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 "namespace.h" 30 #include <errno.h> 31 #include <pthread.h> 32 #include "un-namespace.h" 33 34 #include "thr_private.h" 35 36 int _pthread_peekjoin_np(pthread_t pthread, void **thread_return); 37 int _pthread_timedjoin_np(pthread_t pthread, void **thread_return, 38 const struct timespec *abstime); 39 static int join_common(pthread_t, void **, const struct timespec *, bool peek); 40 41 __weak_reference(_thr_join, pthread_join); 42 __weak_reference(_thr_join, _pthread_join); 43 __weak_reference(_pthread_timedjoin_np, pthread_timedjoin_np); 44 __weak_reference(_pthread_peekjoin_np, pthread_peekjoin_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 _thr_join(pthread_t pthread, void **thread_return) 58 { 59 return (join_common(pthread, thread_return, NULL, false)); 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, false)); 71 } 72 73 int 74 _pthread_peekjoin_np(pthread_t pthread, void **thread_return) 75 { 76 return (join_common(pthread, thread_return, NULL, true)); 77 } 78 79 /* 80 * Cancellation behavior: 81 * if the thread is canceled, joinee is not recycled. 82 */ 83 static int 84 join_common(pthread_t pthread, void **thread_return, 85 const struct timespec *abstime, bool peek) 86 { 87 struct pthread *curthread = _get_curthread(); 88 struct timespec ts, ts2, *tsp; 89 void *tmp; 90 long tid; 91 int ret; 92 93 if (pthread == NULL) 94 return (EINVAL); 95 96 if (pthread == curthread) 97 return (EDEADLK); 98 99 if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) 100 return (ESRCH); 101 102 if ((pthread->flags & THR_FLAGS_DETACHED) != 0) { 103 ret = EINVAL; 104 } else if (pthread->joiner != NULL) { 105 /* Multiple joiners are not supported. */ 106 ret = ENOTSUP; 107 } 108 if (ret != 0) { 109 THR_THREAD_UNLOCK(curthread, pthread); 110 return (ret); 111 } 112 113 /* Only peek into status, do not gc the thread. */ 114 if (peek) { 115 if (pthread->tid != TID_TERMINATED) 116 ret = EBUSY; 117 else if (thread_return != NULL) 118 *thread_return = pthread->ret; 119 THR_THREAD_UNLOCK(curthread, pthread); 120 return (ret); 121 } 122 123 /* Set the running thread to be the joiner: */ 124 pthread->joiner = curthread; 125 126 THR_THREAD_UNLOCK(curthread, pthread); 127 128 THR_CLEANUP_PUSH(curthread, backout_join, pthread); 129 _thr_cancel_enter(curthread); 130 131 tid = pthread->tid; 132 while (pthread->tid != TID_TERMINATED) { 133 _thr_testcancel(curthread); 134 if (abstime != NULL) { 135 clock_gettime(CLOCK_REALTIME, &ts); 136 TIMESPEC_SUB(&ts2, abstime, &ts); 137 if (ts2.tv_sec < 0) { 138 ret = ETIMEDOUT; 139 break; 140 } 141 tsp = &ts2; 142 } else 143 tsp = NULL; 144 ret = _thr_umtx_wait(&pthread->tid, tid, tsp); 145 if (ret == ETIMEDOUT) 146 break; 147 } 148 149 _thr_cancel_leave(curthread, 0); 150 THR_CLEANUP_POP(curthread, 0); 151 152 if (ret == ETIMEDOUT) { 153 THR_THREAD_LOCK(curthread, pthread); 154 pthread->joiner = NULL; 155 THR_THREAD_UNLOCK(curthread, pthread); 156 } else { 157 ret = 0; 158 tmp = pthread->ret; 159 THR_THREAD_LOCK(curthread, pthread); 160 pthread->flags |= THR_FLAGS_DETACHED; 161 pthread->joiner = NULL; 162 _thr_try_gc(curthread, pthread); /* thread lock released */ 163 164 if (thread_return != NULL) 165 *thread_return = tmp; 166 } 167 return (ret); 168 } 169