1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2005, David Xu <davidxu@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "namespace.h" 33 #include <errno.h> 34 #include <pthread.h> 35 #include "un-namespace.h" 36 37 #include "thr_private.h" 38 39 int _pthread_timedjoin_np(pthread_t pthread, void **thread_return, 40 const struct timespec *abstime); 41 static int join_common(pthread_t, void **, const struct timespec *); 42 43 __weak_reference(_pthread_join, pthread_join); 44 __weak_reference(_pthread_timedjoin_np, pthread_timedjoin_np); 45 46 static void backout_join(void *arg) 47 { 48 struct pthread *pthread = (struct pthread *)arg; 49 struct pthread *curthread = _get_curthread(); 50 51 THR_THREAD_LOCK(curthread, pthread); 52 pthread->joiner = NULL; 53 THR_THREAD_UNLOCK(curthread, pthread); 54 } 55 56 int 57 _pthread_join(pthread_t pthread, void **thread_return) 58 { 59 return (join_common(pthread, thread_return, NULL)); 60 } 61 62 int 63 _pthread_timedjoin_np(pthread_t pthread, void **thread_return, 64 const struct timespec *abstime) 65 { 66 if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 || 67 abstime->tv_nsec >= 1000000000) 68 return (EINVAL); 69 70 return (join_common(pthread, thread_return, abstime)); 71 } 72 73 /* 74 * Cancellation behavior: 75 * if the thread is canceled, joinee is not recycled. 76 */ 77 static int 78 join_common(pthread_t pthread, void **thread_return, 79 const struct timespec *abstime) 80 { 81 struct pthread *curthread = _get_curthread(); 82 struct timespec ts, ts2, *tsp; 83 void *tmp; 84 long tid; 85 int ret = 0; 86 87 if (pthread == NULL) 88 return (EINVAL); 89 90 if (pthread == curthread) 91 return (EDEADLK); 92 93 if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) 94 return (ESRCH); 95 96 if ((pthread->flags & THR_FLAGS_DETACHED) != 0) { 97 ret = EINVAL; 98 } else if (pthread->joiner != NULL) { 99 /* Multiple joiners are not supported. */ 100 ret = ENOTSUP; 101 } 102 if (ret) { 103 THR_THREAD_UNLOCK(curthread, pthread); 104 return (ret); 105 } 106 /* Set the running thread to be the joiner: */ 107 pthread->joiner = curthread; 108 109 THR_THREAD_UNLOCK(curthread, pthread); 110 111 THR_CLEANUP_PUSH(curthread, backout_join, pthread); 112 _thr_cancel_enter(curthread); 113 114 tid = pthread->tid; 115 while (pthread->tid != TID_TERMINATED) { 116 _thr_testcancel(curthread); 117 if (abstime != NULL) { 118 clock_gettime(CLOCK_REALTIME, &ts); 119 TIMESPEC_SUB(&ts2, abstime, &ts); 120 if (ts2.tv_sec < 0) { 121 ret = ETIMEDOUT; 122 break; 123 } 124 tsp = &ts2; 125 } else 126 tsp = NULL; 127 ret = _thr_umtx_wait(&pthread->tid, tid, tsp); 128 if (ret == ETIMEDOUT) 129 break; 130 } 131 132 _thr_cancel_leave(curthread, 0); 133 THR_CLEANUP_POP(curthread, 0); 134 135 if (ret == ETIMEDOUT) { 136 THR_THREAD_LOCK(curthread, pthread); 137 pthread->joiner = NULL; 138 THR_THREAD_UNLOCK(curthread, pthread); 139 } else { 140 ret = 0; 141 tmp = pthread->ret; 142 THR_THREAD_LOCK(curthread, pthread); 143 pthread->flags |= THR_FLAGS_DETACHED; 144 pthread->joiner = NULL; 145 _thr_try_gc(curthread, pthread); /* thread lock released */ 146 147 if (thread_return != NULL) 148 *thread_return = tmp; 149 } 150 return (ret); 151 } 152