1 /* 2 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by John Birrell. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD: src/lib/libpthread/thread/thr_join.c,v 1.28 2003/12/09 02:20:56 davidxu Exp $ 33 * $DragonFly: src/lib/libthread_xu/thread/thr_join.c,v 1.2 2005/03/15 11:24:23 davidxu Exp $ 34 */ 35 #include <errno.h> 36 #include <pthread.h> 37 #include "thr_private.h" 38 39 __weak_reference(_pthread_join, pthread_join); 40 41 static void backout_join(void *arg) 42 { 43 struct pthread *curthread = _get_curthread(); 44 struct pthread *pthread = (struct pthread *)arg; 45 46 THREAD_LIST_LOCK(curthread); 47 pthread->joiner = NULL; 48 THREAD_LIST_UNLOCK(curthread); 49 } 50 51 int 52 _pthread_join(pthread_t pthread, void **thread_return) 53 { 54 struct pthread *curthread = _get_curthread(); 55 void *tmp; 56 long state; 57 int oldcancel; 58 int ret = 0; 59 60 if (pthread == NULL) 61 return (EINVAL); 62 63 if (pthread == curthread) 64 return (EDEADLK); 65 66 THREAD_LIST_LOCK(curthread); 67 if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) { 68 ret = ESRCH; 69 } else if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) { 70 ret = ESRCH; 71 } else if (pthread->joiner != NULL) { 72 /* Multiple joiners are not supported. */ 73 ret = ENOTSUP; 74 } 75 if (ret) { 76 THREAD_LIST_UNLOCK(curthread); 77 return (ret); 78 } 79 /* Set the running thread to be the joiner: */ 80 pthread->joiner = curthread; 81 82 THREAD_LIST_UNLOCK(curthread); 83 84 THR_CLEANUP_PUSH(curthread, backout_join, pthread); 85 oldcancel = _thr_cancel_enter(curthread); 86 87 while ((state = pthread->state) != PS_DEAD) { 88 _thr_umtx_wait(&pthread->state, state, NULL, 0); 89 } 90 91 _thr_cancel_leave(curthread, oldcancel); 92 THR_CLEANUP_POP(curthread, 0); 93 94 tmp = pthread->ret; 95 THREAD_LIST_LOCK(curthread); 96 pthread->tlflags |= TLFLAGS_DETACHED; 97 THR_GCLIST_ADD(pthread); 98 THREAD_LIST_UNLOCK(curthread); 99 100 if (thread_return != NULL) 101 *thread_return = tmp; 102 103 return (ret); 104 } 105