My app metrics shows that some devices crash with the following information:
Exception Type: EXC_CRASH (SIGKILL)
Process Visibility: Foreground
Watchdog Event: scene-update (other reports has scene-create)
Watchdog Visibility: Background
Termination Code: 0x8badf00d
Stack traces:
UIKitCore -[_UIFlowLayoutRow layoutRow]
UIKitCore -[_UIFlowLayoutRow layoutRow]
UIKitCore -[_UIFlowLayoutSection computeLayoutInRect:forSection:invalidating:invalidationContext:]
UIKitCore __76-[UICollectionViewFlowLayout _updateItemsLayoutForRect:allowsPartialUpdate:]_block_invoke
CoreFoundation __NSARRAY_IS_CALLING_OUT_TO_A_BLOCK__
CoreFoundation -[__NSArrayM enumerateObjectsWithOptions:usingBlock:]
UIKitCore -[UICollectionViewFlowLayout _updateItemsLayoutForRect:allowsPartialUpdate:]
UIKitCore -[UICollectionViewFlowLayout _fetchItemsInfoForRect:]
UIKitCore -[UICollectionViewFlowLayout prepareLayout]
UIKitCore -[UICollectionViewData _prepareToLoadData]
UIKitCore -[UICollectionViewData validateLayoutInRect:]
UIKitCore -[UICollectionViewData layoutAttributesForElementsInRect:]
UIKitCore -[UICollectionView _indexPathForItemAtPoint:]
UIKitCore -[UICollectionView indexPathForItemAtPoint:]
MyApp - [MyAppCollectionViewController gestureRecognizer:shouldReceiveTouch:]
UIKitCore -[UIGestureRecognizer _delegateShouldReceiveTouch:forEvent:]
UIKitCore -[UIGestureRecognizer _internalShouldReceiveTouch:forEvent:recognizerView:]
UIKitCore __80-[UITouchesEvent _addGestureRecognizersForGestureOwner:toTouch:forContinuation:]_block_invoke
UIKitCore __70-[UITouchesEvent _collectGestureRecognizersForGestureOwner:withBlock:]_block_invoke
UIKitCore -[UITouchesEvent _collectGestureRecognizersForGestureOwner:withBlock:]
UIKitCore -[UITouchesEvent _addGestureRecognizersForGestureOwner:toTouch:forContinuation:]
UIKitCore -[UITouchesEvent _addTouch:forDelayedDelivery:]
UIKitCore _AddTouchToEventAndDetermineIfNeedsCancel
UIKitCore ____updateTouchesWithDigitizerEventAndDetermineIfShouldSend_block_invoke.51
CoreFoundation __NSDICTIONARY_IS_CALLING_OUT_TO_A_BLOCK__
CoreFoundation ____NSDictionaryEnumerate_block_invoke_2
CoreFoundation CFBasicHashApply
CoreFoundation __NSDictionaryEnumerate
UIKitCore __dispatchPreprocessedEventFromEventQueue
UIKitCore __processEventQueue
UIKitCore __eventFetcherSourceCallback
CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
CoreFoundation __CFRunLoopDoSource0
CoreFoundation __CFRunLoopDoSources0
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
GraphicsServices GSEventRunModal
UIKitCore -[UIApplication _run]
UIKitCore UIApplicationMain
Thread ID: 0
Stacktrace:
libsystem_kernel.dylib poll
MyApp pollset_work(grpc_pollset*, grpc_pollset_worker**, grpc_core::Timestamp)
MyApp cq_next(grpc_completion_queue*, gpr_timespec, void*)
MyApp __27-[GRPCCompletionQueue init]_block_invoke_2
libdispatch.dylib _dispatch_call_block_and_release
libdispatch.dylib _dispatch_client_callout
libdispatch.dylib _dispatch_root_queue_drain
libdispatch.dylib _dispatch_worker_thread2
libsystem_pthread.dylib _pthread_wqthread
libsystem_pthread.dylib start_wqthread
Thread ID: 1
Stacktrace:
libsystem_pthread.dylib start_wqthread
Thread ID: 2
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
CoreFoundation __CFRunLoopServiceMachPort
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
Foundation -[NSRunLoop(NSRunLoop) runMode:beforeDate:]
Foundation -[NSRunLoop(NSRunLoop) runUntilDate:]
UIKitCore -[UIEventFetcher threadMain]
Foundation __NSThread__start__
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 3
Stacktrace:
libsystem_pthread.dylib start_wqthread
Thread ID: 4
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
MyApp crashpad::MachMessageWithDeadline(mach_msg_header_t*, int, unsigned int, unsigned int, unsigned long long, unsigned int, bool)
MyApp crashpad::MachMessageServer::Run()
MyApp crashpad::(anonymous namespace)::CrashHandler::ThreadMain()
MyApp crashpad::Thread::ThreadEntryThunk(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 5
Stacktrace:
libsystem_pthread.dylib start_wqthread
Thread ID: 6
Stacktrace:
libsystem_kernel.dylib semaphore_timedwait_trap
libdispatch.dylib _dispatch_sema4_timedwait
libdispatch.dylib _dispatch_semaphore_wait_slow
MyApp crashpad::Semaphore::TimedWait(double)
MyApp crashpad::internal::WorkerThreadImpl::ThreadMain()
MyApp crashpad::Thread::ThreadEntryThunk(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 7
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
CoreFoundation __CFRunLoopServiceMachPort
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
CFNetwork _CFURLStorageSessionDisableCache
Foundation __NSThread__start__
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 8
Stacktrace:
libsystem_kernel.dylib semaphore_timedwait_trap
libdispatch.dylib _dispatch_sema4_timedwait
libdispatch.dylib _dispatch_semaphore_wait_slow
MyApp crashpad::Semaphore::TimedWait(double)
MyApp crashpad::internal::WorkerThreadImpl::ThreadMain()
MyApp crashpad::Thread::ThreadEntryThunk(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 9
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp gpr_cv_wait
MyApp grpc_core::Executor::ThreadMain(void*)
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 10
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp gpr_cv_wait
MyApp grpc_core::Executor::ThreadMain(void*)
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 11
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp gpr_cv_wait
MyApp timer_thread(void*)
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 12
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 13
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 14
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 15
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 16
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 17
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp grpc_event_engine::experimental::OriginalThreadPool::Queue::Step()
MyApp grpc_event_engine::experimental::OriginalThreadPool::StartThread()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 18
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::TimedWait(absl::synchronization_internal::KernelTimeout)
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp absl::CondVar::WaitWithTimeout(absl::Mutex*, absl::Duration)
MyApp grpc_event_engine::experimental::TimerManager::WaitUntil(grpc_core::Timestamp)
MyApp grpc_event_engine::experimental::TimerManager::MainLoop()
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 19
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
CoreFoundation __CFRunLoopServiceMachPort
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
CoreFoundation _legacyStreamRunLoop_workThread
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 20
Stacktrace:
libsystem_kernel.dylib __select
CoreFoundation __CFSocketManager
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 21
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
CoreFoundation __CFRunLoopServiceMachPort
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
CFNetwork _CFURLStorageSessionDisableCache
Foundation __NSThread__start__
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 22
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
CoreFoundation __CFRunLoopServiceMachPort
CoreFoundation __CFRunLoopRun
CoreFoundation CFRunLoopRunSpecific
Foundation -[NSRunLoop(NSRunLoop) runMode:beforeDate:]
MyAppWebView base::MessagePumpNSRunLoop::DoRun(base::MessagePump::Delegate*)
MyAppWebView base::MessagePumpCFRunLoopBase::Run(base::MessagePump::Delegate*)
MyAppWebView base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::Run(bool, base::TimeDelta)
MyAppWebView base::RunLoop::Run(base::Location const&)
MyAppWebView base::Thread::Run(base::RunLoop*)
MyAppWebView base::Thread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 23
Stacktrace:
libsystem_kernel.dylib kevent64
MyAppWebView base::MessagePumpKqueue::DoInternalWork(base::MessagePump::Delegate*, base::MessagePump::Delegate::NextWorkInfo*)
MyAppWebView base::MessagePumpKqueue::Run(base::MessagePump::Delegate*)
MyAppWebView base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::Run(bool, base::TimeDelta)
MyAppWebView base::RunLoop::Run(base::Location const&)
MyAppWebView base::Thread::Run(base::RunLoop*)
MyAppWebView base::internal::ServiceThread::Run(base::RunLoop*)
MyAppWebView base::Thread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 24
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
MyAppWebView base::WaitableEvent::TimedWaitImpl(base::TimeDelta)
MyAppWebView base::WaitableEvent::TimedWait(base::TimeDelta)
MyAppWebView base::internal::WorkerThread::Delegate::WaitForWork(base::WaitableEvent*)
MyAppWebView base::internal::WorkerThread::RunWorker()(
MyAppWebView base::internal::WorkerThread::RunPooledWorker()
MyAppWebView base::internal::WorkerThread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 25
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
MyAppWebView base::WaitableEvent::TimedWaitImpl(base::TimeDelta)
MyAppWebView base::WaitableEvent::TimedWait(base::TimeDelta)
MyAppWebView base::internal::WorkerThread::Delegate::WaitForWork(base::WaitableEvent*)
MyAppWebView base::internal::WorkerThread::RunWorker()
MyAppWebView base::internal::WorkerThread::RunBackgroundPooledWorker()
MyAppWebView base::internal::WorkerThread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 26
Stacktrace:
libsystem_kernel.dylib kevent64
MyAppWebView base::MessagePumpKqueue::DoInternalWork(base::MessagePump::Delegate*, base::MessagePump::Delegate::NextWorkInfo*)
MyAppWebView base::MessagePumpKqueue::Run(base::MessagePump::Delegate*)
MyAppWebView base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::Run(bool, base::TimeDelta)
MyAppWebView base::RunLoop::Run(base::Location const&)
MyAppWebView base::Thread::Run(base::RunLoop*)
MyAppWebView web::WebSubThread::IOThreadRun(base::RunLoop*)
MyAppWebView base::Thread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 27
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
MyAppWebView base::WaitableEvent::TimedWaitImpl(base::TimeDelta)
MyAppWebView base::WaitableEvent::TimedWait(base::TimeDelta)
MyAppWebView base::internal::WorkerThread::Delegate::WaitForWork(base::WaitableEvent*)
MyAppWebView base::internal::WorkerThread::RunWorker()
MyAppWebView base::internal::WorkerThread::RunPooledWorker()
MyAppWebView base::internal::WorkerThread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 28
Stacktrace:
libsystem_kernel.dylib mach_msg2_trap
libsystem_kernel.dylib mach_msg2_internal
libsystem_kernel.dylib mach_msg_overwrite
libsystem_kernel.dylib mach_msg
MyAppWebView base::WaitableEvent::TimedWaitImpl(base::TimeDelta)
MyAppWebView base::WaitableEvent::TimedWait(base::TimeDelta)
MyAppWebView base::internal::WorkerThread::Delegate::WaitForWork
MyAppWebView base::internal::WorkerThread::RunWorker()
MyAppWebView base::internal::WorkerThread::RunBackgroundPooledWorker()
MyAppWebView base::internal::WorkerThread::ThreadMain()
MyAppWebView base::(anonymous namespace)::ThreadFunc(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
Thread ID: 29
Stacktrace:
libsystem_kernel.dylib __psynch_cvwait
libsystem_pthread.dylib _pthread_cond_wait
MyApp absl::synchronization_internal::PthreadWaiter::TimedWait(absl::synchronization_internal::KernelTimeout)
MyApp absl::synchronization_internal::PthreadWaiter::Wait(absl::synchronization_internal::KernelTimeout)
MyApp AbslInternalPerThreadSemWait
MyApp absl::CondVar::WaitCommon(absl::Mutex*, absl::synchronization_internal::KernelTimeout)
MyApp absl::CondVar::WaitWithTimeout(absl::Mutex*, absl::Duration)
MyApp gpr_cv_wait
MyApp timer_thread(void*)
MyApp Thread::ThreadBody(void*)
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
There is a similar unanswered question on Apple Developer forum. I checked Apple Watchdog termination documentation but it didn't help much.
I tried to reproduce it on my iPhone or simulator but I couldn't. Did anyone have the same issue before and how did you fix it?
The bug is related to the layout configuration:
I implemented a custom UICollectionViewFlowLayout where estimatedItemSize = UICollectionViewFlowLayoutAutomaticSize
Each cell implemented its own preferredLayoutAttributesFittingAttributes.
I implemented a custom UICollectionViewController. It implemented UICollectionViewDelegate and returned NO for @selector(collectionView:layout:sizeForItemAtIndexPath:) so that the UICollectionView uses automatic cell sizing, except for a special cell where I wanted the UICollectionView to use manual sizing by calling UICollectionViewDelegate's sizeForItemAtIndexPath.
My guess is that the new logic which returned YES in @selector(collectionView:layout:sizeForItemAtIndexPath:) for the special cell somehow affected some other cells and caused the crash. I fixed it by getting rid of the manual cell sizing logic. Now, UICollectionViewDelegate returns NO in @selector(collectionView:layout:sizeForItemAtIndexPath:) for all cells and automatic cell sizing is used for all cells.