/*+
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    SDL - Simple DirectMedia Layer+
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    Copyright (C) 1997-2006 Sam Lantinga+
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+
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    This library is free software; you can redistribute it and/or+
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    modify it under the terms of the GNU Lesser General Public+
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    License as published by the Free Software Foundation; either+
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    version 2.1 of the License, or (at your option) any later version.+
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+
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    This library is distributed in the hope that it will be useful,+
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    but WITHOUT ANY WARRANTY; without even the implied warranty of+
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU+
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    Lesser General Public License for more details.+
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+
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    You should have received a copy of the GNU Lesser General Public+
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    License along with this library; if not, write to the Free Software+
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    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA+
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+
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    Sam Lantinga+
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    slouken@libsdl.org+
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*/+
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#include "SDL_config.h"+
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+
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/* Semaphores in the BeOS environment */+
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+
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#include <be/kernel/OS.h>+
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+
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#include "SDL_thread.h"+
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+
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+
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struct SDL_semaphore {+
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	sem_id id;+
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};+
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+
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/* Create a counting semaphore */+
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SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)+
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{+
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	SDL_sem *sem;+
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+
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	sem = (SDL_sem *)SDL_malloc(sizeof(*sem));+
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	if ( sem ) {+
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		sem->id = create_sem(initial_value, "SDL semaphore");+
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		if ( sem->id < B_NO_ERROR ) {+
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			SDL_SetError("create_sem() failed");+
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			SDL_free(sem);+
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			sem = NULL;+
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		}+
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	} else {+
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		SDL_OutOfMemory();+
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	}+
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	return(sem);+
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}+
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+
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/* Free the semaphore */+
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void SDL_DestroySemaphore(SDL_sem *sem)+
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{+
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	if ( sem ) {+
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		if ( sem->id >= B_NO_ERROR ) {+
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			delete_sem(sem->id);+
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		}+
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		SDL_free(sem);+
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	}+
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}+
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+
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int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)+
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{+
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	int32 val;+
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	int retval;+
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+
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	if ( ! sem ) {+
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		SDL_SetError("Passed a NULL semaphore");+
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		return -1;+
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	}+
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+
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  tryagain:+
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	if ( timeout == SDL_MUTEX_MAXWAIT ) {+
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		val = acquire_sem(sem->id);+
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	} else {+
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		timeout *= 1000; /* BeOS uses a timeout in microseconds */+
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		val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);+
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	}+
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	switch (val) {+
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	    case B_INTERRUPTED:+
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		goto tryagain;+
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	    case B_NO_ERROR:+
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		retval = 0;+
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		break;+
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	    case B_TIMED_OUT:+
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		retval = SDL_MUTEX_TIMEDOUT;+
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		break;+
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	    case B_WOULD_BLOCK:+
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		retval = SDL_MUTEX_TIMEDOUT;+
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		break;+
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	    default:+
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		SDL_SetError("acquire_sem() failed");+
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		retval = -1;+
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		break;+
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	}+
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+
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	return retval;+
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}+
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+
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int SDL_SemTryWait(SDL_sem *sem)+
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{+
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	return SDL_SemWaitTimeout(sem, 0);+
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}+
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+
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int SDL_SemWait(SDL_sem *sem)+
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{+
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	return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);+
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}+
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+
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/* Returns the current count of the semaphore */+
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Uint32 SDL_SemValue(SDL_sem *sem)+
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{+
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	int32 count;+
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	Uint32 value;+
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+
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	value = 0;+
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	if ( sem ) {+
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		get_sem_count(sem->id, &count);+
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		if ( count > 0 ) {+
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			value = (Uint32)count;+
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		}+
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	}+
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	return value;+
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}+
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+
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/* Atomically increases the semaphore's count (not blocking) */+
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int SDL_SemPost(SDL_sem *sem)+
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{+
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	if ( ! sem ) {+
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		SDL_SetError("Passed a NULL semaphore");+
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		return -1;+
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	}+
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+
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	if ( release_sem(sem->id) != B_NO_ERROR ) {+
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		SDL_SetError("release_sem() failed");+
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		return -1;+
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	}+
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	return 0;+
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}+
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