/project/jni/sdl-1.3/src/thread/beos/SDL_syssem.c
https://github.com/aichunyu/FFPlayer · C · 155 lines · 108 code · 21 blank · 26 comment · 15 complexity · 248efb7536dca3ece7fc3c84ab905c25 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"
- #ifdef SDL_THREAD_BEOS
- /* Semaphores in the BeOS environment */
- #include <be/kernel/OS.h>
- #include "SDL_thread.h"
- struct SDL_semaphore
- {
- sem_id id;
- };
- /* Create a counting semaphore */
- SDL_sem *
- SDL_CreateSemaphore(Uint32 initial_value)
- {
- SDL_sem *sem;
- sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
- if (sem) {
- sem->id = create_sem(initial_value, "SDL semaphore");
- if (sem->id < B_NO_ERROR) {
- SDL_SetError("create_sem() failed");
- SDL_free(sem);
- sem = NULL;
- }
- } else {
- SDL_OutOfMemory();
- }
- return (sem);
- }
- /* Free the semaphore */
- void
- SDL_DestroySemaphore(SDL_sem * sem)
- {
- if (sem) {
- if (sem->id >= B_NO_ERROR) {
- delete_sem(sem->id);
- }
- SDL_free(sem);
- }
- }
- int
- SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
- {
- int32 val;
- int retval;
- if (!sem) {
- SDL_SetError("Passed a NULL semaphore");
- return -1;
- }
- tryagain:
- if (timeout == SDL_MUTEX_MAXWAIT) {
- val = acquire_sem(sem->id);
- } else {
- timeout *= 1000; /* BeOS uses a timeout in microseconds */
- val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);
- }
- switch (val) {
- case B_INTERRUPTED:
- goto tryagain;
- case B_NO_ERROR:
- retval = 0;
- break;
- case B_TIMED_OUT:
- retval = SDL_MUTEX_TIMEDOUT;
- break;
- case B_WOULD_BLOCK:
- retval = SDL_MUTEX_TIMEDOUT;
- break;
- default:
- SDL_SetError("acquire_sem() 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)
- {
- int32 count;
- Uint32 value;
- value = 0;
- if (sem) {
- get_sem_count(sem->id, &count);
- if (count > 0) {
- value = (Uint32) count;
- }
- }
- return value;
- }
- /* Atomically increases the semaphore's count (not blocking) */
- int
- SDL_SemPost(SDL_sem * sem)
- {
- if (!sem) {
- SDL_SetError("Passed a NULL semaphore");
- return -1;
- }
- if (release_sem(sem->id) != B_NO_ERROR) {
- SDL_SetError("release_sem() failed");
- return -1;
- }
- return 0;
- }
- #endif /* SDL_THREAD_BEOS */
- /* vi: set ts=4 sw=4 expandtab: */