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 1.3 2005/03/29 19:26:20 joerg Exp $ 34 */ 35 36 #include <machine/tls.h> 37 38 #include <errno.h> 39 #include <pthread.h> 40 #include "thr_private.h" 41 42 __weak_reference(_pthread_join, pthread_join); 43 44 static void backout_join(void *arg) 45 { 46 struct pthread *curthread = tls_get_curthread(); 47 struct pthread *pthread = (struct pthread *)arg; 48 49 THREAD_LIST_LOCK(curthread); 50 pthread->joiner = NULL; 51 THREAD_LIST_UNLOCK(curthread); 52 } 53 54 int 55 _pthread_join(pthread_t pthread, void **thread_return) 56 { 57 struct pthread *curthread = tls_get_curthread(); 58 void *tmp; 59 long state; 60 int oldcancel; 61 int ret = 0; 62 63 if (pthread == NULL) 64 return (EINVAL); 65 66 if (pthread == curthread) 67 return (EDEADLK); 68 69 THREAD_LIST_LOCK(curthread); 70 if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) { 71 ret = ESRCH; 72 } else if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) { 73 ret = ESRCH; 74 } else if (pthread->joiner != NULL) { 75 /* Multiple joiners are not supported. */ 76 ret = ENOTSUP; 77 } 78 if (ret) { 79 THREAD_LIST_UNLOCK(curthread); 80 return (ret); 81 } 82 /* Set the running thread to be the joiner: */ 83 pthread->joiner = curthread; 84 85 THREAD_LIST_UNLOCK(curthread); 86 87 THR_CLEANUP_PUSH(curthread, backout_join, pthread); 88 oldcancel = _thr_cancel_enter(curthread); 89 90 while ((state = pthread->state) != PS_DEAD) { 91 _thr_umtx_wait(&pthread->state, state, NULL, 0); 92 } 93 94 _thr_cancel_leave(curthread, oldcancel); 95 THR_CLEANUP_POP(curthread, 0); 96 97 tmp = pthread->ret; 98 THREAD_LIST_LOCK(curthread); 99 pthread->tlflags |= TLFLAGS_DETACHED; 100 THR_GCLIST_ADD(pthread); 101 THREAD_LIST_UNLOCK(curthread); 102 103 if (thread_return != NULL) 104 *thread_return = tmp; 105 106 return (ret); 107 } 108