xref: /freebsd/lib/libthr/thread/thr_autoinit.c (revision f8bbbce458194ff4312c610d32a64ff4a3a71d45)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 2002 Alfred Perlstein <alfred@freebsd.org>.
5  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by John Birrell.
19  * 4. Neither the name of the author nor the names of any co-contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <pthread.h>
37 
38 #include "thr_private.h"
39 
40 /*
41  * This module uses GCC extensions to initialize the
42  * threads package at program start-up time.
43  */
44 
45 void	_thread_init_hack(void) __attribute__ ((constructor));
46 
47 void
_thread_init_hack(void)48 _thread_init_hack(void)
49 {
50 
51 	_thread_init();
52 }
53 
54 /*
55  * For the shared version of the threads library, the above is sufficient.
56  * But for the archive version of the library, we need a little bit more.
57  * Namely, we must arrange for this particular module to be pulled in from
58  * the archive library at link time.  To accomplish that, we define and
59  * initialize a variable, "_thread_autoinit_dummy_decl".  This variable is
60  * referenced (as an extern) from libc/stdlib/exit.c. This will always
61  * create a need for this module, ensuring that it is present in the
62  * executable.
63  */
64 extern int _thread_autoinit_dummy_decl;
65 int _thread_autoinit_dummy_decl = 0;
66