thr_join.c revision 37146 
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 REGENTS 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 */
33#include <errno.h>
34#ifdef _THREAD_SAFE
35#include <pthread.h>
36#include "pthread_private.h"
37
38int
39pthread_join(pthread_t pthread, void **thread_return)
40{
41	int ret = 0;
42	pthread_t pthread1 = NULL;
43
44	/* Check if the caller has specified an invalid thread: */
45	if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
46		/* Invalid thread: */
47		return(EINVAL);
48
49	/* Check if the caller has specified itself: */
50	if (pthread == _thread_run)
51		/* Avoid a deadlock condition: */
52		return(EDEADLK);
53
54	/*
55	 * Find the thread in the list of active threads or in the
56	 * list of dead threads:
57	 */
58	if (_find_thread(pthread) == 0 ||
59	    _find_dead_thread(pthread) == 0)
60		pthread1  = pthread;
61
62	if (pthread1 == NULL)
63		/* Return an error: */
64		ret = ESRCH;
65
66	/* Check if this thread has been detached: */
67	else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0)
68		/* Return an error: */
69		ret = ESRCH;
70
71	/* Check if the thread is not dead: */
72	else if (pthread->state != PS_DEAD) {
73		/* Add the running thread to the join queue: */
74		_thread_queue_enq(&(pthread->join_queue), _thread_run);
75
76		/* Schedule the next thread: */
77		_thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__);
78
79		/* Check if the thread is not detached: */
80		if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) {
81			/* Check if the return value is required: */
82			if (thread_return)
83				/* Return the thread's return value: */
84				*thread_return = pthread->ret;
85		}
86		else
87			/* Return an error: */
88			ret = ESRCH;
89
90	/* Check if the return value is required: */
91	} else if (thread_return != NULL)
92		/* Return the thread's return value: */
93		*thread_return = pthread->ret;
94
95	/* Return the completion status: */
96	return (ret);
97}
98#endif
99