diff --git a/src/core/surface/call.c b/src/core/surface/call.c
index e08273e451c..e18c0be1073 100644
--- a/src/core/surface/call.c
+++ b/src/core/surface/call.c
@@ -1182,18 +1182,22 @@ void grpc_call_destroy(grpc_call *c) {
   c->cancel_alarm |= c->have_alarm;
   cancel = c->read_state != READ_STATE_STREAM_CLOSED;
   unlock(c);
-  if (cancel) grpc_call_cancel(c);
+  if (cancel) grpc_call_cancel(c, NULL);
   GRPC_CALL_INTERNAL_UNREF(c, "destroy", 1);
 }
 
-grpc_call_error grpc_call_cancel(grpc_call *call) {
-  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled");
+grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved) {
+  (void) reserved;
+  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled",
+                                      NULL);
 }
 
 grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
                                              grpc_status_code status,
-                                             const char *description) {
+                                             const char *description,
+                                             void *reserved) {
   grpc_call_error r;
+  (void) reserved;
   lock(c);
   r = cancel_with_status(c, status, description);
   unlock(c);
@@ -1420,13 +1424,14 @@ static int are_write_flags_valid(gpr_uint32 flags) {
 }
 
 grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
-                                      size_t nops, void *tag) {
+                                      size_t nops, void *tag, void *reserved) {
   grpc_ioreq reqs[GRPC_IOREQ_OP_COUNT];
   size_t in;
   size_t out;
   const grpc_op *op;
   grpc_ioreq *req;
   void (*finish_func)(grpc_call *, int, void *) = finish_batch;
+  (void) reserved;
 
   GRPC_CALL_LOG_BATCH(GPR_INFO, call, ops, nops, tag);
 
diff --git a/src/core/surface/channel.c b/src/core/surface/channel.c
index a6438ff512a..d16600d7c82 100644
--- a/src/core/surface/channel.c
+++ b/src/core/surface/channel.c
@@ -154,7 +154,8 @@ static grpc_call *grpc_channel_create_call_internal(
 grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     grpc_completion_queue *cq,
                                     const char *method, const char *host,
-                                    gpr_timespec deadline) {
+                                    gpr_timespec deadline, void *reserved) {
+  (void) reserved;
   return grpc_channel_create_call_internal(
       channel, cq,
       grpc_mdelem_from_metadata_strings(
@@ -167,8 +168,9 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
 }
 
 void *grpc_channel_register_call(grpc_channel *channel, const char *method,
-                                 const char *host) {
+                                 const char *host, void *reserved) {
   registered_call *rc = gpr_malloc(sizeof(registered_call));
+  (void) reserved;
   rc->path = grpc_mdelem_from_metadata_strings(
       channel->metadata_context, GRPC_MDSTR_REF(channel->path_string),
       grpc_mdstr_from_string(channel->metadata_context, method));
@@ -184,8 +186,9 @@ void *grpc_channel_register_call(grpc_channel *channel, const char *method,
 
 grpc_call *grpc_channel_create_registered_call(
     grpc_channel *channel, grpc_completion_queue *completion_queue,
-    void *registered_call_handle, gpr_timespec deadline) {
+    void *registered_call_handle, gpr_timespec deadline, void *reserved) {
   registered_call *rc = registered_call_handle;
+  (void) reserved;
   return grpc_channel_create_call_internal(
       channel, completion_queue, GRPC_MDELEM_REF(rc->path),
       GRPC_MDELEM_REF(rc->authority), deadline);
diff --git a/src/core/surface/channel_create.c b/src/core/surface/channel_create.c
index 91c7b35550a..44aacea6522 100644
--- a/src/core/surface/channel_create.c
+++ b/src/core/surface/channel_create.c
@@ -152,7 +152,8 @@ static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
                    - connect to it (trying alternatives as presented)
                    - perform handshakes */
 grpc_channel *grpc_channel_create(const char *target,
-                                  const grpc_channel_args *args) {
+                                  const grpc_channel_args *args,
+                                  void *reserved) {
   grpc_channel *channel = NULL;
 #define MAX_FILTERS 3
   const grpc_channel_filter *filters[MAX_FILTERS];
@@ -160,6 +161,7 @@ grpc_channel *grpc_channel_create(const char *target,
   subchannel_factory *f;
   grpc_mdctx *mdctx = grpc_mdctx_create();
   int n = 0;
+  (void) reserved;
   /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;
diff --git a/src/core/surface/completion_queue.c b/src/core/surface/completion_queue.c
index 3f60b0b0ba3..82b5ff23c54 100644
--- a/src/core/surface/completion_queue.c
+++ b/src/core/surface/completion_queue.c
@@ -62,8 +62,9 @@ struct grpc_completion_queue {
   int is_server_cq;
 };
 
-grpc_completion_queue *grpc_completion_queue_create(void) {
+grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   grpc_completion_queue *cc = gpr_malloc(sizeof(grpc_completion_queue));
+  (void) reserved;
   memset(cc, 0, sizeof(*cc));
   /* Initial ref is dropped by grpc_completion_queue_shutdown */
   gpr_ref_init(&cc->pending_events, 1);
@@ -145,8 +146,10 @@ void grpc_cq_end_op(grpc_completion_queue *cc, void *tag, int success,
 }
 
 grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
-                                      gpr_timespec deadline) {
+                                      gpr_timespec deadline,
+                                      void *reserved) {
   grpc_event ret;
+  (void) reserved;
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 
@@ -185,10 +188,11 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
 }
 
 grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
-                                       gpr_timespec deadline) {
+                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
+  (void) reserved;
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index 439452aea27..ae53127b7c6 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -726,8 +726,10 @@ static const grpc_channel_filter server_surface_filter = {
 };
 
 void grpc_server_register_completion_queue(grpc_server *server,
-                                           grpc_completion_queue *cq) {
+                                           grpc_completion_queue *cq,
+                                           void *reserved) {
   size_t i, n;
+  (void) reserved;
   for (i = 0; i < server->cq_count; i++) {
     if (server->cqs[i] == cq) return;
   }
diff --git a/src/core/surface/server_create.c b/src/core/surface/server_create.c
index 1e26c67693d..9237eb5a904 100644
--- a/src/core/surface/server_create.c
+++ b/src/core/surface/server_create.c
@@ -36,8 +36,9 @@
 #include "src/core/surface/server.h"
 #include "src/core/channel/compress_filter.h"
 
-grpc_server *grpc_server_create(const grpc_channel_args *args) {
+grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
   const grpc_channel_filter *filters[] = {&grpc_compress_filter};
+  (void) reserved;
   return grpc_server_create_from_filters(filters, GPR_ARRAY_SIZE(filters),
                                          args);
 }
diff --git a/src/cpp/client/channel.cc b/src/cpp/client/channel.cc
index da31d000b3c..83733fdaae1 100644
--- a/src/cpp/client/channel.cc
+++ b/src/cpp/client/channel.cc
@@ -63,12 +63,13 @@ Call Channel::CreateCall(const RpcMethod& method, ClientContext* context,
       method.channel_tag() && context->authority().empty()
           ? grpc_channel_create_registered_call(c_channel_, cq->cq(),
                                                 method.channel_tag(),
-                                                context->raw_deadline())
+                                                context->raw_deadline(),
+                                                nullptr)
           : grpc_channel_create_call(c_channel_, cq->cq(), method.name(),
                                      context->authority().empty()
                                          ? target_.c_str()
                                          : context->authority().c_str(),
-                                     context->raw_deadline());
+                                     context->raw_deadline(), nullptr);
   grpc_census_call_set_context(c_call, context->get_census_context());
   GRPC_TIMER_MARK(GRPC_PTAG_CPP_CALL_CREATED, c_call);
   context->set_call(c_call, shared_from_this());
@@ -82,12 +83,13 @@ void Channel::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
   GRPC_TIMER_BEGIN(GRPC_PTAG_CPP_PERFORM_OPS, call->call());
   ops->FillOps(cops, &nops);
   GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call->call(), cops, nops, ops));
+             grpc_call_start_batch(call->call(), cops, nops, ops, nullptr));
   GRPC_TIMER_END(GRPC_PTAG_CPP_PERFORM_OPS, call->call());
 }
 
 void* Channel::RegisterMethod(const char* method) {
-  return grpc_channel_register_call(c_channel_, method, target_.c_str());
+  return grpc_channel_register_call(c_channel_, method, target_.c_str(),
+                                    nullptr);
 }
 
 }  // namespace grpc
diff --git a/src/cpp/client/client_context.cc b/src/cpp/client/client_context.cc
index 14ab772e503..d8e6fcbf528 100644
--- a/src/cpp/client/client_context.cc
+++ b/src/cpp/client/client_context.cc
@@ -56,9 +56,11 @@ ClientContext::~ClientContext() {
   if (cq_) {
     // Drain cq_.
     grpc_completion_queue_shutdown(cq_);
-    while (grpc_completion_queue_next(cq_, gpr_inf_future(GPR_CLOCK_REALTIME))
-               .type != GRPC_QUEUE_SHUTDOWN)
-      ;
+    gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+    grpc_event event;
+    do {
+      event = grpc_completion_queue_next(cq_, deadline, nullptr);
+    } while (event.type != GRPC_QUEUE_SHUTDOWN);
     grpc_completion_queue_destroy(cq_);
   }
 }
@@ -75,19 +77,19 @@ void ClientContext::set_call(grpc_call* call,
   channel_ = channel;
   if (creds_ && !creds_->ApplyToCall(call_)) {
     grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED,
-                                 "Failed to set credentials to rpc.");
+                                 "Failed to set credentials to rpc.", nullptr);
   }
 }
 
 void ClientContext::set_compression_algorithm(
     grpc_compression_algorithm algorithm) {
-  char* algorithm_name = NULL;
+  char* algorithm_name = nullptr;
   if (!grpc_compression_algorithm_name(algorithm, &algorithm_name)) {
     gpr_log(GPR_ERROR, "Name for compression algorithm '%d' unknown.",
             algorithm);
     abort();
   }
-  GPR_ASSERT(algorithm_name != NULL);
+  GPR_ASSERT(algorithm_name != nullptr);
   AddMetadata(GRPC_COMPRESS_REQUEST_ALGORITHM_KEY, algorithm_name);
 }
 
@@ -100,7 +102,7 @@ std::shared_ptr<const AuthContext> ClientContext::auth_context() const {
 
 void ClientContext::TryCancel() {
   if (call_) {
-    grpc_call_cancel(call_);
+    grpc_call_cancel(call_, nullptr);
   }
 }
 
diff --git a/src/cpp/client/insecure_credentials.cc b/src/cpp/client/insecure_credentials.cc
index 5ad87845675..cc37c33c7b1 100644
--- a/src/cpp/client/insecure_credentials.cc
+++ b/src/cpp/client/insecure_credentials.cc
@@ -49,7 +49,7 @@ class InsecureCredentialsImpl GRPC_FINAL : public Credentials {
     grpc_channel_args channel_args;
     args.SetChannelArgs(&channel_args);
     return std::shared_ptr<ChannelInterface>(new Channel(
-        target, grpc_channel_create(target.c_str(), &channel_args)));
+        target, grpc_channel_create(target.c_str(), &channel_args, nullptr)));
   }
 
   // InsecureCredentials should not be applied to a call.
diff --git a/src/cpp/common/completion_queue.cc b/src/cpp/common/completion_queue.cc
index 593963f672f..fca33f8f542 100644
--- a/src/cpp/common/completion_queue.cc
+++ b/src/cpp/common/completion_queue.cc
@@ -40,7 +40,9 @@
 
 namespace grpc {
 
-CompletionQueue::CompletionQueue() { cq_ = grpc_completion_queue_create(); }
+CompletionQueue::CompletionQueue() {
+  cq_ = grpc_completion_queue_create(nullptr);
+}
 
 CompletionQueue::CompletionQueue(grpc_completion_queue* take) : cq_(take) {}
 
@@ -51,7 +53,7 @@ void CompletionQueue::Shutdown() { grpc_completion_queue_shutdown(cq_); }
 CompletionQueue::NextStatus CompletionQueue::AsyncNextInternal(
     void** tag, bool* ok, gpr_timespec deadline) {
   for (;;) {
-    auto ev = grpc_completion_queue_next(cq_, deadline);
+    auto ev = grpc_completion_queue_next(cq_, deadline, nullptr);
     switch (ev.type) {
       case GRPC_QUEUE_TIMEOUT:
         return TIMEOUT;
@@ -70,8 +72,8 @@ CompletionQueue::NextStatus CompletionQueue::AsyncNextInternal(
 }
 
 bool CompletionQueue::Pluck(CompletionQueueTag* tag) {
-  auto ev =
-      grpc_completion_queue_pluck(cq_, tag, gpr_inf_future(GPR_CLOCK_REALTIME));
+  auto deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  auto ev = grpc_completion_queue_pluck(cq_, tag, deadline, nullptr);
   bool ok = ev.success != 0;
   void* ignored = tag;
   GPR_ASSERT(tag->FinalizeResult(&ignored, &ok));
@@ -81,8 +83,8 @@ bool CompletionQueue::Pluck(CompletionQueueTag* tag) {
 }
 
 void CompletionQueue::TryPluck(CompletionQueueTag* tag) {
-  auto ev =
-      grpc_completion_queue_pluck(cq_, tag, gpr_time_0(GPR_CLOCK_REALTIME));
+  auto deadline = gpr_time_0(GPR_CLOCK_REALTIME);
+  auto ev = grpc_completion_queue_pluck(cq_, tag, deadline, nullptr);
   if (ev.type == GRPC_QUEUE_TIMEOUT) return;
   bool ok = ev.success != 0;
   void* ignored = tag;
diff --git a/src/cpp/server/server.cc b/src/cpp/server/server.cc
index ab87b22f5fb..da2bc946391 100644
--- a/src/cpp/server/server.cc
+++ b/src/cpp/server/server.cc
@@ -84,7 +84,7 @@ class Server::SyncRequest GRPC_FINAL : public CompletionQueueTag {
     return mrd;
   }
 
-  void SetupRequest() { cq_ = grpc_completion_queue_create(); }
+  void SetupRequest() { cq_ = grpc_completion_queue_create(nullptr); }
 
   void TeardownRequest() {
     grpc_completion_queue_destroy(cq_);
@@ -170,9 +170,9 @@ static grpc_server* CreateServer(int max_message_size) {
     arg.key = const_cast<char*>(GRPC_ARG_MAX_MESSAGE_LENGTH);
     arg.value.integer = max_message_size;
     grpc_channel_args args = {1, &arg};
-    return grpc_server_create(&args);
+    return grpc_server_create(&args, nullptr);
   } else {
-    return grpc_server_create(nullptr);
+    return grpc_server_create(nullptr, nullptr);
   }
 }
 
@@ -186,7 +186,7 @@ Server::Server(ThreadPoolInterface* thread_pool, bool thread_pool_owned,
       server_(CreateServer(max_message_size)),
       thread_pool_(thread_pool),
       thread_pool_owned_(thread_pool_owned) {
-  grpc_server_register_completion_queue(server_, cq_.cq());
+  grpc_server_register_completion_queue(server_, cq_.cq(), nullptr);
 }
 
 Server::~Server() {
@@ -297,8 +297,8 @@ void Server::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
   size_t nops = 0;
   grpc_op cops[MAX_OPS];
   ops->FillOps(cops, &nops);
-  GPR_ASSERT(GRPC_CALL_OK ==
-             grpc_call_start_batch(call->call(), cops, nops, ops));
+  auto result = grpc_call_start_batch(call->call(), cops, nops, ops, nullptr);
+  GPR_ASSERT(GRPC_CALL_OK == result);
 }
 
 Server::BaseAsyncRequest::BaseAsyncRequest(
diff --git a/src/cpp/server/server_builder.cc b/src/cpp/server/server_builder.cc
index f723d4611ae..ce7682e8a77 100644
--- a/src/cpp/server/server_builder.cc
+++ b/src/cpp/server/server_builder.cc
@@ -103,7 +103,8 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
   std::unique_ptr<Server> server(
       new Server(thread_pool_, thread_pool_owned, max_message_size_));
   for (auto cq = cqs_.begin(); cq != cqs_.end(); ++cq) {
-    grpc_server_register_completion_queue(server->server_, (*cq)->cq());
+    grpc_server_register_completion_queue(server->server_, (*cq)->cq(),
+                                          nullptr);
   }
   for (auto service = services_.begin(); service != services_.end();
        service++) {