1 /* 2 * Copyright (c) 2021 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 #ifndef THREAD_POOL_H 16 #define THREAD_POOL_H 17 18 #include "nocopyable.h" 19 20 #include <thread> 21 #include <mutex> 22 #include <functional> 23 #include <string> 24 #include <condition_variable> 25 #include <deque> 26 #include <vector> 27 28 namespace OHOS { 29 30 const int INVALID_SEMA_VALUE = -1; 31 32 class ThreadPool : public NoCopyable { 33 public: 34 typedef std::function<void()> Task; 35 36 explicit ThreadPool(const std::string &name = std::string()); 37 ~ThreadPool(); 38 39 uint32_t Start(int threadsNum); 40 void Stop(); 41 void AddTask(const Task& f); SetMaxTaskNum(int maxSize)42 void SetMaxTaskNum(int maxSize) { maxTaskNum_ = maxSize; } 43 44 // for testability GetMaxTaskNum()45 size_t GetMaxTaskNum() const { return maxTaskNum_; } 46 size_t GetCurTaskNum(); GetThreadsNum()47 size_t GetThreadsNum() const { return threads_.size(); } GetName()48 std::string GetName() const { return myName_; } 49 50 private: 51 // tasks in the queue reach the maximum set by maxQueueSize, means thread pool is full load. 52 bool Overloaded() const; 53 void WorkInThread(); // main function in each thread. 54 Task ScheduleTask(); // fetch a task from the queue and execute 55 56 private: 57 std::string myName_; 58 std::mutex mutex_; 59 std::condition_variable hasTaskToDo_; 60 std::condition_variable acceptNewTask_; 61 std::vector<std::thread> threads_; 62 std::deque<Task> tasks_; 63 size_t maxTaskNum_; 64 bool running_; 65 }; 66 67 } // namespace OHOS 68 69 #endif 70 71