QElapsedTimer::elapsed() restarts after ~11000ms on WinXP Home SP3

[lukass]

Hello,
QElapsedTimer::elapsed() always restarts after ~11000ms on Windows XP Home SP3 and Qt 4.8. On Qt 4.7.4 is OK.
Can anyone confirm this?

Example code:

main_window.cpp:

#include "main_window.h"
#include <QTimer>
#include <QMessageBox>
#include <QDebug>
 
main_window::main_window(QWidget * parent) :
  QMainWindow(parent)
{
  ui.setupUi(this);
 
  refresh_timer = new QTimer(this);
  refresh_timer->setInterval(1000);
  connect(refresh_timer, SIGNAL(timeout()), SLOT(refresh_ui()));
 
  const int clock_type = QElapsedTimer::clockType();
  const bool is_monotonic = QElapsedTimer::isMonotonic();
  qDebug() << "QElapsedTimer::clockType() = " << clock_type;
  qDebug() << "isMonotonic: " << is_monotonic;
 
  QMessageBox::information(this, "info",
                           QString("QElapsedTimer::clockType() = %1\n"
                                   "isMonotonic: %2")
                           .arg(QString::number(clock_type), is_monotonic ? "true" : "false"));
 
  elapsed_timer.start();
  refresh_timer->start();
}
 
void main_window::refresh_ui()
{
  // BUG? On Qt 4.8 and Windows XP Home SP3 32bit - elapsed() always returning value from 0 to 11000
  qint64 diff = elapsed_timer.elapsed();
  qDebug() << diff;
  ui.label->setText(QString::number(diff));
}

#include "main_window.h"
#include <QTimer>
#include <QMessageBox>
#include <QDebug>

main_window::main_window(QWidget * parent) :
  QMainWindow(parent)
{
  ui.setupUi(this);

  refresh_timer = new QTimer(this);
  refresh_timer->setInterval(1000);
  connect(refresh_timer, SIGNAL(timeout()), SLOT(refresh_ui()));

  const int clock_type = QElapsedTimer::clockType();
  const bool is_monotonic = QElapsedTimer::isMonotonic();
  qDebug() << "QElapsedTimer::clockType() = " << clock_type;
  qDebug() << "isMonotonic: " << is_monotonic;

  QMessageBox::information(this, "info",
                           QString("QElapsedTimer::clockType() = %1\n"
                                   "isMonotonic: %2")
                           .arg(QString::number(clock_type), is_monotonic ? "true" : "false"));

  elapsed_timer.start();
  refresh_timer->start();
}

void main_window::refresh_ui()
{
  // BUG? On Qt 4.8 and Windows XP Home SP3 32bit - elapsed() always returning value from 0 to 11000
  qint64 diff = elapsed_timer.elapsed();
  qDebug() << diff;
  ui.label->setText(QString::number(diff));
}

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main_window.h:

#ifndef MAIN_WINDOW_H
#define MAIN_WINDOW_H
 
#include "ui_main_window.h"
#include <QElapsedTimer>
 
class QTimer;
 
class main_window : public QMainWindow
{
  Q_OBJECT
public:
  main_window(QWidget * parent = 0);
 
public slots:
  void refresh_ui();
 
private:
  Ui::main_window ui;
  QTimer * refresh_timer;
  QElapsedTimer elapsed_timer;
};
 
#endif // MAIN_WINDOW_H

#ifndef MAIN_WINDOW_H
#define MAIN_WINDOW_H

#include "ui_main_window.h"
#include <QElapsedTimer>

class QTimer;

class main_window : public QMainWindow
{
  Q_OBJECT
public:
  main_window(QWidget * parent = 0);

public slots:
  void refresh_ui();
  
private:
  Ui::main_window ui;
  QTimer * refresh_timer;
  QElapsedTimer elapsed_timer;
};

#endif // MAIN_WINDOW_H

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elapsed_timer_test.pro:

QT       += core gui
 
TEMPLATE = app
 
HEADERS += main_window.h
 
SOURCES += main.cpp main_window.cpp
 
FORMS += main_window.ui

QT       += core gui

TEMPLATE = app

HEADERS += main_window.h

SOURCES += main.cpp main_window.cpp

FORMS += main_window.ui

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[mentalmushroom]

Try this code. It works fine on w7 + qt 4.7.2

#include <iostream>
#include <QtCore>
 
class Worker: public QObject
{
	Q_OBJECT
 
public:
	Worker(): QObject() 
	{
		updateTimer.setInterval(1000);
		connect(&updateTimer, SIGNAL(timeout()), this, SLOT(showTimeElapsed()));
	}
 
public slots:
	void start() 
	{
		elapsedTimer.start();
		updateTimer.start();
	}
 
private:
	QElapsedTimer elapsedTimer;
	QTimer updateTimer;
 
private slots:
	void showTimeElapsed()
	{
		std::cout << elapsedTimer.elapsed() << std::endl;
	}
};
 
int main(int argc, char *argv[])
{
	QCoreApplication a(argc, argv);
	Worker worker;
	QTimer::singleShot(0, &worker, SLOT(start()));		
	return a.exec();
}
 
#include "main.moc"

#include <iostream>
#include <QtCore>

class Worker: public QObject
{
	Q_OBJECT

public:
	Worker(): QObject() 
	{
		updateTimer.setInterval(1000);
		connect(&updateTimer, SIGNAL(timeout()), this, SLOT(showTimeElapsed()));
	}

public slots:
	void start() 
	{
		elapsedTimer.start();
		updateTimer.start();
	}

private:
	QElapsedTimer elapsedTimer;
	QTimer updateTimer;

private slots:
	void showTimeElapsed()
	{
		std::cout << elapsedTimer.elapsed() << std::endl;
	}
};

int main(int argc, char *argv[])
{
	QCoreApplication a(argc, argv);
	Worker worker;
	QTimer::singleShot(0, &worker, SLOT(start()));		
	return a.exec();
}

#include "main.moc"

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[lukass]

Try this code. It works fine on w7 + qt 4.7.2

http://troll.me/images/futurama-fry/...ust-stupid.jpg

https://bugreports.qt-project.org/browse/QTBUG-24362
https://bugreports.qt-project.org/browse/QTBUG-23150