Details
P3: Somewhat important Description
While debugging an application, I often encounter a crash due to os_unfair_lock, f.ex.:
1 _os_unfair_lock_recursive_abort (x86_64) /usr/lib/system/libsystem_platform.dylib 0x7fff7389343c 2 _os_unfair_lock_lock_slow (x86_64) /usr/lib/system/libsystem_platform.dylib 0x7fff7388eceb 3 look_up_class (x86_64h) /usr/lib/libobjc.A.dylib 0x7fff72326d11 4 __40-[NSArray descriptionWithLocale:indent:]_block_invoke (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c4bd040 5 -[NSArray descriptionWithLocale:indent:] (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c3cc733 6 _NSDescriptionWithLocaleFunc (x86_64) /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation 0x7fff3ea15d6a 7 __CFStringAppendFormatCore (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c3710d1 8 _CFStringCreateWithFormatAndArgumentsAux2 (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c36ee5c 9 +[NSString stringWithFormat:] (x86_64) /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation 0x7fff3ea15bd3 10 -[_NSScreenSharedInfo description] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff39e75e39 11 _NS_os_log_callback (x86_64) /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation 0x7fff3ea35cad 12 _os_log_fmt_flatten_NSCF (x86_64) /usr/lib/system/libsystem_trace.dylib 0x7fff738b8fa7 13 _os_log_fmt_flatten_object (x86_64) /usr/lib/system/libsystem_trace.dylib 0x7fff738bd182 14 _os_log_impl_flatten_and_send (x86_64) /usr/lib/system/libsystem_trace.dylib 0x7fff738b598e 15 _os_log (x86_64) /usr/lib/system/libsystem_trace.dylib 0x7fff738c222c 16 _os_log_impl (x86_64) /usr/lib/system/libsystem_trace.dylib 0x7fff738c2b84 17 -[_NSScreenSharedInfo _finishUpdating] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395a5db6 18 _NSScreenConfigurationUpdateSharedInfoForReason (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395a4826 19 +[_NSScreenConfiguration invalidateConfigurationIfNeededForReason:] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395ba4f2 20 _NSApplicationInvalidateScreenConfigurationIfNeeded (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff3a0c2173 21 -[NSApplication(ScreenHandling) _reactToPresentationChanged] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395ba453 22 _systemUIModeChanged (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395ba37b 23 DispatchEventToHandlers(EventTargetRec *, OpaqueEventRef *, HandlerCallRec *) (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af1abb1 24 SendEventToEventTargetInternal(OpaqueEventRef *, OpaqueEventTargetRef *, HandlerCallRec *) (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af19f80 25 SendEventToEventTargetWithOptions (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af19e23 26 HIToolboxLSNotificationCallbackAllASNsFunc (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af2696d 27 ___LSScheduleNotificationFunction_block_invoke_2 (x86_64) /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/LaunchServices 0x7fff3db2d768 28 __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c3cdc0b 29 __CFRunLoopDoBlocks (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c390e0d 30 __CFRunLoopRun (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c390581 31 CFRunLoopRunSpecific (x86_64h) /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation 0x7fff3c38fe13 32 RunCurrentEventLoopInMode (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af1cb2d 33 ReceiveNextEventCommon (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af1c779 34 _BlockUntilNextEventMatchingListInModeWithFilter (x86_64) /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox 0x7fff3af1c5f7 35 _DPSNextEvent (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395b2ac4 36 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395b1834 37 -[NSApplication run] (x86_64) /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit 0x7fff395abfd4 38 QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) qcocoaeventdispatcher.mm 431 0x108c37b00 39 QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) qeventloop.cpp 134 0x1037605f4 40 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) qeventloop.cpp 212 0x10376080b 41 QCoreApplication::exec() qcoreapplication.cpp 1297 0x10376693c 42 QGuiApplication::exec() qguiapplication.cpp 1679 0x102c36046 43 QApplication::exec() qapplication.cpp 2910 0x1022e7e39 44 main main.cpp 67 0x1005f344b 45 start (x86_64) /usr/lib/system/libdyld.dylib 0x7fff7368f405