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/* | ||
Simple DirectMedia Layer | ||
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org> | ||
This software is provided 'as-is', without any express or implied | ||
warranty. In no event will the authors be held liable for any damages | ||
arising from the use of this software. | ||
Permission is granted to anyone to use this software for any purpose, | ||
including commercial applications, and to alter it and redistribute it | ||
freely, subject to the following restrictions: | ||
1. The origin of this software must not be misrepresented; you must not | ||
claim that you wrote the original software. If you use this software | ||
in a product, an acknowledgment in the product documentation would be | ||
appreciated but is not required. | ||
2. Altered source versions must be plainly marked as such, and must not be | ||
misrepresented as being the original software. | ||
3. This notice may not be removed or altered from any source distribution. | ||
*/ | ||
#include "SDL_config.h" | ||
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#if defined(__WIN32__) || defined(__WINRT__) | ||
#include "../core/windows/SDL_windows.h" | ||
#endif | ||
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#include "SDL_atomic.h" | ||
#include "SDL_mutex.h" | ||
#include "SDL_timer.h" | ||
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/* This function is where all the magic happens... */ | ||
SDL_bool | ||
SDL_AtomicTryLock(SDL_SpinLock *lock) | ||
{ | ||
#if SDL_ATOMIC_DISABLED | ||
/* Terrible terrible damage */ | ||
static SDL_mutex *_spinlock_mutex; | ||
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if (!_spinlock_mutex) { | ||
/* Race condition on first lock... */ | ||
_spinlock_mutex = SDL_CreateMutex(); | ||
} | ||
SDL_LockMutex(_spinlock_mutex); | ||
if (*lock == 0) { | ||
*lock = 1; | ||
SDL_UnlockMutex(_spinlock_mutex); | ||
return SDL_TRUE; | ||
} else { | ||
SDL_UnlockMutex(_spinlock_mutex); | ||
return SDL_FALSE; | ||
} | ||
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#elif defined(_MSC_VER) | ||
SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long)); | ||
return (InterlockedExchange((long*)lock, 1) == 0); | ||
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#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET | ||
return (__sync_lock_test_and_set(lock, 1) == 0); | ||
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#elif defined(__GNUC__) && defined(__arm__) && \ | ||
(defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__) || \ | ||
defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5TE__) || \ | ||
defined(__ARM_ARCH_5TEJ__)) | ||
int result; | ||
__asm__ __volatile__ ( | ||
"swp %0, %1, [%2]\n" | ||
: "=&r,&r" (result) : "r,0" (1), "r,r" (lock) : "memory"); | ||
return (result == 0); | ||
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#elif defined(__GNUC__) && defined(__arm__) | ||
int result; | ||
__asm__ __volatile__ ( | ||
"ldrex %0, [%2]\nteq %0, #0\nstrexeq %0, %1, [%2]" | ||
: "=&r" (result) : "r" (1), "r" (lock) : "cc", "memory"); | ||
return (result == 0); | ||
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#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) | ||
int result; | ||
__asm__ __volatile__( | ||
"lock ; xchgl %0, (%1)\n" | ||
: "=r" (result) : "r" (lock), "0" (1) : "cc", "memory"); | ||
return (result == 0); | ||
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#elif defined(__MACOSX__) || defined(__IPHONEOS__) | ||
/* Maybe used for PowerPC, but the Intel asm or gcc atomics are favored. */ | ||
return OSAtomicCompareAndSwap32Barrier(0, 1, lock); | ||
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#elif HAVE_PTHREAD_SPINLOCK | ||
/* pthread instructions */ | ||
return (pthread_spin_trylock(lock) == 0); | ||
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#else | ||
#error Please implement for your platform. | ||
return SDL_FALSE; | ||
#endif | ||
} | ||
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void | ||
SDL_AtomicLock(SDL_SpinLock *lock) | ||
{ | ||
/* FIXME: Should we have an eventual timeout? */ | ||
while (!SDL_AtomicTryLock(lock)) { | ||
SDL_Delay(0); | ||
} | ||
} | ||
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void | ||
SDL_AtomicUnlock(SDL_SpinLock *lock) | ||
{ | ||
#if defined(_MSC_VER) | ||
_ReadWriteBarrier(); | ||
*lock = 0; | ||
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#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET | ||
__sync_lock_release(lock); | ||
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#elif HAVE_PTHREAD_SPINLOCK | ||
pthread_spin_unlock(lock); | ||
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#else | ||
*lock = 0; | ||
#endif | ||
} | ||
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/* vi: set ts=4 sw=4 expandtab: */ | ||
/* | ||
Simple DirectMedia Layer | ||
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org> | ||
This software is provided 'as-is', without any express or implied | ||
warranty. In no event will the authors be held liable for any damages | ||
arising from the use of this software. | ||
Permission is granted to anyone to use this software for any purpose, | ||
including commercial applications, and to alter it and redistribute it | ||
freely, subject to the following restrictions: | ||
1. The origin of this software must not be misrepresented; you must not | ||
claim that you wrote the original software. If you use this software | ||
in a product, an acknowledgment in the product documentation would be | ||
appreciated but is not required. | ||
2. Altered source versions must be plainly marked as such, and must not be | ||
misrepresented as being the original software. | ||
3. This notice may not be removed or altered from any source distribution. | ||
*/ | ||
#include "SDL_config.h" | ||
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#if defined(__WIN32__) || defined(__WINRT__) | ||
#include "../core/windows/SDL_windows.h" | ||
#endif | ||
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#include "SDL_atomic.h" | ||
#include "SDL_mutex.h" | ||
#include "SDL_timer.h" | ||
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/* This function is where all the magic happens... */ | ||
SDL_bool | ||
SDL_AtomicTryLock(SDL_SpinLock *lock) | ||
{ | ||
#if SDL_ATOMIC_DISABLED | ||
/* Terrible terrible damage */ | ||
static SDL_mutex *_spinlock_mutex; | ||
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if (!_spinlock_mutex) { | ||
/* Race condition on first lock... */ | ||
_spinlock_mutex = SDL_CreateMutex(); | ||
} | ||
SDL_LockMutex(_spinlock_mutex); | ||
if (*lock == 0) { | ||
*lock = 1; | ||
SDL_UnlockMutex(_spinlock_mutex); | ||
return SDL_TRUE; | ||
} else { | ||
SDL_UnlockMutex(_spinlock_mutex); | ||
return SDL_FALSE; | ||
} | ||
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#elif defined(_MSC_VER) | ||
SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long)); | ||
return (InterlockedExchange((long*)lock, 1) == 0); | ||
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#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET | ||
return (__sync_lock_test_and_set(lock, 1) == 0); | ||
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#elif defined(__GNUC__) && defined(__arm__) && \ | ||
(defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__) || \ | ||
defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5TE__) || \ | ||
defined(__ARM_ARCH_5TEJ__)) | ||
int result; | ||
__asm__ __volatile__ ( | ||
"swp %0, %1, [%2]\n" | ||
: "=&r,&r" (result) : "r,0" (1), "r,r" (lock) : "memory"); | ||
return (result == 0); | ||
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#elif defined(__GNUC__) && defined(__arm__) | ||
int result; | ||
__asm__ __volatile__ ( | ||
"ldrex %0, [%2]\nteq %0, #0\nstrexeq %0, %1, [%2]" | ||
: "=&r" (result) : "r" (1), "r" (lock) : "cc", "memory"); | ||
return (result == 0); | ||
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#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) | ||
int result; | ||
__asm__ __volatile__( | ||
"lock ; xchgl %0, (%1)\n" | ||
: "=r" (result) : "r" (lock), "0" (1) : "cc", "memory"); | ||
return (result == 0); | ||
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#elif defined(__MACOSX__) || defined(__IPHONEOS__) | ||
/* Maybe used for PowerPC, but the Intel asm or gcc atomics are favored. */ | ||
return OSAtomicCompareAndSwap32Barrier(0, 1, lock); | ||
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#elif HAVE_PTHREAD_SPINLOCK | ||
/* pthread instructions */ | ||
return (pthread_spin_trylock(lock) == 0); | ||
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#else | ||
#error Please implement for your platform. | ||
return SDL_FALSE; | ||
#endif | ||
} | ||
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void | ||
SDL_AtomicLock(SDL_SpinLock *lock) | ||
{ | ||
/* FIXME: Should we have an eventual timeout? */ | ||
while (!SDL_AtomicTryLock(lock)) { | ||
SDL_Delay(0); | ||
} | ||
} | ||
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void | ||
SDL_AtomicUnlock(SDL_SpinLock *lock) | ||
{ | ||
#if defined(_MSC_VER) | ||
_ReadWriteBarrier(); | ||
*lock = 0; | ||
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#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET | ||
__sync_lock_release(lock); | ||
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#elif HAVE_PTHREAD_SPINLOCK | ||
pthread_spin_unlock(lock); | ||
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#else | ||
*lock = 0; | ||
#endif | ||
} | ||
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/* vi: set ts=4 sw=4 expandtab: */ |
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