1/*	$NetBSD: pthread_specific.c,v 1.28 2022/04/10 10:38:33 riastradh 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 1.28 2022/04/10 10:38:33 riastradh Exp $");
34
35/* Need to use libc-private names for atomic operations. */
36#include "../../common/lib/libc/atomic/atomic_op_namespace.h"
37
38/* Functions and structures dealing with thread-specific data */
39
40#include "pthread.h"
41#include "pthread_int.h"
42#include "reentrant.h"
43
44#include <string.h>
45#include <sys/lwpctl.h>
46
47#include "../libc/include/extern.h" /* for _sys_setcontext() */
48
49int	pthread_setcontext(const ucontext_t *);
50
51__strong_alias(__libc_thr_setspecific,pthread_setspecific)
52__strong_alias(__libc_thr_getspecific,pthread_getspecific)
53__strong_alias(__libc_thr_curcpu,pthread_curcpu_np)
54
55__strong_alias(setcontext,pthread_setcontext)
56
57int
58pthread_setspecific(pthread_key_t key, const void *value)
59{
60	pthread_t self;
61
62	if (__predict_false(__uselibcstub))
63		return __libc_thr_setspecific_stub(key, value);
64
65	self = pthread__self();
66	/*
67	 * We can't win here on constness. Having been given a
68	 * "const void *", we can only assign it to other const void *,
69	 * and return it from functions that are const void *, without
70	 * generating a warning.
71	 */
72	return pthread__add_specific(self, key, value);
73}
74
75void *
76pthread_getspecific(pthread_key_t key)
77{
78	if (__predict_false(__uselibcstub))
79		return __libc_thr_getspecific_stub(key);
80
81	return pthread__self()->pt_specific[key].pts_value;
82}
83
84unsigned int
85pthread_curcpu_np(void)
86{
87	if (__predict_false(__uselibcstub))
88		return __libc_thr_curcpu_stub();
89
90	{
91		const int curcpu = pthread__self()->pt_lwpctl->lc_curcpu;
92
93		pthread__assert(curcpu != LWPCTL_CPU_NONE);
94		pthread__assert(curcpu != LWPCTL_CPU_EXITED);
95		pthread__assert(curcpu >= 0);
96		return curcpu;
97	}
98}
99
100/*
101 * Override setcontext so that pthread private pointer is preserved
102 */
103int
104pthread_setcontext(const ucontext_t *ucp)
105{
106#ifdef _UC_TLSBASE
107	ucontext_t uc;
108	/*
109	 * Only copy and clear _UC_TLSBASE if it is set.
110	 */
111	if (ucp->uc_flags & _UC_TLSBASE) {
112		uc = *ucp;
113		uc.uc_flags &= ~_UC_TLSBASE;
114		ucp = &uc;
115	}
116#endif /* _UC_TLSBASE */
117	return _sys_setcontext(ucp);
118}
119