c++ - QThread内存泄漏

Question

主要.cpp:

#include <QCoreApplication>
#include <QtCore>
#include "myobject.h"

QThread* cThread;
MyObject* cObject;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    cThread = new QThread();
    cObject = new MyObject();
    cObject->moveToThread(cThread);

    QObject::connect(cThread, SIGNAL(started()),
                     cObject, SLOT(doWork()));

    QObject::connect(cThread, SIGNAL(finished()),
                     cThread, SLOT(deleteLater()));

    QObject::connect(cThread, SIGNAL(finished()),
                     cObject, SLOT(deleteLater()));

    cThread->start();

    return a.exec();
}

我的对象.cpp:

#include "myobject.h"

MyObject::MyObject(QObject *parent) :
    QObject(parent)
{
}

void MyObject::doWork()
{
    qDebug() << "Hi";
    QThread::currentThread()->quit();
    return;
}

我的对象.h:

#ifndef MYOBJECT_H
#define MYOBJECT_H

#include <QtCore>

class MyObject : public QObject
{
    Q_OBJECT
public:
    explicit MyObject(QObject *parent = 0);

signals:

public slots:
    void doWork();

};

#endif // MYOBJECT_H

显然，根据:https://stackoverflow.com/a/16062717 , 有内存泄漏，但我该如何解决呢？我想我必须返回到事件循环然后调用退出？但问题是我无权访问事件循环。

Answer 1

没有内存泄漏。如果您坚持其 object model，Qt 确实会正确清理, 和 object trees and ownership .我也喜欢关注 documented examples .

这是您引用的示例，在 deleteLater() 上添加了观察。

主要.cpp

#include <QCoreApplication>
#include <QtCore>
#include <QThread>

class MyThread : public QThread
{
    Q_OBJECT
public slots:
    void deleteLater()
    {
        qDebug() << Q_FUNC_INFO;
        QThread::deleteLater();
    }
};


class MyObject : public QObject
{
    Q_OBJECT
public:
    explicit MyObject(QObject *parent = 0){}

signals:

public slots:
    void deleteLater()
    {
        qDebug() << Q_FUNC_INFO;
        QObject::deleteLater();
    }

    void doWork()
    {
        qDebug() << "Hi";
        QThread::currentThread()->quit(); // It is supposed to stop here, but it doesn't.
        return;
        for (int i = 0; i < 1000000; i++) {
            qDebug() << i;
        }
    }

};

QThread* cThread;
MyObject* cObject;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    cThread = new MyThread();
    cObject = new MyObject();
    cObject->moveToThread(cThread);

    QObject::connect(cThread, SIGNAL(started()),
                     cObject, SLOT(doWork()));

    QObject::connect(cThread, SIGNAL(finished()),
                     cThread, SLOT(deleteLater()));

    QObject::connect(cThread, SIGNAL(finished()),
                     cObject, SLOT(deleteLater()));

    cThread->start();

    return a.exec();
}

输出:

Hi
void __thiscall MyObject::deleteLater(void)
void __thiscall MyThread::deleteLater(void)

希望对您有所帮助。