1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009 Hudson River Trading LLC
5 * Written by: John H. Baldwin <jhb@FreeBSD.org>
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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include "namespace.h"
31 #include <pthread.h>
32 #include "un-namespace.h"
33 #include "libc_private.h"
34
35 /* This implements pthread_once() for the single-threaded case. */
36 static int
_libc_once(pthread_once_t * once_control,void (* init_routine)(void))37 _libc_once(pthread_once_t *once_control, void (*init_routine)(void))
38 {
39
40 if (once_control->state == PTHREAD_DONE_INIT)
41 return (0);
42 init_routine();
43 once_control->state = PTHREAD_DONE_INIT;
44 return (0);
45 }
46
47 /*
48 * This is the internal interface provided to libc. It will use
49 * pthread_once() from the threading library in a multi-threaded
50 * process and _libc_once() for a single-threaded library. Because
51 * _libc_once() uses the same ABI for the values in the pthread_once_t
52 * structure as the threading library, it is safe for a process to
53 * switch from _libc_once() to pthread_once() when threading is
54 * enabled.
55 */
56 int
_once(pthread_once_t * once_control,void (* init_routine)(void))57 _once(pthread_once_t *once_control, void (*init_routine)(void))
58 {
59
60 if (__isthreaded)
61 return (_pthread_once(once_control, init_routine));
62 return (_libc_once(once_control, init_routine));
63 }
64