thr_once.c revision 112918
1112918Sjeff/* 2112918Sjeff * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. 3112918Sjeff * All rights reserved. 4112918Sjeff * 5112918Sjeff * Redistribution and use in source and binary forms, with or without 6112918Sjeff * modification, are permitted provided that the following conditions 7112918Sjeff * are met: 8112918Sjeff * 1. Redistributions of source code must retain the above copyright 9112918Sjeff * notice, this list of conditions and the following disclaimer. 10112918Sjeff * 2. Redistributions in binary form must reproduce the above copyright 11112918Sjeff * notice, this list of conditions and the following disclaimer in the 12112918Sjeff * documentation and/or other materials provided with the distribution. 13112918Sjeff * 3. All advertising materials mentioning features or use of this software 14112918Sjeff * must display the following acknowledgement: 15112918Sjeff * This product includes software developed by John Birrell. 16112918Sjeff * 4. Neither the name of the author nor the names of any co-contributors 17112918Sjeff * may be used to endorse or promote products derived from this software 18112918Sjeff * without specific prior written permission. 19112918Sjeff * 20112918Sjeff * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 21112918Sjeff * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22112918Sjeff * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23112918Sjeff * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24112918Sjeff * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25112918Sjeff * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26112918Sjeff * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27112918Sjeff * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28112918Sjeff * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29112918Sjeff * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30112918Sjeff * SUCH DAMAGE. 31112918Sjeff * 32112918Sjeff * $FreeBSD: head/lib/libthr/thread/thr_once.c 112918 2003-04-01 03:46:29Z jeff $ 33112918Sjeff */ 34112918Sjeff#include <pthread.h> 35112918Sjeff#include "thr_private.h" 36112918Sjeff 37112918Sjeff__weak_reference(_pthread_once, pthread_once); 38112918Sjeff 39112918Sjeffint 40112918Sjeff_pthread_once(pthread_once_t * once_control, void (*init_routine) (void)) 41112918Sjeff{ 42112918Sjeff if (once_control->state == PTHREAD_NEEDS_INIT) { 43112918Sjeff if (_thread_initial == NULL) 44112918Sjeff _thread_init(); 45112918Sjeff pthread_mutex_lock(&(once_control->mutex)); 46112918Sjeff if (once_control->state == PTHREAD_NEEDS_INIT) { 47112918Sjeff init_routine(); 48112918Sjeff once_control->state = PTHREAD_DONE_INIT; 49112918Sjeff } 50112918Sjeff pthread_mutex_unlock(&(once_control->mutex)); 51112918Sjeff } 52112918Sjeff return (0); 53112918Sjeff} 54