Mercurial > sdl-ios-xcode
view src/thread/beos/SDL_syssem.c @ 4347:38f22ed3a433 SDL-1.2
Option to fix bug #851
For some people setting the period size works better (and is what SDL 1.2.13 did), but for most people it's the same or worse. You can use an environment variable to pick which one you want.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sat, 17 Oct 2009 06:55:17 +0000 |
parents | a1b03ba2fcd0 |
children |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 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" /* 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; }