src/cpp/server/server_cc.cc - third_party/grpc - Git at Google

 /*
  * 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++/server.h>

 #include <cstdlib>
 #include <sstream>
 #include <utility>

 #include <grpc++/completion_queue.h>
 #include <grpc++/generic/async_generic_service.h>
 #include <grpc++/impl/codegen/async_unary_call.h>
 #include <grpc++/impl/codegen/completion_queue_tag.h>
 #include <grpc++/impl/grpc_library.h>
 #include <grpc++/impl/method_handler_impl.h>
 #include <grpc++/impl/rpc_service_method.h>
 #include <grpc++/impl/server_initializer.h>
 #include <grpc++/impl/service_type.h>
 #include <grpc++/security/server_credentials.h>
 #include <grpc++/server_context.h>
 #include <grpc++/support/time.h>
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>

 #include "src/core/ext/transport/inproc/inproc_transport.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/surface/call.h"
 #include "src/cpp/client/create_channel_internal.h"
 #include "src/cpp/server/health/default_health_check_service.h"
 #include "src/cpp/thread_manager/thread_manager.h"

 namespace grpc {

 class DefaultGlobalCallbacks final : public Server::GlobalCallbacks {
  public:
   ~DefaultGlobalCallbacks() override {}
   void PreSynchronousRequest(ServerContext* context) override {}
   void PostSynchronousRequest(ServerContext* context) override {}
 };

 static std::shared_ptr<Server::GlobalCallbacks> g_callbacks = nullptr;
 static gpr_once g_once_init_callbacks = GPR_ONCE_INIT;

 static void InitGlobalCallbacks() {
   if (!g_callbacks) {
     g_callbacks.reset(new DefaultGlobalCallbacks());
   }
 }

 class Server::UnimplementedAsyncRequestContext {
  protected:
   UnimplementedAsyncRequestContext() : generic_stream_(&server_context_) {}

   GenericServerContext server_context_;
   GenericServerAsyncReaderWriter generic_stream_;
 };

 class Server::UnimplementedAsyncRequest final
     : public UnimplementedAsyncRequestContext,
       public GenericAsyncRequest {
  public:
   UnimplementedAsyncRequest(Server* server, ServerCompletionQueue* cq)
       : GenericAsyncRequest(server, &server_context_, &generic_stream_, cq, cq,
                             NULL, false),
         server_(server),
         cq_(cq) {}

   bool FinalizeResult(void** tag, bool* status) override;

   ServerContext* context() { return &server_context_; }
   GenericServerAsyncReaderWriter* stream() { return &generic_stream_; }

  private:
   Server* const server_;
   ServerCompletionQueue* const cq_;
 };

 typedef SneakyCallOpSet<CallOpSendInitialMetadata, CallOpServerSendStatus>
     UnimplementedAsyncResponseOp;
 class Server::UnimplementedAsyncResponse final
     : public UnimplementedAsyncResponseOp {
  public:
   UnimplementedAsyncResponse(UnimplementedAsyncRequest* request);
   ~UnimplementedAsyncResponse() { delete request_; }

   bool FinalizeResult(void** tag, bool* status) override {
     bool r = UnimplementedAsyncResponseOp::FinalizeResult(tag, status);
     delete this;
     return r;
   }

  private:
   UnimplementedAsyncRequest* const request_;
 };

 class ShutdownTag : public CompletionQueueTag {
  public:
   bool FinalizeResult(void** tag, bool* status) { return false; }
 };

 class DummyTag : public CompletionQueueTag {
  public:
   bool FinalizeResult(void** tag, bool* status) {
     *status = true;
     return true;
   }
 };

 class Server::SyncRequest final : public CompletionQueueTag {
  public:
   SyncRequest(RpcServiceMethod* method, void* tag)
       : method_(method),
         tag_(tag),
         in_flight_(false),
         has_request_payload_(method->method_type() == RpcMethod::NORMAL_RPC ||
                              method->method_type() ==
                                  RpcMethod::SERVER_STREAMING),
         call_details_(nullptr),
         cq_(nullptr) {
     grpc_metadata_array_init(&request_metadata_);
   }

   ~SyncRequest() {
     if (call_details_) {
       delete call_details_;
     }
     grpc_metadata_array_destroy(&request_metadata_);
   }

   void SetupRequest() { cq_ = grpc_completion_queue_create_for_pluck(nullptr); }

   void TeardownRequest() {
     grpc_completion_queue_destroy(cq_);
     cq_ = nullptr;
   }

   void Request(grpc_server* server, grpc_completion_queue* notify_cq) {
     GPR_ASSERT(cq_ && !in_flight_);
     in_flight_ = true;
     if (tag_) {
       if (GRPC_CALL_OK !=
           grpc_server_request_registered_call(
               server, tag_, &call_, &deadline_, &request_metadata_,
               has_request_payload_ ? &request_payload_ : nullptr, cq_,
               notify_cq, this)) {
         TeardownRequest();
         return;
       }
     } else {
       if (!call_details_) {
         call_details_ = new grpc_call_details;
         grpc_call_details_init(call_details_);
       }
       if (grpc_server_request_call(server, &call_, call_details_,
                                    &request_metadata_, cq_, notify_cq,
                                    this) != GRPC_CALL_OK) {
         TeardownRequest();
         return;
       }
     }
   }

   bool FinalizeResult(void** tag, bool* status) override {
     if (!*status) {
       grpc_completion_queue_destroy(cq_);
     }
     if (call_details_) {
       deadline_ = call_details_->deadline;
       grpc_call_details_destroy(call_details_);
       grpc_call_details_init(call_details_);
     }
     return true;
   }

   class CallData final {
    public:
     explicit CallData(Server* server, SyncRequest* mrd)
         : cq_(mrd->cq_),
           call_(mrd->call_, server, &cq_, server->max_receive_message_size()),
           ctx_(mrd->deadline_, &mrd->request_metadata_),
           has_request_payload_(mrd->has_request_payload_),
           request_payload_(mrd->request_payload_),
           method_(mrd->method_) {
       ctx_.set_call(mrd->call_);
       ctx_.cq_ = &cq_;
       GPR_ASSERT(mrd->in_flight_);
       mrd->in_flight_ = false;
       mrd->request_metadata_.count = 0;
     }

     ~CallData() {
       if (has_request_payload_ && request_payload_) {
         grpc_byte_buffer_destroy(request_payload_);
       }
     }

     void Run(std::shared_ptr<GlobalCallbacks> global_callbacks) {
       ctx_.BeginCompletionOp(&call_);
       global_callbacks->PreSynchronousRequest(&ctx_);
       method_->handler()->RunHandler(
           MethodHandler::HandlerParameter(&call_, &ctx_, request_payload_));
       global_callbacks->PostSynchronousRequest(&ctx_);
       request_payload_ = nullptr;

       cq_.Shutdown();

       CompletionQueueTag* op_tag = ctx_.GetCompletionOpTag();
       cq_.TryPluck(op_tag, gpr_inf_future(GPR_CLOCK_REALTIME));

       /* Ensure the cq_ is shutdown */
       DummyTag ignored_tag;
       GPR_ASSERT(cq_.Pluck(&ignored_tag) == false);
     }

    private:
     CompletionQueue cq_;
     Call call_;
     ServerContext ctx_;
     const bool has_request_payload_;
     grpc_byte_buffer* request_payload_;
     RpcServiceMethod* const method_;
   };

  private:
   RpcServiceMethod* const method_;
   void* const tag_;
   bool in_flight_;
   const bool has_request_payload_;
   grpc_call* call_;
   grpc_call_details* call_details_;
   gpr_timespec deadline_;
   grpc_metadata_array request_metadata_;
   grpc_byte_buffer* request_payload_;
   grpc_completion_queue* cq_;
 };

 // Implementation of ThreadManager. Each instance of SyncRequestThreadManager
 // manages a pool of threads that poll for incoming Sync RPCs and call the
 // appropriate RPC handlers
 class Server::SyncRequestThreadManager : public ThreadManager {
  public:
   SyncRequestThreadManager(Server* server, CompletionQueue* server_cq,
                            std::shared_ptr<GlobalCallbacks> global_callbacks,
                            int min_pollers, int max_pollers,
                            int cq_timeout_msec)
       : ThreadManager(min_pollers, max_pollers),
         server_(server),
         server_cq_(server_cq),
         cq_timeout_msec_(cq_timeout_msec),
         global_callbacks_(global_callbacks) {}

   WorkStatus PollForWork(void** tag, bool* ok) override {
     *tag = nullptr;
     gpr_timespec deadline =
         gpr_time_from_millis(cq_timeout_msec_, GPR_TIMESPAN);

     switch (server_cq_->AsyncNext(tag, ok, deadline)) {
       case CompletionQueue::TIMEOUT:
         return TIMEOUT;
       case CompletionQueue::SHUTDOWN:
         return SHUTDOWN;
       case CompletionQueue::GOT_EVENT:
         return WORK_FOUND;
     }

     GPR_UNREACHABLE_CODE(return TIMEOUT);
   }

   void DoWork(void* tag, bool ok) override {
     SyncRequest* sync_req = static_cast<SyncRequest*>(tag);

     if (!sync_req) {
       // No tag. Nothing to work on. This is an unlikley scenario and possibly a
       // bug in RPC Manager implementation.
       gpr_log(GPR_ERROR, "Sync server. DoWork() was called with NULL tag");
       return;
     }

     if (ok) {
       // Calldata takes ownership of the completion queue inside sync_req
       SyncRequest::CallData cd(server_, sync_req);
       // Prepare for the next request
       if (!IsShutdown()) {
         sync_req->SetupRequest();  // Create new completion queue for sync_req
         sync_req->Request(server_->c_server(), server_cq_->cq());
       }

       GPR_TIMER_SCOPE("cd.Run()", 0);
       cd.Run(global_callbacks_);
     }
     // TODO (sreek) If ok is false here (which it isn't in case of
     // grpc_request_registered_call), we should still re-queue the request
     // object
   }

   void AddSyncMethod(RpcServiceMethod* method, void* tag) {
     sync_requests_.emplace_back(new SyncRequest(method, tag));
   }

   void AddUnknownSyncMethod() {
     if (!sync_requests_.empty()) {
       unknown_method_.reset(new RpcServiceMethod(
           "unknown", RpcMethod::BIDI_STREAMING, new UnknownMethodHandler));
       sync_requests_.emplace_back(
           new SyncRequest(unknown_method_.get(), nullptr));
     }
   }

   void Shutdown() override {
     ThreadManager::Shutdown();
     server_cq_->Shutdown();
   }

   void Wait() override {
     ThreadManager::Wait();
     // Drain any pending items from the queue
     void* tag;
     bool ok;
     while (server_cq_->Next(&tag, &ok)) {
       // Do nothing
     }
   }

   void Start() {
     if (!sync_requests_.empty()) {
       for (auto m = sync_requests_.begin(); m != sync_requests_.end(); m++) {
         (*m)->SetupRequest();
         (*m)->Request(server_->c_server(), server_cq_->cq());
       }

       Initialize();  // ThreadManager's Initialize()
     }
   }

  private:
   Server* server_;
   CompletionQueue* server_cq_;
   int cq_timeout_msec_;
   std::vector<std::unique_ptr<SyncRequest>> sync_requests_;
   std::unique_ptr<RpcServiceMethod> unknown_method_;
   std::unique_ptr<RpcServiceMethod> health_check_;
   std::shared_ptr<Server::GlobalCallbacks> global_callbacks_;
 };

 static internal::GrpcLibraryInitializer g_gli_initializer;
 Server::Server(
     int max_receive_message_size, ChannelArguments* args,
     std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
         sync_server_cqs,
     int min_pollers, int max_pollers, int sync_cq_timeout_msec)
     : max_receive_message_size_(max_receive_message_size),
       sync_server_cqs_(sync_server_cqs),
       started_(false),
       shutdown_(false),
       shutdown_notified_(false),
       has_generic_service_(false),
       server_(nullptr),
       server_initializer_(new ServerInitializer(this)),
       health_check_service_disabled_(false) {
   g_gli_initializer.summon();
   gpr_once_init(&g_once_init_callbacks, InitGlobalCallbacks);
   global_callbacks_ = g_callbacks;
   global_callbacks_->UpdateArguments(args);

   for (auto it = sync_server_cqs_->begin(); it != sync_server_cqs_->end();
        it++) {
     sync_req_mgrs_.emplace_back(new SyncRequestThreadManager(
         this, (*it).get(), global_callbacks_, min_pollers, max_pollers,
         sync_cq_timeout_msec));
   }

   grpc_channel_args channel_args;
   args->SetChannelArgs(&channel_args);

   for (size_t i = 0; i < channel_args.num_args; i++) {
     if (0 ==
         strcmp(channel_args.args[i].key, kHealthCheckServiceInterfaceArg)) {
       if (channel_args.args[i].value.pointer.p == nullptr) {
         health_check_service_disabled_ = true;
       } else {
         health_check_service_.reset(static_cast<HealthCheckServiceInterface*>(
             channel_args.args[i].value.pointer.p));
       }
       break;
     }
   }

   server_ = grpc_server_create(&channel_args, nullptr);
 }

 Server::~Server() {
   {
     std::unique_lock<std::mutex> lock(mu_);
     if (started_ && !shutdown_) {
       lock.unlock();
       Shutdown();
     } else if (!started_) {
       // Shutdown the completion queues
       for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
         (*it)->Shutdown();
       }
     }
   }

   grpc_server_destroy(server_);
 }

 void Server::SetGlobalCallbacks(GlobalCallbacks* callbacks) {
   GPR_ASSERT(!g_callbacks);
   GPR_ASSERT(callbacks);
   g_callbacks.reset(callbacks);
 }

 grpc_server* Server::c_server() { return server_; }

 std::shared_ptr<Channel> Server::InProcessChannel(
     const ChannelArguments& args) {
   grpc_channel_args channel_args = args.c_channel_args();
   return CreateChannelInternal(
       "inproc", grpc_inproc_channel_create(server_, &channel_args, nullptr));
 }

 static grpc_server_register_method_payload_handling PayloadHandlingForMethod(
     RpcServiceMethod* method) {
   switch (method->method_type()) {
     case RpcMethod::NORMAL_RPC:
     case RpcMethod::SERVER_STREAMING:
       return GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER;
     case RpcMethod::CLIENT_STREAMING:
     case RpcMethod::BIDI_STREAMING:
       return GRPC_SRM_PAYLOAD_NONE;
   }
   GPR_UNREACHABLE_CODE(return GRPC_SRM_PAYLOAD_NONE;);
 }

 bool Server::RegisterService(const grpc::string* host, Service* service) {
   bool has_async_methods = service->has_async_methods();
   if (has_async_methods) {
     GPR_ASSERT(service->server_ == nullptr &&
                "Can only register an asynchronous service against one server.");
     service->server_ = this;
   }

   const char* method_name = nullptr;
   for (auto it = service->methods_.begin(); it != service->methods_.end();
        ++it) {
     if (it->get() == nullptr) {  // Handled by generic service if any.
       continue;
     }

     RpcServiceMethod* method = it->get();
     void* tag = grpc_server_register_method(
         server_, method->name(), host ? host->c_str() : nullptr,
         PayloadHandlingForMethod(method), 0);
     if (tag == nullptr) {
       gpr_log(GPR_DEBUG, "Attempt to register %s multiple times",
               method->name());
       return false;
     }

     if (method->handler() == nullptr) {  // Async method
       method->set_server_tag(tag);
     } else {
       for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
         (*it)->AddSyncMethod(method, tag);
       }
     }

     method_name = method->name();
   }

   // Parse service name.
   if (method_name != nullptr) {
     std::stringstream ss(method_name);
     grpc::string service_name;
     if (std::getline(ss, service_name, '/') &&
         std::getline(ss, service_name, '/')) {
       services_.push_back(service_name);
     }
   }
   return true;
 }

 void Server::RegisterAsyncGenericService(AsyncGenericService* service) {
   GPR_ASSERT(service->server_ == nullptr &&
              "Can only register an async generic service against one server.");
   service->server_ = this;
   has_generic_service_ = true;
 }

 int Server::AddListeningPort(const grpc::string& addr,
                              ServerCredentials* creds) {
   GPR_ASSERT(!started_);
   int port = creds->AddPortToServer(addr, server_);
   global_callbacks_->AddPort(this, addr, creds, port);
   return port;
 }

 void Server::Start(ServerCompletionQueue** cqs, size_t num_cqs) {
   GPR_ASSERT(!started_);
   global_callbacks_->PreServerStart(this);
   started_ = true;

   // Only create default health check service when user did not provide an
   // explicit one.
   if (health_check_service_ == nullptr && !health_check_service_disabled_ &&
       DefaultHealthCheckServiceEnabled()) {
     if (sync_server_cqs_->empty()) {
       gpr_log(GPR_INFO,
               "Default health check service disabled at async-only server.");
     } else {
       auto* default_hc_service = new DefaultHealthCheckService;
       health_check_service_.reset(default_hc_service);
       RegisterService(nullptr, default_hc_service->GetHealthCheckService());
     }
   }

   grpc_server_start(server_);

   if (!has_generic_service_) {
     for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
       (*it)->AddUnknownSyncMethod();
     }

     for (size_t i = 0; i < num_cqs; i++) {
       if (cqs[i]->IsFrequentlyPolled()) {
         new UnimplementedAsyncRequest(this, cqs[i]);
       }
     }
   }

   for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
     (*it)->Start();
   }
 }

 void Server::ShutdownInternal(gpr_timespec deadline) {
   std::unique_lock<std::mutex> lock(mu_);
   if (!shutdown_) {
     shutdown_ = true;

     /// The completion queue to use for server shutdown completion notification
     CompletionQueue shutdown_cq;
     ShutdownTag shutdown_tag;  // Dummy shutdown tag
     grpc_server_shutdown_and_notify(server_, shutdown_cq.cq(), &shutdown_tag);

     shutdown_cq.Shutdown();

     void* tag;
     bool ok;
     CompletionQueue::NextStatus status =
         shutdown_cq.AsyncNext(&tag, &ok, deadline);

     // If this timed out, it means we are done with the grace period for a clean
     // shutdown. We should force a shutdown now by cancelling all inflight calls
     if (status == CompletionQueue::NextStatus::TIMEOUT) {
       grpc_server_cancel_all_calls(server_);
     }
     // Else in case of SHUTDOWN or GOT_EVENT, it means that the server has
     // successfully shutdown

     // Shutdown all ThreadManagers. This will try to gracefully stop all the
     // threads in the ThreadManagers (once they process any inflight requests)
     for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
       (*it)->Shutdown();  // ThreadManager's Shutdown()
     }

     // Wait for threads in all ThreadManagers to terminate
     for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
       (*it)->Wait();
     }

     // Drain the shutdown queue (if the previous call to AsyncNext() timed out
     // and we didn't remove the tag from the queue yet)
     while (shutdown_cq.Next(&tag, &ok)) {
       // Nothing to be done here. Just ignore ok and tag values
     }

     shutdown_notified_ = true;
     shutdown_cv_.notify_all();
   }
 }

 void Server::Wait() {
   std::unique_lock<std::mutex> lock(mu_);
   while (started_ && !shutdown_notified_) {
     shutdown_cv_.wait(lock);
   }
 }

 void Server::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
   static const size_t MAX_OPS = 8;
   size_t nops = 0;
   grpc_op cops[MAX_OPS];
   ops->FillOps(call->call(), cops, &nops);
   auto result = grpc_call_start_batch(call->call(), cops, nops, ops, nullptr);
   if (result != GRPC_CALL_OK) {
     gpr_log(GPR_ERROR, "Fatal: grpc_call_start_batch returned %d", result);
     grpc_call_log_batch(__FILE__, __LINE__, GPR_LOG_SEVERITY_ERROR,
                         call->call(), cops, nops, ops);
     abort();
   }
 }

 ServerInterface::BaseAsyncRequest::BaseAsyncRequest(
     ServerInterface* server, ServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag,
     bool delete_on_finalize)
     : server_(server),
       context_(context),
       stream_(stream),
       call_cq_(call_cq),
       tag_(tag),
       delete_on_finalize_(delete_on_finalize),
       call_(nullptr) {
   call_cq_->RegisterAvalanching();  // This op will trigger more ops
 }

 ServerInterface::BaseAsyncRequest::~BaseAsyncRequest() {
   call_cq_->CompleteAvalanching();
 }

 bool ServerInterface::BaseAsyncRequest::FinalizeResult(void** tag,
                                                        bool* status) {
   if (*status) {
     context_->client_metadata_.FillMap();
   }
   context_->set_call(call_);
   context_->cq_ = call_cq_;
   Call call(call_, server_, call_cq_, server_->max_receive_message_size());
   if (*status && call_) {
     context_->BeginCompletionOp(&call);
   }
   // just the pointers inside call are copied here
   stream_->BindCall(&call);
   *tag = tag_;
   if (delete_on_finalize_) {
     delete this;
   }
   return true;
 }

 ServerInterface::RegisteredAsyncRequest::RegisteredAsyncRequest(
     ServerInterface* server, ServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag)
     : BaseAsyncRequest(server, context, stream, call_cq, tag, true) {}

 void ServerInterface::RegisteredAsyncRequest::IssueRequest(
     void* registered_method, grpc_byte_buffer** payload,
     ServerCompletionQueue* notification_cq) {
   GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_registered_call(
                                  server_->server(), registered_method, &call_,
                                  &context_->deadline_,
                                  context_->client_metadata_.arr(), payload,
                                  call_cq_->cq(), notification_cq->cq(), this));
 }

 ServerInterface::GenericAsyncRequest::GenericAsyncRequest(
     ServerInterface* server, GenericServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq,
     ServerCompletionQueue* notification_cq, void* tag, bool delete_on_finalize)
     : BaseAsyncRequest(server, context, stream, call_cq, tag,
                        delete_on_finalize) {
   grpc_call_details_init(&call_details_);
   GPR_ASSERT(notification_cq);
   GPR_ASSERT(call_cq);
   GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
                                  server->server(), &call_, &call_details_,
                                  context->client_metadata_.arr(), call_cq->cq(),
                                  notification_cq->cq(), this));
 }

 bool ServerInterface::GenericAsyncRequest::FinalizeResult(void** tag,
                                                           bool* status) {
   // TODO(yangg) remove the copy here.
   if (*status) {
     static_cast<GenericServerContext*>(context_)->method_ =
         StringFromCopiedSlice(call_details_.method);
     static_cast<GenericServerContext*>(context_)->host_ =
         StringFromCopiedSlice(call_details_.host);
     context_->deadline_ = call_details_.deadline;
   }
   grpc_slice_unref(call_details_.method);
   grpc_slice_unref(call_details_.host);
   return BaseAsyncRequest::FinalizeResult(tag, status);
 }

 bool Server::UnimplementedAsyncRequest::FinalizeResult(void** tag,
                                                        bool* status) {
   if (GenericAsyncRequest::FinalizeResult(tag, status) && *status) {
     new UnimplementedAsyncRequest(server_, cq_);
     new UnimplementedAsyncResponse(this);
   } else {
     delete this;
   }
   return false;
 }

 Server::UnimplementedAsyncResponse::UnimplementedAsyncResponse(
     UnimplementedAsyncRequest* request)
     : request_(request) {
   Status status(StatusCode::UNIMPLEMENTED, "");
   UnknownMethodHandler::FillOps(request_->context(), this);
   request_->stream()->call_.PerformOps(this);
 }

 ServerInitializer* Server::initializer() { return server_initializer_.get(); }

 }  // namespace grpc
	/*
	* 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++/server.h>

	#include <cstdlib>
	#include <sstream>
	#include <utility>

	#include <grpc++/completion_queue.h>
	#include <grpc++/generic/async_generic_service.h>
	#include <grpc++/impl/codegen/async_unary_call.h>
	#include <grpc++/impl/codegen/completion_queue_tag.h>
	#include <grpc++/impl/grpc_library.h>
	#include <grpc++/impl/method_handler_impl.h>
	#include <grpc++/impl/rpc_service_method.h>
	#include <grpc++/impl/server_initializer.h>
	#include <grpc++/impl/service_type.h>
	#include <grpc++/security/server_credentials.h>
	#include <grpc++/server_context.h>
	#include <grpc++/support/time.h>
	#include <grpc/grpc.h>
	#include <grpc/support/alloc.h>
	#include <grpc/support/log.h>

	#include "src/core/ext/transport/inproc/inproc_transport.h"
	#include "src/core/lib/profiling/timers.h"
	#include "src/core/lib/surface/call.h"
	#include "src/cpp/client/create_channel_internal.h"
	#include "src/cpp/server/health/default_health_check_service.h"
	#include "src/cpp/thread_manager/thread_manager.h"

	namespace grpc {

	class DefaultGlobalCallbacks final : public Server::GlobalCallbacks {
	public:
	~DefaultGlobalCallbacks() override {}
	void PreSynchronousRequest(ServerContext* context) override {}
	void PostSynchronousRequest(ServerContext* context) override {}
	};

	static std::shared_ptr<Server::GlobalCallbacks> g_callbacks = nullptr;
	static gpr_once g_once_init_callbacks = GPR_ONCE_INIT;

	static void InitGlobalCallbacks() {
	if (!g_callbacks) {
	g_callbacks.reset(new DefaultGlobalCallbacks());
	}
	}

	class Server::UnimplementedAsyncRequestContext {
	protected:
	UnimplementedAsyncRequestContext() : generic_stream_(&server_context_) {}

	GenericServerContext server_context_;
	GenericServerAsyncReaderWriter generic_stream_;
	};

	class Server::UnimplementedAsyncRequest final
	: public UnimplementedAsyncRequestContext,
	public GenericAsyncRequest {
	public:
	UnimplementedAsyncRequest(Server* server, ServerCompletionQueue* cq)
	: GenericAsyncRequest(server, &server_context_, &generic_stream_, cq, cq,
	NULL, false),
	server_(server),
	cq_(cq) {}

	bool FinalizeResult(void** tag, bool* status) override;

	ServerContext* context() { return &server_context_; }
	GenericServerAsyncReaderWriter* stream() { return &generic_stream_; }

	private:
	Server* const server_;
	ServerCompletionQueue* const cq_;
	};

	typedef SneakyCallOpSet<CallOpSendInitialMetadata, CallOpServerSendStatus>
	UnimplementedAsyncResponseOp;
	class Server::UnimplementedAsyncResponse final
	: public UnimplementedAsyncResponseOp {
	public:
	UnimplementedAsyncResponse(UnimplementedAsyncRequest* request);
	~UnimplementedAsyncResponse() { delete request_; }

	bool FinalizeResult(void** tag, bool* status) override {
	bool r = UnimplementedAsyncResponseOp::FinalizeResult(tag, status);
	delete this;
	return r;
	}

	private:
	UnimplementedAsyncRequest* const request_;
	};

	class ShutdownTag : public CompletionQueueTag {
	public:
	bool FinalizeResult(void** tag, bool* status) { return false; }
	};

	class DummyTag : public CompletionQueueTag {
	public:
	bool FinalizeResult(void** tag, bool* status) {
	*status = true;
	return true;
	}
	};

	class Server::SyncRequest final : public CompletionQueueTag {
	public:
	SyncRequest(RpcServiceMethod* method, void* tag)
	: method_(method),
	tag_(tag),
	in_flight_(false),
	has_request_payload_(method->method_type() == RpcMethod::NORMAL_RPC \|\|
	method->method_type() ==
	RpcMethod::SERVER_STREAMING),
	call_details_(nullptr),
	cq_(nullptr) {
	grpc_metadata_array_init(&request_metadata_);
	}

	~SyncRequest() {
	if (call_details_) {
	delete call_details_;
	}
	grpc_metadata_array_destroy(&request_metadata_);
	}

	void SetupRequest() { cq_ = grpc_completion_queue_create_for_pluck(nullptr); }

	void TeardownRequest() {
	grpc_completion_queue_destroy(cq_);
	cq_ = nullptr;
	}

	void Request(grpc_server* server, grpc_completion_queue* notify_cq) {
	GPR_ASSERT(cq_ && !in_flight_);
	in_flight_ = true;
	if (tag_) {
	if (GRPC_CALL_OK !=
	grpc_server_request_registered_call(
	server, tag_, &call_, &deadline_, &request_metadata_,
	has_request_payload_ ? &request_payload_ : nullptr, cq_,
	notify_cq, this)) {
	TeardownRequest();
	return;
	}
	} else {
	if (!call_details_) {
	call_details_ = new grpc_call_details;
	grpc_call_details_init(call_details_);
	}
	if (grpc_server_request_call(server, &call_, call_details_,
	&request_metadata_, cq_, notify_cq,
	this) != GRPC_CALL_OK) {
	TeardownRequest();
	return;
	}
	}
	}

	bool FinalizeResult(void** tag, bool* status) override {
	if (!*status) {
	grpc_completion_queue_destroy(cq_);
	}
	if (call_details_) {
	deadline_ = call_details_->deadline;
	grpc_call_details_destroy(call_details_);
	grpc_call_details_init(call_details_);
	}
	return true;
	}

	class CallData final {
	public:
	explicit CallData(Server* server, SyncRequest* mrd)
	: cq_(mrd->cq_),
	call_(mrd->call_, server, &cq_, server->max_receive_message_size()),
	ctx_(mrd->deadline_, &mrd->request_metadata_),
	has_request_payload_(mrd->has_request_payload_),
	request_payload_(mrd->request_payload_),
	method_(mrd->method_) {
	ctx_.set_call(mrd->call_);
	ctx_.cq_ = &cq_;
	GPR_ASSERT(mrd->in_flight_);
	mrd->in_flight_ = false;
	mrd->request_metadata_.count = 0;
	}

	~CallData() {
	if (has_request_payload_ && request_payload_) {
	grpc_byte_buffer_destroy(request_payload_);
	}
	}

	void Run(std::shared_ptr<GlobalCallbacks> global_callbacks) {
	ctx_.BeginCompletionOp(&call_);
	global_callbacks->PreSynchronousRequest(&ctx_);
	method_->handler()->RunHandler(
	MethodHandler::HandlerParameter(&call_, &ctx_, request_payload_));
	global_callbacks->PostSynchronousRequest(&ctx_);
	request_payload_ = nullptr;

	cq_.Shutdown();

	CompletionQueueTag* op_tag = ctx_.GetCompletionOpTag();
	cq_.TryPluck(op_tag, gpr_inf_future(GPR_CLOCK_REALTIME));

	/* Ensure the cq_ is shutdown */
	DummyTag ignored_tag;
	GPR_ASSERT(cq_.Pluck(&ignored_tag) == false);
	}

	private:
	CompletionQueue cq_;
	Call call_;
	ServerContext ctx_;
	const bool has_request_payload_;
	grpc_byte_buffer* request_payload_;
	RpcServiceMethod* const method_;
	};

	private:
	RpcServiceMethod* const method_;
	void* const tag_;
	bool in_flight_;
	const bool has_request_payload_;
	grpc_call* call_;
	grpc_call_details* call_details_;
	gpr_timespec deadline_;
	grpc_metadata_array request_metadata_;
	grpc_byte_buffer* request_payload_;
	grpc_completion_queue* cq_;
	};

	// Implementation of ThreadManager. Each instance of SyncRequestThreadManager
	// manages a pool of threads that poll for incoming Sync RPCs and call the
	// appropriate RPC handlers
	class Server::SyncRequestThreadManager : public ThreadManager {
	public:
	SyncRequestThreadManager(Server* server, CompletionQueue* server_cq,
	std::shared_ptr<GlobalCallbacks> global_callbacks,
	int min_pollers, int max_pollers,
	int cq_timeout_msec)
	: ThreadManager(min_pollers, max_pollers),
	server_(server),
	server_cq_(server_cq),
	cq_timeout_msec_(cq_timeout_msec),
	global_callbacks_(global_callbacks) {}

	WorkStatus PollForWork(void** tag, bool* ok) override {
	*tag = nullptr;
	gpr_timespec deadline =
	gpr_time_from_millis(cq_timeout_msec_, GPR_TIMESPAN);

	switch (server_cq_->AsyncNext(tag, ok, deadline)) {
	case CompletionQueue::TIMEOUT:
	return TIMEOUT;
	case CompletionQueue::SHUTDOWN:
	return SHUTDOWN;
	case CompletionQueue::GOT_EVENT:
	return WORK_FOUND;
	}

	GPR_UNREACHABLE_CODE(return TIMEOUT);
	}

	void DoWork(void* tag, bool ok) override {
	SyncRequest* sync_req = static_cast<SyncRequest*>(tag);

	if (!sync_req) {
	// No tag. Nothing to work on. This is an unlikley scenario and possibly a
	// bug in RPC Manager implementation.
	gpr_log(GPR_ERROR, "Sync server. DoWork() was called with NULL tag");
	return;
	}

	if (ok) {
	// Calldata takes ownership of the completion queue inside sync_req
	SyncRequest::CallData cd(server_, sync_req);
	// Prepare for the next request
	if (!IsShutdown()) {
	sync_req->SetupRequest(); // Create new completion queue for sync_req
	sync_req->Request(server_->c_server(), server_cq_->cq());
	}

	GPR_TIMER_SCOPE("cd.Run()", 0);
	cd.Run(global_callbacks_);
	}
	// TODO (sreek) If ok is false here (which it isn't in case of
	// grpc_request_registered_call), we should still re-queue the request
	// object
	}

	void AddSyncMethod(RpcServiceMethod* method, void* tag) {
	sync_requests_.emplace_back(new SyncRequest(method, tag));
	}

	void AddUnknownSyncMethod() {
	if (!sync_requests_.empty()) {
	unknown_method_.reset(new RpcServiceMethod(
	"unknown", RpcMethod::BIDI_STREAMING, new UnknownMethodHandler));
	sync_requests_.emplace_back(
	new SyncRequest(unknown_method_.get(), nullptr));
	}
	}

	void Shutdown() override {
	ThreadManager::Shutdown();
	server_cq_->Shutdown();
	}

	void Wait() override {
	ThreadManager::Wait();
	// Drain any pending items from the queue
	void* tag;
	bool ok;
	while (server_cq_->Next(&tag, &ok)) {
	// Do nothing
	}
	}

	void Start() {
	if (!sync_requests_.empty()) {
	for (auto m = sync_requests_.begin(); m != sync_requests_.end(); m++) {
	(*m)->SetupRequest();
	(*m)->Request(server_->c_server(), server_cq_->cq());
	}

	Initialize(); // ThreadManager's Initialize()
	}
	}

	private:
	Server* server_;
	CompletionQueue* server_cq_;
	int cq_timeout_msec_;
	std::vector<std::unique_ptr<SyncRequest>> sync_requests_;
	std::unique_ptr<RpcServiceMethod> unknown_method_;
	std::unique_ptr<RpcServiceMethod> health_check_;
	std::shared_ptr<Server::GlobalCallbacks> global_callbacks_;
	};

	static internal::GrpcLibraryInitializer g_gli_initializer;
	Server::Server(
	int max_receive_message_size, ChannelArguments* args,
	std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
	sync_server_cqs,
	int min_pollers, int max_pollers, int sync_cq_timeout_msec)
	: max_receive_message_size_(max_receive_message_size),
	sync_server_cqs_(sync_server_cqs),
	started_(false),
	shutdown_(false),
	shutdown_notified_(false),
	has_generic_service_(false),
	server_(nullptr),
	server_initializer_(new ServerInitializer(this)),
	health_check_service_disabled_(false) {
	g_gli_initializer.summon();
	gpr_once_init(&g_once_init_callbacks, InitGlobalCallbacks);
	global_callbacks_ = g_callbacks;
	global_callbacks_->UpdateArguments(args);

	for (auto it = sync_server_cqs_->begin(); it != sync_server_cqs_->end();
	it++) {
	sync_req_mgrs_.emplace_back(new SyncRequestThreadManager(
	this, (*it).get(), global_callbacks_, min_pollers, max_pollers,
	sync_cq_timeout_msec));
	}

	grpc_channel_args channel_args;
	args->SetChannelArgs(&channel_args);

	for (size_t i = 0; i < channel_args.num_args; i++) {
	if (0 ==
	strcmp(channel_args.args[i].key, kHealthCheckServiceInterfaceArg)) {
	if (channel_args.args[i].value.pointer.p == nullptr) {
	health_check_service_disabled_ = true;
	} else {
	health_check_service_.reset(static_cast<HealthCheckServiceInterface*>(
	channel_args.args[i].value.pointer.p));
	}
	break;
	}
	}

	server_ = grpc_server_create(&channel_args, nullptr);
	}

	Server::~Server() {
	{
	std::unique_lock<std::mutex> lock(mu_);
	if (started_ && !shutdown_) {
	lock.unlock();
	Shutdown();
	} else if (!started_) {
	// Shutdown the completion queues
	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->Shutdown();
	}
	}
	}

	grpc_server_destroy(server_);
	}

	void Server::SetGlobalCallbacks(GlobalCallbacks* callbacks) {
	GPR_ASSERT(!g_callbacks);
	GPR_ASSERT(callbacks);
	g_callbacks.reset(callbacks);
	}

	grpc_server* Server::c_server() { return server_; }

	std::shared_ptr<Channel> Server::InProcessChannel(
	const ChannelArguments& args) {
	grpc_channel_args channel_args = args.c_channel_args();
	return CreateChannelInternal(
	"inproc", grpc_inproc_channel_create(server_, &channel_args, nullptr));
	}

	static grpc_server_register_method_payload_handling PayloadHandlingForMethod(
	RpcServiceMethod* method) {
	switch (method->method_type()) {
	case RpcMethod::NORMAL_RPC:
	case RpcMethod::SERVER_STREAMING:
	return GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER;
	case RpcMethod::CLIENT_STREAMING:
	case RpcMethod::BIDI_STREAMING:
	return GRPC_SRM_PAYLOAD_NONE;
	}
	GPR_UNREACHABLE_CODE(return GRPC_SRM_PAYLOAD_NONE;);
	}

	bool Server::RegisterService(const grpc::string* host, Service* service) {
	bool has_async_methods = service->has_async_methods();
	if (has_async_methods) {
	GPR_ASSERT(service->server_ == nullptr &&
	"Can only register an asynchronous service against one server.");
	service->server_ = this;
	}

	const char* method_name = nullptr;
	for (auto it = service->methods_.begin(); it != service->methods_.end();
	++it) {
	if (it->get() == nullptr) { // Handled by generic service if any.
	continue;
	}

	RpcServiceMethod* method = it->get();
	void* tag = grpc_server_register_method(
	server_, method->name(), host ? host->c_str() : nullptr,
	PayloadHandlingForMethod(method), 0);
	if (tag == nullptr) {
	gpr_log(GPR_DEBUG, "Attempt to register %s multiple times",
	method->name());
	return false;
	}

	if (method->handler() == nullptr) { // Async method
	method->set_server_tag(tag);
	} else {
	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->AddSyncMethod(method, tag);
	}
	}

	method_name = method->name();
	}

	// Parse service name.
	if (method_name != nullptr) {
	std::stringstream ss(method_name);
	grpc::string service_name;
	if (std::getline(ss, service_name, '/') &&
	std::getline(ss, service_name, '/')) {
	services_.push_back(service_name);
	}
	}
	return true;
	}

	void Server::RegisterAsyncGenericService(AsyncGenericService* service) {
	GPR_ASSERT(service->server_ == nullptr &&
	"Can only register an async generic service against one server.");
	service->server_ = this;
	has_generic_service_ = true;
	}

	int Server::AddListeningPort(const grpc::string& addr,
	ServerCredentials* creds) {
	GPR_ASSERT(!started_);
	int port = creds->AddPortToServer(addr, server_);
	global_callbacks_->AddPort(this, addr, creds, port);
	return port;
	}

	void Server::Start(ServerCompletionQueue** cqs, size_t num_cqs) {
	GPR_ASSERT(!started_);
	global_callbacks_->PreServerStart(this);
	started_ = true;

	// Only create default health check service when user did not provide an
	// explicit one.
	if (health_check_service_ == nullptr && !health_check_service_disabled_ &&
	DefaultHealthCheckServiceEnabled()) {
	if (sync_server_cqs_->empty()) {
	gpr_log(GPR_INFO,
	"Default health check service disabled at async-only server.");
	} else {
	auto* default_hc_service = new DefaultHealthCheckService;
	health_check_service_.reset(default_hc_service);
	RegisterService(nullptr, default_hc_service->GetHealthCheckService());
	}
	}

	grpc_server_start(server_);

	if (!has_generic_service_) {
	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->AddUnknownSyncMethod();
	}

	for (size_t i = 0; i < num_cqs; i++) {
	if (cqs[i]->IsFrequentlyPolled()) {
	new UnimplementedAsyncRequest(this, cqs[i]);
	}
	}
	}

	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->Start();
	}
	}

	void Server::ShutdownInternal(gpr_timespec deadline) {
	std::unique_lock<std::mutex> lock(mu_);
	if (!shutdown_) {
	shutdown_ = true;

	/// The completion queue to use for server shutdown completion notification
	CompletionQueue shutdown_cq;
	ShutdownTag shutdown_tag; // Dummy shutdown tag
	grpc_server_shutdown_and_notify(server_, shutdown_cq.cq(), &shutdown_tag);

	shutdown_cq.Shutdown();

	void* tag;
	bool ok;
	CompletionQueue::NextStatus status =
	shutdown_cq.AsyncNext(&tag, &ok, deadline);

	// If this timed out, it means we are done with the grace period for a clean
	// shutdown. We should force a shutdown now by cancelling all inflight calls
	if (status == CompletionQueue::NextStatus::TIMEOUT) {
	grpc_server_cancel_all_calls(server_);
	}
	// Else in case of SHUTDOWN or GOT_EVENT, it means that the server has
	// successfully shutdown

	// Shutdown all ThreadManagers. This will try to gracefully stop all the
	// threads in the ThreadManagers (once they process any inflight requests)
	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->Shutdown(); // ThreadManager's Shutdown()
	}

	// Wait for threads in all ThreadManagers to terminate
	for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
	(*it)->Wait();
	}

	// Drain the shutdown queue (if the previous call to AsyncNext() timed out
	// and we didn't remove the tag from the queue yet)
	while (shutdown_cq.Next(&tag, &ok)) {
	// Nothing to be done here. Just ignore ok and tag values
	}

	shutdown_notified_ = true;
	shutdown_cv_.notify_all();
	}
	}

	void Server::Wait() {
	std::unique_lock<std::mutex> lock(mu_);
	while (started_ && !shutdown_notified_) {
	shutdown_cv_.wait(lock);
	}
	}

	void Server::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) {
	static const size_t MAX_OPS = 8;
	size_t nops = 0;
	grpc_op cops[MAX_OPS];
	ops->FillOps(call->call(), cops, &nops);
	auto result = grpc_call_start_batch(call->call(), cops, nops, ops, nullptr);
	if (result != GRPC_CALL_OK) {
	gpr_log(GPR_ERROR, "Fatal: grpc_call_start_batch returned %d", result);
	grpc_call_log_batch(__FILE__, __LINE__, GPR_LOG_SEVERITY_ERROR,
	call->call(), cops, nops, ops);
	abort();
	}
	}

	ServerInterface::BaseAsyncRequest::BaseAsyncRequest(
	ServerInterface* server, ServerContext* context,
	ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag,
	bool delete_on_finalize)
	: server_(server),
	context_(context),
	stream_(stream),
	call_cq_(call_cq),
	tag_(tag),
	delete_on_finalize_(delete_on_finalize),
	call_(nullptr) {
	call_cq_->RegisterAvalanching(); // This op will trigger more ops
	}

	ServerInterface::BaseAsyncRequest::~BaseAsyncRequest() {
	call_cq_->CompleteAvalanching();
	}

	bool ServerInterface::BaseAsyncRequest::FinalizeResult(void** tag,
	bool* status) {
	if (*status) {
	context_->client_metadata_.FillMap();
	}
	context_->set_call(call_);
	context_->cq_ = call_cq_;
	Call call(call_, server_, call_cq_, server_->max_receive_message_size());
	if (*status && call_) {
	context_->BeginCompletionOp(&call);
	}
	// just the pointers inside call are copied here
	stream_->BindCall(&call);
	*tag = tag_;
	if (delete_on_finalize_) {
	delete this;
	}
	return true;
	}

	ServerInterface::RegisteredAsyncRequest::RegisteredAsyncRequest(
	ServerInterface* server, ServerContext* context,
	ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag)
	: BaseAsyncRequest(server, context, stream, call_cq, tag, true) {}

	void ServerInterface::RegisteredAsyncRequest::IssueRequest(
	void* registered_method, grpc_byte_buffer** payload,
	ServerCompletionQueue* notification_cq) {
	GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_registered_call(
	server_->server(), registered_method, &call_,
	&context_->deadline_,
	context_->client_metadata_.arr(), payload,
	call_cq_->cq(), notification_cq->cq(), this));
	}

	ServerInterface::GenericAsyncRequest::GenericAsyncRequest(
	ServerInterface* server, GenericServerContext* context,
	ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq,
	ServerCompletionQueue* notification_cq, void* tag, bool delete_on_finalize)
	: BaseAsyncRequest(server, context, stream, call_cq, tag,
	delete_on_finalize) {
	grpc_call_details_init(&call_details_);
	GPR_ASSERT(notification_cq);
	GPR_ASSERT(call_cq);
	GPR_ASSERT(GRPC_CALL_OK == grpc_server_request_call(
	server->server(), &call_, &call_details_,
	context->client_metadata_.arr(), call_cq->cq(),
	notification_cq->cq(), this));
	}

	bool ServerInterface::GenericAsyncRequest::FinalizeResult(void** tag,
	bool* status) {
	// TODO(yangg) remove the copy here.
	if (*status) {
	static_cast<GenericServerContext*>(context_)->method_ =
	StringFromCopiedSlice(call_details_.method);
	static_cast<GenericServerContext*>(context_)->host_ =
	StringFromCopiedSlice(call_details_.host);
	context_->deadline_ = call_details_.deadline;
	}
	grpc_slice_unref(call_details_.method);
	grpc_slice_unref(call_details_.host);
	return BaseAsyncRequest::FinalizeResult(tag, status);
	}

	bool Server::UnimplementedAsyncRequest::FinalizeResult(void** tag,
	bool* status) {
	if (GenericAsyncRequest::FinalizeResult(tag, status) && *status) {
	new UnimplementedAsyncRequest(server_, cq_);
	new UnimplementedAsyncResponse(this);
	} else {
	delete this;
	}
	return false;
	}

	Server::UnimplementedAsyncResponse::UnimplementedAsyncResponse(
	UnimplementedAsyncRequest* request)
	: request_(request) {
	Status status(StatusCode::UNIMPLEMENTED, "");
	UnknownMethodHandler::FillOps(request_->context(), this);
	request_->stream()->call_.PerformOps(this);
	}

	ServerInitializer* Server::initializer() { return server_initializer_.get(); }

	} // namespace grpc