thr_find_thread.c revision 78873 
1/*
2 * Copyright (c) 1998 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_find_thread.c 78873 2001-06-27 11:41:15Z jasone $
33 */
34#include <errno.h>
35#include <pthread.h>
36#include "pthread_private.h"
37
38/* Find a thread in the linked list of active threads: */
39int
40_find_thread(pthread_t pthread)
41{
42	pthread_t pthread1;
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	/*
50	 * Defer signals to protect the thread list from access
51	 * by the signal handler:
52	 */
53	_thread_kern_sig_defer();
54
55	/* Search for the specified thread: */
56	TAILQ_FOREACH(pthread1, &_thread_list, tle) {
57		if (pthread == pthread1)
58			break;
59	}
60
61	/* Undefer and handle pending signals, yielding if necessary: */
62	_thread_kern_sig_undefer();
63
64	/* Return zero if the thread exists: */
65	return ((pthread1 != NULL) ? 0:ESRCH);
66}
67