Details
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Bug
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Resolution: Done
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P2: Important
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6.2.0 Beta1
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None
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Linux/Wayland
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d68bd21b9d144fcc4552209591d353d791f498ac (qt/qtwayland/dev) 27979837f0770b8c4efa65d227d807516084b508 (qt/qtwayland/6.2)
Description
After porting from Qt 5.15 to 6.2 we have a recurring crash in the QtApplicationManager (AM), which is a Wayland compositor based on QtWaylandCompositor.
This is a timing issue: mostly when exiting the AM while Wayland clients are still running, but also when closing clients and immediately quitting the AM process.
Please note: this is not reproducible with the example compositors in the qtwayland module. The difference is that the AM actively shuts down the clients via IPC and/or SIGQUIT, before exiting itself.
What happens is that we are leaking one Texture resource for each Wayland window on RHI shutdown on the main thread. Later the deleteLater() handlers for the matching QSGPlainTextures in the QWaylandQuickItems are executed on the render thread, but this leads to a crash due to RHI being gone already (see backtrace below).
If I change the QWaylandSurfaceTextureProvider destructor in qwaylandquickitem.cpp to delete immediately instead of calling deleteLater, everything works fine: no crashes, no other weird behavior.
Apart from that, I think we still shouldn't crash the render thread if RHI is already shutdown, but simply do nothing or print an error message.
[WARN | default] QRhi 0x7fcba4004870 going down with 3 unreleased resources that own native graphics objects. This is not nice. [qrhi.cpp:4449] [WARN | default] Texture resource 0x7fcba47bc4b0 () [qrhi.cpp:4452] [WARN | default] Texture resource 0x7fcba47d05a0 () [qrhi.cpp:4452] [WARN | default] Texture resource 0x7fcba47dd5f0 () [qrhi.cpp:4452] *** process appman (36143) crashed *** > why: uncaught signal 11 (Segmentation fault) > where: QSGRenderThread thread, TID: 36162, pthread ID: 7fcbce633700 > C++ backtrace: 0: _FUN [564c4d66bbcb] in /home/sandman/git/qtapplicationmanager/src/common-lib/unixsignalhandler.cpp:156 1: ? [7fcbfa06813f] 2: QRhiGles2::DeferredReleaseEntry& QList<QRhiGles2::DeferredReleaseEntry>::emplaceBack<QRhiGles2::DeferredReleaseEntry const&>(QRhiGles2::DeferredReleaseEntry const&) [7fcbfbca179b] in /home/sandman/git/qt-6/qtbase/src/corelib/tools/qlist.h:817 3: QList<QRhiGles2::DeferredReleaseEntry>::append(QRhiGles2::DeferredReleaseEntry const&) [7fcbfbc9e340] in /home/sandman/git/qt-6/qtbase/src/corelib/tools/qlist.h:396 4: QGles2Texture::destroy() [7fcbfbc9412c] in /home/sandman/git/qt-6/qtbase/src/gui/rhi/qrhigles2.cpp:4525 5: QGles2Texture::~QGles2Texture() [7fcbfbc94077] in /home/sandman/git/qt-6/qtbase/src/gui/rhi/qrhigles2.cpp:4506 6: QGles2Texture::~QGles2Texture() [7fcbfbc9409f] in /home/sandman/git/qt-6/qtbase/src/gui/rhi/qrhigles2.cpp:4507 7: QSGPlainTexture::~QSGPlainTexture() [7fcbfc694189] in /home/sandman/git/qt-6/qtdeclarative/src/quick/scenegraph/util/qsgplaintexture.cpp:80 8: QSGPlainTexture::~QSGPlainTexture() [7fcbfc6941c1] in /home/sandman/git/qt-6/qtdeclarative/src/quick/scenegraph/util/qsgplaintexture.cpp:81 9: qDeleteInEventHandler(QObject*) [7fcbfa28c840] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qobject.cpp:4715 10: QObject::event(QEvent*) [7fcbfa283d6e] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qobject.cpp:1319 11: QCoreApplicationPrivate::notify_helper(QObject*, QEvent*) [7fcbfa2102b9] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1222 12: doNotify [7fcbfa20fedd] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1151 13: QCoreApplication::notify(QObject*, QEvent*) [7fcbfa20fe4f] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1137 14: QGuiApplication::notify(QObject*, QEvent*) [7fcbfb873644] in /home/sandman/git/qt-6/qtbase/src/gui/kernel/qguiapplication.cpp:1942 15: QCoreApplication::notifyInternal2(QObject*, QEvent*) [7fcbfa20fd99] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1061 16: QCoreApplication::sendEvent(QObject*, QEvent*) [7fcbfa210745] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1469 17: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) [7fcbfa211467] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1828 18: QCoreApplication::sendPostedEvents(QObject*, int) [7fcbfa210dbf] in /home/sandman/git/qt-6/qtbase/src/corelib/kernel/qcoreapplication.cpp:1687 19: QThreadPrivate::finish(void*) [7fcbfa4535ee] in /home/sandman/git/qt-6/qtbase/src/corelib/thread/qthread_unix.cpp:370 20: __pthread_cleanup_class::~__pthread_cleanup_class() [7fcbfa4543a2] in /usr/include/pthread.h:537 21: QThreadPrivate::start(void*) [7fcbfa4534cd] in /home/sandman/git/qt-6/qtbase/src/corelib/thread/qthread_unix.cpp:286 22: start_thread [7fcbfa05cea6] in ./nptl/pthread_create.c:477 23: __clone [7fcbf9cb3dee] 24: ? [ffffffffffffffff]
Attachments
| For Gerrit Dashboard: QTBUG-95394 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V |
| 362132,7 | rhi: Be more graceful when one destroys a resource after the QRhi | dev | qt/qtbase | Status: MERGED | +2 | 0 |
| 362820,2 | rhi: Be more graceful when one destroys a resource after the QRhi | 6.2 | qt/qtbase | Status: MERGED | +2 | 0 |
| 362840,4 | Delete texture resource immediately to prevent race on shutdown | dev | qt/qtwayland | Status: MERGED | +2 | 0 |
| 363127,2 | Delete texture resource immediately to prevent race on shutdown | 6.2 | qt/qtwayland | Status: MERGED | +2 | 0 |