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 * $FreeBSD$
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
41int
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