1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPC_INTERNAL_CPP_DYNAMIC_THREAD_POOL_H 20 #define GRPC_INTERNAL_CPP_DYNAMIC_THREAD_POOL_H 21 22 #include <condition_variable> 23 #include <list> 24 #include <memory> 25 #include <mutex> 26 #include <queue> 27 28 #include <grpcpp/support/config.h> 29 30 #include "src/core/lib/gprpp/thd.h" 31 #include "src/cpp/server/thread_pool_interface.h" 32 33 namespace grpc { 34 35 class DynamicThreadPool final : public ThreadPoolInterface { 36 public: 37 explicit DynamicThreadPool(int reserve_threads); 38 ~DynamicThreadPool(); 39 40 void Add(const std::function<void()>& callback) override; 41 42 private: 43 class DynamicThread { 44 public: 45 DynamicThread(DynamicThreadPool* pool); 46 ~DynamicThread(); 47 48 private: 49 DynamicThreadPool* pool_; 50 grpc_core::Thread thd_; 51 void ThreadFunc(); 52 }; 53 std::mutex mu_; 54 std::condition_variable cv_; 55 std::condition_variable shutdown_cv_; 56 bool shutdown_; 57 std::queue<std::function<void()>> callbacks_; 58 int reserve_threads_; 59 int nthreads_; 60 int threads_waiting_; 61 std::list<DynamicThread*> dead_threads_; 62 63 void ThreadFunc(); 64 static void ReapThreads(std::list<DynamicThread*>* tlist); 65 }; 66 67 } // namespace grpc 68 69 #endif // GRPC_INTERNAL_CPP_DYNAMIC_THREAD_POOL_H 70