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Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.

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Changed the CAS return value to bool, so it's efficient with OSAtomicCompareAndSwap32Barrier()
Added an atomic test adapted from code by Michael Davidsaver
This commit is contained in:
Sam Lantinga 2011-01-16 15:16:39 -08:00
parent 1bc8fe69ce
commit b0e0f61c7e
8 changed files with 301 additions and 62 deletions
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65
include/SDL_atomic.h
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@ -108,7 +108,62 @@ extern DECLSPEC void SDLCALL SDL_AtomicUnlock(SDL_SpinLock *lock);
/*@}*//*SDL AtomicLock*/
/* Platform specific optimized versions of the atomic functions */
/* None yet... */
#if defined(__WIN32__)
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#define SDL_AtomicSet(a, v) InterlockedExchange(&(a)->value, v)
#define SDL_AtomicGet(a) ((a)->value)
#define SDL_AtomicAdd(a, v) InterlockedAdd(&(a)->value, v)
#define SDL_AtomicCAS(a, oldval, newval) (InterlockedCompareExchange(&(a)->value, newval, oldval) == (oldval))
#define SDL_AtomicSetPtr(a, v) InterlockedExchangePointer(a, v)
#define SDL_AtomicGetPtr(a) (*(a))
#define SDL_AtomicCASPtr(a, oldval, newval) (InterlockedCompareExchangePointer(a, newval, oldval) == (oldval))
#elif defined(__MACOSX__)
#include <libkern/OSAtomic.h>
#define SDL_AtomicSet(a, v) \
({ \
int oldvalue; \
\
do { \
oldvalue = (a)->value; \
} while (!OSAtomicCompareAndSwap32Barrier(oldvalue, v, &(a)->value)); \
\
oldvalue; \
})
#define SDL_AtomicGet(a) ((a)->value)
#define SDL_AtomicAdd(a, v) \
({ \
int oldvalue; \
\
do { \
oldvalue = (a)->value; \
} while (!OSAtomicCompareAndSwap32Barrier(oldvalue, oldvalue+v, &(a)->value)); \
\
oldvalue; \
})
#define SDL_AtomicCAS(a, oldval, newval) OSAtomicCompareAndSwap32Barrier(oldval, newval, &(a)->value)
#define SDL_AtomicSetPtr(a, v) (*(a) = v, OSMemoryBarrier())
#define SDL_AtomicGetPtr(a) (*(a))
#if SIZEOF_VOIDP == 4
#define SDL_AtomicCASPtr(a, oldval, newval) OSAtomicCompareAndSwap32Barrier((int32_t)(oldval), (int32_t)(newval), (int32_t*)(a))
#elif SIZEOF_VOIDP == 8
#define SDL_AtomicCASPtr(a, oldval, newval) OSAtomicCompareAndSwap64Barrier((int64_t)(oldval), (int64_t)(newval), (int64_t*)(a))
#endif
#elif defined(HAVE_GCC_ATOMICS)
#define SDL_AtomicSet(a, v) __sync_lock_test_and_set(&(a)->value, v)
#define SDL_AtomicGet(a) ((a)->value)
#define SDL_AtomicAdd(a, v) __sync_fetch_and_add(&(a)->value, v)
#define SDL_AtomicCAS(a, oldval, newval) __sync_bool_compare_and_swap(&(a)->value, oldval, newval)
#define SDL_AtomicSetPtr(a, v) (*(a) = v, __sync_synchronize())
#define SDL_AtomicGetPtr(a) (*(a))
#define SDL_AtomicCASPtr(a, oldval, newval) __sync_bool_compare_and_swap(a, oldval, newval)
#endif
/**
* \brief A type representing an atomic integer value. It is a struct
@ -163,12 +218,12 @@ extern DECLSPEC SDL_bool SDLCALL SDL_AtomicDecRef(SDL_atomic_t *a);
/**
* \brief Set an atomic variable to a new value if it is currently an old value.
*
* \return The previous value of the atomic variable
* \return SDL_TRUE if the atomic variable was set, SDL_FALSE otherwise.
*
* \note If you don't know what this function is for, you shouldn't use it!
*/
#ifndef SDL_AtomicCAS
extern DECLSPEC int SDLCALL SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval);
extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval);
#endif
/**
@ -188,12 +243,12 @@ extern DECLSPEC void* SDLCALL SDL_AtomicGetPtr(void** a);
/**
* \brief Set a pointer to a new value if it is currently an old value.
*
* \return The previous value of the pointer
* \return SDL_TRUE if the pointer was set, SDL_FALSE otherwise.
*
* \note If you don't know what this function is for, you shouldn't use it!
*/
#ifndef SDL_AtomicCASPtr
extern DECLSPEC void* SDLCALL SDL_AtomicCASPtr(void **a, void *oldval, void *newval);
extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCASPtr(void **a, void *oldval, void *newval);
#endif
/* Ends C function definitions when using C++ */