From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 27 Dec 2025 12:03:39 -0800 Subject: Initial commit --- contrib/SDL-3.2.8/src/atomic/SDL_atomic.c | 382 ++++++++++++++++++++++++++++++ 1 file changed, 382 insertions(+) create mode 100644 contrib/SDL-3.2.8/src/atomic/SDL_atomic.c (limited to 'contrib/SDL-3.2.8/src/atomic/SDL_atomic.c') diff --git a/contrib/SDL-3.2.8/src/atomic/SDL_atomic.c b/contrib/SDL-3.2.8/src/atomic/SDL_atomic.c new file mode 100644 index 0000000..5e7774d --- /dev/null +++ b/contrib/SDL-3.2.8/src/atomic/SDL_atomic.c @@ -0,0 +1,382 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + 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_internal.h" + +#if defined(_MSC_VER) && (_MSC_VER >= 1900) +#include +#define HAVE_MSC_ATOMICS 1 +#endif + +#ifdef SDL_PLATFORM_MACOS // !!! FIXME: should we favor gcc atomics? +#include +#endif + +#if !defined(HAVE_GCC_ATOMICS) && defined(SDL_PLATFORM_SOLARIS) +#include +#endif + +// The __atomic_load_n() intrinsic showed up in different times for different compilers. +#ifdef __clang__ +#if __has_builtin(__atomic_load_n) || defined(HAVE_GCC_ATOMICS) +/* !!! FIXME: this advertises as available in the NDK but uses an external symbol we don't have. + It might be in a later NDK or we might need an extra library? --ryan. */ +#ifndef SDL_PLATFORM_ANDROID +#define HAVE_ATOMIC_LOAD_N 1 +#endif +#endif +#elif defined(__GNUC__) +#if (__GNUC__ >= 5) +#define HAVE_ATOMIC_LOAD_N 1 +#endif +#endif + +/* *INDENT-OFF* */ // clang-format off +#if defined(__WATCOMC__) && defined(__386__) +SDL_COMPILE_TIME_ASSERT(intsize, 4==sizeof(int)); +#define HAVE_WATCOM_ATOMICS +extern __inline int _SDL_xchg_watcom(volatile int *a, int v); +#pragma aux _SDL_xchg_watcom = \ + "lock xchg [ecx], eax" \ + parm [ecx] [eax] \ + value [eax] \ + modify exact [eax]; + +extern __inline unsigned char _SDL_cmpxchg_watcom(volatile int *a, int newval, int oldval); +#pragma aux _SDL_cmpxchg_watcom = \ + "lock cmpxchg [edx], ecx" \ + "setz al" \ + parm [edx] [ecx] [eax] \ + value [al] \ + modify exact [eax]; + +extern __inline int _SDL_xadd_watcom(volatile int *a, int v); +#pragma aux _SDL_xadd_watcom = \ + "lock xadd [ecx], eax" \ + parm [ecx] [eax] \ + value [eax] \ + modify exact [eax]; + +#endif // __WATCOMC__ && __386__ +/* *INDENT-ON* */ // clang-format on + +/* + If any of the operations are not provided then we must emulate some + of them. That means we need a nice implementation of spin locks + that avoids the "one big lock" problem. We use a vector of spin + locks and pick which one to use based on the address of the operand + of the function. + + To generate the index of the lock we first shift by 3 bits to get + rid on the zero bits that result from 32 and 64 bit alignment of + data. We then mask off all but 5 bits and use those 5 bits as an + index into the table. + + Picking the lock this way insures that accesses to the same data at + the same time will go to the same lock. OTOH, accesses to different + data have only a 1/32 chance of hitting the same lock. That should + pretty much eliminate the chances of several atomic operations on + different data from waiting on the same "big lock". If it isn't + then the table of locks can be expanded to a new size so long as + the new size is a power of two. + + Contributed by Bob Pendleton, bob@pendleton.com +*/ + +#if !defined(HAVE_MSC_ATOMICS) && !defined(HAVE_GCC_ATOMICS) && !defined(SDL_PLATFORM_MACOS) && !defined(SDL_PLATFORM_SOLARIS) && !defined(HAVE_WATCOM_ATOMICS) +#define EMULATE_CAS 1 +#endif + +#ifdef EMULATE_CAS +static SDL_SpinLock locks[32]; + +static SDL_INLINE void enterLock(void *a) +{ + uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f); + + SDL_LockSpinlock(&locks[index]); +} + +static SDL_INLINE void leaveLock(void *a) +{ + uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f); + + SDL_UnlockSpinlock(&locks[index]); +} +#endif + +bool SDL_CompareAndSwapAtomicInt(SDL_AtomicInt *a, int oldval, int newval) +{ +#ifdef HAVE_MSC_ATOMICS + SDL_COMPILE_TIME_ASSERT(atomic_cas, sizeof(long) == sizeof(a->value)); + return _InterlockedCompareExchange((long *)&a->value, (long)newval, (long)oldval) == (long)oldval; +#elif defined(HAVE_WATCOM_ATOMICS) + return _SDL_cmpxchg_watcom((volatile int *)&a->value, newval, oldval); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_bool_compare_and_swap(&a->value, oldval, newval); +#elif defined(SDL_PLATFORM_MACOS) // this is deprecated in 10.12 sdk; favor gcc atomics. + return OSAtomicCompareAndSwap32Barrier(oldval, newval, &a->value); +#elif defined(SDL_PLATFORM_SOLARIS) + SDL_COMPILE_TIME_ASSERT(atomic_cas, sizeof(uint_t) == sizeof(a->value)); + return ((int)atomic_cas_uint((volatile uint_t *)&a->value, (uint_t)oldval, (uint_t)newval) == oldval); +#elif defined(EMULATE_CAS) + bool result = false; + + enterLock(a); + if (a->value == oldval) { + a->value = newval; + result = true; + } + leaveLock(a); + + return result; +#else +#error Please define your platform. +#endif +} + +bool SDL_CompareAndSwapAtomicU32(SDL_AtomicU32 *a, Uint32 oldval, Uint32 newval) +{ +#ifdef HAVE_MSC_ATOMICS + SDL_COMPILE_TIME_ASSERT(atomic_cas, sizeof(long) == sizeof(a->value)); + return _InterlockedCompareExchange((long *)&a->value, (long)newval, (long)oldval) == (long)oldval; +#elif defined(HAVE_WATCOM_ATOMICS) + SDL_COMPILE_TIME_ASSERT(atomic_cas, sizeof(int) == sizeof(a->value)); + return _SDL_cmpxchg_watcom((volatile int *)&a->value, (int)newval, (int)oldval); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_bool_compare_and_swap(&a->value, oldval, newval); +#elif defined(SDL_PLATFORM_MACOS) // this is deprecated in 10.12 sdk; favor gcc atomics. + return OSAtomicCompareAndSwap32Barrier((int32_t)oldval, (int32_t)newval, (int32_t*)&a->value); +#elif defined(SDL_PLATFORM_SOLARIS) + SDL_COMPILE_TIME_ASSERT(atomic_cas, sizeof(uint_t) == sizeof(a->value)); + return ((Uint32)atomic_cas_uint((volatile uint_t *)&a->value, (uint_t)oldval, (uint_t)newval) == oldval); +#elif defined(EMULATE_CAS) + bool result = false; + + enterLock(a); + if (a->value == oldval) { + a->value = newval; + result = true; + } + leaveLock(a); + + return result; +#else +#error Please define your platform. +#endif +} + +bool SDL_CompareAndSwapAtomicPointer(void **a, void *oldval, void *newval) +{ +#ifdef HAVE_MSC_ATOMICS + return _InterlockedCompareExchangePointer(a, newval, oldval) == oldval; +#elif defined(HAVE_WATCOM_ATOMICS) + return _SDL_cmpxchg_watcom((int *)a, (long)newval, (long)oldval); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_bool_compare_and_swap(a, oldval, newval); +#elif defined(SDL_PLATFORM_MACOS) && defined(__LP64__) // this is deprecated in 10.12 sdk; favor gcc atomics. + return OSAtomicCompareAndSwap64Barrier((int64_t)oldval, (int64_t)newval, (int64_t *)a); +#elif defined(SDL_PLATFORM_MACOS) && !defined(__LP64__) // this is deprecated in 10.12 sdk; favor gcc atomics. + return OSAtomicCompareAndSwap32Barrier((int32_t)oldval, (int32_t)newval, (int32_t *)a); +#elif defined(SDL_PLATFORM_SOLARIS) + return (atomic_cas_ptr(a, oldval, newval) == oldval); +#elif defined(EMULATE_CAS) + bool result = false; + + enterLock(a); + if (*a == oldval) { + *a = newval; + result = true; + } + leaveLock(a); + + return result; +#else +#error Please define your platform. +#endif +} + +int SDL_SetAtomicInt(SDL_AtomicInt *a, int v) +{ +#ifdef HAVE_MSC_ATOMICS + SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(long) == sizeof(a->value)); + return _InterlockedExchange((long *)&a->value, v); +#elif defined(HAVE_WATCOM_ATOMICS) + return _SDL_xchg_watcom(&a->value, v); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_lock_test_and_set(&a->value, v); +#elif defined(SDL_PLATFORM_SOLARIS) + SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(uint_t) == sizeof(a->value)); + return (int)atomic_swap_uint((volatile uint_t *)&a->value, v); +#else + int value; + do { + value = a->value; + } while (!SDL_CompareAndSwapAtomicInt(a, value, v)); + return value; +#endif +} + +Uint32 SDL_SetAtomicU32(SDL_AtomicU32 *a, Uint32 v) +{ +#ifdef HAVE_MSC_ATOMICS + SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(long) == sizeof(a->value)); + return _InterlockedExchange((long *)&a->value, v); +#elif defined(HAVE_WATCOM_ATOMICS) + return _SDL_xchg_watcom(&a->value, v); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_lock_test_and_set(&a->value, v); +#elif defined(SDL_PLATFORM_SOLARIS) + SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(uint_t) == sizeof(a->value)); + return (Uint32)atomic_swap_uint((volatile uint_t *)&a->value, v); +#else + Uint32 value; + do { + value = a->value; + } while (!SDL_CompareAndSwapAtomicU32(a, value, v)); + return value; +#endif +} + +void *SDL_SetAtomicPointer(void **a, void *v) +{ +#ifdef HAVE_MSC_ATOMICS + return _InterlockedExchangePointer(a, v); +#elif defined(HAVE_WATCOM_ATOMICS) + return (void *)_SDL_xchg_watcom((int *)a, (long)v); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_lock_test_and_set(a, v); +#elif defined(SDL_PLATFORM_SOLARIS) + return atomic_swap_ptr(a, v); +#else + void *value; + do { + value = *a; + } while (!SDL_CompareAndSwapAtomicPointer(a, value, v)); + return value; +#endif +} + +int SDL_AddAtomicInt(SDL_AtomicInt *a, int v) +{ +#ifdef HAVE_MSC_ATOMICS + SDL_COMPILE_TIME_ASSERT(atomic_add, sizeof(long) == sizeof(a->value)); + return _InterlockedExchangeAdd((long *)&a->value, v); +#elif defined(HAVE_WATCOM_ATOMICS) + SDL_COMPILE_TIME_ASSERT(atomic_add, sizeof(int) == sizeof(a->value)); + return _SDL_xadd_watcom((volatile int *)&a->value, v); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_fetch_and_add(&a->value, v); +#elif defined(SDL_PLATFORM_SOLARIS) + int pv = a->value; + membar_consumer(); + atomic_add_int((volatile uint_t *)&a->value, v); + return pv; +#else + int value; + do { + value = a->value; + } while (!SDL_CompareAndSwapAtomicInt(a, value, (value + v))); + return value; +#endif +} + +int SDL_GetAtomicInt(SDL_AtomicInt *a) +{ +#ifdef HAVE_ATOMIC_LOAD_N + return __atomic_load_n(&a->value, __ATOMIC_SEQ_CST); +#elif defined(HAVE_MSC_ATOMICS) + SDL_COMPILE_TIME_ASSERT(atomic_get, sizeof(long) == sizeof(a->value)); + return _InterlockedOr((long *)&a->value, 0); +#elif defined(HAVE_WATCOM_ATOMICS) + return _SDL_xadd_watcom(&a->value, 0); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_or_and_fetch(&a->value, 0); +#elif defined(SDL_PLATFORM_MACOS) // this is deprecated in 10.12 sdk; favor gcc atomics. + return sizeof(a->value) == sizeof(uint32_t) ? OSAtomicOr32Barrier(0, (volatile uint32_t *)&a->value) : OSAtomicAdd64Barrier(0, (volatile int64_t *)&a->value); +#elif defined(SDL_PLATFORM_SOLARIS) + return atomic_or_uint_nv((volatile uint_t *)&a->value, 0); +#else + int value; + do { + value = a->value; + } while (!SDL_CompareAndSwapAtomicInt(a, value, value)); + return value; +#endif +} + +Uint32 SDL_GetAtomicU32(SDL_AtomicU32 *a) +{ +#ifdef HAVE_ATOMIC_LOAD_N + return __atomic_load_n(&a->value, __ATOMIC_SEQ_CST); +#elif defined(HAVE_MSC_ATOMICS) + SDL_COMPILE_TIME_ASSERT(atomic_get, sizeof(long) == sizeof(a->value)); + return (Uint32)_InterlockedOr((long *)&a->value, 0); +#elif defined(HAVE_WATCOM_ATOMICS) + SDL_COMPILE_TIME_ASSERT(atomic_get, sizeof(int) == sizeof(a->value)); + return (Uint32)_SDL_xadd_watcom((volatile int *)&a->value, 0); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_or_and_fetch(&a->value, 0); +#elif defined(SDL_PLATFORM_MACOS) // this is deprecated in 10.12 sdk; favor gcc atomics. + return OSAtomicOr32Barrier(0, (volatile uint32_t *)&a->value); +#elif defined(SDL_PLATFORM_SOLARIS) + SDL_COMPILE_TIME_ASSERT(atomic_get, sizeof(uint_t) == sizeof(a->value)); + return (Uint32)atomic_or_uint_nv((volatile uint_t *)&a->value, 0); +#else + Uint32 value; + do { + value = a->value; + } while (!SDL_CompareAndSwapAtomicU32(a, value, value)); + return value; +#endif +} + +void *SDL_GetAtomicPointer(void **a) +{ +#ifdef HAVE_ATOMIC_LOAD_N + return __atomic_load_n(a, __ATOMIC_SEQ_CST); +#elif defined(HAVE_MSC_ATOMICS) + return _InterlockedCompareExchangePointer(a, NULL, NULL); +#elif defined(HAVE_GCC_ATOMICS) + return __sync_val_compare_and_swap(a, (void *)0, (void *)0); +#elif defined(SDL_PLATFORM_SOLARIS) + return atomic_cas_ptr(a, (void *)0, (void *)0); +#else + void *value; + do { + value = *a; + } while (!SDL_CompareAndSwapAtomicPointer(a, value, value)); + return value; +#endif +} + +#ifdef SDL_MEMORY_BARRIER_USES_FUNCTION +#error This file should be built in arm mode so the mcr instruction is available for memory barriers +#endif + +void SDL_MemoryBarrierReleaseFunction(void) +{ + SDL_MemoryBarrierRelease(); +} + +void SDL_MemoryBarrierAcquireFunction(void) +{ + SDL_MemoryBarrierAcquire(); +} -- cgit v1.2.3