QT 线程退出的几种方式

QTread 退出，可以几种方式，使用变量； 也可以使用 QWaitCondition；

1. 使用变量 ，外部将变量置为 false

#define WORKOBJECT_H


#include <QObject>
#include <QThread>
#include <QDebug>

#include<QMutexLocker>
#include<QMutex>
#include<QWaitCondition>

class WorkObject : public QObject
{

  Q_OBJECT
public:
     explicit WorkObject(QObject *parent = nullptr);

signals:

public slots:
    void doWork();

    void stopWork();
private:
    bool exitflag;

    QWaitCondition mWaitStatusCondition;
    QMutex mWaitMutex;
};

#endif // WORKOBJECT_H

cpp

#include "workobject.h"

WorkObject::WorkObject(QObject *parent) : QObject(parent)
{

}
void WorkObject::doWork()
{
  
    while(true)
    {
        QMutexLocker locker(&mWaitMutex);
        if(!exitflag)
        {
            qDebug() << "MyThread eixt ================  :" ;
            return;
        }
      //  if(mWaitStatusCondition.wait(&mWaitMutex,1))
       // {
      //    qDebug() << "MyThread eixt ================  :" ;
       //   return;
       // }

        qDebug() << "MyThread thread id:" << QThread::currentThreadId();
        //sleep(10);
        //QThread::sleep(1);
    }

    qDebug() << "doWork thread exit========:" << QThread::currentThreadId();
}

void WorkObject::stopWork()
{
    QMutexLocker locker(&mWaitMutex);
   {
      exitflag = false;
     //   mWaitStatusCondition.wakeAll();
  
   }
}

2. 也可以使用 QWaitCondition

QWaitCondition最大的好处，我以为，是能在一个线程中唤醒一个或多个其它线程，固然前提是，其它线程在等待某个QWaitCondition，不然不起做用，你唤醒也没用。QWaitCondition必须与QMutex或者QReadwriteLock一块儿用

 mWaitStatusCondition.wakeAll();

#include "workobject.h"

WorkObject::WorkObject(QObject *parent) : QObject(parent)
{

}
void WorkObject::doWork()
{
  
    while(true)
    {
        QMutexLocker locker(&mWaitMutex);
        if(!exitflag)
        {
            return;
        }
        if(mWaitStatusCondition.wait(&mWaitMutex,1))
        {
          qDebug() << "MyThread eixt ================  :" ;
          return;
        }

        qDebug() << "MyThread thread id:" << QThread::currentThreadId();
        //sleep(10);
        //QThread::sleep(1);
    }

    qDebug() << "doWork thread exit========:" << QThread::currentThreadId();
}

void WorkObject::stopWork()
{
    QMutexLocker locker(&mWaitMutex);
   {
      //exitflag = false;
        mWaitStatusCondition.wakeAll();
  
   }
}