Can't receive signal from another thread.

[useryy]

Can't receive signal from another thread as following.
Using connect type as Qt::BlockingQueuedConnection, the thread blocks. But signal not received.

main.cpp


#include "myclass.h"




int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);


MyClass myClass;
myClass.startAll();

return a.exec();
}


thread.h


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

#include <QDebug>



class Thread1 : public QThread
{
Q_OBJECT
public:
void run( void )
{
qDebug() << "thread 1 started";
int i = 0;
while(1)
{
msleep( 10 );
i++;
qDebug() << "i is: " + QString::number(i);
if(i==1000)
{
qDebug() << "Got I";
emit MyThread1Signal();
exit();
}
}
}
signals:
void MyThread1Signal();
};





myclass.cpp


MyClass::MyClass(QObject *parent) :
QObject(parent)
{
thread1 = new Thread1();
connect(thread1, SIGNAL(MyThread1Signal()), this, SLOT(myClassSlot1()), Qt::BlockingQueuedConnection);
}


void MyClass::startAll()
{
thread1->start();
thread1->wait();
}


void MyClass::myClassSlot1()
{
qDebug()<<"Signal received";
}


myclass.h


#ifndef MYCLASS_H
#define MYCLASS_H

#include <QObject>

#include "threads.h"

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

void startAll();

signals:

public slots:
void myClassSlot1();

private:
Thread1* thread1;
};

#endif // MYCLASS_H

[Lesiok]

Because You never launch main event loop. Why wait for the end of the second thread in the method MyClass::startAll calling thread1->wait() ?

[useryy]

Hi,

For It needs not receive any event in thread, so I don't think exec() is required.


Remove wait(), it is ok. It's this wait() that makes the thread never give up execution. Right?

Please correct me if my understanding is wrong.

[Lesiok]

Yes, a problem is wait(). But I'm talking about main exec. You have a connection with attribute Qt::BlockingQueuedConnection. This means that the event is delivered through the recipient's message queue thread. This is not the same as Qt:: DirectConnection.