Can not find origin of "This application is modifying the autolayout engine from a background thread"
My app crash only the first time i log into it. It used the GoogleMaps (3.7.0) pod, and I suspect the error comes from that library:
Stack:(
0 Foundation 0x000000018c1b8550 80C31587-F538-3437-966F-300F6632EB95 + 2331984
1 Foundation 0x000000018bfb18c4 80C31587-F538-3437-966F-300F6632EB95 + 207044
2 Foundation 0x000000018bfb17d8 80C31587-F538-3437-966F-300F6632EB95 + 206808
3 Foundation 0x000000018bfb1448 80C31587-F538-3437-966F-300F6632EB95 + 205896
4 UIKitCore 0x000000019025a824 AA897CA9-8D15-3DD7-BB4F-8D90F9A28571 + 15611940
5 UIKitCore 0x000000019026db1c AA897CA9-8D15-3DD7-BB4F-8D90F9A28571 + 15690524
6 libobjc.A.dylib 0x000000018b9e0a4c A486C2B3-41B0-3F23-AF40-C5579F5BE97E + 6732
7 QuartzCore 0x0000000192883a9c A3363F67-6783-3979-8FA9-5563ABD4737D + 1403548
8 QuartzCore 0x0000000192883eec A3363F67-6783-3979-8FA9-5563ABD4737D + 1404652
9 QuartzCore 0x0000000192896614 A3363F67-6783-3979-8FA9-5563ABD4737D + 1480212
10 QuartzCore 0x00000001927db1c4 A3363F67-6783-3979-8FA9-5563ABD4737D + 713156
11 QuartzCore 0x0000000192805fd0 A3363F67-6783-3979-8FA9-5563ABD4737D + 888784
12 QuartzCore 0x0000000192806fb8 A3363F67-6783-3979-8FA9-5563ABD4737D + 892856
13 libsystem_pthread.dylib 0x000000018b9dd104 5F848A4C-4907-3FC9-A76D-378FE8F2E4FC + 37124
14 libsystem_pthread.dylib 0x000000018b9d58a0 5F848A4C-4907-3FC9-A76D-378FE8F2E4FC + 6304
15 libsystem_pthread.dylib 0x000000018b9d7a20 5F848A4C-4907-3FC9-A76D-378FE8F2E4FC + 14880
16 libsystem_pthread.dylib 0x000000018b9d7760 _pthread_wqthread + 424
17 libsystem_pthread.dylib 0x000000018b9dd9e8 start_wqthread + 8
)
This is the traces log that is shown XCode.
Editor screenshot:
This is how I received the callbacks from my ViewModel. I added DispatchQueue.main in all the outputs to try to avoid this exception, but is still popping up....
disposeBag.insert(
viewModel.outputs.onShowLoading
.bind { show in
DispatchQueue.main.async {
self.showLoading(show: show)
}
},
viewModel.outputs.onLoadDone
.bind { mapInfo in
DispatchQueue.main.async {
self.loadMap(mapInfo: mapInfo)
}
},
viewModel.outputs.onLoadError
.bind { error in
DispatchQueue.main.async {
print("ON LOAD ASSETS ERROR: \(error.localizedDescription)")
}
},
viewModel.outputs.onMultiClusterTap
.bind { paths in
DispatchQueue.main.async {
self.centerMap(paths: paths)
}
},
viewModel.outputs.onLoadAssetsInfoDone
.bind { assets in
DispatchQueue.main.async {
self.showBottomSheet(assets: assets)
}
},
viewModel.outputs.onDeviceChanged
.bind {
DispatchQueue.main.async {
self!.showDeviceChangedError()
}
}
)
Edit (02/05/2020): I try to find the error using NBUIKitMainThreadGuard
But still I couldn't find the source of thes error. In addition, I found out that the error also occurs after a log out - login. So is not just the first time I install the app.
Edit (07/05/2020): Maybe as Werner Altewischer pointed out, there is a graphic library that is messing this out. This is my podfile, maybe helps solve this:
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '11.0'
use_frameworks!
target 'WatchmanDoor' do
pod 'DropDown', '2.3.13'
pod 'GoogleMaps', '3.7.0'
pod 'GooglePlaces'
pod 'DKImagePickerController', '4.2.1'
pod 'Alamofire', '4.9.1'
pod 'iOSDFULibrary', '4.6.1'
pod 'RxSwift', '~> 5.0.1'
pod 'RxCocoa', '~> 5.0.1'
pod 'Swinject', '~> 2.7.1'
pod 'SwinjectAutoregistration', '~> 2.7.0'
pod 'SwinjectStoryboard', '~> 2.2.0'
pod 'FittedSheets', :git => 'https://github.com/WatchmanDoor/FittedSheets.git', :commit => '9824dd171499967226a4dd160aedc7d4d9db3a11'
pod 'SDWebImage', '~> 5.5.0'
pod 'NavigationDrawer', '1.0.2'
end
Could it be that the FittedSheets pod is the one that provokes the error? I fork the repository to update it to support Swift 5, but maybe is the one causing the exception.
UPDATE: Still facing the same error ... can not find anything else -_- Any idea where to start?
Full Crash Report:
Incident Identifier: 34A039F6-9E4A-4E5C-B9B4-AB531A8E8D93
CrashReporter Key: 5f326dac824b350bd2afaacbdb938d680de621bc
Hardware Model: iPhone8,4
Process: WatchmanDoor [476]
Path: /private/var/containers/Bundle/Application/717E7E5E-4E42-4950-B8C8-FC2042C09EDC/WatchmanDoor.app/WatchmanDoor
Identifier: com.stmseguridad.WatchmanDoor
Version: 1 (2.0.9)
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd [1]
Coalition: com.stmseguridad.WatchmanDoor [625]
Date/Time: 2020-04-16 14:21:00.9449 +0200
Launch Time: 2020-04-16 14:18:12.7530 +0200
OS Version: iPhone OS 13.4 (17E255)
Release Type: User
Baseband Version: 9.52.01
Report Version: 104
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x00000001a9d2d6e0
Termination Signal: Trace/BPT trap: 5
Termination Reason: Namespace SIGNAL, Code 0x5
Terminating Process: exc handler [476]
Triggered by Thread: 3
Last Exception Backtrace:
0 CoreFoundation 0x1aa0cc5f0 __exceptionPreprocess + 224
1 libobjc.A.dylib 0x1a9deebcc objc_exception_throw + 55
2 Foundation 0x1aa5a3dac _AssertAutolayoutOnAllowedThreadsOnly + 419
3 Foundation 0x1aa3b0c2c -[NSISEngine _optimizeWithoutRebuilding] + 67
4 Foundation 0x1aa3b0b48 -[NSISEngine optimize] + 111
5 Foundation 0x1aa3b07bc -[NSISEngine performPendingChangeNotifications] + 111
6 UIKitCore 0x1ae6132d0 -[UIView+ 15499984 (Hierarchy) layoutSubviews] + 307
7 UIKitCore 0x1ae625c7c -[UIView+ 15576188 (CALayerDelegate) layoutSublayersOfLayer:] + 2143
8 QuartzCore 0x1b0bbf4ac -[CALayer layoutSublayers] + 283
9 QuartzCore 0x1b0bc5604 CA::Layer::layout_if_needed+ 1406468 (CA::Transaction*) + 467
10 QuartzCore 0x1b0bd0148 CA::Layer::layout_and_display_if_needed+ 1450312 (CA::Transaction*) + 139
11 QuartzCore 0x1b0b18e34 CA::Context::commit_transaction+ 699956 (CA::Transaction*, double) + 295
12 QuartzCore 0x1b0b427c4 CA::Transaction::commit+ 870340 () + 675
13 QuartzCore 0x1b0b43764 CA::Transaction::release_thread+ 874340 (void*) + 227
14 libsystem_pthread.dylib 0x1a9de5f8c _pthread_tsd_cleanup + 579
15 libsystem_pthread.dylib 0x1a9de2df4 _pthread_exit + 79
16 libsystem_pthread.dylib 0x1a9de3e64 _pthread_wqthread_exit + 95
17 libsystem_pthread.dylib 0x1a9de3c04 _pthread_wqthread + 415
18 libsystem_pthread.dylib 0x1a9de6740 start_wqthread + 7
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0:
0 libobjc.A.dylib 0x00000001a9deab4c objc_msgSend + 44
1 AppleMetalGLRenderer 0x00000001c4b60624 GLDContextRec::setRenderState+ 54820 (unsigned int) + 84
2 AppleMetalGLRenderer 0x00000001c4b67084 gldRenderVertexArray+ 82052 (GLDContextRec*, unsigned int, unsigned int, int, int, unsigned int, void const*, int, void const*) + 1108
3 GLEngine 0x00000001c4ae3cd0 glDrawElements_ACC_ES2Exec + 416
4 WatchmanDoor 0x0000000103a12fcc 0x102c50000 + 14430156
5 WatchmanDoor 0x0000000103a17be0 0x102c50000 + 14449632
6 WatchmanDoor 0x0000000103ad4bb0 0x102c50000 + 15223728
7 WatchmanDoor 0x0000000103a1088c 0x102c50000 + 14420108
8 WatchmanDoor 0x0000000103a9ece8 0x102c50000 + 15002856
9 WatchmanDoor 0x0000000103a82788 0x102c50000 + 14886792
10 WatchmanDoor 0x0000000103acfc5c 0x102c50000 + 15203420
11 WatchmanDoor 0x0000000103a80da8 0x102c50000 + 14880168
12 WatchmanDoor 0x0000000103a7fc74 0x102c50000 + 14875764
13 QuartzCore 0x00000001b0a7f368 CA::Display::DisplayLink::dispatch_items+ 70504 (unsigned long long, unsigned long long, unsigned long long) + 516
14 IOKit 0x00000001ab010628 IODispatchCalloutFromCFMessage + 480
15 CoreFoundation 0x00000001aa021bc0 __CFMachPortPerform + 172
16 CoreFoundation 0x00000001aa04b200 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 56
17 CoreFoundation 0x00000001aa04a90c __CFRunLoopDoSource1 + 444
18 CoreFoundation 0x00000001aa0456c0 __CFRunLoopRun + 1888
19 CoreFoundation 0x00000001aa044c34 CFRunLoopRunSpecific + 424
20 GraphicsServices 0x00000001b418e38c GSEventRunModal + 160
21 UIKitCore 0x00000001ae17722c UIApplicationMain + 1932
22 WatchmanDoor 0x000000010360fa9c 0x102c50000 + 10222236
23 libdyld.dylib 0x00000001a9ecc800 start + 4
Thread 1 name: com.apple.uikit.eventfetch-thread
Thread 1:
0 libsystem_kernel.dylib 0x00000001a9ea0198 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001a9e9f60c mach_msg + 72
2 CoreFoundation 0x00000001aa04a3b4 __CFRunLoopServiceMachPort + 148
3 CoreFoundation 0x00000001aa0453e8 __CFRunLoopRun + 1160
4 CoreFoundation 0x00000001aa044c34 CFRunLoopRunSpecific + 424
5 Foundation 0x00000001aa387bcc -[NSRunLoop+ 31692 (NSRunLoop) runMode:beforeDate:] + 228
6 Foundation 0x00000001aa387aac -[NSRunLoop+ 31404 (NSRunLoop) runUntilDate:] + 88
7 UIKitCore 0x00000001ae219160 -[UIEventFetcher threadMain] + 152
8 Foundation 0x00000001aa4b69d0 __NSThread__start__ + 848
9 libsystem_pthread.dylib 0x00000001a9de2d98 _pthread_start + 156
10 libsystem_pthread.dylib 0x00000001a9de674c thread_start + 8
Thread 2:
0 libsystem_pthread.dylib 0x00000001a9de6738 start_wqthread + 0
Thread 3 Crashed:
0 libsystem_c.dylib 0x00000001a9d2d6e0 __abort + 144
1 libsystem_c.dylib 0x00000001a9d2d6e0 __abort + 144
2 libsystem_c.dylib 0x00000001a9d2d650 __abort + 0
3 libc++abi.dylib 0x00000001a9e95cc0 __cxxabiv1::__aligned_malloc_with_fallback+ 76992 (unsigned long) + 0
4 libc++abi.dylib 0x00000001a9e87e10 demangling_unexpected_handler+ 19984 () + 0
5 libobjc.A.dylib 0x00000001a9deee80 _objc_terminate+ 24192 () + 124
6 libc++abi.dylib 0x00000001a9e9514c std::__terminate(void (*)+ 74060 ()) + 16
7 libc++abi.dylib 0x00000001a9e97bd8 __cxa_get_exception_ptr + 0
8 libc++abi.dylib 0x00000001a9e97b98 __cxxabiv1::exception_cleanup_func+ 84888 (_Unwind_Reason_Code, _Unwind_Exception*) + 0
9 libobjc.A.dylib 0x00000001a9deecf8 _objc_exception_destructor+ 23800 (void*) + 0
10 Foundation 0x00000001aa5a3dac -[NSISEngine tryToOptimizeReturningMutuallyExclusiveConstraints] + 0
11 Foundation 0x00000001aa3b0c2c -[NSISEngine _optimizeWithoutRebuilding] + 68
12 Foundation 0x00000001aa3b0b48 -[NSISEngine optimize] + 112
13 Foundation 0x00000001aa3b07bc -[NSISEngine performPendingChangeNotifications] + 112
14 UIKitCore 0x00000001ae6132d0 -[UIView+ 15499984 (Hierarchy) layoutSubviews] + 308
15 UIKitCore 0x00000001ae625c7c -[UIView+ 15576188 (CALayerDelegate) layoutSublayersOfLayer:] + 2144
16 QuartzCore 0x00000001b0bbf4ac -[CALayer layoutSublayers] + 284
17 QuartzCore 0x00000001b0bc5604 CA::Layer::layout_if_needed+ 1406468 (CA::Transaction*) + 468
18 QuartzCore 0x00000001b0bd0148 CA::Layer::layout_and_display_if_needed+ 1450312 (CA::Transaction*) + 140
19 QuartzCore 0x00000001b0b18e34 CA::Context::commit_transaction+ 699956 (CA::Transaction*, double) + 296
20 QuartzCore 0x00000001b0b427c4 CA::Transaction::commit+ 870340 () + 676
21 QuartzCore 0x00000001b0b43764 CA::Transaction::release_thread+ 874340 (void*) + 228
22 libsystem_pthread.dylib 0x00000001a9de5f8c _pthread_tsd_cleanup + 580
23 libsystem_pthread.dylib 0x00000001a9de2df4 _pthread_exit + 80
24 libsystem_pthread.dylib 0x00000001a9de3e64 _pthread_wqthread_legacy_worker_wrap + 0
25 libsystem_pthread.dylib 0x00000001a9de3c04 _pthread_wqthread + 416
26 libsystem_pthread.dylib 0x00000001a9de6740 start_wqthread + 8
Thread 4 name: com.apple.NSURLConnectionLoader
Thread 4:
0 libsystem_kernel.dylib 0x00000001a9ea0198 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001a9e9f60c mach_msg + 72
2 CoreFoundation 0x00000001aa04a3b4 __CFRunLoopServiceMachPort + 148
3 CoreFoundation 0x00000001aa0453e8 __CFRunLoopRun + 1160
4 CoreFoundation 0x00000001aa044c34 CFRunLoopRunSpecific + 424
5 CFNetwork 0x00000001ad309c44 0x1ad308000 + 7236
6 Foundation 0x00000001aa4b69d0 __NSThread__start__ + 848
7 libsystem_pthread.dylib 0x00000001a9de2d98 _pthread_start + 156
8 libsystem_pthread.dylib 0x00000001a9de674c thread_start + 8
Thread 5 name: com.google.Maps.LabelingBehavior
Thread 5:
0 libsystem_kernel.dylib 0x00000001a9ea0198 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001a9e9f60c mach_msg + 72
2 CoreFoundation 0x00000001aa04a3b4 __CFRunLoopServiceMachPort + 148
3 CoreFoundation 0x00000001aa0453e8 __CFRunLoopRun + 1160
4 CoreFoundation 0x00000001aa044c34 CFRunLoopRunSpecific + 424
5 Foundation 0x00000001aa387bcc -[NSRunLoop+ 31692 (NSRunLoop) runMode:beforeDate:] + 228
6 WatchmanDoor 0x0000000103b4e330 0x102c50000 + 15721264
7 Foundation 0x00000001aa4b69d0 __NSThread__start__ + 848
8 libsystem_pthread.dylib 0x00000001a9de2d98 _pthread_start + 156
9 libsystem_pthread.dylib 0x00000001a9de674c thread_start + 8
Thread 6:
0 libsystem_pthread.dylib 0x00000001a9de6738 start_wqthread + 0
Thread 7:
0 libsystem_pthread.dylib 0x00000001a9de6738 start_wqthread + 0
Thread 8:
0 libsystem_pthread.dylib 0x00000001a9de6738 start_wqthread + 0
Thread 3 crashed with ARM Thread State (64-bit):
x0: 0x0000000000000000 x1: 0x0000000000000000 x2: 0x0000000000000000 x3: 0x0000000000000001
x4: 0x0000000000000000 x5: 0x0000000000989680 x6: 0x000000000000006e x7: 0x0000000000000001
x8: 0x0000000000000000 x9: 0x0000000000000002 x10: 0x000000002daafd89 x11: 0x000000000000000b
x12: 0x00000001e48ea080 x13: 0x0000000000000000 x14: 0x0000000000000010 x15: 0x0000000000000000
x16: 0x0000000000000030 x17: 0x00000002d7ffffff x18: 0x0000000000000000 x19: 0x000000016d57ec48
x20: 0x00000001f3404c80 x21: 0x000000016d57ed00 x22: 0x0000000169ba05b0 x23: 0x00000001e4b8c000
x24: 0x0000000000000001 x25: 0x0000000000000068 x26: 0x000000000000009c x27: 0x0000000000000068
x28: 0x000000002b310019 fp: 0x000000016d57ec60 lr: 0x00000001a9d2d6e0
sp: 0x000000016d57ec30 pc: 0x00000001a9d2d6e0 cpsr: 0x80000000
esr: 0xf2000001 Address size fault
IMPORTANT UPDATE: I found out that, when the app crashes, my stack view is full of UITRANSITIONVIEW. Don't know if this is related ...
SOLUTION [13/05/2020] So I think I found where the error came from. See the answer below.
asked on Stack Overflow Jan 23, 2020 by 
Carlos Cáceres González • edited May 15, 2020 by Carlos Cáceres González
Carlos Cáceres González • edited May 15, 2020 by Carlos Cáceres González2 Answers
Obviously the background thread in question (Thread 17) is accessing some UIKit method directly which in general is not allowed (can only be done from the main thread).
Did you dispatch some method on a background thread using GCD's dispatch async?
answered on Stack Overflow Jan 23, 2020 by 
Werner Altewischer
Werner AltewischerSo I think I found where the error came from. When I received the response from my API with the asset list, I create a MapInfoModel like this:
private func generateMapInfo(assets: [APIAssetModel]) -> MapInfoModel {
var markers = [ClusterMarkerItem]()
var locations = [CLLocationCoordinate2D]()
assets.forEach({ asset in
if nil != asset.lat && nil != asset.lng {
if asset.lat! > -85 && asset.lat! < 85 {
let latlng = CLLocationCoordinate2D(latitude: asset.lat!, longitude: asset.lng!)
for index in 0..<(asset.productsCount ?? 0) {
let marker = GMSMarker(position: latlng)
marker.title = "\(asset.id)_\(index)"
markers.append(ClusterMarkerItem(position: latlng,
marker: marker,
asset: asset,
prod_position: index))
}
locations.append(latlng)
}
}
})
return MapInfoModel(assetList: assets, clusterList: markers, locationList: locations)
}
This method was called from a background thread and, as you can see, I was instantiating a GMSMarker. This doesn't rise any error/warning and the map is loaded and showing the clusters well. But, here is the thing, I suspect that after loading the cluster, Google Maps SDK does something with the GMSMarkers loaded in it, and I suspect that, that action is been called from the thread where GMSMarker was created, so, if it was created from a background thread, XCode will show the error:
This application is modifying the autolayout engine from a background thread
I'm just guessing but, I am waiting for Google to confirm this. So the solution was to instantiate GMSMarker from Main thread (in this case I use DispatchQueue.main.async{}).
UPDATE Google just email me and confirm it. This is what they said:
Our specialists have confirmed that all Marker creation and updates should be happening on the main thread.
This is because all drawing and rendering in iOS has to happen on the main thread, and updates done to the markers translates into that directly.
We will be working on including this information in our official documentation for future references.
answered on Stack Overflow May 15, 2020 by Carlos Cáceres González
Carlos Cáceres GonzálezUser contributions licensed under CC BY-SA 3.0