1 /* $NetBSD: pthread_once.c,v 1.2 2012/03/13 01:05:55 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 2001, 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nathan J. Williams, and by Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __RCSID("$NetBSD: pthread_once.c,v 1.2 2012/03/13 01:05:55 joerg Exp $"); 41 42 #include "pthread.h" 43 44 static void 45 once_cleanup(void *closure) 46 { 47 48 pthread_mutex_unlock((pthread_mutex_t *)closure); 49 } 50 51 int 52 pthread_once(pthread_once_t *once_control, void (*routine)(void)) 53 { 54 55 if (once_control->pto_done == 0) { 56 pthread_mutex_lock(&once_control->pto_mutex); 57 pthread_cleanup_push(&once_cleanup, &once_control->pto_mutex); 58 if (once_control->pto_done == 0) { 59 routine(); 60 once_control->pto_done = 1; 61 } 62 pthread_cleanup_pop(1); 63 } 64 65 return 0; 66 } 67 68 __strong_alias(__libc_thr_once,pthread_once) 69