thr_detach.c revision 113661 
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. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: head/lib/libkse/thread/thr_detach.c 113661 2003-04-18 07:09:43Z deischen $
33 */
34#include <sys/types.h>
35#include <machine/atomic.h>
36#include <errno.h>
37#include <pthread.h>
38#include "thr_private.h"
39
40__weak_reference(_pthread_detach, pthread_detach);
41
42int
43_pthread_detach(pthread_t pthread)
44{
45	struct pthread *curthread = _get_curthread();
46	struct pthread *joiner;
47	kse_critical_t crit;
48	int dead;
49	int rval = 0;
50
51	/* Check for invalid calling parameters: */
52	if (pthread == NULL || pthread->magic != THR_MAGIC)
53		/* Return an invalid argument error: */
54		rval = EINVAL;
55
56	else if ((rval = _thr_ref_add(curthread, pthread,
57	    /*include dead*/1)) != 0) {
58		/* Return an error: */
59		_thr_leave_cancellation_point(curthread);
60	}
61
62	/* Check if the thread is already detached: */
63	else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
64		/* Return an error: */
65		_thr_ref_delete(curthread, pthread);
66		rval = EINVAL;
67	} else {
68		/* Lock the detached thread: */
69		THR_SCHED_LOCK(curthread, pthread);
70
71		/* Flag the thread as detached: */
72		pthread->attr.flags |= PTHREAD_DETACHED;
73
74		/* Retrieve any joining thread and remove it: */
75		joiner = pthread->joiner;
76		pthread->joiner = NULL;
77		if (joiner->kseg == pthread->kseg) {
78			/*
79			 * We already own the scheduler lock for the joiner.
80			 * Take advantage of that and make the joiner runnable.
81			 */
82			if (joiner->join_status.thread == pthread) {
83				/*
84				 * Set the return value for the woken thread:
85				 */
86				joiner->join_status.error = ESRCH;
87				joiner->join_status.ret = NULL;
88				joiner->join_status.thread = NULL;
89
90				_thr_setrunnable_unlocked(joiner);
91			}
92			joiner = NULL;
93		}
94		dead = (pthread->flags & THR_FLAGS_GC_SAFE) != 0;
95		THR_SCHED_UNLOCK(curthread, pthread);
96
97		if (dead != 0) {
98			crit = _kse_critical_enter();
99			KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
100			THR_GCLIST_ADD(pthread);
101			KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
102			_kse_critical_leave(crit);
103		}
104		_thr_ref_delete(curthread, pthread);
105
106		/* See if there is a thread waiting in pthread_join(): */
107		if (joiner != NULL) {
108			/* Lock the joiner before fiddling with it. */
109			THR_SCHED_LOCK(curthread, joiner);
110			if (joiner->join_status.thread == pthread) {
111				/*
112				 * Set the return value for the woken thread:
113				 */
114				joiner->join_status.error = ESRCH;
115				joiner->join_status.ret = NULL;
116				joiner->join_status.thread = NULL;
117
118				_thr_setrunnable_unlocked(joiner);
119			}
120			THR_SCHED_UNLOCK(curthread, joiner);
121		}
122	}
123
124	/* Return the completion status: */
125	return (rval);
126}
127