AVCaptureSession can't stopRunning between calls to beginConfiguration / commitConfiguration
tettoffensive opened this issue · comments
Getting this crash from some of our users:
AVCaptureSession can't stopRunning between calls to beginConfiguration / commitConfiguration
Fatal Exception: NSGenericException
0 CoreFoundation 0x18118ae38 __exceptionPreprocess
1 libobjc.A.dylib 0x1807eff80 objc_exception_throw
2 AVFoundation 0x1878ca0fc -[AVCaptureSession stopRunning]
3 PBJVision 0x1011b66a4 __24-[PBJVision stopPreview]_block_invoke (PBJVision.m:1214)
4 libdispatch.dylib 0x180bd54bc _dispatch_call_block_and_release
5 libdispatch.dylib 0x180bd547c _dispatch_client_callout
6 libdispatch.dylib 0x180be14c0 _dispatch_queue_drain
7 libdispatch.dylib 0x180bd8f80 _dispatch_queue_invoke
8 libdispatch.dylib 0x180bd547c _dispatch_client_callout
9 libdispatch.dylib 0x180be3914 _dispatch_root_queue_drain
10 libdispatch.dylib 0x180be30b0 _dispatch_worker_thread3
11 libsystem_pthread.dylib 0x180ded470 _pthread_wqthread
12 libsystem_pthread.dylib 0x180ded020 start_wqthread
This is also a hugely common crash for our app as recorded by crashlytics.
My guess is this is a concurrency issue:
Since most places begin/commit we're on the capture session queue. but not in this block of code in - (void)_sessionStarted:(NSNotification *)notification. Here's what I'm thinking to modify.
AVCaptureDevice *device = [_currentInput device];
if (device) {
[self _enqueueBlockOnCaptureSessionQueue:^{
[self willChangeValueForKey:@"currentDevice"];
[self _setCurrentDevice:device];
[self didChangeValueForKey:@"currentDevice"];
}];
}
Hey @tettoffensive thanks for the interest in the library and your comments. I haven't been able to work on contributions due to a contract I'm involved with at the moment. If you or others submit a pull request, I can get a collaborator to get it merged in.