Mercurial > sdl-ios-xcode
diff include/SDL_atomic.h @ 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> |
|---|---|
| date | Mon, 29 Jun 2009 19:54:43 +0000 |
| parents | 3e1bf2b8bd81 |
| children | 48a80f2a7ff2 |
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--- a/include/SDL_atomic.h Wed Jun 24 22:24:23 2009 +0000 +++ b/include/SDL_atomic.h Mon Jun 29 19:54:43 2009 +0000 @@ -29,7 +29,6 @@ #ifndef _SDL_atomic_h_ #define _SDL_atomic_h_ - #include "SDL_stdinc.h" #include "SDL_platform.h" @@ -42,72 +41,51 @@ /* *INDENT-ON* */ #endif -/* *INDENT-OFF* */ /** - * \def SDL_AtomicBusyWait32 (ptr) - * - * \brief Implements a simple busy wait for use with - * SDL_AtomicTestThenSet and SDL_AtomicClear. - * - * Note: This can be an infinite loop. - * - */ -#define SDL_AtomicBusyWait32(ptr) \ - { \ - while (!SDL_AtomicTestThenSet32(ptr) \ - { \ - }; \ - }; - -/** - * \def SDL_AtomicWait32(ptr) - * - * \brief A safer way to wait for a test-then-set lock to be cleared. - * - * This assumes that the SDL_Sleep(0) call acts as a thread_yeild - * operation. - * + * These operations may, or may not, actually be implemented using + * processor specific atomic operations. When possible they are + * implemented as true processor specific atomic operations. When that + * is not possible the are implemented using locks that *do* use the + * available atomic operations. In rare cases they may be implemented + * using SDL's mutex fuctions. */ -#define SDL_AtomicWait32(ptr) \ - { \ - while (!SDL_AtomicTestThenSet32(ptr) \ - { \ - SDL_Sleep(0); \ - }; \ - }; - -/** - * \def SDL_AtomicBusyWait64(ptr) - * - * \brief 64 bit version of busy wait - * - * \sa SDL_AtomicBusyWait32 - */ -#define SDL_AtomicBusyWait64(ptr) \ - { \ - while (!SDL_AtomicTestThenSet64(ptr) \ - { \ - }; \ - }; - -/** - * \def SDL_AtomicWait64(ptr) - * - * \brief 64 bit version of SDL_AtomicWait32 - * - * \sa SDL_AtomicWait32 - */ -#define SDL_AtomicWait64(ptr) \ - { \ - while (!SDL_AtomicTestThenSet64(ptr) \ - { \ - SDL_Sleep(0); \ - }; \ - }; -/* *INDENT-ON* */ /* Function prototypes */ +/* 8 bit atomic operations */ + +extern DECLSPEC Uint8 SDLCALL SDL_AtomicExchange8(Uint8 * ptr, Uint8 value); +extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCompareThenSet8(Uint8 * ptr, + Uint8 oldvalue, Uint8 newvalue); +extern DECLSPEC SDL_bool SDLCALL SDL_AtomicTestThenSet8(Uint8 * ptr); +extern DECLSPEC void SDLCALL SDL_AtomicClear8(Uint8 * ptr); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicFetchThenIncrement8(Uint8 * ptr); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicFetchThenDecrement8(Uint8 * ptr); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicFetchThenAdd8(Uint8 * ptr, Uint8 value); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicFetchThenSubtract8(Uint8 * ptr, Uint8 value); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicIncrementThenFetch8(Uint8 * ptr); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicDecrementThenFetch8(Uint8 * ptr); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicAddThenFetch8(Uint8 * ptr, Uint8 value); +extern DECLSPEC Uint8 SDLCALL SDL_AtomicSubtractThenFetch8(Uint8 * ptr, Uint8 value); + +/* 16 bit atomic operations */ + +extern DECLSPEC Uint16 SDLCALL SDL_AtomicExchange16(Uint16 * ptr, Uint16 value); +extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCompareThenSet16(Uint16 * ptr, + Uint16 oldvalue, Uint16 newvalue); +extern DECLSPEC SDL_bool SDLCALL SDL_AtomicTestThenSet16(Uint16 * ptr); +extern DECLSPEC void SDLCALL SDL_AtomicClear16(Uint16 * ptr); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicFetchThenIncrement16(Uint16 * ptr); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicFetchThenDecrement16(Uint16 * ptr); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicFetchThenAdd16(Uint16 * ptr, Uint16 value); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicFetchThenSubtract16(Uint16 * ptr, Uint16 value); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicIncrementThenFetch16(Uint16 * ptr); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicDecrementThenFetch16(Uint16 * ptr); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicAddThenFetch16(Uint16 * ptr, Uint16 value); +extern DECLSPEC Uint16 SDLCALL SDL_AtomicSubtractThenFetch16(Uint16 * ptr, Uint16 value); + +/* 32 bit atomic operations */ + /** * \fn int SDL_AtomicExchange32(Uint32 * ptr, Uint32 value) * @@ -252,6 +230,7 @@ */ extern DECLSPEC Uint32 SDLCALL SDL_AtomicSubtractThenFetch32(Uint32 * ptr, Uint32 value); +/* 64 bit atomic operations */ #ifdef SDL_HAS_64BIT_TYPE extern DECLSPEC Uint64 SDLCALL SDL_AtomicExchange64(Uint64 * ptr, Uint64 value); @@ -267,7 +246,7 @@ extern DECLSPEC Uint64 SDLCALL SDL_AtomicDecrementThenFetch64(Uint64 * ptr); extern DECLSPEC Uint64 SDLCALL SDL_AtomicAddThenFetch64(Uint64 * ptr, Uint64 value); extern DECLSPEC Uint64 SDLCALL SDL_AtomicSubtractThenFetch64(Uint64 * ptr, Uint64 value); -#endif +#endif /* SDL_HAS_64BIT_TYPE */ /* Ends C function definitions when using C++ */ #ifdef __cplusplus