C++11中std::thread线程实现暂停(挂起)功能

本文主要介绍了C++11中std::thread线程实现暂停(挂起)功能，文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值，需要的朋友们下面随着小编来一起学习学习吧

一、封装Thread类

我们基于C++11中与平台无关的线程类std::thread，封装Thread类，并提供start()、stop()、pause()、resume()线程控制方法。

为了让线程在暂停期间，处于休眠，不消耗CPU，我们使用C++11提供的锁和条件变量来实现。

std::mutex
std::condition_variable

Thread.h

#ifndef THREAD_H #define THREAD_H #include  #include  #include  #include  class Thread { public:     Thread();     virtual ~Thread();     enum State     {         Stoped,     ///<停止状态，包括从未启动过和启动后被停止         Running,    ///<运行状态         Paused      ///<暂停状态     };     State state() const;     void start();     void stop();     void pause();     void resume(); protected:     virtual void process() = 0; private:     void run(); private:     std::thread* _thread;     std::mutex _mutex;     std::condition_variable _condition;     std::atomic_bool _pauseFlag;   ///<暂停标识     std::atomic_bool _stopFlag;   ///<停止标识     State _state; }; #endif // THREAD_H

Thread.cpp

#include "Thread.h" #include  using namespace std; Thread::Thread()     : _thread(nullptr),       _pauseFlag(false),       _stopFlag(false),       _state(Stoped) { } Thread::~Thread() {     stop(); } Thread::State Thread::state() const {     return _state; } void Thread::start() {     if (_thread == nullptr)     {         _thread = new thread(&Thread::run, this);         _pauseFlag = false;         _stopFlag = false;         _state = Running;     } } void Thread::stop() {     if (_thread != nullptr)     {         _pauseFlag = false;         _stopFlag = true;         _condition.notify_all();  // Notify one waiting thread, if there is one.         _thread->join(); // wait for thread finished         delete _thread;         _thread = nullptr;         _state = Stoped;     } } void Thread::pause() {     if (_thread != nullptr)     {         _pauseFlag = true;         _state = Paused;     } } void Thread::resume() {     if (_thread != nullptr)     {         _pauseFlag = false;         _condition.notify_all();         _state = Running;     } } void Thread::run() {     cout << "enter thread:" << this_thread::get_id() << endl;     while (!_stopFlag)     {         process();         if (_pauseFlag)         {             unique_lock locker(_mutex);             while (_pauseFlag)             {                 _condition.wait(locker); // Unlock _mutex and wait to be notified             }             locker.unlock();         }     }     _pauseFlag = false;     _stopFlag = false;     cout << "exit thread:" << this_thread::get_id() << endl; }

二、测试代码

main.cpp

#include  #include  #include "Thread.h" using namespace std; void mySleep(int s) {     std::this_thread::sleep_for(std::chrono::duration(s)); } class MyThread : public Thread { protected:     virtual void process() override     {         cout << "do my something" << endl;         mySleep(1);     } }; int main(int argc, char *argv[]) {     QCoreApplication a(argc, argv);     MyThread thread;     cout << "start thread" << endl;     thread.start();     cout << "thread state:" << thread.state() << endl;     mySleep(3);     cout << "pause thread" << endl;     thread.pause();     cout << "thread state:" << thread.state() << endl;     mySleep(3);     cout << "resume thread" << endl;     thread.resume();     cout << "thread state:" << thread.state() << endl;     mySleep(3);     cout << "stop thread" << endl;     thread.stop();     cout << "thread state:" << thread.state() << endl;     mySleep(3);     return a.exec(); }

运行结果：