iPhone: OpenAL & AudioToolbox leak

问题

I work with OpenAL to play sounds in my app. When I test it using Instruments tool, it finds a leak:
LeakedObject = GeneralBlock-512
Size = 512 Bytes
Responsible Library = AudioToolbox
Responsible Frame = AU3DMixerEmbeddedInputElement::Initialize()

Stack trace:

   0 libSystem.B.dylib malloc
   1 libstdc++.6.dylib operator new(unsigned long)
   2 libstdc++.6.dylib operator new[](unsigned long)
   3 AudioToolbox AU3DMixerEmbeddedInputElement::Initialize()
   4 AudioToolbox AU3DMixerEmbedded::SetProperty(unsigned long, unsigned long, unsigned long, void const*, unsigned long)
   5 AudioToolbox AUBase::DispatchSetProperty(unsigned long, unsigned long, unsigned long, void const*, unsigned long)
   6 AudioToolbox AUMethodSetProperty(void*, unsigned long, unsigned long, unsigned long, void const*, unsigned long)
   7 OpenAL OALContext::InitializeMixer(unsigned long)
   8 OpenAL OALContext::OALContext(unsigned long, OALDevice*, int const*, unsigned long&, double&)
   9 OpenAL alcCreateContext
  10 myApp -[myAudioManager initOpenAL] /Users/kpower/Documents/projects/myApp/Classes/myAudioManager.m:197
  11 myApp -[myAudioManager init] /Users/kpower/Documents/projects/myApp/Classes/myAudioManager.m:83
  12 myApp +[myAudioManager sharedInstance] /Users/kpower/Documents/projects/myApp/Classes/myAudioManager.m:316
  13 myApp -[myMainMenu viewDidLoad] /Users/kpower/Documents/projects/myApp/Classes/myMainMenu.m:46
  14 UIKit -[UIViewController view]
  15 UIKit -[UIViewController contentScrollView]
  16 UIKit -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:]
  17 UIKit -[UINavigationController _layoutViewController:]
  18 UIKit -[UINavigationController _startTransition:fromViewController:toViewController:]
  19 UIKit -[UINavigationController _startDeferredTransitionIfNeeded]
  20 UIKit -[UINavigationController viewWillLayoutSubviews]
  21 UIKit -[UILayoutContainerView layoutSubviews]
  22 UIKit -[UIView(CALayerDelegate) _layoutSublayersOfLayer:]
  23 CoreFoundation -[NSObject(NSObject) performSelector:withObject:]
  24 QuartzCore -[CALayer layoutSublayers]
  25 QuartzCore CALayerLayoutIfNeeded
  26 QuartzCore -[CALayer layoutIfNeeded]
  27 UIKit -[UIView(Hierarchy) layoutIfNeeded]
  28 UIKit -[UIViewController window:willAnimateRotationToInterfaceOrientation:duration:]
  29 UIKit -[UIWindow _setRotatableClient:toOrientation:duration:force:]
  30 UIKit -[UIWindow _setRotatableViewOrientation:duration:force:]
  31 UIKit -[UIWindow _updateToInterfaceOrientation:duration:force:]
  32 UIKit -[UIWindow setAutorotates:forceUpdateInterfaceOrientation:]
  33 UIKit -[UIWindow setDelegate:]
  34 UIKit -[UIViewController _tryBecomeRootViewControllerInWindow:]
  35 UIKit -[UIViewController viewDidMoveToWindow:shouldAppearOrDisappear:]
  36 UIKit -[UINavigationController viewDidMoveToWindow:shouldAppearOrDisappear:]
  37 UIKit -[UIView(Internal) _didMoveFromWindow:toWindow:]
  38 UIKit -[UIView(Hierarchy) _postMovedFromSuperview:]
  39 UIKit -[UIView(Internal) _addSubview:positioned:relativeTo:]
  40 UIKit -[UIView(Hierarchy) addSubview:]
  41 myApp -[myAppAppDelegate applicationDidFinishLaunching:] /Users/kpower/Documents/projects/myApp/Classes/myAppAppDelegate.m:19
  42 UIKit -[UIApplication _callInitializationDelegatesForURL:payload:suspended:]
  43 UIKit -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:]
  44 UIKit -[UIApplication handleEvent:withNewEvent:]
  45 UIKit -[UIApplication sendEvent:]
  46 UIKit _UIApplicationHandleEvent
  47 GraphicsServices PurpleEventCallback
  48 CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__
  49 CoreFoundation __CFRunLoopDoSource1
  50 CoreFoundation __CFRunLoopRun
  51 CoreFoundation CFRunLoopRunSpecific
  52 CoreFoundation CFRunLoopRunInMode
  53 UIKit -[UIApplication _run]
  54 UIKit UIApplicationMain
  55 myApp main /Users/kpower/Documents/projects/myApp/Classes/../main.m:13
  56 myApp start

Code in initOpenAL (near the line 197):

device = alcOpenDevice(NULL);
if (NULL == device) return NO;

context = alcCreateContext(device, 0);  // line 197 - tried using NULL instead of 0 - same result
if (NULL == context) return NO;

alcMakeContextCurrent(context);  

It's not critical (it doesn't repeat from time to time, consuming memory), but how can I fix it?

回答1:

I think this is a problem with the library itself as I also get problems and others report the same. Blame Apple for this. Hopefully they will sort this out soon.

来源：https://stackoverflow.com/questions/3837294/iphone-openal-audiotoolbox-leak