Signals / Slots increase the memory usage with Qt::QueuedConnection

[h0nki]

Hello,
first of all i want to say hello to this great forum

Here my problem (I tried to find it on the internet, but I did not have luck):

If i connect a simple slot (only writes a string on the console) to a signals and emit this signal a lot of times, the program's memory usage increases.
But only, if i connect the signal to the slot with Qt::QueuedConnection. If it is direct connected, the memory sticks at the same size, as if i would never emit the signal.
Why does this happens?
Thank you and good night

Here my code:

main.cpp

#include <QtCore/QCoreApplication>
#include "a.h"
 
int main(int argc, char *argv[]) {
	QCoreApplication app(argc, argv);
	A a;
	QObject::connect(&a, SIGNAL(testSig()), &a, SLOT(testSlot())/*, Qt::QueuedConnection*/);
	for (int i = 0; i < 50000; ++i) a.test();
	return app.exec();
}

#include <QtCore/QCoreApplication>
#include "a.h"

int main(int argc, char *argv[]) {
	QCoreApplication app(argc, argv);
	A a;
	QObject::connect(&a, SIGNAL(testSig()), &a, SLOT(testSlot())/*, Qt::QueuedConnection*/);
	for (int i = 0; i < 50000; ++i) a.test();
	return app.exec();
}

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a.h

#ifndef A_H
#define A_H
 
#include <QObject>
 
class A : public QObject {
 
	Q_OBJECT
 
public:
	A();
	void test();
 
public slots:
	void testSlot();
 
signals:
	void testSig();
};
 
#endif // A_H

#ifndef A_H
#define A_H

#include <QObject>

class A : public QObject {

	Q_OBJECT

public:
	A();
	void test();

public slots:
	void testSlot();

signals:
	void testSig();
};

#endif // A_H

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a.cpp

#include "a.h"
 
A::A() {
}
 
void A::testSlot() {
	qDebug("hi");
}
 
void A::test() {
	emit testSig();
}

#include "a.h"

A::A() {
}

void A::testSlot() {
	qDebug("hi");
}

void A::test() {
	emit testSig();
}

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