Pekaboo crashes on iOS with "startRunning may not be called between calls to beginConfiguration and commitConfiguration"

[shtolik]

There were crashes on iOS devices when retaking images again and initialCameraMode is passed to rememberPeekabooCameraState.

Not on every image retake, but quite often. I was able to reproduce the problem by adding it into sample code of camera setup in this repo as well. val state = rememberPeekabooCameraState(initialCameraMode = cameraMode, onCapture = onCapture) where cameraMode is passed as variable to PeekabooCameraView (i think it wasn't crashing if i just set locally initialCameraMode = CameraMode.Back, but not sure).

That's the crash description

** Terminating app due to uncaught exception 'NSGenericException', reason: '*** -[AVCaptureSession startRunning] startRunning may not be called between calls to beginConfiguration and commitConfiguration'

And then debug breakpoint is activate in the place below.

PeekabooCamera.ios.kt
...

@OptIn(ExperimentalForeignApi::class)
@Composable
private fun RealDeviceCamera(
    state: PeekabooCameraState,
    camera: AVCaptureDevice,
    modifier: Modifier,
) {
....
    UIKitView(
        modifier = modifier,
        background = Color.Black,
        factory = {
            val dispatchGroup = dispatch_group_create()
            val cameraContainer = UIView()
            cameraContainer.layer.addSublayer(cameraPreviewLayer)
            cameraPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
            dispatch_group_enter(dispatchGroup)
            dispatch_async(queue) {
-- crash break point -->                captureSession.startRunning()
                dispatch_group_leave(dispatchGroup)
            }

So I stopped passing that variable in my app and I think it helped, but need to test on more device - so there is a workaround, but would be great to fix it.

[shtolik]

So it may not be this camerMode related, still crashes without setting it on ios quite often:(

[nickfaces]

@shtolik

In PeekabooCamera.ios.kt try change this

        dispatch_group_enter(dispatchGroup)
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT.toLong(), 0UL)) {
            captureSession.startRunning()
            dispatch_group_leave(dispatchGroup)
        }
        captureSession.commitConfiguration()

        dispatch_group_notify(dispatchGroup, dispatch_get_main_queue()) {
            onCameraReady()
        }

to

        captureSession.commitConfiguration()

        dispatch_async(queue) {
            captureSession.startRunning()

            dispatch_async(dispatch_get_main_queue()) {
                state.onCameraReady()
            }
        }