combiner;
+  g_on_resolution_invocations_count = 0;
+  g_resolution_count = 0;
+  constexpr int kMinResolutionPeriodMs = 1000;
+
+  grpc_arg cooldown_arg;
+  cooldown_arg.key =
+      const_cast<char*>(GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS);
+  cooldown_arg.type = GRPC_ARG_INTEGER;
+  cooldown_arg.value.integer = kMinResolutionPeriodMs;
+  auto* cooldown_channel_args =
+      grpc_channel_args_copy_and_add(nullptr, &cooldown_arg, 1);
+  args.args = cooldown_channel_args;
+  resolver = grpc_resolver_factory_create_resolver(factory, &args);
+  grpc_channel_args_destroy(cooldown_channel_args);
+  GPR_ASSERT(resolver != nullptr);
+  res_cb_arg->resolver = resolver;
+  res_cb_arg->delay_before_second_resolution = kMinResolutionPeriodMs;
+  // First resolution, would incur in system-level resolution.
+  grpc_resolver_next_locked(
+      resolver, &res_cb_arg->result,
+      GRPC_CLOSURE_CREATE(on_first_resolution, res_cb_arg,
+                          grpc_combiner_scheduler(g_combiner)));
+  grpc_uri_destroy(uri);
+  grpc_resolver_factory_unref(factory);
+}
+
+static void test_cooldown(bool using_cares) {
+  grpc_core::ExecCtx exec_ctx;
+  if (using_cares) iomgr_args_init(&g_iomgr_args);
+  on_resolution_cb_arg* res_cb_arg =
+      static_cast<on_resolution_cb_arg*>(gpr_zalloc(sizeof(*res_cb_arg)));
+  res_cb_arg->uri_str = "dns:127.0.0.1";
+  res_cb_arg->using_cares = using_cares;
+
+  GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(start_test_under_combiner, res_cb_arg,
+                                         grpc_combiner_scheduler(g_combiner)),
+                     GRPC_ERROR_NONE);
+  if (using_cares) {
+    grpc_core::ExecCtx::Get()->Flush();
+    poll_pollset_until_request_done(&g_iomgr_args);
+    iomgr_args_finish(&g_iomgr_args);
+  }
+}
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  grpc_init();
+
+  g_combiner = grpc_combiner_create();
+
+  const bool using_cares = (grpc_resolve_address == grpc_resolve_address_ares);
+  g_default_grpc_resolve_address = grpc_resolve_address;
+  g_default_dns_lookup_ares = grpc_dns_lookup_ares;
+  grpc_dns_lookup_ares = test_dns_lookup_ares;
+  grpc_resolve_address = test_resolve_address_impl;
+
+  test_cooldown(using_cares);
+
+  {
+    grpc_core::ExecCtx exec_ctx;
+    GRPC_COMBINER_UNREF(g_combiner, "test");
+  }
+  grpc_shutdown();
+  GPR_ASSERT(g_all_callbacks_invoked);
+  return 0;
+}
diff --git a/test/core/end2end/h2_ssl_cert_test.cc b/test/core/end2end/h2_ssl_cert_test.cc
index 3383d6d5d1..9adb96e926 100644
--- a/test/core/end2end/h2_ssl_cert_test.cc
+++ b/test/core/end2end/h2_ssl_cert_test.cc
@@ -272,6 +272,20 @@ static void drain_cq(grpc_completion_queue* cq) {
 
 static void shutdown_server(grpc_end2end_test_fixture* f) {
   if (!f->server) return;
+  /* Perform a completion queue next, so that any pending operations can be
+   * finished, and resources can be released. This is so that, shutdown does not
+   * hang. For example, the server might be stuck in the handshaking code, which
+   * keeps a ref to a listener. Unless, it is unref'd, shutdown won't be able
+   * to proceed.
+   *
+   * (If shutdown times out, it is probably because 100ms wasn't enough. In that
+   * case, the deadline can be increased. Or, we could simply have another
+   * thread for the server to poll the completion queue while the shutdown
+   * progresses.)
+   */
+  GPR_ASSERT(grpc_completion_queue_next(
+                 f->cq, grpc_timeout_milliseconds_to_deadline(100), nullptr)
+                 .type == GRPC_QUEUE_TIMEOUT);
   grpc_server_shutdown_and_notify(f->server, f->shutdown_cq, tag(1000));
   GPR_ASSERT(grpc_completion_queue_pluck(f->shutdown_cq, tag(1000),
                                          grpc_timeout_seconds_to_deadline(5),
@@ -288,8 +302,8 @@ static void shutdown_client(grpc_end2end_test_fixture* f) {
 }
 
 static void end_test(grpc_end2end_test_fixture* f) {
-  shutdown_server(f);
   shutdown_client(f);
+  shutdown_server(f);
 
   grpc_completion_queue_shutdown(f->cq);
   drain_cq(f->cq);
diff --git a/test/core/end2end/tests/streaming_error_response.cc b/test/core/end2end/tests/streaming_error_response.cc
index fe53fda9ef..6ad1cec086 100644
--- a/test/core/end2end/tests/streaming_error_response.cc
+++ b/test/core/end2end/tests/streaming_error_response.cc
@@ -111,7 +111,7 @@ static void test(grpc_end2end_test_config config, bool request_status_early) {
   grpc_byte_buffer* response_payload1_recv = nullptr;
   grpc_byte_buffer* response_payload2_recv = nullptr;
   grpc_call_details call_details;
-  grpc_status_code status;
+  grpc_status_code status = GRPC_STATUS_OK;
   grpc_call_error error;
   grpc_slice details;
   int was_cancelled = 2;
diff --git a/test/core/fling/client.cc b/test/core/fling/client.cc
index b6d6cb9518..66810975fd 100644
--- a/test/core/fling/client.cc
+++ b/test/core/fling/client.cc
@@ -74,7 +74,7 @@ static void init_ping_pong_request(void) {
 }
 
 static void step_ping_pong_request(void) {
-  GPR_TIMER_BEGIN("ping_pong", 1);
+  GPR_TIMER_SCOPE("ping_pong", 1);
   grpc_slice host = grpc_slice_from_static_string("localhost");
   call = grpc_channel_create_call(
       channel, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
@@ -87,7 +87,6 @@ static void step_ping_pong_request(void) {
   grpc_call_unref(call);
   grpc_byte_buffer_destroy(response_payload_recv);
   call = nullptr;
-  GPR_TIMER_END("ping_pong", 1);
 }
 
 static void init_ping_pong_stream(void) {
@@ -117,13 +116,12 @@ static void init_ping_pong_stream(void) {
 }
 
 static void step_ping_pong_stream(void) {
+  GPR_TIMER_SCOPE("ping_pong", 1);
   grpc_call_error error;
-  GPR_TIMER_BEGIN("ping_pong", 1);
   error = grpc_call_start_batch(call, stream_step_ops, 2, (void*)1, nullptr);
   GPR_ASSERT(GRPC_CALL_OK == error);
   grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME), nullptr);
   grpc_byte_buffer_destroy(response_payload_recv);
-  GPR_TIMER_END("ping_pong", 1);
 }
 
 static double now(void) {
diff --git a/test/core/http/BUILD b/test/core/http/BUILD
index a5ae6272db..03b8f4edfe 100644
--- a/test/core/http/BUILD
+++ b/test/core/http/BUILD
@@ -66,7 +66,12 @@ grpc_cc_test(
     name = "httpcli_test",
     srcs = ["httpcli_test.cc"],
     language = "C++",
-    data = ["test_server.py"],
+    data = [
+        "python_wrapper.sh",
+        "test_server.py",
+        "//src/core/tsi/test_creds:server1.pem",
+        "//src/core/tsi/test_creds:server1.key"
+    ],
     deps = [
         "//:gpr",
         "//:grpc",
@@ -80,7 +85,13 @@ grpc_cc_test(
     name = "httpscli_test",
     srcs = ["httpscli_test.cc"],
     language = "C++",
-    data = ["test_server.py"],
+    data = [
+        "python_wrapper.sh",
+        "test_server.py",
+        "//src/core/tsi/test_creds:ca.pem",
+        "//src/core/tsi/test_creds:server1.pem",
+        "//src/core/tsi/test_creds:server1.key"
+    ],
     deps = [
         "//:gpr",
         "//:grpc",
diff --git a/test/core/http/httpcli_test.cc b/test/core/http/httpcli_test.cc
index aa9416c3dd..3d892b939c 100644
--- a/test/core/http/httpcli_test.cc
+++ b/test/core/http/httpcli_test.cc
@@ -155,10 +155,17 @@ int main(int argc, char** argv) {
     int arg_shift = 0;
     /* figure out where we are */
     char* root;
-    if (lslash) {
-      root = static_cast<char*>(gpr_malloc((size_t)(lslash - me + 1)));
+    if (lslash != nullptr) {
+      /* Hack for bazel target */
+      if ((unsigned)(lslash - me) >= (sizeof("http") - 1) &&
+          strncmp(me + (lslash - me) - sizeof("http") + 1, "http",
+                  sizeof("http") - 1) == 0) {
+        lslash = me + (lslash - me) - sizeof("http");
+      }
+      root = static_cast<char*>(
+          gpr_malloc((size_t)(lslash - me + sizeof("/../.."))));
       memcpy(root, me, (size_t)(lslash - me));
-      root[lslash - me] = 0;
+      memcpy(root + (lslash - me), "/../..", sizeof("/../.."));
     } else {
       root = gpr_strdup(".");
     }
@@ -168,8 +175,8 @@ int main(int argc, char** argv) {
       args[0] = gpr_strdup(argv[1]);
     } else {
       arg_shift = 1;
-      gpr_asprintf(&args[0], "%s/../../tools/distrib/python_wrapper.sh", root);
-      gpr_asprintf(&args[1], "%s/../../test/core/http/test_server.py", root);
+      gpr_asprintf(&args[0], "%s/test/core/http/python_wrapper.sh", root);
+      gpr_asprintf(&args[1], "%s/test/core/http/test_server.py", root);
     }
 
     /* start the server */
diff --git a/test/core/http/httpscli_test.cc b/test/core/http/httpscli_test.cc
index ed2016e643..7e99ad4249 100644
--- a/test/core/http/httpscli_test.cc
+++ b/test/core/http/httpscli_test.cc
@@ -21,11 +21,13 @@
 #include <string.h>
 
 #include <grpc/grpc.h>
+#include <grpc/grpc_security_constants.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "test/core/util/port.h"
 #include "test/core/util/subprocess.h"
@@ -153,10 +155,17 @@ int main(int argc, char** argv) {
   int arg_shift = 0;
   /* figure out where we are */
   char* root;
-  if (lslash) {
-    root = static_cast<char*>(gpr_malloc((size_t)(lslash - me + 1)));
+  if (lslash != nullptr) {
+    /* Hack for bazel target */
+    if ((unsigned)(lslash - me) >= (sizeof("http") - 1) &&
+        strncmp(me + (lslash - me) - sizeof("http") + 1, "http",
+                sizeof("http") - 1) == 0) {
+      lslash = me + (lslash - me) - sizeof("http");
+    }
+    root = static_cast<char*>(
+        gpr_malloc((size_t)(lslash - me + sizeof("/../.."))));
     memcpy(root, me, (size_t)(lslash - me));
-    root[lslash - me] = 0;
+    memcpy(root + (lslash - me), "/../..", sizeof("/../.."));
   } else {
     root = gpr_strdup(".");
   }
@@ -166,10 +175,16 @@ int main(int argc, char** argv) {
     args[0] = gpr_strdup(argv[1]);
   } else {
     arg_shift = 1;
-    gpr_asprintf(&args[0], "%s/../../tools/distrib/python_wrapper.sh", root);
-    gpr_asprintf(&args[1], "%s/../../test/core/http/test_server.py", root);
+    gpr_asprintf(&args[0], "%s/test/core/http/python_wrapper.sh", root);
+    gpr_asprintf(&args[1], "%s/test/core/http/test_server.py", root);
   }
 
+  /* Set the environment variable for the SSL certificate file */
+  char* pem_file;
+  gpr_asprintf(&pem_file, "%s/src/core/tsi/test_creds/ca.pem", root);
+  gpr_setenv(GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR, pem_file);
+  gpr_free(pem_file);
+
   /* start the server */
   args[1 + arg_shift] = const_cast<char*>("--port");
   gpr_asprintf(&args[2 + arg_shift], "%d", port);
diff --git a/test/core/http/python_wrapper.sh b/test/core/http/python_wrapper.sh
new file mode 120000
index 0000000000..9ed6e3293f
--- /dev/null
+++ b/test/core/http/python_wrapper.sh
@@ -0,0 +1 @@
+../../../tools/distrib/python_wrapper.sh
\ No newline at end of file
diff --git a/test/core/memory_usage/server.cc b/test/core/memory_usage/server.cc
index 4303ec70ec..7ee591dfac 100644
--- a/test/core/memory_usage/server.cc
+++ b/test/core/memory_usage/server.cc
@@ -289,6 +289,7 @@ int main(int argc, char** argv) {
             }
           // no break here since we want to continue to case
           // FLING_SERVER_SEND_STATUS_SNAPSHOT to destroy the snapshot call
+          /* fallthrough */
           case FLING_SERVER_SEND_STATUS_SNAPSHOT:
             grpc_byte_buffer_destroy(payload_buffer);
             grpc_byte_buffer_destroy(terminal_buffer);
diff --git a/test/core/surface/BUILD b/test/core/surface/BUILD
index 6cec7feabc..d27123d1a3 100644
--- a/test/core/surface/BUILD
+++ b/test/core/surface/BUILD
@@ -19,18 +19,6 @@ licenses(["notice"])  # Apache v2
 grpc_package(name = "test/core/surface")
 
 grpc_cc_test(
-    name = "alarm_test",
-    srcs = ["alarm_test.cc"],
-    language = "C++",
-    deps = [
-        "//:gpr",
-        "//:grpc",
-        "//test/core/util:gpr_test_util",
-        "//test/core/util:grpc_test_util",
-    ],
-)
-
-grpc_cc_test(
     name = "grpc_byte_buffer_reader_test",
     srcs = ["byte_buffer_reader_test.cc"],
     language = "C++",
diff --git a/test/core/surface/alarm_test.cc b/test/core/surface/alarm_test.cc
deleted file mode 100644
index 67fc6833a5..0000000000
--- a/test/core/surface/alarm_test.cc
+++ /dev/null
@@ -1,116 +0,0 @@
-/*
- *
- * Copyright 2015 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 <grpc/grpc.h>
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/time.h>
-#include <grpc/support/useful.h>
-#include "test/core/util/test_config.h"
-
-#define LOG_TEST(x) gpr_log(GPR_INFO, "%s", x)
-
-static void* create_test_tag(void) {
-  static intptr_t i = 0;
-  return (void*)(++i);
-}
-
-/* helper for tests to shutdown correctly and tersely */
-static void shutdown_and_destroy(grpc_completion_queue* cc) {
-  grpc_event ev;
-  grpc_completion_queue_shutdown(cc);
-  /* By the time grpc_completion_queue_shutdown runs, the cq's internal
-     pending event counter might not have been updated yet by a previous
-     cq_end_op_for_next (which releases a completed event first and only later
-     updates the pending event counter), so we can't rely on a no-polling
-     cq_next to never return GRPC_QUEUE_TIMEOUT. Using a deadline in the future
-     solves the problem. See https://github.com/grpc/grpc/issues/13693.
-     */
-  ev = grpc_completion_queue_next(cc, grpc_timeout_seconds_to_deadline(2),
-                                  nullptr);
-  GPR_ASSERT(ev.type == GRPC_QUEUE_SHUTDOWN);
-  grpc_completion_queue_destroy(cc);
-}
-
-static void test_alarm(void) {
-  grpc_completion_queue* cc;
-
-  LOG_TEST("test_alarm");
-  cc = grpc_completion_queue_create_for_next(nullptr);
-  {
-    /* regular expiry */
-    grpc_event ev;
-    void* tag = create_test_tag();
-    grpc_alarm* alarm = grpc_alarm_create(nullptr);
-    grpc_alarm_set(alarm, cc, grpc_timeout_seconds_to_deadline(1), tag,
-                   nullptr);
-
-    ev = grpc_completion_queue_next(cc, grpc_timeout_seconds_to_deadline(2),
-                                    nullptr);
-    GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
-    GPR_ASSERT(ev.tag == tag);
-    GPR_ASSERT(ev.success);
-    grpc_alarm_destroy(alarm, nullptr);
-  }
-  {
-    /* cancellation */
-    grpc_event ev;
-    void* tag = create_test_tag();
-    grpc_alarm* alarm = grpc_alarm_create(nullptr);
-    grpc_alarm_set(alarm, cc, grpc_timeout_seconds_to_deadline(2), tag,
-                   nullptr);
-
-    grpc_alarm_cancel(alarm, nullptr);
-    ev = grpc_completion_queue_next(cc, grpc_timeout_seconds_to_deadline(1),
-                                    nullptr);
-    GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
-    GPR_ASSERT(ev.tag == tag);
-    GPR_ASSERT(ev.success == 0);
-    grpc_alarm_destroy(alarm, nullptr);
-  }
-  {
-    /* alarm_destroy before cq_next */
-    grpc_event ev;
-    void* tag = create_test_tag();
-    grpc_alarm* alarm = grpc_alarm_create(nullptr);
-    grpc_alarm_set(alarm, cc, grpc_timeout_seconds_to_deadline(2), tag,
-                   nullptr);
-
-    grpc_alarm_destroy(alarm, nullptr);
-    ev = grpc_completion_queue_next(cc, grpc_timeout_seconds_to_deadline(1),
-                                    nullptr);
-    GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
-    GPR_ASSERT(ev.tag == tag);
-    GPR_ASSERT(ev.success == 0);
-  }
-  {
-    /* alarm_destroy before set */
-    grpc_alarm* alarm = grpc_alarm_create(nullptr);
-    grpc_alarm_destroy(alarm, nullptr);
-  }
-
-  shutdown_and_destroy(cc);
-}
-
-int main(int argc, char** argv) {
-  grpc_test_init(argc, argv);
-  grpc_init();
-  test_alarm();
-  grpc_shutdown();
-  return 0;
-}
diff --git a/test/core/surface/byte_buffer_reader_test.cc b/test/core/surface/byte_buffer_reader_test.cc
index 0c8a07c7fd..91662b027a 100644
--- a/test/core/surface/byte_buffer_reader_test.cc
+++ b/test/core/surface/byte_buffer_reader_test.cc
@@ -205,8 +205,8 @@ static void test_readall(void) {
 
   LOG_TEST("test_readall");
 
-  memset(lotsa_as, 'a', 512);
-  memset(lotsa_bs, 'b', 1024);
+  memset(lotsa_as, 'a', 512 * sizeof(lotsa_as[0]));
+  memset(lotsa_bs, 'b', 1024 * sizeof(lotsa_bs[0]));
   /* use slices large enough to overflow inlining */
   slices[0] = grpc_slice_malloc(512);
   memcpy(GRPC_SLICE_START_PTR(slices[0]), lotsa_as, 512);
@@ -240,8 +240,8 @@ static void test_byte_buffer_copy(void) {
 
   LOG_TEST("test_byte_buffer_copy");
 
-  memset(lotsa_as, 'a', 512);
-  memset(lotsa_bs, 'b', 1024);
+  memset(lotsa_as, 'a', 512 * sizeof(lotsa_as[0]));
+  memset(lotsa_bs, 'b', 1024 * sizeof(lotsa_bs[0]));
   /* use slices large enough to overflow inlining */
   slices[0] = grpc_slice_malloc(512);
   memcpy(GRPC_SLICE_START_PTR(slices[0]), lotsa_as, 512);
diff --git a/test/core/surface/public_headers_must_be_c89.c b/test/core/surface/public_headers_must_be_c89.c
index a191987577..91554fe2a3 100644
--- a/test/core/surface/public_headers_must_be_c89.c
+++ b/test/core/surface/public_headers_must_be_c89.c
@@ -95,10 +95,6 @@ int main(int argc, char **argv) {
   printf("%lx", (unsigned long) grpc_completion_queue_destroy);
   printf("%lx", (unsigned long) grpc_completion_queue_thread_local_cache_init);
   printf("%lx", (unsigned long) grpc_completion_queue_thread_local_cache_flush);
-  printf("%lx", (unsigned long) grpc_alarm_create);
-  printf("%lx", (unsigned long) grpc_alarm_set);
-  printf("%lx", (unsigned long) grpc_alarm_cancel);
-  printf("%lx", (unsigned long) grpc_alarm_destroy);
   printf("%lx", (unsigned long) grpc_channel_check_connectivity_state);
   printf("%lx", (unsigned long) grpc_channel_num_external_connectivity_watchers);
   printf("%lx", (unsigned long) grpc_channel_watch_connectivity_state);
diff --git a/test/core/transport/chttp2/settings_timeout_test.cc b/test/core/transport/chttp2/settings_timeout_test.cc
index d7d6ee7508..7fb395d4b6 100644
--- a/test/core/transport/chttp2/settings_timeout_test.cc
+++ b/test/core/transport/chttp2/settings_timeout_test.cc
@@ -169,7 +169,7 @@ class Client {
 
     grpc_closure* closure() { return &closure_; }
 
-    bool done() const { return done_; }
+    bool done() const { return gpr_atm_acq_load(&done_atm_) != 0; }
 
     // Caller does NOT take ownership of the error.
     grpc_error* error() const { return error_; }
@@ -179,11 +179,11 @@ class Client {
       gpr_log(GPR_INFO, "OnEventDone(): %s", grpc_error_string(error));
       EventState* state = (EventState*)arg;
       state->error_ = GRPC_ERROR_REF(error);
-      state->done_ = true;
+      gpr_atm_rel_store(&state->done_atm_, 1);
     }
 
     grpc_closure closure_;
-    bool done_ = false;
+    gpr_atm done_atm_ = 0;
     grpc_error* error_ = GRPC_ERROR_NONE;
   };
 
diff --git a/test/core/tsi/ssl_transport_security_test.cc b/test/core/tsi/ssl_transport_security_test.cc
index 8939c0434b..bf54383c54 100644
--- a/test/core/tsi/ssl_transport_security_test.cc
+++ b/test/core/tsi/ssl_transport_security_test.cc
@@ -667,9 +667,15 @@ int main(int argc, char** argv) {
   ssl_tsi_test_do_handshake_with_server_name_indication_wild_star_domain();
   ssl_tsi_test_do_handshake_with_bad_server_cert();
   ssl_tsi_test_do_handshake_with_bad_client_cert();
-  ssl_tsi_test_do_handshake_alpn_client_no_server();
+  // TODO: BoringSSL and OpenSSL have different behaviors on handling mismatched
+  // ALPN. Re-enable this test if we can detect in the runtime which SSL library
+  // is used.
+  // ssl_tsi_test_do_handshake_alpn_client_no_server();
   ssl_tsi_test_do_handshake_alpn_server_no_client();
-  ssl_tsi_test_do_handshake_alpn_client_server_mismatch();
+  // TODO: BoringSSL and OpenSSL have different behaviors on handling mismatched
+  // ALPN. Re-enable this test if we can detect in the runtime which SSL library
+  // is used.
+  // ssl_tsi_test_do_handshake_alpn_client_server_mismatch();
   ssl_tsi_test_do_handshake_alpn_client_server_ok();
   ssl_tsi_test_do_round_trip_for_all_configs();
   ssl_tsi_test_do_round_trip_odd_buffer_size();
diff --git a/test/core/util/passthru_endpoint.cc b/test/core/util/passthru_endpoint.cc
index 5f127cb960..0da0765979 100644
--- a/test/core/util/passthru_endpoint.cc
+++ b/test/core/util/passthru_endpoint.cc
@@ -48,8 +48,6 @@ struct passthru_endpoint {
   gpr_mu mu;
   int halves;
   grpc_passthru_endpoint_stats* stats;
-  grpc_passthru_endpoint_stats
-      dummy_stats;  // used if constructor stats == nullptr
   bool shutdown;
   half client;
   half server;
@@ -137,6 +135,7 @@ static void me_destroy(grpc_endpoint* ep) {
   if (0 == --p->halves) {
     gpr_mu_unlock(&p->mu);
     gpr_mu_destroy(&p->mu);
+    grpc_passthru_endpoint_stats_destroy(p->stats);
     grpc_slice_buffer_destroy_internal(&p->client.read_buffer);
     grpc_slice_buffer_destroy_internal(&p->server.read_buffer);
     grpc_resource_user_unref(p->client.resource_user);
@@ -194,11 +193,30 @@ void grpc_passthru_endpoint_create(grpc_endpoint** client,
   passthru_endpoint* m = (passthru_endpoint*)gpr_malloc(sizeof(*m));
   m->halves = 2;
   m->shutdown = 0;
-  m->stats = stats == nullptr ? &m->dummy_stats : stats;
-  memset(m->stats, 0, sizeof(*m->stats));
+  if (stats == nullptr) {
+    m->stats = grpc_passthru_endpoint_stats_create();
+  } else {
+    gpr_ref(&stats->refs);
+    m->stats = stats;
+  }
   half_init(&m->client, m, resource_quota, "client");
   half_init(&m->server, m, resource_quota, "server");
   gpr_mu_init(&m->mu);
   *client = &m->client.base;
   *server = &m->server.base;
 }
+
+grpc_passthru_endpoint_stats* grpc_passthru_endpoint_stats_create() {
+  grpc_passthru_endpoint_stats* stats =
+      (grpc_passthru_endpoint_stats*)gpr_malloc(
+          sizeof(grpc_passthru_endpoint_stats));
+  memset(stats, 0, sizeof(*stats));
+  gpr_ref_init(&stats->refs, 1);
+  return stats;
+}
+
+void grpc_passthru_endpoint_stats_destroy(grpc_passthru_endpoint_stats* stats) {
+  if (gpr_unref(&stats->refs)) {
+    gpr_free(stats);
+  }
+}
diff --git a/test/core/util/passthru_endpoint.h b/test/core/util/passthru_endpoint.h
index bddd8ea6a2..a46c775505 100644
--- a/test/core/util/passthru_endpoint.h
+++ b/test/core/util/passthru_endpoint.h
@@ -23,7 +23,11 @@
 
 #include "src/core/lib/iomgr/endpoint.h"
 
+/* The struct is refcounted, always use grpc_passthru_endpoint_stats_create and
+ * grpc_passthru_endpoint_stats_destroy, rather then embedding it in your
+ * objects by value. */
 typedef struct {
+  gpr_refcount refs;
   gpr_atm num_writes;
 } grpc_passthru_endpoint_stats;
 
@@ -32,4 +36,8 @@ void grpc_passthru_endpoint_create(grpc_endpoint** client,
                                    grpc_resource_quota* resource_quota,
                                    grpc_passthru_endpoint_stats* stats);
 
+grpc_passthru_endpoint_stats* grpc_passthru_endpoint_stats_create();
+
+void grpc_passthru_endpoint_stats_destroy(grpc_passthru_endpoint_stats* stats);
+
 #endif