Question

So here’s my problem: I’ve created a custom AVCaptureSession that takes pictures. I’m not sure why, but the third time you call startRunning, it crashes. I implemented didReceiveMemoryWarning, and it wasn’t called before it crashed. I also ran instruments on it and there were no memory leaks associated with the AVCaptureSession. There were also no logs via console in XCode.

So my question is… is it a memory problem even though the didReceiveMemoryWarning wasn’t called? Here’s some of my code.

viewWillDisappear (ViewController)

- (void)viewWillDisappear:(BOOL)animated {
if (cameraFlashButton) { [cameraFlashButton release]; }
if (switchCamera) { [switchCamera release]; }
if (cameraBadgeBack) { [cameraBadgeBack release]; }
if (cameraBadgeNumber) { [cameraBadgeNumber release]; }
if (cameraUseButton) { [cameraUseButton release]; }
if (cameraOverlayView) { [cameraOverlayView release]; }
if (blackOverlay) { [blackOverlay release]; }
if (loadingIndicator) { [loadingIndicator release]; }
if (cameraPickButton) { [cameraPickButton release]; }
if (whiteOverlay) { [whiteOverlay release]; }
if (imageOverlay) { [imageOverlay release]; }
if (captureManager) { [captureManager release], captureManager = nil; }
if (theCaptureSession) { [theCaptureSession release], theCaptureSession = nil; }
[super viewWillDisappear:YES];
}

dealloc (CaptureSessionManager)

- (void)dealloc {
if ([self captureSession]) { [[self captureSession] stopRunning]; }
if (previewLayer) { [previewLayer release], previewLayer = nil; }
if (captureSession) { [captureSession release], captureSession = nil; }
if (stillImageOutput) { [stillImageOutput release], stillImageOutput = nil; }
if (stillImage) { [stillImage release], stillImage = nil; }
[super dealloc];
}

Ideas? If you need to see anything else, just ask! Thanks in advance.

Answer 1

If didReceiveMemoryWarning was properly implemented and it was never called, your problem is likely not due to running out of memory. There are many other ways you can get a crash when you start your capture session running. You’d need to post more of your implementation along with details of the crash to help debug this.

However, the code you posted has a number of inefficiencies and style problems. Note in Objective-C messages to nil are perfectly fine. So in your viewWillDisappear and dealloc methods you can and should remove every if test readability. For example, instead of:

if (cameraFlashButton) { [cameraFlashButton release]; }

just use:

[cameraFlashButton release];

If you are using properly synthesized accessors it is also much better to replace lines like

if (previewLayer) { [previewLayer release], previewLayer = nil; }

with simply

self.previewLayer = nil;