pthread_specific.c revision 1.26 
1/*	$NetBSD: pthread_specific.c,v 1.26 2013/03/21 16:49:12 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2001, 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nathan J. Williams.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__RCSID("$NetBSD: pthread_specific.c,v 1.26 2013/03/21 16:49:12 christos Exp $");
34
35/* Functions and structures dealing with thread-specific data */
36
37#include "pthread.h"
38#include "pthread_int.h"
39#include "reentrant.h"
40
41#include <string.h>
42#include <sys/lwpctl.h>
43
44#include "../libc/include/extern.h" /* for _sys_setcontext() */
45
46int	pthread_setcontext(const ucontext_t *);
47
48__strong_alias(__libc_thr_setspecific,pthread_setspecific)
49__strong_alias(__libc_thr_getspecific,pthread_getspecific)
50__strong_alias(__libc_thr_curcpu,pthread_curcpu_np)
51
52__strong_alias(setcontext,pthread_setcontext)
53
54int
55pthread_setspecific(pthread_key_t key, const void *value)
56{
57	pthread_t self;
58
59	if (__predict_false(__uselibcstub))
60		return __libc_thr_setspecific_stub(key, value);
61
62	self = pthread__self();
63	/*
64	 * We can't win here on constness. Having been given a
65	 * "const void *", we can only assign it to other const void *,
66	 * and return it from functions that are const void *, without
67	 * generating a warning.
68	 */
69	return pthread__add_specific(self, key, value);
70}
71
72void *
73pthread_getspecific(pthread_key_t key)
74{
75	if (__predict_false(__uselibcstub))
76		return __libc_thr_getspecific_stub(key);
77
78	return pthread__self()->pt_specific[key].pts_value;
79}
80
81unsigned int
82pthread_curcpu_np(void)
83{
84	if (__predict_false(__uselibcstub))
85		return __libc_thr_curcpu_stub();
86
87	{
88		const int curcpu = pthread__self()->pt_lwpctl->lc_curcpu;
89
90		pthread__assert(curcpu != LWPCTL_CPU_NONE);
91		pthread__assert(curcpu != LWPCTL_CPU_EXITED);
92		pthread__assert(curcpu >= 0);
93		return curcpu;
94	}
95}
96
97/*
98 * Override setcontext so that pthread private pointer is preserved
99 */
100int
101pthread_setcontext(const ucontext_t *ucp)
102{
103#ifdef _UC_TLSBASE
104	ucontext_t uc;
105	/*
106	 * Only copy and clear _UC_TLSBASE if it is set.
107	 */
108	if (ucp->uc_flags & _UC_TLSBASE) {
109		uc = *ucp;
110		uc.uc_flags &= ~_UC_TLSBASE;
111		ucp = &uc;
112	}
113#endif /* _UC_TLSBASE */
114	return _sys_setcontext(ucp);
115}
116