diff options
Diffstat (limited to 'source/3rd-party/SDL2/src/thread/windows/SDL_syssem.c')
-rw-r--r-- | source/3rd-party/SDL2/src/thread/windows/SDL_syssem.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/source/3rd-party/SDL2/src/thread/windows/SDL_syssem.c b/source/3rd-party/SDL2/src/thread/windows/SDL_syssem.c new file mode 100644 index 0000000..dcb36fa --- /dev/null +++ b/source/3rd-party/SDL2/src/thread/windows/SDL_syssem.c @@ -0,0 +1,152 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2018 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_internal.h" + +#if SDL_THREAD_WINDOWS + +/* Semaphore functions using the Win32 API */ + +#include "../../core/windows/SDL_windows.h" + +#include "SDL_thread.h" + +struct SDL_semaphore +{ + HANDLE id; + LONG count; +}; + + +/* Create a semaphore */ +SDL_sem * +SDL_CreateSemaphore(Uint32 initial_value) +{ + SDL_sem *sem; + + /* Allocate sem memory */ + sem = (SDL_sem *) SDL_malloc(sizeof(*sem)); + if (sem) { + /* Create the semaphore, with max value 32K */ +#if __WINRT__ + sem->id = CreateSemaphoreEx(NULL, initial_value, 32 * 1024, NULL, 0, SEMAPHORE_ALL_ACCESS); +#else + sem->id = CreateSemaphore(NULL, initial_value, 32 * 1024, NULL); +#endif + sem->count = initial_value; + if (!sem->id) { + SDL_SetError("Couldn't create semaphore"); + SDL_free(sem); + sem = NULL; + } + } else { + SDL_OutOfMemory(); + } + return (sem); +} + +/* Free the semaphore */ +void +SDL_DestroySemaphore(SDL_sem * sem) +{ + if (sem) { + if (sem->id) { + CloseHandle(sem->id); + sem->id = 0; + } + SDL_free(sem); + } +} + +int +SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout) +{ + int retval; + DWORD dwMilliseconds; + + if (!sem) { + return SDL_SetError("Passed a NULL sem"); + } + + if (timeout == SDL_MUTEX_MAXWAIT) { + dwMilliseconds = INFINITE; + } else { + dwMilliseconds = (DWORD) timeout; + } + switch (WaitForSingleObjectEx(sem->id, dwMilliseconds, FALSE)) { + case WAIT_OBJECT_0: + InterlockedDecrement(&sem->count); + retval = 0; + break; + case WAIT_TIMEOUT: + retval = SDL_MUTEX_TIMEDOUT; + break; + default: + retval = SDL_SetError("WaitForSingleObject() failed"); + break; + } + return retval; +} + +int +SDL_SemTryWait(SDL_sem * sem) +{ + return SDL_SemWaitTimeout(sem, 0); +} + +int +SDL_SemWait(SDL_sem * sem) +{ + return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); +} + +/* Returns the current count of the semaphore */ +Uint32 +SDL_SemValue(SDL_sem * sem) +{ + if (!sem) { + SDL_SetError("Passed a NULL sem"); + return 0; + } + return (Uint32)sem->count; +} + +int +SDL_SemPost(SDL_sem * sem) +{ + if (!sem) { + return SDL_SetError("Passed a NULL sem"); + } + /* Increase the counter in the first place, because + * after a successful release the semaphore may + * immediately get destroyed by another thread which + * is waiting for this semaphore. + */ + InterlockedIncrement(&sem->count); + if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) { + InterlockedDecrement(&sem->count); /* restore */ + return SDL_SetError("ReleaseSemaphore() failed"); + } + return 0; +} + +#endif /* SDL_THREAD_WINDOWS */ + +/* vi: set ts=4 sw=4 expandtab: */ |