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
backout_join(void * arg)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
_thr_join(pthread_t pthread,void ** thread_return)57 _thr_join(pthread_t pthread, void **thread_return)
58 {
59 return (join_common(pthread, thread_return, NULL, false));
60 }
61
62 int
_pthread_timedjoin_np(pthread_t pthread,void ** thread_return,const struct timespec * abstime)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
_pthread_peekjoin_np(pthread_t pthread,void ** thread_return)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
join_common(pthread_t pthread,void ** thread_return,const struct timespec * abstime,bool peek)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