Mercurial > sdl-ios-xcode
view src/thread/beos/SDL_syssem.c @ 2697:c9121b04cffa gsoc2008_nds
Some more work on the audio driver.
author | Darren Alton <dalton@stevens.edu> |
---|---|
date | Thu, 21 Aug 2008 12:38:21 +0000 |
parents | c121d94672cb |
children | 99210400e8b9 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 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; } /* vi: set ts=4 sw=4 expandtab: */