How can multiple threads have the same thread ID?

[deleted286]

Hi. I have 2 different threads in my program. I've write it in both threads:

qDebug() << "im running on gui thread " << GetCurrentThreadId();

It gives me the same id. Shouldn't it have given different ids?

[KroMignon]

@suslucoder said in How can multiple threads have the same thread ID?:

Shouldn't it have given different ids?

Are you really sure the code is executed in different threads?

[deleted286]

@KroMignon I'm sure but if it has to be give different id's, i will review it

myThreadObject = new MyThread();
    myQThread = new QThread();

    myThreadObject->moveToThread(myQThread);

    connect(this, SIGNAL(startWriting()),myThreadObject, SLOT(writeData()));
    connect(myThreadObject, SIGNAL(writingDone()), this, SLOT(writingDoneByThread()));

    // Start the new thread
    myQThread->start();
}

Because of I moved my thread, is it normal to get same id?

[jsulm]

@suslucoder Where and when do you check the thread id?

[KroMignon]

@suslucoder said in How can multiple threads have the same thread ID?:

connect(myThreadObject, SIGNAL(writingDone()), this, SLOT(writingDoneByThread()));

If the check is done in writingDoneByThread() , this will be executed in the thread used by this, not from emitter thread (in which myThreadObject is running).

[deleted286]

@jsulm the first one is main.cpp, which I learned it is the main thread. Like;

qDebug() << "im running on gui thread " << GetCurrentThreadId();

The second one is here:

mythread.cpp

void mythread::writeData()
{
    QFile::copy("C:/Users/ilknu/Documents/ThreadExample/read.txt", "C:/Users/ilknu/Documents/ThreadExample/write.txt" );
    QFile file2("C:/Users/ilknu/Documents/ThreadExample/write.txt");
    if(file.open(QIODevice::ReadOnly)) {
        QTextStream in(&file);
        while (!in.atEnd())
        {
            QString line2=in.readLine();
            QStringList list2 = line2.split(QLatin1Char(' '), Qt::SkipEmptyParts);
            for(const QString &entry : list2)
            {
                double num = entry.toDouble();
                queue.enqueue(num);
                qDebug() << num;
            }
        }
    }
    qDebug() << "Source exists?" << QFile::exists("C:/Users/ilknu/Documents/ThreadExample/deneme.txt");
    qDebug() << "Destination exists?" << QFile::exists("C:/Users/ilknu/Documents/ThreadExample/write.txt");
    **qDebug() << "im working in writing thread" << GetCurrentThreadId() ;**

    emit writingDone();
}

[deleted286]

@KroMignon I will fix it thank you