62 lines
2.6 KiB
C
62 lines
2.6 KiB
C
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/* ==== pthread_once.c =======================================================
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* Copyright (c) 1993, 1994 by Chris Provenzano, proven@mit.edu
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Chris Provenzano.
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* 4. The name of Chris Provenzano may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* Description : pthread_once function.
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*
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* 1.00 93/12/12 proven
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* -Started coding this file.
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*/
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#ifndef lint
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static const char rcsid[] = "$Id: pthread_once.c,v 1.1 1994/02/07 22:04:27 proven Exp $ $provenid: pthread_once.c,v 1.4 1994/02/07 02:19:22 proven Exp $";
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#endif
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#include <pthread.h>
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/* ==========================================================================
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* pthread_once()
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*/
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static pthread_mutex_t __pthread_once_mutex = PTHREAD_MUTEX_INITIALIZER;
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int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
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{
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/* Check first for speed */
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if (*once_control == PTHREAD_ONCE_INIT) {
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pthread_mutex_lock(&__pthread_once_mutex);
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if (*once_control == PTHREAD_ONCE_INIT) {
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init_routine();
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(*once_control)++;
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}
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pthread_mutex_unlock(&__pthread_once_mutex);
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}
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return(OK);
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}
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