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 16 #ifndef TASK_POOL_IMPL_H 17 #define TASK_POOL_IMPL_H 18 19 #include <condition_variable> 20 #include <map> 21 #include <mutex> 22 #include <string> 23 #include <thread> 24 25 #include "task_pool.h" 26 #include "task_queue.h" 27 28 namespace DistributedDB { 29 class TaskPoolImpl : public TaskPool { 30 public: 31 // maxThreads > 0. 32 TaskPoolImpl(int maxThreads, int minThreads); 33 34 // Start the task pool. 35 int Start() override; 36 37 // Stop the task pool. 38 void Stop() override; 39 40 // Schedule a task, the task can be ran in any thread. 41 int Schedule(const Task &task) override; 42 43 // Schedule tasks one by one. 44 int Schedule(const std::string &queueTag, const Task &task) override; 45 46 // Shrink memory associated with the given tag if possible. 47 void ShrinkMemory(const std::string &tag) override; 48 49 protected: 50 ~TaskPoolImpl(); 51 52 private: 53 int SpawnThreads(bool isStart); 54 bool IdleExit(std::unique_lock<std::mutex> &lock); 55 void SetThreadFree(); 56 Task ReapTask(TaskQueue *&queue); 57 int GetTask(Task &task, TaskQueue *&queue); 58 bool IsGenericWorker() const; 59 void BecomeGenericWorker(); 60 void ExitWorker(); 61 void TaskWorker(); 62 void FinishExecuteTask(TaskQueue *taskQueue); 63 void TryToSpawnThreads(); 64 65 // Member Variables. 66 static constexpr int IDLE_WAIT_PERIOD = 1; // wait 1 second before exiting. 67 std::mutex tasksMutex_; 68 std::condition_variable hasTasks_; 69 std::map<std::string, TaskQueue> queuedTasks_; 70 TaskQueue genericTasks_; 71 std::thread::id genericThread_; // execute generic task only. 72 int genericTaskCount_; 73 int queuedTaskCount_; 74 bool isStarted_; 75 bool isStopping_; // Stop() invoked. 76 std::condition_variable allThreadsExited_; 77 78 // Thread counter. 79 int maxThreads_; 80 int minThreads_; 81 int curThreads_; 82 int idleThreads_; 83 }; 84 } // namespace DistributedDB 85 86 #endif // TASK_POOL_IMPL_H 87