Hi,
I have a problem with QTimer class. My application tries to maintain a sliding time window. It does process IP packets and uses the reception time of the packets to trigger some action every 5 seconds. The QTimer is used to maintain this action if there are no packets flowing in. That means that as long as there are packets arriving, I want to reset the QTimer so that it doesn't trigger.
Here is some sample code which outlines what I try to do. The run() method does represent the packet capture routine. Every second I do reset the timer, if IP packets arrive. Below in the sample to speed up things, I do invoke QTimer::start() for every iteration of the loop. On 32-Bit system this does finish after 2-3 seconds. On 64-Bit it does run forever, and after 2 day's of running in my app, I get a seg fault when a timer event expires.

Qt Code: 
  1. CVO_Appl::CVO_Appl(QObject* parent)
  2. 		: QThread(parent)
  3. {
  4. 	m_byExitCount = 0;
  5. 	connect(&m_tTimer, SIGNAL(timeout()), this, SLOT(timeout()));
  6. 	m_tTimer.setInterval(5000);
  7. 	QTimer::singleShot(1000, this, SLOT(startThread()));
  8. } // end method
  9.  
  10. CVO_Appl::~CVO_Appl()
  11. {
  12. } // end method
  13.  
  14. void CVO_Appl::startThread()
  15. {
  16. 	m_tTimer.start();
  17. 	start();
  18. } // end method
  19.  
  20. // thread method
  21. void CVO_Appl::run()
  22. {
  23. 	qDebug() << "Thread started";
  24. 	for (int n = 0; n < 2000000; n++)
  25. 	{
  26. 		//m_tTimer.stop();
  27. 		//sleep(0);
  28. 		m_tTimer.start();
  29. 	} // end for
  30. 	qDebug() << "Thread stopped";
  31. } // end method
  32.  
  33. // protected slot
  34. void CVO_Appl::timeout()
  35. {
  36. 	m_byExitCount++;
  37. 	qDebug() << QString("Timer timeout %1...").arg(m_byExitCount);
  38. 	if (3 <= m_byExitCount)
  39. 	{
  41. 	} // end if
  42. } // end method
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Did anyone happen to see this as well? The core dump from the crash indicates that some timer is corrupt in the timerlist:

Qt Code: 
  1. (gdb) bt
  2. #0  0x00007fc407711527 in kill () from /lib/libc.so.6
  3. #1  0x00000000004368cc in CVO_DaemonUtils::sigSegvHandler () at modules/config/cvo_daemonutils.cpp:390
  4. #2  <signal handler called>
  5. #3  QCoreApplication::notifyInternal (this=0x7fff119f6000, receiver=0x0, event=0x7fff119f5b60) at ../../include/QtCore/../../src/corelib/kernel/qobject.h:97
  6. #4  0x00007fc40898409c in QTimerInfoList::activateTimers (this=0x6de130) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:193
  7. #5  0x00007fc408984cd8 in QEventDispatcherUNIX::processEvents (this=0x6dc5b0, flags=@0x7fff119f5c20) at kernel/qeventdispatcher_unix.cpp:877
  8. #6  0x00007fc408959625 in QEventLoop::processEvents (this=<value optimized out>, flags=@0x7fff119f5c60) at kernel/qeventloop.cpp:127
  9. #7  0x00007fc40895977b in QEventLoop::exec (this=0x7fff119f5ca0, flags=@0x7fff119f5cb0) at kernel/qeventloop.cpp:178
  10. #8  0x00007fc40895b729 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:827
  11. #9  0x000000000040bd54 in main (argc=2, argv=0x7fff119f61e8) at main.cpp:437
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Take a look at frame 3 above. The receiver is NULL which for sure did cause the crash. It seems that resetting the QTimer instance doesn't work right on 64-Bit platforms, because on 32-Bit this does never occur.