1 /*	$OpenBSD: uthread_detach.c,v 1.8 2002/03/07 22:36:03 fgsch Exp $	*/
2 /*
3  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by John Birrell.
17  * 4. Neither the name of the author nor the names of any co-contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: uthread_detach.c,v 1.10 1999/08/28 00:03:28 peter Exp $
34  */
35 #include <errno.h>
36 #ifdef _THREAD_SAFE
37 #include <pthread.h>
38 #include "pthread_private.h"
39 
40 int
pthread_detach(pthread_t pthread)41 pthread_detach(pthread_t pthread)
42 {
43 	int             rval = 0;
44 
45 	/* Check for invalid calling parameters: */
46 	if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
47 		/* Return an invalid argument error: */
48 		rval = EINVAL;
49 
50 	/* Check if the thread has not been detached: */
51 	else if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) {
52 		/* Flag the thread as detached: */
53 		pthread->attr.flags |= PTHREAD_DETACHED;
54 
55 		/*
56 		 * Defer signals to protect the scheduling queues from
57 		 * access by the signal handler:
58 		 */
59 		_thread_kern_sig_defer();
60 
61 		/* Check if there is a joiner: */
62 		if (pthread->joiner != NULL) {
63 			struct pthread	*joiner = pthread->joiner;
64 
65 			/* Make the thread runnable: */
66 			PTHREAD_NEW_STATE(joiner, PS_RUNNING);
67 
68 			/* Set the return value for the woken thread: */
69 			joiner->join_status.error = ESRCH;
70 			joiner->join_status.ret = NULL;
71 			joiner->join_status.thread = NULL;
72 
73 			/*
74 			 * Disconnect the joiner from the thread being detached:
75 			 */
76 			pthread->joiner = NULL;
77 		}
78 
79 		/*
80 		 * Undefer and handle pending signals, yielding if a
81 		 * scheduling signal occurred while in the critical region.
82 		 */
83 		_thread_kern_sig_undefer();
84 	} else
85 		/* Return an error: */
86 		rval = EINVAL;
87 
88 	/* Return the completion status: */
89 	return (rval);
90 }
91 #endif
92