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 * $FreeBSD$ 27 * 28 */ 29 30 #include <pthread.h> 31 32 #include "thr_private.h" 33 34 __weak_reference(_pthread_cancel, pthread_cancel); 35 __weak_reference(_pthread_setcancelstate, pthread_setcancelstate); 36 __weak_reference(_pthread_setcanceltype, pthread_setcanceltype); 37 __weak_reference(_pthread_testcancel, pthread_testcancel); 38 39 int _pthread_setcanceltype(int type, int *oldtype); 40 41 int 42 _pthread_cancel(pthread_t pthread) 43 { 44 struct pthread *curthread = _get_curthread(); 45 int oldval, newval = 0; 46 int oldtype; 47 int ret; 48 49 /* 50 * POSIX says _pthread_cancel should be async cancellation safe, 51 * so we temporarily disable async cancellation. 52 */ 53 _pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype); 54 if ((ret = _thr_ref_add(curthread, pthread, 0)) != 0) { 55 _pthread_setcanceltype(oldtype, NULL); 56 return (ret); 57 } 58 59 do { 60 oldval = pthread->cancelflags; 61 if (oldval & THR_CANCEL_NEEDED) 62 break; 63 newval = oldval | THR_CANCEL_NEEDED; 64 } while (!atomic_cmpset_acq_int(&pthread->cancelflags, oldval, newval)); 65 66 if (!(oldval & THR_CANCEL_NEEDED) && SHOULD_ASYNC_CANCEL(newval)) 67 _thr_send_sig(pthread, SIGCANCEL); 68 69 _thr_ref_delete(curthread, pthread); 70 _pthread_setcanceltype(oldtype, NULL); 71 return (0); 72 } 73 74 static inline void 75 testcancel(struct pthread *curthread) 76 { 77 int newval; 78 79 newval = curthread->cancelflags; 80 if (SHOULD_CANCEL(newval)) 81 pthread_exit(PTHREAD_CANCELED); 82 } 83 84 int 85 _pthread_setcancelstate(int state, int *oldstate) 86 { 87 struct pthread *curthread = _get_curthread(); 88 int oldval, ret; 89 90 oldval = curthread->cancelflags; 91 if (oldstate != NULL) 92 *oldstate = ((oldval & THR_CANCEL_DISABLE) ? 93 PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE); 94 switch (state) { 95 case PTHREAD_CANCEL_DISABLE: 96 atomic_set_int(&curthread->cancelflags, THR_CANCEL_DISABLE); 97 ret = 0; 98 break; 99 case PTHREAD_CANCEL_ENABLE: 100 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_DISABLE); 101 testcancel(curthread); 102 ret = 0; 103 break; 104 default: 105 ret = EINVAL; 106 } 107 108 return (ret); 109 } 110 111 int 112 _pthread_setcanceltype(int type, int *oldtype) 113 { 114 struct pthread *curthread = _get_curthread(); 115 int oldval, ret; 116 117 oldval = curthread->cancelflags; 118 if (oldtype != NULL) 119 *oldtype = ((oldval & THR_CANCEL_AT_POINT) ? 120 PTHREAD_CANCEL_ASYNCHRONOUS : 121 PTHREAD_CANCEL_DEFERRED); 122 switch (type) { 123 case PTHREAD_CANCEL_ASYNCHRONOUS: 124 atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 125 testcancel(curthread); 126 ret = 0; 127 break; 128 case PTHREAD_CANCEL_DEFERRED: 129 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 130 ret = 0; 131 break; 132 default: 133 ret = EINVAL; 134 } 135 136 return (ret); 137 } 138 139 void 140 _pthread_testcancel(void) 141 { 142 testcancel(_get_curthread()); 143 } 144 145 int 146 _thr_cancel_enter(struct pthread *curthread) 147 { 148 int oldval; 149 150 oldval = curthread->cancelflags; 151 if (!(oldval & THR_CANCEL_AT_POINT)) { 152 atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 153 testcancel(curthread); 154 } 155 return (oldval); 156 } 157 158 void 159 _thr_cancel_leave(struct pthread *curthread, int previous) 160 { 161 if (!(previous & THR_CANCEL_AT_POINT)) 162 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 163 } 164