Remove async grpc helper (7b65a503) · Commits · e / os / android_packages_modules_Bluetooth

system/gd/grpc/async_grpc.h

deleted100644 → 0

+0 −165

Original line number	Diff line number	Diff line
		/*
		* Copyright 2019 The Android Open Source Project
		*
		* 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.
		*/

		#pragma once

		#include <functional>
		#include <future>
		#include <memory>
		#include <mutex>

		#include <grpc++/grpc++.h>

		#include "os/log.h"

		namespace bluetooth {
		namespace grpc {

		// To be passed to gRPC async invocations as tag.
		// Function is called when the CompletionQueue.Next() returns this tag.
		// Then, user needs to delete this object.
		using GrpcAsyncEventCallback = std::function<void(bool)>;

		template <typename REQ, typename RES>
		class GrpcAsyncServerStreamingHandler {
		public:
		virtual ~GrpcAsyncServerStreamingHandler() = default;

		// Implementation for requesting the next specific type RPC, using provided parameters.
		virtual void OnReadyForNextRequest(::grpc::ServerContext, REQ req, ::grpc::ServerAsyncWriter<RES>* res,
		::grpc::CompletionQueue* new_call_cq,
		::grpc::ServerCompletionQueue* notification_cq, void* tag) = 0;

		virtual void OnRpcRequestReceived(REQ req) = 0;

		virtual void OnRpcRequestFailed() {}

		virtual void OnRpcFinished() {}

		virtual void OnWriteSuccess() {}
		};

		// Provides API to upper layer users to control (request, write, finish) a server-streaming asynchronous RPC.
		// When each API is done, callback will be sent to the given GrpcAsyncServerStreamingHandler.
		// Each control box can take one active RPC at one time.

		// TODO: problems with this control box:
		// 1. RequestNewRpc is async, but Write and Stop is blocking users. Do we want to do this?
		// 2. Callback to user is done in the gRPC thread. Let's create a pool thread to give it to user?
		// 3. Currently it uses promise to synchronize between events. If we use os/handler it should be easier.
		template <typename REQ, typename RES>
		class GrpcAsyncServerStreamingControlBox {
		public:
		GrpcAsyncServerStreamingControlBox(GrpcAsyncServerStreamingHandler<REQ, RES>* async_handler,
		::grpc::ServerCompletionQueue* cq)
		: async_handler_(async_handler), cq_(cq) {}

		void RequestNewRpc() {
		ASSERT(my_state_ == MyState::IDLE);
		context_ = std::make_unique<::grpc::ServerContext>();
		req_ = std::make_unique<REQ>();
		res_ = std::make_unique<::grpc::ServerAsyncWriter<RES>>(context_.get());
		request_done_ = std::make_unique<GrpcAsyncEventCallback>([this](bool ok) { this->RequestDone(ok); });
		async_handler_->OnReadyForNextRequest(context_.get(), req_.get(), res_.get(), cq_, cq_, request_done_.get());
		my_state_ = MyState::REQUESTING;
		}

		void Write(const RES& res) {
		std::unique_lock<std::mutex> lock(mutex_);
		if (my_state_ == MyState::IDLE \|\| my_state_ == MyState::REQUESTING) {
		LOG_INFO("stream already stopped");
		return;
		}
		ASSERT(my_state_ == MyState::OPEN);
		write_done_ = std::make_unique<GrpcAsyncEventCallback>([this](bool ok) { this->WriteDone(ok); });
		my_state_ = MyState::WRITING;
		res_->Write(res, write_done_.get());
		promise_ = new std::promise<void>();
		auto future = promise_->get_future();
		future.wait();
		}

		void StopStreaming() {
		std::unique_lock<std::mutex> lock(mutex_);
		ASSERT(my_state_ == MyState::OPEN);
		rpc_finish_ = std::make_unique<GrpcAsyncEventCallback>([this](bool ok) { this->RpcFinish(ok); });
		my_state_ = MyState::FINISHING;
		res_->Finish(::grpc::Status::OK, rpc_finish_.get());
		promise_ = new std::promise<void>();
		auto future = promise_->get_future();
		future.wait();
		}

		private:
		void RequestDone(bool ok) {
		ASSERT(my_state_ == MyState::REQUESTING);
		if (ok) {
		async_handler_->OnRpcRequestReceived(*req_);
		my_state_ = MyState::OPEN;
		} else {
		clean_up();
		async_handler_->OnRpcRequestFailed();
		my_state_ = MyState::IDLE;
		}
		}

		void WriteDone(bool ok) {
		ASSERT(my_state_ == MyState::WRITING);
		if (ok) {
		my_state_ = MyState::OPEN;
		async_handler_->OnWriteSuccess();
		} else {
		clean_up();
		my_state_ = MyState::IDLE;
		async_handler_->OnRpcFinished();
		}
		promise_->set_value();
		}

		void RpcFinish(bool ok) {
		ASSERT(ok);
		ASSERT(my_state_ == MyState::FINISHING);
		clean_up();
		my_state_ = MyState::IDLE;
		async_handler_->OnRpcFinished();
		promise_->set_value();
		}

		void clean_up() {
		context_ = nullptr;
		req_ = nullptr;
		res_ = nullptr;
		}

		mutable std::mutex mutex_;
		std::promise<void>* promise_ = nullptr;

		GrpcAsyncServerStreamingHandler<REQ, RES>* async_handler_;
		::grpc::ServerCompletionQueue* cq_;

		std::unique_ptr<::grpc::ServerContext> context_ = nullptr;
		std::unique_ptr<REQ> req_ = nullptr;
		std::unique_ptr<::grpc::ServerAsyncWriter<RES>> res_ = nullptr;

		std::unique_ptr<GrpcAsyncEventCallback> request_done_ = nullptr;
		std::unique_ptr<GrpcAsyncEventCallback> write_done_ = nullptr;
		std::unique_ptr<GrpcAsyncEventCallback> rpc_finish_ = nullptr;

		enum class MyState { IDLE, REQUESTING, OPEN, WRITING, FINISHING } my_state_ = MyState::IDLE;
		};

		} // namespace grpc
		} // namespace bluetooth

system/gd/grpc/grpc_module.cc

+1 −4

Original line number	Diff line number	Diff line
		@@ -17,7 +17,6 @@
		#include "grpc/grpc_module.h"

		#include "os/log.h"
		#include "grpc/async_grpc.h"

		using ::grpc::Server;
		using ::grpc::ServerBuilder;
		@@ -53,7 +52,7 @@ void GrpcModule::StartServer(const std::string& address, int port) {
		ASSERT(server_ != nullptr);

		for (const auto& facade : facades_) {
		facade->OnServerStarted(completion_queue_.get());
		facade->OnServerStarted();
		}
		}

		@@ -97,8 +96,6 @@ void GrpcModule::RunGrpcLoop() {
		LOG_INFO("gRPC is shutdown");
		break;
		}
		auto* data = static_cast<GrpcAsyncEventCallback*>(tag);
		(*data)(ok);
		}
		}

system/gd/grpc/grpc_module.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -69,7 +69,7 @@ class GrpcFacadeModule : public ::bluetooth::Module {

		virtual ::grpc::Service* GetService() const = 0;

		virtual void OnServerStarted(::grpc::ServerCompletionQueue* cq) {}
		virtual void OnServerStarted() {}

		virtual void OnServerStopped() {}