Mercurial > sdl-ios-xcode
diff src/thread/beos/SDL_syssem.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 | e8157fcb3114 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/thread/beos/SDL_syssem.c Thu Apr 26 16:45:43 2001 +0000 @@ -0,0 +1,141 @@ +/* + 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 + +/* Semaphores in the BeOS environment */ + +#include <be/kernel/OS.h> + +#include "SDL_error.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 *)malloc(sizeof(*sem)); + if ( sem ) { + sem->id = create_sem(initial_value, "SDL semaphore"); + if ( sem->id < B_NO_ERROR ) { + SDL_SetError("create_sem() failed"); + 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); + } + 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; + 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; +}