/* 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. 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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 #include #pragma intrinsic(_InterlockedOr) #pragma intrinsic(_InterlockedAnd) #else #include #include #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__