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  1. Qt
  2. QTBUG-25627

100% CPU Usage in QNetworkAccessCache::timerEvent for a momment

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Details

    • Bug
    • Resolution: Duplicate
    • Not Evaluated
    • 4.8.2
    • 4.7.3
    • Network: Cache
    • None
    • Mac OS X 10.7.4

    Description

      if you look at the cpu usage, you see a huge spike for 1-2 seconds. If you start a stack trace sampling just in that moment, the app hangs in QNetworkAccessCache::timerEvent.

      It seems to be related with two different threads using it's own thread specific NAM at the same time.

      This is a small extract on the sampling:
      ---------
      1349 QCoreApplication::notifyInternal(QObject*, QEvent*) (in QtCore) + 98
      1347 QApplication::notify(QObject*, QEvent*) (in QtGui) + 2132
      1345 QApplicationPrivate::notify_helper(QObject*, QEvent*) (in QtGui) + 175
      1345 QObject::event(QEvent*) (in QtCore) + 424
      1195 QNetworkAccessCache::timerEvent(QTimerEvent*) (in QtNetwork) + 134
      1018 QNetworkAccessCache::updateTimer() (in QtNetwork) + 61
      512 QDateTime::secsTo(QDateTime const&) const (in QtCore) + 96
      412 QDateTimePrivate::getUTC(QDate&, QTime&) const (in QtCore) + 231
      ---------

      And it looks to especially related to Mac OS X, because we were not able to reproduce this on other platforms.

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            shkearns Shane Kearns
            sebastianphilipp Sebastian Philipp
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              Updated:
              Resolved: