/project/jni/sdl-1.3/src/thread/windows/SDL_syssem.c
https://github.com/aichunyu/FFPlayer · C · 176 lines · 125 code · 19 blank · 32 comment · 23 complexity · 559459122376f662091fb41f28e335a4 MD5 · raw file
- /*
- Simple DirectMedia Layer
- Copyright (C) 1997-2012 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"
- #if SDL_THREAD_WINDOWS
- /* Semaphore functions using the Win32 API */
- #include "../../core/windows/SDL_windows.h"
- #include "SDL_thread.h"
- #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- #include "win_ce_semaphore.h"
- #endif
- struct SDL_semaphore
- {
- #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- SYNCHHANDLE id;
- #else
- HANDLE id;
- #endif
- 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 defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- sem->id = CreateSemaphoreCE(NULL, initial_value, 32 * 1024, NULL);
- #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) {
- #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- CloseSynchHandle(sem->id);
- #else
- CloseHandle(sem->id);
- #endif
- sem->id = 0;
- }
- SDL_free(sem);
- }
- }
- int
- SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
- {
- int retval;
- DWORD dwMilliseconds;
- if (!sem) {
- SDL_SetError("Passed a NULL sem");
- return -1;
- }
- if (timeout == SDL_MUTEX_MAXWAIT) {
- dwMilliseconds = INFINITE;
- } else {
- dwMilliseconds = (DWORD) timeout;
- }
- #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- switch (WaitForSemaphoreCE(sem->id, dwMilliseconds)) {
- #else
- switch (WaitForSingleObject(sem->id, dwMilliseconds)) {
- #endif
- case WAIT_OBJECT_0:
- InterlockedDecrement(&sem->count);
- retval = 0;
- break;
- case WAIT_TIMEOUT:
- retval = SDL_MUTEX_TIMEDOUT;
- break;
- default:
- SDL_SetError("WaitForSingleObject() failed");
- retval = -1;
- 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) {
- SDL_SetError("Passed a NULL sem");
- return -1;
- }
- /* 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 defined(_WIN32_WCE) && (_WIN32_WCE < 300)
- if (ReleaseSemaphoreCE(sem->id, 1, NULL) == FALSE) {
- #else
- if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) {
- #endif
- InterlockedDecrement(&sem->count); /* restore */
- SDL_SetError("ReleaseSemaphore() failed");
- return -1;
- }
- return 0;
- }
- #endif /* SDL_THREAD_WINDOWS */
- /* vi: set ts=4 sw=4 expandtab: */