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 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 * 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 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 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