UIKit calls on a background thread? about dznphotopickercontroller

[dzenbot]

Every UIKit call is made on the main thread. I don't think that's the cause.

The only multi-thread calls are made by its dependecies, AFNetworking and SDWebImage. Perhaps that's where you should look at.

[Alifar]

Thak you for your quick reply. Did you tested it yourself from your sample code?

[dzenbot]

I haven't test it myself yet (afk), but will do it as soon as I can.
I remember the sample project was working perfectly before, perhaps some latest commits introduced this bug.

[Alifar]

Hi there, did you tested already?

[dzenbot]

I've tested this on iOS7 and iOS8, without being able to reproduce. Sorry.
Did you find a workaround?

[tjanela]

From my understanding, [DZNPhotoEditorViewContoller editImage] is accessed from a BG thread on the [DZNPhotoEditorViewController acceptEdition] method, since the code creates a new background queue and invokes editImage inside the BG dispatch block.

Since the editImage accesses several properties of views this triggers the UI Thread checker of iOS.

Maybe this is where the problem lies.

=================================================================
Main Thread Checker: UI API called on a background thread: -[UIView bounds]
PID: 5925, TID: 12886857, Thread name: (none), Queue name: com.apple.root.background-qos, QoS: 9
Backtrace:
4   DZNPhotoPickerController            0x000000010fa1fb00 -[DZNPhotoEditorViewController cropSize] + 208
5   DZNPhotoPickerController            0x000000010fa1fdaa -[DZNPhotoEditorViewController guideRect] + 250
6   DZNPhotoPickerController            0x000000010fa212c5 -[DZNPhotoEditorViewController editedImage] + 245
7   DZNPhotoPickerController            0x000000010fa22d96 __46-[DZNPhotoEditorViewController acceptEdition:]_block_invoke + 54
8   libdispatch.dylib                   0x000000011514c595 _dispatch_call_block_and_release + 12
9   libdispatch.dylib                   0x000000011514d602 _dispatch_client_callout + 8
10  libdispatch.dylib                   0x000000011515e1eb _dispatch_root_queue_drain + 832
11  libdispatch.dylib                   0x000000011515e9af _dispatch_worker_thread2 + 130
12  libsystem_pthread.dylib             0x000000011553c70e _pthread_wqthread + 619
13  libsystem_pthread.dylib             0x000000011553c435 start_wqthread + 13
2018-12-01 12:34:27.442665-0500 ...[5925:12886857] [reports] Main Thread Checker: UI API called on a background thread: -[UIView bounds]
PID: 5925, TID: 12886857, Thread name: (none), Queue name: com.apple.root.background-qos, QoS: 9
Backtrace:
4   DZNPhotoPickerController            0x000000010fa1fb00 -[DZNPhotoEditorViewController cropSize] + 208
5   DZNPhotoPickerController            0x000000010fa1fdaa -[DZNPhotoEditorViewController guideRect] + 250
6   DZNPhotoPickerController            0x000000010fa212c5 -[DZNPhotoEditorViewController editedImage] + 245
7   DZNPhotoPickerController            0x000000010fa22d96 __46-[DZNPhotoEditorViewController acceptEdition:]_block_invoke + 54
8   libdispatch.dylib                   0x000000011514c595 _dispatch_call_block_and_release + 12
9   libdispatch.dylib                   0x000000011514d602 _dispatch_client_callout + 8
10  libdispatch.dylib                   0x000000011515e1eb _dispatch_root_queue_drain + 832
11  libdispatch.dylib                   0x000000011515e9af _dispatch_worker_thread2 + 130
12  libsystem_pthread.dylib             0x000000011553c70e _pthread_wqthread + 619
13  libsystem_pthread.dylib             0x000000011553c435 start_wqthread + 13