Details
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Bug
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Resolution: Out of scope
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P1: Critical
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None
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5.5.0
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QNX660 with Qt5.5.0
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QNX
Description
The UI hangs (not responsive), all other threads continue working.
I am using a QGLWidget that has a timer to call the update function to force a paintGL call. Next to that I have other UI elements drawn on a see-through UI widget that is layed on top of the QGLWidget.
The problems is a race condition.
When the interval of the timer is set to 15 then the problem does not occur, however when I set the interval higher (e.g. 60) then the problem occurs.
It will also happen at a random moment, faster when there is a lot of UI interaction.
The problem was also seen on Qt 5.4.2.
A workaround is to set QSG_RENDER_LOOP=basic
I build Qt 5.5.0 with
./configure -confirm-license -opensource -debug -force-debug-info -developer-build -opengl es2 -egl -no-cups -no-iconv -nomake tests -nomake examples -xplatform qnx-armle-v7-qcc -skip qtserialport -skip qtwebkit
I debugged the target with gdb.
Under normal circumstances I have the following threads:
Id Target Id Frame 8 pid 991289 tid 8 name "buffer-swap-t..." (STOPPED) 0x010452a4 in MsgSend () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 7 pid 991289 tid 7 name "QSGRenderThread" (CONDVAR) 0x01045808 in SyncCondvarWait_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 6 pid 991289 tid 6 name "buffer-swap-t..." (STOPPED) 0x010452a4 in MsgSend () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 5 pid 991289 tid 5 name "QQmlThread" (SIGWAITINFO) 0x01045794 in SignalWaitinfo () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 4 pid 991289 tid 4 (STOPPED) 0x01045ba4 in TimerTimeout () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 3 pid 991289 tid 3 name "QQnxScreenEve..." (REPLY) 0x010452a4 in MsgSend () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 2 pid 991289 tid 2 (STOPPED) 0x010453c8 in MsgSendv () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 *thread pid 991289 tid 1 (MUTEX) 0x01045890 in SyncMutexLock_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3
Thread 7 - QSGRenderThread:
#0 0x01045ba4 in TimerTimeout () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #1 0x010462e8 in timer_timeout () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #2 0x01024e28 in nanosleep () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #3 0x79843d28 in qt_nanosleep (amount=...) at tools/qelapsedtimer_unix.cpp:185 #4 0x797a3f06 in QThread::msleep (msecs=16) at thread/qthread_unix.cpp:470 #5 0x7b095cd0 in QSGRenderThread::syncAndRender (this=0x9fe32c0) at scenegraph/qsgthreadedrenderloop.cpp:570 #6 0x7b09684c in QSGRenderThread::run (this=0x9fe32c0) at scenegraph/qsgthreadedrenderloop.cpp:674 #7 0x797a3bfa in QThreadPrivate::start (arg=0x9fe32c0) at thread/qthread_unix.cpp:331 #8 0x010257bc in timer_settime () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3
Thread 3 - QQnxScreenEvent:
#0 0x010452a4 in MsgSend () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #1 0x796b74e0 in screen_get_event () from /opt/qnx660/target/qnx6/armle-v7/usr/lib/libscreen.so.1 #2 0x7a1a88ce in ?? () #3 0x7a1a88ce in ?? ()
And when the UI hangs:
8 pid 978951 tid 8 name "buffer-swap-t..." (STOPPED) 0x010453c8 in MsgSendv () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 7 pid 978951 tid 7 name "QSGRenderThread" (CONDVAR) 0x01045808 in SyncCondvarWait_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 6 pid 978951 tid 6 name "buffer-swap-t..." (MUTEX) 0x01045890 in SyncMutexLock_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 5 pid 978951 tid 5 name "QQmlThread" (SIGWAITINFO) 0x01045794 in SignalWaitinfo () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 4 pid 978951 tid 4 (STOPPED) 0x01045ba4 in TimerTimeout () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 * 3 pid 978951 tid 3 name "QQnxScreenEve..." (CONDVAR) 0x01045808 in SyncCondvarWait_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 2 pid 978951 tid 2 (STOPPED) 0x010453c8 in MsgSendv () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 1 pid 978951 tid 1 (MUTEX) 0x01045890 in SyncMutexLock_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3
Thread 7 - QSGRenderThread:
#0 0x01045808 in SyncCondvarWait_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #1 0x01025e58 in pthread_cond_wait () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #2 0x797a5458 in QWaitConditionPrivate::wait (this=0x9f2f910, time=4294967295) at thread/qwaitcondition_unix.cpp:136 #3 0x797a4ff4 in QWaitCondition::wait (this=0x9fe3318, mutex=0x9fe3314, time=4294967295) at thread/qwaitcondition_unix.cpp:208 #4 0x7b09a3b6 in QSGRenderThreadEventQueue::takeEvent (this=0x9fe3310, wait=true) at scenegraph/qsgthreadedrenderloop.cpp:224 #5 0x7b0965ce in QSGRenderThread::processEventsAndWaitForMore (this=0x9fe32c0) at scenegraph/qsgthreadedrenderloop.cpp:654 #6 0x7b09691a in QSGRenderThread::run (this=0x9fe32c0) at scenegraph/qsgthreadedrenderloop.cpp:683 #7 0x797a3bfa in QThreadPrivate::start (arg=0x9fe32c0) at thread/qthread_unix.cpp:331 #8 0x010257bc in timer_settime () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3
Thread 3 - QQnxScreenEvent:
#0 0x01045808 in SyncCondvarWait_r () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #1 0x01025e58 in pthread_cond_wait () from /opt/qnx660/target/qnx6/armle-v7/lib/libc.so.3 #2 0x796b3e44 in __screen_flush () from /opt/qnx660/target/qnx6/armle-v7/usr/lib/libscreen.so.1 #3 0x796b4566 in screen_flush_context () from /opt/qnx660/target/qnx6/armle-v7/usr/lib/libscreen.so.1 #4 0x7a1a830e in ?? () #5 0x7a1a830e in ?? ()