Xcode 9 Main Thread Checker warnings

[phucnm]

I notice that when I enable Main Thread Checker in Xcode 9, I see these warnings when GetAppController() method in UnityAppController.h is called.

Calling UI API from another thread rather than Main thread more or less cause some lags in the UI drawing I believe. Does anyone suggest a good way to fix this ?

Thanks in advanced.

Here's full log:

2017-10-26 11:57:16.365031+0700 nexus[3836:955175] [reports] Main Thread Checker: UI API called on a background thread: -[UIApplication delegate]
PID: 3836, TID: 955175, Thread name: (none), Queue name: NSOperationQueue 0x1c4e3ee00 (QOS: UNSPECIFIED), QoS: 0
Backtrace:
4   nexus                               0x000000010083cf04 UnityCurrentOrientation + 64
5   nexus                               0x00000001015debac _Z20UnityReorientVector3fff + 36
6   nexus                               0x00000001015deaa4 __UnityCoreMotionStart_block_invoke + 292
7   Foundation                          0x0000000183e72310 <redacted> + 16
8   Foundation                          0x0000000183db29e4 <redacted> + 72
9   Foundation                          0x0000000183da2620 <redacted> + 848
10  libdispatch.dylib                   0x000000010f10545c _dispatch_client_callout + 16
11  libdispatch.dylib                   0x000000010f111b74 _dispatch_block_invoke_direct + 268
12  libdispatch.dylib                   0x000000010f10545c _dispatch_client_callout + 16
13  libdispatch.dylib                   0x000000010f111b74 _dispatch_block_invoke_direct + 268
14  libdispatch.dylib                   0x000000010f111a34 dispatch_block_perform + 104
15  Foundation                          0x0000000183e73fe8 <redacted> + 376
16  libdispatch.dylib                   0x000000010f10545c _dispatch_client_callout + 16
17  libdispatch.dylib                   0x000000010f112800 _dispatch_continuation_pop + 592
18  libdispatch.dylib                   0x000000010f11109c _dispatch_async_redirect_invoke + 628
19  libdispatch.dylib                   0x000000010f116b54 _dispatch_root_queue_drain + 616
20  libdispatch.dylib                   0x000000010f116880 _dispatch_worker_thread3 + 136
21  libsystem_pthread.dylib             0x00000001830d3130 _pthread_wqthread + 1268
22  libsystem_pthread.dylib             0x00000001830d2c30 start_wqthread + 4

[basiralam]

I am facing the similar warnings:

Main Thread Checker: UI API called on a background thread: -[UIApplication delegate]
PID: 12605, TID: 2082348, Thread name: (none), Queue name: NSOperationQueue 0x1c42368c0 (QOS: UNSPECIFIED), QoS: 0
Backtrace:
4   TestUnity                    0x0000000100b7b65c UnityCurrentOrientation + 60
5   TestUnity                    0x0000000100b689e8 __UnityCoreMotionStart_block_invoke + 108
6   Foundation                          0x0000000182f36310 <redacted> + 16
7   Foundation                          0x0000000182e769e4 <redacted> + 72
8   Foundation                          0x0000000182e66620 <redacted> + 848
9   libdispatch.dylib                   0x0000000181ef1048 <redacted> + 16
10  libdispatch.dylib                   0x0000000181ef86c8 <redacted> + 288
11  libdispatch.dylib                   0x0000000181ef1048 <redacted> + 16
12  libdispatch.dylib                   0x0000000181ef86c8 <redacted> + 288
13  libdispatch.dylib                   0x0000000181ef8574 <redacted> + 104
14  Foundation                          0x0000000182f37fe8 <redacted> + 376
15  libdispatch.dylib                   0x0000000181ef1048 <redacted> + 16
16  libdispatch.dylib                   0x0000000181ef93d4 <redacted> + 428
17  libdispatch.dylib                   0x0000000181ef7cd4 <redacted> + 604
18  libdispatch.dylib                   0x0000000181efe1c8 <redacted> + 596
19  libdispatch.dylib                   0x0000000181efdf10 <redacted> + 120
20  libsystem_pthread.dylib             0x0000000182197130 _pthread_wqthread + 1268
21  libsystem_pthread.dylib             0x0000000182196c30 start_wqthread + 4

[piechart]

Did anybody managed to solve this? Also faced that warning

UPD: ok, I used a dirty trick to overcome this issue by searing for GetAppController() and wrap this line to dispatch_async(dispatch_get_main_queue(), ^{ });
In mostly all UIViewController lifecycle methods and a few starting extern "C" as if you add this wrap everywhere, you're good to get yet another crash
Main thread checker warning has gone

[phucnm]

https://issuetracker.unity3d.com/issues/ios11-api-called-on-a-background-thread-uiapplication-delegate-unitycurrentorientation-on-launch-in-an-empty-project

It seems to be fixed in 2018.1