1/* 2 * Copyright (c) 2005, David Xu <davidxu@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: stable/11/lib/libthr/thread/thr_cancel.c 358141 2020-02-20 01:24:45Z kib $"); 29 30#include "namespace.h" 31#include <pthread.h> 32#include "un-namespace.h" 33 34#include "thr_private.h" 35 36__weak_reference(_pthread_cancel, pthread_cancel); 37__weak_reference(_pthread_setcancelstate, pthread_setcancelstate); 38__weak_reference(_pthread_setcanceltype, pthread_setcanceltype); 39__weak_reference(_pthread_testcancel, pthread_testcancel); 40 41static inline void 42testcancel(struct pthread *curthread) 43{ 44 if (__predict_false(SHOULD_CANCEL(curthread) && 45 !THR_IN_CRITICAL(curthread))) 46 _pthread_exit(PTHREAD_CANCELED); 47} 48 49void 50_thr_testcancel(struct pthread *curthread) 51{ 52 testcancel(curthread); 53} 54 55int 56_pthread_cancel(pthread_t pthread) 57{ 58 struct pthread *curthread = _get_curthread(); 59 int ret; 60 61 /* 62 * POSIX says _pthread_cancel should be async cancellation safe. 63 * _thr_find_thread and THR_THREAD_UNLOCK will enter and leave critical 64 * region automatically. 65 */ 66 if ((ret = _thr_find_thread(curthread, pthread, 1)) == 0) { 67 if (!pthread->cancel_pending) { 68 pthread->cancel_pending = 1; 69 if (pthread->state != PS_DEAD) 70 _thr_send_sig(pthread, SIGCANCEL); 71 } 72 THR_THREAD_UNLOCK(curthread, pthread); 73 } 74 return (ret); 75} 76 77int 78_pthread_setcancelstate(int state, int *oldstate) 79{ 80 struct pthread *curthread = _get_curthread(); 81 int oldval; 82 83 oldval = curthread->cancel_enable; 84 switch (state) { 85 case PTHREAD_CANCEL_DISABLE: 86 curthread->cancel_enable = 0; 87 break; 88 case PTHREAD_CANCEL_ENABLE: 89 curthread->cancel_enable = 1; 90 if (curthread->cancel_async) 91 testcancel(curthread); 92 break; 93 default: 94 return (EINVAL); 95 } 96 97 if (oldstate) { 98 *oldstate = oldval ? PTHREAD_CANCEL_ENABLE : 99 PTHREAD_CANCEL_DISABLE; 100 } 101 return (0); 102} 103 104int 105_pthread_setcanceltype(int type, int *oldtype) 106{ 107 struct pthread *curthread = _get_curthread(); 108 int oldval; 109 110 oldval = curthread->cancel_async; 111 switch (type) { 112 case PTHREAD_CANCEL_ASYNCHRONOUS: 113 curthread->cancel_async = 1; 114 testcancel(curthread); 115 break; 116 case PTHREAD_CANCEL_DEFERRED: 117 curthread->cancel_async = 0; 118 break; 119 default: 120 return (EINVAL); 121 } 122 123 if (oldtype) { 124 *oldtype = oldval ? PTHREAD_CANCEL_ASYNCHRONOUS : 125 PTHREAD_CANCEL_DEFERRED; 126 } 127 return (0); 128} 129 130void 131_pthread_testcancel(void) 132{ 133 struct pthread *curthread; 134 135 _thr_check_init(); 136 curthread = _get_curthread(); 137 testcancel(curthread); 138} 139 140void 141_thr_cancel_enter(struct pthread *curthread) 142{ 143 curthread->cancel_point = 1; 144 testcancel(curthread); 145} 146 147void 148_thr_cancel_enter2(struct pthread *curthread, int maycancel) 149{ 150 curthread->cancel_point = 1; 151 if (__predict_false(SHOULD_CANCEL(curthread) && 152 !THR_IN_CRITICAL(curthread))) { 153 if (!maycancel) 154 thr_wake(curthread->tid); 155 else 156 _pthread_exit(PTHREAD_CANCELED); 157 } 158} 159 160void 161_thr_cancel_leave(struct pthread *curthread, int maycancel) 162{ 163 curthread->cancel_point = 0; 164 if (__predict_false(SHOULD_CANCEL(curthread) && 165 !THR_IN_CRITICAL(curthread) && maycancel)) 166 _pthread_exit(PTHREAD_CANCELED); 167} 168 169void 170_pthread_cancel_enter(int maycancel) 171{ 172 _thr_cancel_enter2(_get_curthread(), maycancel); 173} 174 175void 176_pthread_cancel_leave(int maycancel) 177{ 178 _thr_cancel_leave(_get_curthread(), maycancel); 179} 180