Qt线程(4) 降低线程占用CPU

• 问题描述：

　　　　一般将计算量大的处理过程单独放置到一个单独的线程处理，因此很有可能你的处理过程需要while(1)或类似的操作。

　　也因此很有可能造成线程在处理时计算机CPU占用过高的情况。

• 解决办法：
  • 降低相应线程优先级
  • sleep

• 具体实现：

　　　　1.创建工作线程

 1 #include <QThread>
 2 #include <QDebug>
 3 #include <QMutex>
 4 #include <QMutexLocker>
 5
 6 #include <unistd.h>
 7
 8 class WorkThread : public QThread
 9 {
10     Q_OBJECT
11 public:
12     explicit WorkThread(QObject *parent = 0):
13         QThread(parent)
14       ,m_bStop(false)
15       ,m_iTest(0)
16     {}
17
18     ~WorkThread()
19     {
20         wait();
21     }
22
23     void stop()
24     {
25         QMutexLocker Locker(&m_mutexLock);
26         m_bStop = true;
27     }
28
29 protected:
30     void run()
31     {
32         do{
33             m_iTest++;
34             emit sigFind(QString::number(m_iTest));
35             sleep(10);//::sleep(10);
36         }while(!m_bStop);
37     }
38
39 signals:
40     void sigFind(const QString &);
41
42 private:
43     bool m_bStop;
44     int m_iTest;
45     QMutex m_mutexLock;
46 };

　　　　2.创建工作对象

 1 #include <QObject>
 2 #include <QDateTime>
 3 #include <QTimerEvent>
 4 #include <QCoreApplication>
 5
 6 #include "workthread.hpp"
 7
 8 class WorkObject : public QObject
 9 {
10     Q_OBJECT
11
12 private:
13     int m_iTimerId_PrintTime;
14     WorkThread *m_threadWork;
15
16 public:
17     explicit WorkObject(QObject *parent = 0):
18         QObject(parent)
19       ,m_iTimerId_PrintTime(-1)
20       ,m_threadWork(0)
21     {
22         //Timer
23         m_iTimerId_PrintTime = startTimer(1000);//print current time: yyyy-MM-dd hh:mm:ss
24
25         // WorkThread
26         m_threadWork = new WorkThread(this);
27         connect(m_threadWork,SIGNAL(sigFind(QString)),this,SLOT(slotFind(QString)));
28         connect(m_threadWork,SIGNAL(finished()),m_threadWork,SLOT(deleteLater()));
29
30         m_threadWork->start();
31     }
32
33     ~WorkObject()
34     {
35         if(m_threadWork)
36             m_threadWork->stop();
37     }
38
39 protected:
40     void timerEvent(QTimerEvent *event)
41     {
42         if(event->timerId() == m_iTimerId_PrintTime)
43         {
44             qDebug()<<QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss");
45         }
46     }
47
48
49 private slots:
50     void slotFind(const QString &s)
51     {
52         qDebug()<<"Find:"<<s;
53     }
54 };

　　　　3.main.cpp

 1 #include <QTimer>
 2 #include <QtCore/QCoreApplication>
 3
 4 #include "workobject.hpp"
 5
 6 int main(int argc, char *argv[])
 7 {
 8     QCoreApplication a(argc, argv);
 9     WorkObject worker;
10
11     QTimer::singleShot(10000, &a, SLOT(quit()));
12     return a.exec();
13 }

　　　　4.执行结果

• 最后：你懂滴,sleep会降低速度...所以测试一下,使用较低优先级或许就可以满足您的要求了呢~~