diff options
Diffstat (limited to 'distrib/sdl-1.2.15/src/thread/pthread/SDL_syssem.c')
| -rw-r--r-- | distrib/sdl-1.2.15/src/thread/pthread/SDL_syssem.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/thread/pthread/SDL_syssem.c b/distrib/sdl-1.2.15/src/thread/pthread/SDL_syssem.c new file mode 100644 index 0000000..a03870f --- /dev/null +++ b/distrib/sdl-1.2.15/src/thread/pthread/SDL_syssem.c @@ -0,0 +1,190 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2012 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_config.h" + +#include <pthread.h> +#include <semaphore.h> +#include <errno.h> +#include <sys/time.h> + +#include "SDL_thread.h" +#include "SDL_timer.h" + +/* Wrapper around POSIX 1003.1b semaphores */ + +#ifdef __MACOSX__ +/* Mac OS X doesn't support sem_getvalue() as of version 10.4 */ +#include "../generic/SDL_syssem.c" +#else + +struct SDL_semaphore { + sem_t sem; +}; + +/* Create a semaphore, initialized with value */ +SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) +{ + SDL_sem *sem = (SDL_sem *) SDL_malloc(sizeof(SDL_sem)); + if ( sem ) { + if ( sem_init(&sem->sem, 0, initial_value) < 0 ) { + SDL_SetError("sem_init() failed"); + SDL_free(sem); + sem = NULL; + } + } else { + SDL_OutOfMemory(); + } + return sem; +} + +void SDL_DestroySemaphore(SDL_sem *sem) +{ + if ( sem ) { + sem_destroy(&sem->sem); + SDL_free(sem); + } +} + +int SDL_SemTryWait(SDL_sem *sem) +{ + int retval; + + if ( ! sem ) { + SDL_SetError("Passed a NULL semaphore"); + return -1; + } + retval = SDL_MUTEX_TIMEDOUT; + if ( sem_trywait(&sem->sem) == 0 ) { + retval = 0; + } + return retval; +} + +int SDL_SemWait(SDL_sem *sem) +{ + int retval; + + if ( ! sem ) { + SDL_SetError("Passed a NULL semaphore"); + return -1; + } + + while ( ((retval = sem_wait(&sem->sem)) == -1) && (errno == EINTR) ) {} + if ( retval < 0 ) { + SDL_SetError("sem_wait() failed"); + } + return retval; +} + +int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) +{ + int retval; +#ifdef HAVE_SEM_TIMEDWAIT + struct timeval now; + struct timespec ts_timeout; +#else + Uint32 end; +#endif + + if ( ! sem ) { + SDL_SetError("Passed a NULL semaphore"); + return -1; + } + + /* Try the easy cases first */ + if ( timeout == 0 ) { + return SDL_SemTryWait(sem); + } + if ( timeout == SDL_MUTEX_MAXWAIT ) { + return SDL_SemWait(sem); + } + +#ifdef HAVE_SEM_TIMEDWAIT + /* Setup the timeout. sem_timedwait doesn't wait for + * a lapse of time, but until we reach a certain time. + * This time is now plus the timeout. + */ + gettimeofday(&now, NULL); + + /* Add our timeout to current time */ + now.tv_usec += (timeout % 1000) * 1000; + now.tv_sec += timeout / 1000; + + /* Wrap the second if needed */ + if ( now.tv_usec >= 1000000 ) { + now.tv_usec -= 1000000; + now.tv_sec ++; + } + + /* Convert to timespec */ + ts_timeout.tv_sec = now.tv_sec; + ts_timeout.tv_nsec = now.tv_usec * 1000; + + /* Wait. */ + do + retval = sem_timedwait(&sem->sem, &ts_timeout); + while (retval == -1 && errno == EINTR); + + if (retval == -1) + SDL_SetError(strerror(errno)); +#else + end = SDL_GetTicks() + timeout; + while ((retval = SDL_SemTryWait(sem)) == SDL_MUTEX_TIMEDOUT) { + if ((SDL_GetTicks() - end) >= 0) { + break; + } + SDL_Delay(0); + } +#endif /* HAVE_SEM_TIMEDWAIT */ + + return retval; +} + +Uint32 SDL_SemValue(SDL_sem *sem) +{ + int ret = 0; + if ( sem ) { + sem_getvalue(&sem->sem, &ret); + if ( ret < 0 ) { + ret = 0; + } + } + return (Uint32)ret; +} + +int SDL_SemPost(SDL_sem *sem) +{ + int retval; + + if ( ! sem ) { + SDL_SetError("Passed a NULL semaphore"); + return -1; + } + + retval = sem_post(&sem->sem); + if ( retval < 0 ) { + SDL_SetError("sem_post() failed"); + } + return retval; +} + +#endif /* __MACOSX__ */ |