I have received a few crash reports for my app "Find Any File" with an assertion failure as follows:
assertion failure: "displayTiming != ((void *)0)" -> %lld
Googling this turns up nothing, though.
I wonder if someone has some insight into why this might happen, and how to prevent it.
One reporting user suggests that it happens when my app shows a very long list of items in an NSTableView (>10000 elements).
I have 4 reports from 3 users, and the main thread is doing something related to the table view each time, though not the same (the few other threads are all idle):
Crash 1, in macOS 14.0 (23A344:
Thread 0:: Dispatch queue: com.apple.main-thread
0 libobjc.A.dylib 0x182c69400 objc_msgSend + 0
1 AppKit 0x186f15400 -[CALayer(NSViewVisibleRect) NS_viewVisibleRectDidChange] + 40
2 AppKit 0x186900e10 NSViewHierarchyInvalidateVisibleRect + 276
3 AppKit 0x186900db0 NSViewHierarchyInvalidateVisibleRect + 180
4 AppKit 0x186900db0 NSViewHierarchyInvalidateVisibleRect + 180
5 AppKit 0x186900db0 NSViewHierarchyInvalidateVisibleRect + 180
6 AppKit 0x186900db0 NSViewHierarchyInvalidateVisibleRect + 180
7 AppKit 0x186900db0 NSViewHierarchyInvalidateVisibleRect + 180
8 AppKit 0x1869990e0 -[NSView translateOriginToPoint:] + 164
9 AppKit 0x186984108 -[NSClipView _immediateScrollToPoint:] + 420
10 AppKit 0x186983eb8 -[NSClipView scrollToPoint:] + 184
11 AppKit 0x186998d80 -[NSScrollView scrollClipView:toPoint:] + 84
12 AppKit 0x1869448dc -[NSClipView _scrollTo:animateScroll:flashScrollerKnobs:] + 480
13 AppKit 0x186b65b24 __62-[NSScrollingBehaviorConcurrentVBL _stopGestureScrollTracking]_block_invoke + 192
14 AppKit 0x186e6a6e8 ___NSMainRunLoopPerformBlockInModes_block_invoke + 44
15 CoreFoundation 0x18310b8c0 __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 28
Crash 2, in macOS 14.1.1 (23B81):
Thread 0:: Dispatch queue: com.apple.main-thread
0 CoreFoundation 0x18ba401f4 DYLD-STUB$$_Block_object_assign + 0
1 libsystem_blocks.dylib 0x18b506118 _call_copy_helpers_excp + 80
2 libsystem_blocks.dylib 0x18b505c68 _Block_copy + 376
3 libdispatch.dylib 0x18b641c7c _dispatch_Block_copy + 32
4 libdispatch.dylib 0x18b658df0 _dispatch_source_set_handler + 92
5 CoreFoundation 0x18b99e1e4 __CFRunLoopCopyMode + 540
6 CoreFoundation 0x18b8b7458 CFRunLoopAddObserver + 220
7 AppKit 0x18f0a687c _PerfAddRunLoopObserver + 192
8 AppKit 0x18f87cd60 -[NSApplication(NSEventRouting) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 368
9 AppKit 0x18f323318 -[_NSScrollingConcurrentEventMonitor startMonitoring] + 380
10 AppKit 0x18f321df8 -[NSScrollingBehaviorConcurrentVBL _scrollView:trackGestureScrollWithEvent:] + 884
11 AppKit 0x18f2e67f8 -[NSScrollingBehaviorConcurrentVBL scrollView:scrollWheelWithEvent:] + 512
12 AppKit 0x18f241770 forwardMethod + 252
13 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
14 AppKit 0x18f241770 forwardMethod + 252
15 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
16 AppKit 0x18f241770 forwardMethod + 252
17 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
18 AppKit 0x18f241770 forwardMethod + 252
19 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
20 AppKit 0x18fc45880 -[NSCollectionView scrollWheel:] + 180
21 AppKit 0x18f241770 forwardMethod + 252
22 AppKit 0x18f241770 forwardMethod + 252
23 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
24 AppKit 0x18f241770 forwardMethod + 252
25 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
26 AppKit 0x18f241770 forwardMethod + 252
27 AppKit 0x18f2e62a0 -[NSView scrollWheel:] + 408
28 AppKit 0x18f1d27b0 -[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:] + 652
As you can see, there's no code of mine involved at the time of crash.
The other (and older) reports are similar, in macOS 13.6.1 and macOS 13.1. All four happened on ARM architecture (which may not be significant due to small number of samples). Memory use of app was not critical (in one case it was about 9 GB total, in others below 4 GB).
The "Binary Images" section only lists Apple libs, apart from my app's. So, there seems to be no 3rd party ext involved.
I've attached a full report as well.
I recommend that you file a bug about this. Please post your bug number, just for the record.
The immediate cause of this bug is that AppKit has a subsystem that monitor’s the display’s timing while you’re scrolling (VBL should sound familiar to you!). This subsystem has asked another subsystem for a timer that’s appropriate for the screen that it’s monitoring. That subsystem has return nil, and thus you trap in this assert.
It’s hard to imagine how your code might be causing this, and hence my recommendation above.
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—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"