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. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: stable/10/lib/libkse/thread/thr_detach.c 174689 2007-12-16 23:29:57Z deischen $
30 */
31 #include "namespace.h"
32 #include <sys/types.h>
33 #include <machine/atomic.h>
34 #include <errno.h>
35 #include <pthread.h>
36 #include "un-namespace.h"
37 #include "thr_private.h"
38
39 __weak_reference(_pthread_detach, pthread_detach);
40
41 int
_pthread_detach(pthread_t pthread)42 _pthread_detach(pthread_t pthread)
43 {
44 struct pthread *curthread = _get_curthread();
45 struct kse_mailbox *kmbx = NULL;
46 struct pthread *joiner;
47 int rval = 0;
48
49 /* Check for invalid calling parameters: */
50 if (pthread == NULL || pthread->magic != THR_MAGIC)
51 /* Return an invalid argument error: */
52 rval = EINVAL;
53
54 else if ((rval = _thr_ref_add(curthread, pthread,
55 /*include dead*/1)) != 0) {
56 /* Return an error: */
57 }
58
59 /* Check if the thread is already detached: */
60 else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
61 /* Return an error: */
62 _thr_ref_delete(curthread, pthread);
63 rval = EINVAL;
64 } else {
65 /* Lock the detached thread: */
66 THR_SCHED_LOCK(curthread, pthread);
67
68 /* Flag the thread as detached: */
69 pthread->attr.flags |= PTHREAD_DETACHED;
70
71 /* Retrieve any joining thread and remove it: */
72 joiner = pthread->joiner;
73 if ((joiner != NULL) && (joiner->kseg == pthread->kseg)) {
74 /*
75 * We already own the scheduler lock for the joiner.
76 * Take advantage of that and make the joiner runnable.
77 */
78 if (joiner->join_status.thread == pthread) {
79 /*
80 * Set the return value for the woken thread:
81 */
82 joiner->join_status.error = ESRCH;
83 joiner->join_status.ret = NULL;
84 joiner->join_status.thread = NULL;
85
86 kmbx = _thr_setrunnable_unlocked(joiner);
87 }
88 joiner = NULL;
89 }
90 THR_SCHED_UNLOCK(curthread, pthread);
91 /* See if there is a thread waiting in pthread_join(): */
92 if ((joiner != NULL) &&
93 (_thr_ref_add(curthread, joiner, 0) == 0)) {
94 /* Lock the joiner before fiddling with it. */
95 THR_SCHED_LOCK(curthread, joiner);
96 if (joiner->join_status.thread == pthread) {
97 /*
98 * Set the return value for the woken thread:
99 */
100 joiner->join_status.error = ESRCH;
101 joiner->join_status.ret = NULL;
102 joiner->join_status.thread = NULL;
103
104 kmbx = _thr_setrunnable_unlocked(joiner);
105 }
106 THR_SCHED_UNLOCK(curthread, joiner);
107 _thr_ref_delete(curthread, joiner);
108 }
109 _thr_ref_delete(curthread, pthread);
110 if (kmbx != NULL)
111 kse_wakeup(kmbx);
112 }
113
114 /* Return the completion status: */
115 return (rval);
116 }
117