livetrax/libs/appleutility/CoreAudio/PublicUtility/CAAtomic.h

/*
     File: CAAtomic.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.
 
*/
/*
	This file implements all Atomic operations using Interlocked functions specified in
	Winbase.h
NOTE: According to Microsoft documentation, all Interlocked functions generates a
full barrier. 
	On Windows:
	As the Interlocked functions returns the Old value, Extra checks and operations 
	are made after the atomic operation to return value consistent with OSX counterparts.
*/
#ifndef __CAAtomic_h__
#define __CAAtomic_h__

#if TARGET_OS_WIN32
	#include <windows.h>
	#include <intrin.h>
	#pragma intrinsic(_InterlockedOr)
	#pragma intrinsic(_InterlockedAnd)
#else
	#include <CoreFoundation/CFBase.h>
	#include <libkern/OSAtomic.h>
#endif

inline void CAMemoryBarrier() 
{
#if TARGET_OS_WIN32
	MemoryBarrier();
#else
	OSMemoryBarrier();
#endif
}

inline SInt32 CAAtomicAdd32Barrier(SInt32 theAmt, volatile SInt32* theValue)
{
#if TARGET_OS_WIN32
	long lRetVal = InterlockedExchangeAdd((volatile long*)theValue, theAmt);
	// InterlockedExchangeAdd returns the original value which differs from OSX version. 
	// At this point the addition would have occurred and hence returning the new value
	// to keep it sync with OSX.
	return lRetVal + theAmt;
#else
	return OSAtomicAdd32Barrier(theAmt, (volatile int32_t *)theValue);
#endif
}

inline SInt32 CAAtomicOr32Barrier(UInt32 theMask, volatile UInt32* theValue)
{
#if TARGET_OS_WIN32
	// InterlockedAnd macro is not defined in x86 platform, and hence using the intrinsic
	// function instead.
	long j = _InterlockedOr((volatile long*)theValue, theMask);
	// _InterlockedOr returns the original value which differs from OSX version.
	// Returning the new value similar to OSX
	return (SInt32)(j | theMask);
#else
	return OSAtomicOr32Barrier(theMask, (volatile uint32_t *)theValue);
#endif
}

inline SInt32 CAAtomicAnd32Barrier(UInt32 theMask, volatile UInt32* theValue)
{
#if TARGET_OS_WIN32
// InterlockedAnd macro is not defined in x86 platform, and hence using the intrinsic
// function instead.
	long j = _InterlockedAnd((volatile long*)theValue, theMask);
	// _InterlockedAnd returns the original value which differs from OSX version.
	// Returning the new value similar to OSX
	return (SInt32)(j & theMask);
#else
	return OSAtomicAnd32Barrier(theMask, (volatile uint32_t *)theValue);
#endif
}

inline bool CAAtomicCompareAndSwap32Barrier(SInt32 oldValue, SInt32 newValue, volatile SInt32 *theValue)
{
#if TARGET_OS_WIN32
	// InterlockedCompareExchange returns the old value. But we need to return bool value.
	long lRetVal = InterlockedCompareExchange((volatile long*)theValue, newValue, oldValue);
// Hence we check if the new value is set and if it is we return true else false.
// If theValue is equal to oldValue then the swap happens. Otherwise swap doesn't happen.
	return (oldValue == lRetVal);
#else
	return OSAtomicCompareAndSwap32Barrier(oldValue, newValue, (volatile int32_t *)theValue);
#endif
}


inline SInt32 CAAtomicIncrement32(volatile SInt32* theValue)
{
#if TARGET_OS_WIN32
	return (SInt32)InterlockedIncrement((volatile long*)theValue);
#else
	return OSAtomicIncrement32((volatile int32_t *)theValue);
#endif
}

inline SInt32 CAAtomicDecrement32(volatile SInt32* theValue)
{
#if TARGET_OS_WIN32
	return (SInt32)InterlockedDecrement((volatile long*)theValue);
#else
	return OSAtomicDecrement32((volatile int32_t *)theValue);
#endif
}

inline SInt32 CAAtomicIncrement32Barrier(volatile SInt32* theValue)
{
#if TARGET_OS_WIN32
	return CAAtomicIncrement32(theValue);
#else
	return OSAtomicIncrement32Barrier((volatile int32_t *)theValue);
#endif
}

inline SInt32 CAAtomicDecrement32Barrier(volatile SInt32* theValue)
{
#if TARGET_OS_WIN32
	return CAAtomicDecrement32(theValue);
#else
	return OSAtomicDecrement32Barrier((volatile int32_t *)theValue);
#endif
}

inline bool CAAtomicTestAndClearBarrier(int bitToClear, void* theAddress)
{
#if TARGET_OS_WIN32
	BOOL bOldVal = InterlockedBitTestAndReset((long*)theAddress, bitToClear);
	return (bOldVal ? true : false);
#else
	return OSAtomicTestAndClearBarrier(bitToClear, (volatile void *)theAddress);
#endif
}

inline bool CAAtomicTestAndClear(int bitToClear, void* theAddress)
{
#if TARGET_OS_WIN32
	BOOL bOldVal = CAAtomicTestAndClearBarrier(bitToClear, (long*)theAddress);
	return (bOldVal ? true : false);
#else
	return OSAtomicTestAndClear(bitToClear, (volatile void *)theAddress);
#endif
}

inline bool CAAtomicTestAndSetBarrier(int bitToSet, void* theAddress)
{
#if TARGET_OS_WIN32
	BOOL bOldVal = InterlockedBitTestAndSet((long*)theAddress, bitToSet);
	return (bOldVal ? true : false);
#else
	return OSAtomicTestAndSetBarrier(bitToSet, (volatile void *)theAddress);
#endif
}

// int32_t flavors -- for C++ only since we can't overload in C
// CFBase.h defines SInt32 as signed int which is similar to int32_t. If CFBase.h is included, then
// this will generate redefinition error. But on Mac, CFBase.h, still includes MacTypes.h where
// SInt32 is defined as signed long so this would work there.
// So in order to fix the redefinition errors, we define these functions only if MacTypes.h is included.
#if defined(__cplusplus) && defined(__MACTYPES__) && !__LP64__
inline int32_t CAAtomicAdd32Barrier(int32_t theAmt, volatile int32_t* theValue)
{
	return CAAtomicAdd32Barrier(theAmt, (volatile SInt32 *)theValue);
}

inline int32_t CAAtomicOr32Barrier(uint32_t theMask, volatile uint32_t* theValue)
{
	return CAAtomicOr32Barrier(theMask, (volatile UInt32 *)theValue);
}

inline int32_t CAAtomicAnd32Barrier(uint32_t theMask, volatile uint32_t* theValue)
{
	return CAAtomicAnd32Barrier(theMask, (volatile UInt32 *)theValue);
}

inline bool CAAtomicCompareAndSwap32Barrier(int32_t oldValue, int32_t newValue, volatile int32_t *theValue)
{
	return CAAtomicCompareAndSwap32Barrier(oldValue, newValue, (volatile SInt32 *)theValue);
}

inline int32_t CAAtomicIncrement32(volatile int32_t* theValue)
{
	return CAAtomicIncrement32((volatile SInt32 *)theValue);
}

inline int32_t CAAtomicDecrement32(volatile int32_t* theValue)
{
	return CAAtomicDecrement32((volatile SInt32 *)theValue);
}

inline int32_t CAAtomicIncrement32Barrier(volatile int32_t* theValue)
{
	return CAAtomicIncrement32Barrier((volatile SInt32 *)theValue);
}

inline int32_t CAAtomicDecrement32Barrier(volatile int32_t* theValue)
{
	return CAAtomicDecrement32Barrier((volatile SInt32 *)theValue);
}
#endif // __cplusplus && !__LP64__

#if __LP64__
inline bool CAAtomicCompareAndSwap64Barrier( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue )
{
	return OSAtomicCompareAndSwap64Barrier(__oldValue, __newValue, __theValue);
}
#endif

inline bool CAAtomicCompareAndSwapPtrBarrier(void *__oldValue, void *__newValue, volatile void ** __theValue)
{
#if __LP64__
	return CAAtomicCompareAndSwap64Barrier((int64_t)__oldValue, (int64_t)__newValue, (int64_t *)__theValue);
#else
	return CAAtomicCompareAndSwap32Barrier((int32_t)__oldValue, (int32_t)__newValue, (int32_t *)__theValue);
#endif
}

/* Spinlocks.  These use memory barriers as required to synchronize access to shared
 * memory protected by the lock.  The lock operation spins, but employs various strategies
 * to back off if the lock is held, making it immune to most priority-inversion livelocks.
 * The try operation immediately returns false if the lock was held, true if it took the
 * lock.  The convention is that unlocked is zero, locked is nonzero.
 */
#define	CA_SPINLOCK_INIT    0

typedef int32_t CASpinLock;

bool    CASpinLockTry( volatile CASpinLock *__lock );
void    CASpinLockLock( volatile CASpinLock *__lock );
void    CASpinLockUnlock( volatile CASpinLock *__lock );

inline void    CASpinLockLock( volatile CASpinLock *__lock )
{
#if TARGET_OS_MAC
	OSSpinLockLock(__lock);
#else
	while (CAAtomicTestAndSetBarrier(0, (void*)__lock))
		usleep(1000); // ???
#endif
}

inline void    CASpinLockUnlock( volatile CASpinLock *__lock )
{
#if TARGET_OS_MAC
	OSSpinLockUnlock(__lock);
#else
	CAAtomicTestAndClearBarrier(0, (void*)__lock);
#endif
}

inline bool    CASpinLockTry( volatile CASpinLock *__lock )
{
#if TARGET_OS_MAC
	return OSSpinLockTry(__lock);
#else
	return (CAAtomicTestAndSetBarrier(0, (void*)__lock) == 0);
#endif
}


#endif // __CAAtomic_h__