After upgrading to iOS 17, Thread Performance Checker is complaining of priority inversion when converting a CVPixelBuffer to UIImage through a CIImage instance. It might be a false-positive or an issue?
- (UIImage *)imageForSampleBuffer:(CMSampleBufferRef)sampleBuffer andOrientation:(UIImageOrientation)orientation {
CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CIImage *ciImage = [CIImage imageWithCVPixelBuffer:pixelBuffer];
UIImage *uiImage = [UIImage imageWithCIImage:ciImage];
NSData *data = UIImageJPEGRepresentation(uiImage, 90);
}
The code snippet above, when running in a thread set to the default priority results in the message below:
Thread Performance Checker: Thread running at User-interactive quality-of-service class waiting on a lower QoS thread running at Default quality-of-service class. Investigate ways to avoid priority inversions
PID: 1188, TID: 723209
Backtrace
=================================================================
3 AGXMetalG14 0x0000000235c77cc8 1FEF1F89-B467-37B0-86F8-E05BC8A2A629 + 2927816
4 AGXMetalG14 0x0000000235ccd784 1FEF1F89-B467-37B0-86F8-E05BC8A2A629 + 3278724
5 AGXMetalG14 0x0000000235ccf6a4 1FEF1F89-B467-37B0-86F8-E05BC8A2A629 + 3286692
6 MetalTools 0x000000022f758b68 E712D983-01AD-3FE5-AB66-E00ABF76CD7F + 568168
7 CoreImage 0x00000001a7c0e580 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 267648
8 CoreImage 0x00000001a7d0cc08 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 1309704
9 CoreImage 0x00000001a7c0e2e0 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 266976
10 CoreImage 0x00000001a7c0e1d0 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 266704
11 libdispatch.dylib 0x0000000105e4a7bc _dispatch_client_callout + 20
12 libdispatch.dylib 0x0000000105e5be24 _dispatch_lane_barrier_sync_invoke_and_complete + 176
13 CoreImage 0x00000001a7c0a784 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 251780
14 CoreImage 0x00000001a7c0a46c 3D2AC243-0880-3BA9-BBF3-A214454875E0 + 250988
15 libdispatch.dylib 0x0000000105e5b764 _dispatch_block_async_invoke2 + 148
16 libdispatch.dylib 0x0000000105e4a7bc _dispatch_client_callout + 20
17 libdispatch.dylib 0x0000000105e5266c _dispatch_lane_serial_drain + 832
18 libdispatch.dylib 0x0000000105e5343c _dispatch_lane_invoke + 460
19 libdispatch.dylib 0x0000000105e524a4 _dispatch_lane_serial_drain + 376
20 libdispatch.dylib 0x0000000105e5343c _dispatch_lane_invoke + 460
21 libdispatch.dylib 0x0000000105e60404 _dispatch_root_queue_drain_deferred_wlh + 328
22 libdispatch.dylib 0x0000000105e5fa38 _dispatch_workloop_worker_thread + 444
23 libsystem_pthread.dylib 0x00000001f35a4f20 _pthread_wqthread + 288
24 libsystem_pthread.dylib 0x00000001f35a4fc0 start_wqthread + 8
