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
49 int pthread_setcontext(const ucontext_t *);
50
__strong_alias(__libc_thr_setspecific,pthread_setspecific)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
57 int
58 pthread_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
75 void *
pthread_getspecific(pthread_key_t key)76 pthread_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
84 unsigned int
pthread_curcpu_np(void)85 pthread_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 */
103 int
pthread_setcontext(const ucontext_t * ucp)104 pthread_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