Crash in cacheKey method

[cujo30227]

Hi,
I'm getting occasional crash reports from the cacheKey method in FXImageView... Anyone has an idea how to resolve?? See crash report below..

1 libsystem_platform.dylib _OSAtomicCompareAndSwap32Barrier + 14
2 libobjc.A.dylib lookUpImpOrForward + 75
3 libobjc.A.dylib _class_lookupMethodAndLoadCache3 + 35
4 libobjc.A.dylib _objc_msgSend_uncached + 25
5 Foundation __NSDescriptionWithLocaleFunc + 53
6 CoreFoundation __CFStringAppendFormatCore + 5623
7 CoreFoundation __CFStringCreateWithFormatAndArgumentsAux + 77
8 Foundation -[NSPlaceholderString initWithFormat:locale:arguments:] + 131
9 Foundation +[NSString stringWithFormat:] + 61
10 APPNAME -FXImageView cacheKey
11 APPNAME -FXImageView processImage
12 APPNAME -FXImageOperation main
13 Foundation -[__NSOperationInternal _start:] + 773

[nicklockwood]

What is the actual exception?

[nicklockwood]

A simple fix is probably just to use a custom cacheKey of your own specification, but I'd like to know what the cause of this was.

[cujo30227]

Exception Type: SIGSEGV
Exception Codes: SEGV_ACCERR at 0xf000000c
Crashed Thread: 21

The symbolised thread is below:
Thread 21 Crashed:
0 libobjc.A.dylib 0x37c09b66 _objc_msgSend + 6
1 Foundation 0x2de7c659 _NSDescriptionWithLocaleFunc + 53
2 CoreFoundation 0x2d53abef __CFStringAppendFormatCore + 5623
3 CoreFoundation 0x2d4a9c4d __CFStringCreateWithFormatAndArgumentsAux + 77
4 Foundation 0x2de7c607 -[NSPlaceholderString initWithFormat:locale:arguments:] + 131
5 Foundation 0x2de7c509 +[NSString stringWithFormat:] + 61
6 APPNAME 0x000c796d -FXImageView cacheKey
7 APPNAME 0x000c7cb1 -FXImageView processImage
8 APPNAME 0x000c71a7 -FXImageOperation main
9 Foundation 0x2de93aa5 -[__NSOperationInternal _start:] + 773
10 Foundation 0x2df3796d __NSOQSchedule_f + 61
11 libdispatch.dylib 0x380f74b7 _dispatch_async_redirect_invoke + 111
12 libdispatch.dylib 0x380f87d9 _dispatch_root_queue_drain + 225
13 libdispatch.dylib 0x380f89c5 _dispatch_worker_thread2 + 57
14 libsystem_pthread.dylib 0x38222dff __pthread_wqthread + 299

Note the line 232 in cacheKey is "NSStringFromCGSize(shadowOffset)," in the following return statement:
return [NSString stringWithFormat:@"%@%@%.2f%.2f_%.2f_%@%@%.2f_%.2f_%i",
_imageContentURL ?: [self imageHash:_originalImage],
NSStringFromCGSize(self.bounds.size),
_reflectionGap,
_reflectionScale,
_reflectionAlpha,
[self colorHash:_shadowColor],
NSStringFromCGSize(_shadowOffset),
_shadowBlur,
_cornerRadius,
self.contentMode];

[cujo30227]

Hi, were you able to find the root cause of this crash? Any suggestions how to solve it? It's currently my second-frequent crash in the apps I have with FXImageView incorporated....

[nicklockwood]

I haven't been able to reproduce the issue yet, but as a workaround, try setting the cacheKey explicitly.

[cujo30227]

Yes, I also have difficulties reproducing it, but it still shows up in my crash reporting. I think I'm just going to try to send out a build with a modified cacheKey: Will let you know whether that solved it...
return [NSString stringWithFormat:@"%@",
[_imageContentURL absoluteString] ?: [self imageHash:_originalImage]];

[tfonfara]

Sometimes I can reproduce a crash in the cacheKey method, at line 202: NSStringFromCGSize(_shadowOffset) but it's not a SIGSEGV it's an EXC BAD ACCESS. The stack trace referes to FXImageOperation:

- (void)main
{
    @autoreleasepool
    {
        [_target processImage];
    }
}

Maybe this information can help to fix the problem?

[FreudGit]

Hi

Also have crashlytics report from some user. Someone have an idea?

Crashed: NSOperationQueue 0x17d095d0 :: NSOperation 0x17db2aa0 (QOS: UTILITY)
Thread : Crashed: NSOperationQueue 0x17d095d0 :: NSOperation 0x17db2aa0 (QOS: UTILITY)
0 libobjc.A.dylib 0x224a3ac6 objc_msgSend + 5
1 Foundation 0x235073b1 _NSDescriptionWithStringProxyFunc + 48
2 CoreFoundation 0x22cc30dd __CFStringAppendFormatCore + 7132
3 CoreFoundation 0x22cc14e1 _CFStringCreateWithFormatAndArgumentsAux2 + 80
4 Foundation 0x2342ea05 -[NSPlaceholderString initWithFormat:locale:arguments:] + 144
5 Foundation 0x2342e8fd +[NSString stringWithFormat:] + 60
6 Poses Model 0x136175 -FXImageView cacheKey
7 Poses Model 0x1364d5 -FXImageView processImage

[alexoverseer]

Hi, same problem.

0 CoreFoundation 0x18166afe0 __exceptionPreprocess
1 libobjc.A.dylib 0x1800cc538 objc_exception_throw
2 CoreFoundation 0x181671ef4 __methodDescriptionForSelector
3 CoreFoundation 0x18166ef54 forwarding
4 CoreFoundation 0x18156ad4c _CF_forwarding_prep_0
5 Foundation 0x1820c324c -[NSURL(NSURL) description]
6 Foundation 0x182056584 _NSDescriptionWithLocaleFunc
7 CoreFoundation 0x18162c8bc __CFStringAppendFormatCore
8 CoreFoundation 0x18162a78c _CFStringCreateWithFormatAndArgumentsAux2
9 Foundation 0x1820563d8 +[NSString stringWithFormat:]
10 MyApp 0x100070fd4 -[FXImageView cacheKey] (FXImageView.m:205)
11 MyApp 0x1000713b8 -[FXImageView processImage] (FXImageView.m:265)
12 MyApp 0x100070664 -[FXImageOperation main] (FXImageView.m:75)
13 Foundation 0x18206eb28 -[__NSOperationInternal _start:]
14 Foundation 0x18213bbb0 __NSOQSchedule_f
15 libdispatch.dylib 0x1805229a0 _dispatch_client_callout
16 libdispatch.dylib 0x180530ad4 _dispatch_queue_serial_drain
17 libdispatch.dylib 0x1805262cc _dispatch_queue_invoke
18 libdispatch.dylib 0x180532a50 _dispatch_root_queue_drain
19 libdispatch.dylib 0x1805327d0 _dispatch_worker_thread3
20 libsystem_pthread.dylib 0x18072b100 _pthread_wqthread
21 libsystem_pthread.dylib 0x18072acac start_wqthread

[art-lucas]

Hi Nick,

Same here, but it happens with Xcode 9.0.1 with iOS 11 on iPhone X (simulator) only; i.e. crashes consistently. However, it works fine on iPhone 6/7/8 and 6+/7+/8+ iOS 10.x and 11.x (simulators).

Main Thread Checker: UI API called on a background thread: -[UIView bounds]
PID: 15217, TID: 9896264, Thread name: (none), Queue name: NSOperationQueue 0x60400022eaa0 (QOS: UNSPECIFIED), QoS: 0
Backtrace:

4   App                       	0x000000010070f657 -[FXImageView cacheKey] + 215
5   App                       	0x000000010070fce4 -[FXImageView processImage] + 52
6   App                       	0x000000010070e96f -[FXImageOperation main] + 63
7   Foundation                          0x0000000103d1acd6 -[__NSOperationInternal _start:] + 778
8   libdispatch.dylib                   0x000000010762743c _dispatch_client_callout + 8
9   libdispatch.dylib                   0x000000010762caf4 _dispatch_block_invoke_direct + 592
10  libdispatch.dylib                   0x000000010762743c _dispatch_client_callout + 8
11  libdispatch.dylib                   0x000000010762caf4 _dispatch_block_invoke_direct + 592
12  libdispatch.dylib                   0x000000010762c884 dispatch_block_perform + 109
13  Foundation                          0x0000000103d16ce4 __NSOQSchedule_f + 342
14  libdispatch.dylib                   0x000000010762743c _dispatch_client_callout + 8
15  libdispatch.dylib                   0x000000010762d856 _dispatch_continuation_pop + 967
16  libdispatch.dylib                   0x000000010762bc86 _dispatch_async_redirect_invoke + 780
17  libdispatch.dylib                   0x00000001076331f9 _dispatch_root_queue_drain + 772
18  libdispatch.dylib                   0x0000000107632e97 _dispatch_worker_thread3 + 132
19  libsystem_pthread.dylib             0x0000000107bbb5a2 _pthread_wqthread + 1299
20  libsystem_pthread.dylib             0x0000000107bbb07d start_wqthread + 13

Any idea on how to trace that?

I'm not sure if that would help, but this part of the same log. I do not know if the cause is in cacheKey or in UIImageView.setPosition. If you need more information, let me know, I'll be happy to help.

2017-11-02 17:43:15.303185-0400 App[15217:9896139] *** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [156.833 nan]'

0   CoreFoundation                      0x00000001070ec1cb __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x0000000106600f41 objc_exception_throw + 48
2   CoreFoundation                      0x0000000107160b95 +[NSException raise:format:] + 197
3   QuartzCore                          0x000000010390e1bc _ZN2CA5Layer12set_positionERKNS_4Vec2IdEEb + 152
4   QuartzCore                          0x00000001038fec76 -[CALayer setPosition:] + 43
5   QuartzCore                          0x00000001038ff30b -[CALayer setFrame:] + 549
6   UIKit                               0x000000010452f45e -[UIView(Geometry) setFrame:] + 368
7   UIKit                               0x00000001046a6a9e -[UIImageView _setViewGeometry:forMetric:] + 176
8   UIKit                               0x00000001046a6db2 -[UIImageView setFrame:] + 58
9   UIKit                               0x000000010457209e -[UIScrollView _layoutVerticalScrollIndicatorWithBounds:effectiveInset:contentOffset:fraction:additionalInset:cornerAdjust:showing:recalcSize:] + 2153
10  UIKit                               0x00000001045714e1 -[UIScrollView _adjustScrollerIndicators:alwaysShowingThem:] + 1521
11  UIKit                               0x000000010455d904 -[UIScrollView setContentOffset:] + 553
12  UIKit                               0x000000010457dc00 _UIScrollViewAdjustForOverlayInsetsChangeIfNecessary + 687
13  UIKit                               0x000000010457df56 -[UIScrollView(UIScrollViewInternal) setSafeAreaInsets:] + 389
14  UIKit                               0x00000001045217b1 -[UIView _updateSafeAreaInsets] + 125
15  UIKit                               0x000000010454f5ee -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1692
16  QuartzCore                          0x000000010390549a -[CALayer layoutSublayers] + 153
17  QuartzCore                          0x0000000103909589 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 401
18  QuartzCore                          0x00000001038920fd _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 365
19  QuartzCore                          0x00000001038bda14 _ZN2CA11Transaction6commitEv + 500
20  UIKit                               0x00000001044a8c03 _afterCACommitHandler + 272
21  CoreFoundation                      0x000000010708edb7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
22  CoreFoundation                      0x000000010708ed0e __CFRunLoopDoObservers + 430
23  CoreFoundation                      0x0000000107073324 __CFRunLoopRun + 1572
24  CoreFoundation                      0x0000000107072a89 CFRunLoopRunSpecific + 409
25  GraphicsServices                    0x00000001083709c6 GSEventRunModal + 62
26  UIKit                               0x000000010447e23c UIApplicationMain + 159
27  App                       		0x000000010070dbdf main + 111
28  libdyld.dylib                       0x00000001076a3d81 start + 1
29  ???                                 0x0000000000000001 0x0 + 1

Thanks.

Hello adrianolucas,

You should try:

- (NSString *)cacheKey
{
    if (_cacheKey) return _cacheKey;
    
    __block NSString* s;
    
    dispatch_block_t block = ^{
        s = [NSString stringWithFormat:@"%@_%@_%.2f_%.2f_%.2f_%@_%@_%.2f_%.2f_%@",
                       _imageContentURL ?: [self imageHash:_originalImage],
                       NSStringFromCGSize(self.bounds.size),
                       _reflectionGap,
                       _reflectionScale,
                       _reflectionAlpha,
                       [self colorHash:_shadowColor],
                       NSStringFromCGSize(_shadowOffset),
                       _shadowBlur,
                       _cornerRadius,
                       @(self.contentMode)];
    };

    if ([NSThread currentThread].isMainThread) {
        block();
    } else {
        dispatch_sync(dispatch_get_main_queue(), block);
    }
    
    return s;
}

For more info:
https://developer.apple.com/documentation/code_diagnostics/main_thread_checker

[art-lucas]

Hi Nick,

That removed the warning as well as the trace log. Thanks a lot. The other part of the crash I mentioned in my post is due to the combination of XCode 9.0.1 with iPhone X, apparently. I'm downloading the freshly released 9.1 version today and will give a try.

Thanks again for your help.

[art-lucas]

Update:

The crash that ended up in --

App[15217:9896139] *** Terminating app due to uncaught exception 'CALayerInvalidGeometry',
reason: 'CALayer position contains NaN: [156.833 nan]'

0   CoreFoundation                      0x00000001070ec1cb __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x0000000106600f41 objc_exception_throw + 48
2   CoreFoundation                      0x0000000107160b95 +[NSException raise:format:] + 197
3   QuartzCore                          0x000000010390e1bc _ZN2CA5Layer12set_positionERKNS_4Vec2IdEEb + 152
4   QuartzCore                          0x00000001038fec76 -[CALayer setPosition:] + 43
5   QuartzCore                          0x00000001038ff30b -[CALayer setFrame:] + 549
6   UIKit                               0x000000010452f45e -[UIView(Geometry) setFrame:] + 368
7   UIKit                               0x00000001046a6a9e -[UIImageView _setViewGeometry:forMetric:] + 176
8   UIKit                               0x00000001046a6db2 -[UIImageView setFrame:] + 58
9   UIKit                               0x000000010457209e -[UIScrollView _layoutVerticalScrollIndicatorWithBounds:effectiveInset:contentOffset:fraction:additionalInset:cornerAdjust:showing:recalcSize:] + 2153
...
...

and that occurred only with iOS 11 on iPhone X (simulator) and Xcode 9.0.1 has been fixed with Xcode 9.1