Mercurial > sdl-ios-xcode
diff src/thread/linux/SDL_syscond.c @ 0:74212992fb08
Initial revision
author | Sam Lantinga <slouken@lokigames.com> |
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date | Thu, 26 Apr 2001 16:45:43 +0000 |
parents | |
children | dc660aee7d7d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/thread/linux/SDL_syscond.c Thu Apr 26 16:45:43 2001 +0000 @@ -0,0 +1,189 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + Sam Lantinga + slouken@devolution.com +*/ + +#ifdef SAVE_RCSID +static char rcsid = + "@(#) $Id$"; +#endif + +#ifdef linux +/* Look to see if glibc is available, and if so, what version */ +#include <features.h> + +#if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) +#warning Working around a bug in glibc 2.0 pthreads +#undef SDL_USE_PTHREADS +/* The bug is actually a problem where threads are suspended, but don't + wake up when the thread manager sends them a signal. This is a problem + with thread creation too, but it happens less often. :-/ + We avoid this by using System V IPC for mutexes. + */ +#endif /* glibc 2.0 */ +#endif /* linux */ + +#ifdef SDL_USE_PTHREADS + +#include <sys/time.h> +#include <unistd.h> +#include <errno.h> +#include <stdlib.h> +#include <pthread.h> + +#include "SDL_error.h" +#include "SDL_thread.h" +#include "SDL_sysmutex_c.h" + + +#if defined(PTHREAD_NO_RECURSIVE_MUTEX) && !defined(__bsdi__) +#error You need to use the generic condition variable implementation +#endif + +struct SDL_cond +{ + pthread_cond_t cond; +}; + +/* Create a condition variable */ +SDL_cond * SDL_CreateCond(void) +{ + SDL_cond *cond; + + cond = (SDL_cond *) malloc(sizeof(SDL_cond)); + if ( cond ) { + if ( pthread_cond_init(&cond->cond, NULL) < 0 ) { + SDL_SetError("pthread_cond_init() failed"); + free(cond); + cond = NULL; + } + } + return(cond); +} + +/* Destroy a condition variable */ +void SDL_DestroyCond(SDL_cond *cond) +{ + if ( cond ) { + pthread_cond_destroy(&cond->cond); + free(cond); + } +} + +/* Restart one of the threads that are waiting on the condition variable */ +int SDL_CondSignal(SDL_cond *cond) +{ + int retval; + + if ( ! cond ) { + SDL_SetError("Passed a NULL condition variable"); + return -1; + } + + retval = 0; + if ( pthread_cond_signal(&cond->cond) != 0 ) { + SDL_SetError("pthread_cond_signal() failed"); + retval = -1; + } + return retval; +} + +/* Restart all threads that are waiting on the condition variable */ +int SDL_CondBroadcast(SDL_cond *cond) +{ + int retval; + + if ( ! cond ) { + SDL_SetError("Passed a NULL condition variable"); + return -1; + } + + retval = 0; + if ( pthread_cond_broadcast(&cond->cond) != 0 ) { + SDL_SetError("pthread_cond_broadcast() failed"); + retval = -1; + } + return retval; +} + +int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) +{ + int retval; + struct timeval delta; + struct timespec abstime; + + if ( ! cond ) { + SDL_SetError("Passed a NULL condition variable"); + return -1; + } + + gettimeofday(&delta, NULL); + + abstime.tv_sec = delta.tv_sec + (ms/1000); + abstime.tv_nsec = (delta.tv_usec+(ms%1000)) * 1000; + if ( abstime.tv_nsec > 1000000 ) { + abstime.tv_sec += 1; + abstime.tv_nsec -= 1000000; + } + + tryagain: + retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime); + switch (retval) { + case EINTR: + goto tryagain; + break; + case ETIMEDOUT: + retval = SDL_MUTEX_TIMEDOUT; + break; + case 0: + break; + default: + SDL_SetError("pthread_cond_timedwait() failed"); + retval = -1; + break; + } + return retval; +} + +/* Wait on the condition variable, unlocking the provided mutex. + The mutex must be locked before entering this function! + */ +int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) +{ + int retval; + + if ( ! cond ) { + SDL_SetError("Passed a NULL condition variable"); + return -1; + } + + retval = 0; + if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) { + SDL_SetError("pthread_cond_wait() failed"); + retval = -1; + } + return retval; +} + +#else /* Use semaphore implementation */ + +#include "generic/SDL_syscond.c" + +#endif /* SDL_USE_PTHREADS */