[Qt-creator] Latest 3.6.0-rc1 slow editor on OS X

[Nils Jeisecke]

Hi list,

since upgrading to 3.6.0-rc1 creator's editor is close to unusable on
my (rather old) Mac Pro (Mac OS X 10.9).

- start creator 3.5.82 (3.6.0-rc1) Qt 5.5.1
- open a simple text file
- moving the cursor or editing is extremely slow

- start creator 3.4.2 (opensource) Qt 5.5.0
- open a simple text file
- editing works as expected

This is the instruments profiling data for 3.5.82:

Running Time Self Symbol Name
259.0ms   45.7% 259,0 0x10b1f8960
259.0ms   45.7% 0,0  0x10b2673e0
259.0ms   45.7% 0,0   QImage::convertToFormat_helper(QImage::Format,
QFlags<Qt::ImageConversionFlag>) const
259.0ms   45.7% 0,0    QPlatformBackingStore::toTexture(QRegion
const&, QSize*, QFlags<QPlatformBackingStore::TextureFlag>*) const
259.0ms   45.7% 0,0
QPlatformBackingStore::composeAndFlush(QWindow*, QRegion const&,
QPoint const&, QPlatformTextureList*, QOpenGLContext*, bool)
259.0ms   45.7% 0,0      0x10abd6a50
259.0ms   45.7% 0,0       0x10abd6e00
259.0ms   45.7% 0,0        0x10abd9c80
259.0ms   45.7% 0,0         0x10abdae50
259.0ms   45.7% 0,0          QWidgetPrivate::syncBackingStore()
259.0ms   45.7% 0,0           QWidget::event(QEvent*)
259.0ms   45.7% 0,0            QMainWindow::event(QEvent*)
259.0ms   45.7% 0,0
QApplicationPrivate::notify_helper(QObject*, QEvent*)
259.0ms   45.7% 0,0              QApplication::notify(QObject*, QEvent*)
259.0ms   45.7% 0,0
QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)
259.0ms   45.7% 0,0                0x10fad5860
259.0ms   45.7% 0,0                 0x10fad6180
259.0ms   45.7% 0,0
__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
259.0ms   45.7% 0,0                   __CFRunLoopDoSources0
259.0ms   45.7% 0,0                    __CFRunLoopRun
259.0ms   45.7% 0,0                     CFRunLoopRunSpecific
259.0ms   45.7% 0,0                      RunCurrentEventLoopInMode
259.0ms   45.7% 0,0                       ReceiveNextEventCommon
259.0ms   45.7% 0,0
_BlockUntilNextEventMatchingListInModeWithFilter
259.0ms   45.7% 0,0                         _DPSNextEvent
259.0ms   45.7% 0,0                          -[NSApplication
nextEventMatchingMask:untilDate:inMode:dequeue:]
259.0ms   45.7% 0,0                           -[NSApplication run]
259.0ms   45.7% 0,0                            0x10fad4800
259.0ms   45.7% 0,0
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
259.0ms   45.7% 0,0                              QCoreApplication::exec()
259.0ms   45.7% 0,0                               main
259.0ms   45.7% 0,0                                start

Is this some regression in Qt?

Nils