1 files changed, 133 insertions, 0 deletions
diff --git a/libs/appleutility/CoreAudio/PublicUtility/CAGuard.h b/libs/appleutility/CoreAudio/PublicUtility/CAGuard.h
new file mode 100644
index 0000000000..ffcb59da8d
--- /dev/null
+++ b/libs/appleutility/CoreAudio/PublicUtility/CAGuard.h
@@ -0,0 +1,133 @@
+/*
+     File: CAGuard.h
+ Abstract: Part of CoreAudio Utility Classes
+  Version: 1.1
+ 
+ Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple
+ Inc. ("Apple") in consideration of your agreement to the following
+ terms, and your use, installation, modification or redistribution of
+ this Apple software constitutes acceptance of these terms.  If you do
+ not agree with these terms, please do not use, install, modify or
+ redistribute this Apple software.
+ 
+ In consideration of your agreement to abide by the following terms, and
+ subject to these terms, Apple grants you a personal, non-exclusive
+ license, under Apple's copyrights in this original Apple software (the
+ "Apple Software"), to use, reproduce, modify and redistribute the Apple
+ Software, with or without modifications, in source and/or binary forms;
+ provided that if you redistribute the Apple Software in its entirety and
+ without modifications, you must retain this notice and the following
+ text and disclaimers in all such redistributions of the Apple Software.
+ Neither the name, trademarks, service marks or logos of Apple Inc. may
+ be used to endorse or promote products derived from the Apple Software
+ without specific prior written permission from Apple.  Except as
+ expressly stated in this notice, no other rights or licenses, express or
+ implied, are granted by Apple herein, including but not limited to any
+ patent rights that may be infringed by your derivative works or by other
+ works in which the Apple Software may be incorporated.
+ 
+ The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
+ MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
+ THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
+ FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
+ OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
+ 
+ IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
+ OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
+ MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
+ AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
+ STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+ 
+ Copyright (C) 2014 Apple Inc. All Rights Reserved.
+ 
+*/
+#if !defined(__CAGuard_h__)
+#define __CAGuard_h__
+
+//==================================================================================================
+//	Includes
+//=============================================================================
+
+//	Super Class Includes
+#include "CAMutex.h"
+
+#if CoreAudio_Debug
+//	#define	Log_Average_Latency	1
+#endif
+
+//==================================================================================================
+//	CAGuard
+//
+//	This is your typical mutex with signalling implemented via pthreads.
+//	Lock() will return true if and only if the guard is locked on that call.
+//	A thread that already has the guard will receive 'false' if it locks it
+//	again. Use of the stack-based CAGuard::Locker class is highly recommended
+//	to properly manage the recursive nesting. The Wait calls with timeouts
+//	will return true if and only if the timeout period expired. They will
+//	return false if they receive notification any other way.
+//==================================================================================================
+
+class	CAGuard : public CAMutex
+{
+
+//	Construction/Destruction
+public:
+					CAGuard(const char* inName);
+	virtual			~CAGuard();
+
+//	Actions
+public:
+	virtual void	Wait();
+	virtual bool	WaitFor(UInt64 inNanos);
+	virtual bool	WaitUntil(UInt64 inNanos);
+	
+	virtual void	Notify();
+	virtual void	NotifyAll();
+
+//	Implementation
+protected:
+#if TARGET_OS_MAC
+	pthread_cond_t	mCondVar;
+#else
+	HANDLE			mEvent;
+#endif
+#if	Log_Average_Latency
+	Float64			mAverageLatencyAccumulator;
+	UInt32			mAverageLatencyCount;
+#endif
+	
+//	Helper class to manage taking and releasing recursively
+public:
+	class			Locker
+	{
+	
+	//	Construction/Destruction
+	public:
+					Locker(CAGuard& inGuard) : mGuard(inGuard), mNeedsRelease(false) { mNeedsRelease = mGuard.Lock(); }
+					~Locker() { if(mNeedsRelease) { mGuard.Unlock(); } }
+	
+	private:
+					Locker(const Locker&);
+		Locker&		operator=(const Locker&);
+	
+	//	Actions
+	public:
+		void		Wait() { mGuard.Wait(); }
+		bool		WaitFor(UInt64 inNanos) { return mGuard.WaitFor(inNanos); }
+		bool		WaitUntil(UInt64 inNanos) { return mGuard.WaitUntil(inNanos); }
+		
+		void		Notify() { mGuard.Notify(); }
+		void		NotifyAll() { mGuard.NotifyAll(); }
+
+	//	Implementation
+	private:
+		CAGuard&	mGuard;
+		bool		mNeedsRelease;	
+	};
+
+};
+
+#endif