Mercurial > sdl-ios-xcode
diff src/atomic/dummy/SDL_atomic.c @ 3202:3aa519a5c676
I've made so many changes I don't dare continue until I check the current stuff in.
/test/testatomic.c performs absolutely basic tests to show that the function work as expected. Need a second test to do more detailed tests.
/include/SDL_atomic.h provides declarations for all included functions.
/src/atomic/linux/SDL_atomic.c provided all the functions. On a generic built the 64 bit functions work, but they are emulated. On a build for -march=pentium and above the 64 bit functions use native instructions
/src/atomic/dummy/SDL_atomic.c emulates all the operations using SDL_mutex.h.
/src/atomic/win32/SDL_atomic.c is a copy of dummy
/src/atomic/macosx/SDL_atomic.s is a copy of dummy
These versions of SDL_atomic.c provide a frame work for building the library with a mixture of native and emulated functions. This allows the whole library to be provided on all platforms. (I hope.)
I hope this fits with the SDL philosophy of either providing a common subset or emulating when the platform is missing a feature.
I have not added dummy, macosx, or win32 to the build. They are there as place holders for future work.
I have modified congifure.in to compile sources in /src/atomic/linux. (The SDL configure.in file is an amazing piece of work and I hope I didn't mess it up. :-)
author | Bob Pendleton <bob@pendleton.com> |
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date | Mon, 29 Jun 2009 19:54:43 +0000 |
parents | |
children | 759032c318d8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/atomic/dummy/SDL_atomic.c Mon Jun 29 19:54:43 2009 +0000 @@ -0,0 +1,1002 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2009 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Sam Lantinga + slouken@libsdl.org +*/ + +#include "SDL_stdinc.h" +#include "SDL_atomic.h" + +/* + This file provides 8, 16, 32, and 64 bit atomic operations. If the + operations are provided by the native hardware and operating system + they are used. If they are not then the operations are emulated + using the SDL mutex operations. + */ + +/* + First, detect whether the operations are supported and create + #defines that indicate that they do exist. The goal is to have all + the system dependent code in the top part of the file so that the + bottom can be use unchanged across all platforms. + + Second, #define all the operations in each size class that are + supported. Doing this allows supported operations to be used along + side of emulated operations. +*/ + +/* + Emmulated version. + + Assume there is no support for atomic operations. All such + operations are implemented using SDL mutex operations. + */ + +#ifdef EMULATED_ATOMIC_OPERATIONS +#undef EMULATED_ATOMIC_OPERATIONS +#endif + +#ifdef EMULATED_ATOMIC_OPERATIONS +#define HAVE_ALL_8_BIT_OPS + +#define nativeExchange8(ptr, value) () +#define nativeCompareThenSet8(ptr, oldvalue, newvalue) () +#define nativeTestThenSet8(ptr) () +#define nativeClear8(ptr) () +#define nativeFetchThenIncrement8(ptr) () +#define nativeFetchThenDecrement8(ptr) () +#define nativeFetchThenAdd8(ptr, value) () +#define nativeFetchThenSubtract8(ptr, value) () +#define nativeIncrementThenFetch8(ptr) () +#define nativeDecrementThenFetch8(ptr) () +#define nativeAddThenFetch8(ptr, value) () +#define nativeSubtractThenFetch8(ptr, value) () +#endif + +#ifdef EMULATED_ATOMIC_OPERATIONS +#define HAVE_ALL_16_BIT_OPS + +#define nativeExchange16(ptr, value) () +#define nativeCompareThenSet16(ptr, oldvalue, newvalue) () +#define nativeTestThenSet16(ptr) () +#define nativeClear16(ptr) () +#define nativeFetchThenIncrement16(ptr) () +#define nativeFetchThenDecrement16(ptr) () +#define nativeFetchThenAdd16(ptr, value) () +#define nativeFetchThenSubtract16(ptr, value) () +#define nativeIncrementThenFetch16(ptr) () +#define nativeDecrementThenFetch16(ptr) () +#define nativeAddThenFetch16(ptr, value) () +#define nativeSubtractThenFetch16(ptr, value) () +#endif + +#ifdef EMULATED_ATOMIC_OPERATIONS +#define HAVE_ALL_32_BIT_OPS + +#define nativeExchange32(ptr, value) () +#define nativeCompareThenSet32(ptr, oldvalue, newvalue) () +#define nativeTestThenSet32(ptr) () +#define nativeClear32(ptr) () +#define nativeFetchThenIncrement32(ptr) () +#define nativeFetchThenDecrement32(ptr) () +#define nativeFetchThenAdd32(ptr, value) () +#define nativeFetchThenSubtract32(ptr, value) () +#define nativeIncrementThenFetch32(ptr) () +#define nativeDecrementThenFetch32(ptr) () +#define nativeAddThenFetch32(ptr, value) () +#define nativeSubtractThenFetch32(ptr, value) () +#endif + +#ifdef EMULATED_ATOMIC_OPERATIONS +#define HAVE_ALL_64_BIT_OPS + +#define nativeExchange64(ptr, value) () +#define nativeCompareThenSet64(ptr, oldvalue, newvalue) () +#define nativeTestThenSet64(ptr) () +#define nativeClear64(ptr) () +#define nativeFetchThenIncrement64(ptr) () +#define nativeFetchThenDecrement64(ptr) () +#define nativeFetchThenAdd64(ptr, value) () +#define nativeFetchThenSubtract64(ptr, value) () +#define nativeIncrementThenFetch64(ptr) () +#define nativeDecrementThenFetch64(ptr) () +#define nativeAddThenFetch64(ptr, value) () +#define nativeSubtractThenFetch64(ptr, value) () +#endif + +/* +If any of the operations are not provided then we must emulate some of +them. + */ + +#if !defined(HAVE_ALL_8_BIT_OPS) || !defined(HAVE_ALL_16_BIT_OPS) || !defined(HAVE_ALL_32_BIT_OPS) || !defined(HAVE_ALL_64_BIT_OPS) + +#include "SDL_mutex.h" +#include "SDL_error.h" + +static SDL_mutex * lock = NULL; + +static __inline__ void +privateWaitLock() +{ + if(NULL == lock) + { + lock = SDL_CreateMutex(); + if (NULL == lock) + { + SDL_SetError("SDL_atomic.c: can't create a mutex"); + return; + } + } + + if (-1 == SDL_LockMutex(lock)) + { + SDL_SetError("SDL_atomic.c: can't lock mutex"); + } +} + +static __inline__ void +privateUnlock() +{ + if (-1 == SDL_UnlockMutex(lock)) + { + SDL_SetError("SDL_atomic.c: can't unlock mutex"); + } +} + +#endif + +/* 8 bit atomic operations */ + +Uint8 +SDL_AtomicExchange8(Uint8 * ptr, Uint8 value) +{ +#ifdef nativeExchange8 + return nativeExchange8(ptr, value); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + *ptr = value; + privateUnlock(); + + return tmp; +#endif +} + +SDL_bool +SDL_AtomicCompareThenSet8(Uint8 * ptr, Uint8 oldvalue, Uint8 newvalue) +{ +#ifdef nativeCompareThenSet8 + return (SDL_bool)nativeCompareThenSet8(ptr, oldvalue, newvalue); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == oldvalue); + if (result) + { + *ptr = newvalue; + } + privateUnlock(); + + return result; +#endif +} + +SDL_bool +SDL_AtomicTestThenSet8(Uint8 * ptr) +{ +#ifdef nativeTestThenSet8 + return (SDL_bool)nativeTestThenSet8(ptr); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == 0); + if (result) + { + *ptr = 1; + } + privateUnlock(); + + return result; +#endif +} + +void +SDL_AtomicClear8(Uint8 * ptr) +{ +#ifdef nativeClear8 + nativeClear8(ptr); +#else + privateWaitLock(); + *ptr = 0; + privateUnlock(); + + return; +#endif +} + +Uint8 +SDL_AtomicFetchThenIncrement8(Uint8 * ptr) +{ +#ifdef nativeFetchThenIncrement8 + return nativeFetchThenIncrement8(ptr); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicFetchThenDecrement8(Uint8 * ptr) +{ +#ifdef nativeFetchThenDecrement8 + return nativeFetchThenDecrement8(ptr); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr) -= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicFetchThenAdd8(Uint8 * ptr, Uint8 value) +{ +#ifdef nativeFetchThenAdd8 + return nativeFetchThenAdd8(ptr, value); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicFetchThenSubtract8(Uint8 * ptr, Uint8 value) +{ +#ifdef nativeFetchThenSubtract8 + return nativeFetchThenSubtract8(ptr, value); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)-= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicIncrementThenFetch8(Uint8 * ptr) +{ +#ifdef nativeIncrementThenFetch8 + return nativeIncrementThenFetch8(ptr); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + (*ptr)+= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicDecrementThenFetch8(Uint8 * ptr) +{ +#ifdef nativeDecrementThenFetch8 + return nativeDecrementThenFetch8(ptr); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + (*ptr)-= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicAddThenFetch8(Uint8 * ptr, Uint8 value) +{ +#ifdef nativeAddThenFetch8 + return nativeAddThenFetch8(ptr, value); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + (*ptr)+= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint8 +SDL_AtomicSubtractThenFetch8(Uint8 * ptr, Uint8 value) +{ +#ifdef nativeSubtractThenFetch8 + return nativeSubtractThenFetch8(ptr, value); +#else + Uint8 tmp = 0;; + + privateWaitLock(); + (*ptr)-= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +/* 16 bit atomic operations */ + +Uint16 +SDL_AtomicExchange16(Uint16 * ptr, Uint16 value) +{ +#ifdef nativeExchange16 + return nativeExchange16(ptr, value); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + *ptr = value; + privateUnlock(); + + return tmp; +#endif +} + +SDL_bool +SDL_AtomicCompareThenSet16(Uint16 * ptr, Uint16 oldvalue, Uint16 newvalue) +{ +#ifdef nativeCompareThenSet16 + return (SDL_bool)nativeCompareThenSet16(ptr, oldvalue, newvalue); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == oldvalue); + if (result) + { + *ptr = newvalue; + } + privateUnlock(); + + return result; +#endif +} + +SDL_bool +SDL_AtomicTestThenSet16(Uint16 * ptr) +{ +#ifdef nativeTestThenSet16 + return (SDL_bool)nativeTestThenSet16(ptr); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == 0); + if (result) + { + *ptr = 1; + } + privateUnlock(); + + return result; +#endif +} + +void +SDL_AtomicClear16(Uint16 * ptr) +{ +#ifdef nativeClear16 + nativeClear16(ptr); +#else + privateWaitLock(); + *ptr = 0; + privateUnlock(); + + return; +#endif +} + +Uint16 +SDL_AtomicFetchThenIncrement16(Uint16 * ptr) +{ +#ifdef nativeFetchThenIncrement16 + return nativeFetchThenIncrement16(ptr); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicFetchThenDecrement16(Uint16 * ptr) +{ +#ifdef nativeFetchThenDecrement16 + return nativeFetchThenDecrement16(ptr); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr) -= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicFetchThenAdd16(Uint16 * ptr, Uint16 value) +{ +#ifdef nativeFetchThenAdd16 + return nativeFetchThenAdd16(ptr, value); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicFetchThenSubtract16(Uint16 * ptr, Uint16 value) +{ +#ifdef nativeFetchThenSubtract16 + return nativeFetchThenSubtract16(ptr, value); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)-= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicIncrementThenFetch16(Uint16 * ptr) +{ +#ifdef nativeIncrementThenFetch16 + return nativeIncrementThenFetch16(ptr); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + (*ptr)+= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicDecrementThenFetch16(Uint16 * ptr) +{ +#ifdef nativeDecrementThenFetch16 + return nativeDecrementThenFetch16(ptr); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + (*ptr)-= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicAddThenFetch16(Uint16 * ptr, Uint16 value) +{ +#ifdef nativeAddThenFetch16 + return nativeAddThenFetch16(ptr, value); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + (*ptr)+= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint16 +SDL_AtomicSubtractThenFetch16(Uint16 * ptr, Uint16 value) +{ +#ifdef nativeSubtractThenFetch16 + return nativeSubtractThenFetch16(ptr, value); +#else + Uint16 tmp = 0;; + + privateWaitLock(); + (*ptr)-= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +/* 32 bit atomic operations */ + +Uint32 +SDL_AtomicExchange32(Uint32 * ptr, Uint32 value) +{ +#ifdef nativeExchange32 + return nativeExchange32(ptr, value); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + *ptr = value; + privateUnlock(); + + return tmp; +#endif +} + +SDL_bool +SDL_AtomicCompareThenSet32(Uint32 * ptr, Uint32 oldvalue, Uint32 newvalue) +{ +#ifdef nativeCompareThenSet32 + return (SDL_bool)nativeCompareThenSet32(ptr, oldvalue, newvalue); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == oldvalue); + if (result) + { + *ptr = newvalue; + } + privateUnlock(); + + return result; +#endif +} + +SDL_bool +SDL_AtomicTestThenSet32(Uint32 * ptr) +{ +#ifdef nativeTestThenSet32 + return (SDL_bool)nativeTestThenSet32(ptr); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == 0); + if (result) + { + *ptr = 1; + } + privateUnlock(); + + return result; +#endif +} + +void +SDL_AtomicClear32(Uint32 * ptr) +{ +#ifdef nativeClear32 + nativeClear32(ptr); +#else + privateWaitLock(); + *ptr = 0; + privateUnlock(); + + return; +#endif +} + +Uint32 +SDL_AtomicFetchThenIncrement32(Uint32 * ptr) +{ +#ifdef nativeFetchThenIncrement32 + return nativeFetchThenIncrement32(ptr); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicFetchThenDecrement32(Uint32 * ptr) +{ +#ifdef nativeFetchThenDecrement32 + return nativeFetchThenDecrement32(ptr); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr) -= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicFetchThenAdd32(Uint32 * ptr, Uint32 value) +{ +#ifdef nativeFetchThenAdd32 + return nativeFetchThenAdd32(ptr, value); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicFetchThenSubtract32(Uint32 * ptr, Uint32 value) +{ +#ifdef nativeFetchThenSubtract32 + return nativeFetchThenSubtract32(ptr, value); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)-= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicIncrementThenFetch32(Uint32 * ptr) +{ +#ifdef nativeIncrementThenFetch32 + return nativeIncrementThenFetch32(ptr); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + (*ptr)+= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicDecrementThenFetch32(Uint32 * ptr) +{ +#ifdef nativeDecrementThenFetch32 + return nativeDecrementThenFetch32(ptr); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + (*ptr)-= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicAddThenFetch32(Uint32 * ptr, Uint32 value) +{ +#ifdef nativeAddThenFetch32 + return nativeAddThenFetch32(ptr, value); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + (*ptr)+= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint32 +SDL_AtomicSubtractThenFetch32(Uint32 * ptr, Uint32 value) +{ +#ifdef nativeSubtractThenFetch32 + return nativeSubtractThenFetch32(ptr, value); +#else + Uint32 tmp = 0;; + + privateWaitLock(); + (*ptr)-= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +/* 64 bit atomic operations */ +#ifdef SDL_HAS_64BIT_TYPE + +Uint64 +SDL_AtomicExchange64(Uint64 * ptr, Uint64 value) +{ +#ifdef nativeExchange64 + return nativeExchange64(ptr, value); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + *ptr = value; + privateUnlock(); + + return tmp; +#endif +} + +SDL_bool +SDL_AtomicCompareThenSet64(Uint64 * ptr, Uint64 oldvalue, Uint64 newvalue) +{ +#ifdef nativeCompareThenSet64 + return (SDL_bool)nativeCompareThenSet64(ptr, oldvalue, newvalue); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == oldvalue); + if (result) + { + *ptr = newvalue; + } + privateUnlock(); + + return result; +#endif +} + +SDL_bool +SDL_AtomicTestThenSet64(Uint64 * ptr) +{ +#ifdef nativeTestThenSet64 + return (SDL_bool)nativeTestThenSet64(ptr); +#else + SDL_bool result = SDL_FALSE; + + privateWaitLock(); + result = (*ptr == 0); + if (result) + { + *ptr = 1; + } + privateUnlock(); + + return result; +#endif +} + +void +SDL_AtomicClear64(Uint64 * ptr) +{ +#ifdef nativeClear64 + nativeClear64(ptr); +#else + privateWaitLock(); + *ptr = 0; + privateUnlock(); + + return; +#endif +} + +Uint64 +SDL_AtomicFetchThenIncrement64(Uint64 * ptr) +{ +#ifdef nativeFetchThenIncrement64 + return nativeFetchThenIncrement64(ptr); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicFetchThenDecrement64(Uint64 * ptr) +{ +#ifdef nativeFetchThenDecrement64 + return nativeFetchThenDecrement64(ptr); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr) -= 1; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicFetchThenAdd64(Uint64 * ptr, Uint64 value) +{ +#ifdef nativeFetchThenAdd64 + return nativeFetchThenAdd64(ptr, value); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)+= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicFetchThenSubtract64(Uint64 * ptr, Uint64 value) +{ +#ifdef nativeFetchThenSubtract64 + return nativeFetchThenSubtract64(ptr, value); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + tmp = *ptr; + (*ptr)-= value; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicIncrementThenFetch64(Uint64 * ptr) +{ +#ifdef nativeIncrementThenFetch64 + return nativeIncrementThenFetch64(ptr); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + (*ptr)+= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicDecrementThenFetch64(Uint64 * ptr) +{ +#ifdef nativeDecrementThenFetch64 + return nativeDecrementThenFetch64(ptr); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + (*ptr)-= 1; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicAddThenFetch64(Uint64 * ptr, Uint64 value) +{ +#ifdef nativeAddThenFetch64 + return nativeAddThenFetch64(ptr, value); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + (*ptr)+= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} + +Uint64 +SDL_AtomicSubtractThenFetch64(Uint64 * ptr, Uint64 value) +{ +#ifdef nativeSubtractThenFetch64 + return nativeSubtractThenFetch64(ptr, value); +#else + Uint64 tmp = 0;; + + privateWaitLock(); + (*ptr)-= value; + tmp = *ptr; + privateUnlock(); + + return tmp; +#endif +} +#endif +