1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include "namespace.h" 31 #include <errno.h> 32 #include <pthread.h> 33 #include "un-namespace.h" 34 35 #include "thr_private.h" 36 37 int _pthread_peekjoin_np(pthread_t pthread, void **thread_return); 38 int _pthread_timedjoin_np(pthread_t pthread, void **thread_return, 39 const struct timespec *abstime); 40 static int join_common(pthread_t, void **, const struct timespec *, bool peek); 41 42 __weak_reference(_thr_join, pthread_join); 43 __weak_reference(_thr_join, _pthread_join); 44 __weak_reference(_pthread_timedjoin_np, pthread_timedjoin_np); 45 __weak_reference(_pthread_peekjoin_np, pthread_peekjoin_np); 46 47 static void backout_join(void *arg) 48 { 49 struct pthread *pthread = (struct pthread *)arg; 50 struct pthread *curthread = _get_curthread(); 51 52 THR_THREAD_LOCK(curthread, pthread); 53 pthread->joiner = NULL; 54 THR_THREAD_UNLOCK(curthread, pthread); 55 } 56 57 int 58 _thr_join(pthread_t pthread, void **thread_return) 59 { 60 return (join_common(pthread, thread_return, NULL, false)); 61 } 62 63 int 64 _pthread_timedjoin_np(pthread_t pthread, void **thread_return, 65 const struct timespec *abstime) 66 { 67 if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 || 68 abstime->tv_nsec >= 1000000000) 69 return (EINVAL); 70 71 return (join_common(pthread, thread_return, abstime, false)); 72 } 73 74 int 75 _pthread_peekjoin_np(pthread_t pthread, void **thread_return) 76 { 77 return (join_common(pthread, thread_return, NULL, true)); 78 } 79 80 /* 81 * Cancellation behavior: 82 * if the thread is canceled, joinee is not recycled. 83 */ 84 static int 85 join_common(pthread_t pthread, void **thread_return, 86 const struct timespec *abstime, bool peek) 87 { 88 struct pthread *curthread = _get_curthread(); 89 struct timespec ts, ts2, *tsp; 90 void *tmp; 91 long tid; 92 int ret; 93 94 if (pthread == NULL) 95 return (EINVAL); 96 97 if (pthread == curthread) 98 return (EDEADLK); 99 100 if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) 101 return (ESRCH); 102 103 if ((pthread->flags & THR_FLAGS_DETACHED) != 0) { 104 ret = EINVAL; 105 } else if (pthread->joiner != NULL) { 106 /* Multiple joiners are not supported. */ 107 ret = ENOTSUP; 108 } 109 if (ret != 0) { 110 THR_THREAD_UNLOCK(curthread, pthread); 111 return (ret); 112 } 113 114 /* Only peek into status, do not gc the thread. */ 115 if (peek) { 116 if (pthread->tid != TID_TERMINATED) 117 ret = EBUSY; 118 else if (thread_return != NULL) 119 *thread_return = pthread->ret; 120 THR_THREAD_UNLOCK(curthread, pthread); 121 return (ret); 122 } 123 124 /* Set the running thread to be the joiner: */ 125 pthread->joiner = curthread; 126 127 THR_THREAD_UNLOCK(curthread, pthread); 128 129 THR_CLEANUP_PUSH(curthread, backout_join, pthread); 130 _thr_cancel_enter(curthread); 131 132 tid = pthread->tid; 133 while (pthread->tid != TID_TERMINATED) { 134 _thr_testcancel(curthread); 135 if (abstime != NULL) { 136 clock_gettime(CLOCK_REALTIME, &ts); 137 TIMESPEC_SUB(&ts2, abstime, &ts); 138 if (ts2.tv_sec < 0) { 139 ret = ETIMEDOUT; 140 break; 141 } 142 tsp = &ts2; 143 } else 144 tsp = NULL; 145 ret = _thr_umtx_wait(&pthread->tid, tid, tsp); 146 if (ret == ETIMEDOUT) 147 break; 148 } 149 150 _thr_cancel_leave(curthread, 0); 151 THR_CLEANUP_POP(curthread, 0); 152 153 if (ret == ETIMEDOUT) { 154 THR_THREAD_LOCK(curthread, pthread); 155 pthread->joiner = NULL; 156 THR_THREAD_UNLOCK(curthread, pthread); 157 } else { 158 ret = 0; 159 tmp = pthread->ret; 160 THR_THREAD_LOCK(curthread, pthread); 161 pthread->flags |= THR_FLAGS_DETACHED; 162 pthread->joiner = NULL; 163 _thr_try_gc(curthread, pthread); /* thread lock released */ 164 165 if (thread_return != NULL) 166 *thread_return = tmp; 167 } 168 return (ret); 169 } 170