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 * $DragonFly: src/lib/libthread_xu/thread/thr_cancel.c,v 1.4 2006/04/06 13:03:09 davidxu Exp $ 27 */ 28 29 #include "namespace.h" 30 #include <machine/tls.h> 31 #include <pthread.h> 32 #include "un-namespace.h" 33 34 #include "thr_private.h" 35 36 int _pthread_setcanceltype(int type, int *oldtype); 37 38 int 39 _pthread_cancel(pthread_t pthread) 40 { 41 struct pthread *curthread = tls_get_curthread(); 42 int oldval, newval = 0; 43 int oldtype; 44 int ret; 45 46 /* 47 * POSIX says _pthread_cancel should be async cancellation safe, 48 * so we temporarily disable async cancellation. 49 */ 50 _pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype); 51 if ((ret = _thr_ref_add(curthread, pthread, 0)) != 0) { 52 _pthread_setcanceltype(oldtype, NULL); 53 return (ret); 54 } 55 56 do { 57 oldval = pthread->cancelflags; 58 if (oldval & THR_CANCEL_NEEDED) 59 break; 60 newval = oldval | THR_CANCEL_NEEDED; 61 } while (!atomic_cmpset_acq_int(&pthread->cancelflags, oldval, newval)); 62 63 if (!(oldval & THR_CANCEL_NEEDED) && SHOULD_ASYNC_CANCEL(newval)) 64 _thr_send_sig(pthread, SIGCANCEL); 65 66 _thr_ref_delete(curthread, pthread); 67 _pthread_setcanceltype(oldtype, NULL); 68 return (0); 69 } 70 71 static inline void 72 testcancel(struct pthread *curthread) 73 { 74 int newval; 75 76 newval = curthread->cancelflags; 77 if (SHOULD_CANCEL(newval)) 78 _pthread_exit(PTHREAD_CANCELED); 79 } 80 81 int 82 _pthread_setcancelstate(int state, int *oldstate) 83 { 84 struct pthread *curthread = tls_get_curthread(); 85 int oldval, ret; 86 87 oldval = curthread->cancelflags; 88 if (oldstate != NULL) 89 *oldstate = ((oldval & THR_CANCEL_DISABLE) ? 90 PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE); 91 switch (state) { 92 case PTHREAD_CANCEL_DISABLE: 93 atomic_set_int(&curthread->cancelflags, THR_CANCEL_DISABLE); 94 ret = 0; 95 break; 96 case PTHREAD_CANCEL_ENABLE: 97 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_DISABLE); 98 testcancel(curthread); 99 ret = 0; 100 break; 101 default: 102 ret = EINVAL; 103 } 104 105 return (ret); 106 } 107 108 int 109 _pthread_setcanceltype(int type, int *oldtype) 110 { 111 struct pthread *curthread = tls_get_curthread(); 112 int oldval, ret; 113 114 oldval = curthread->cancelflags; 115 if (oldtype != NULL) 116 *oldtype = ((oldval & THR_CANCEL_AT_POINT) ? 117 PTHREAD_CANCEL_ASYNCHRONOUS : 118 PTHREAD_CANCEL_DEFERRED); 119 switch (type) { 120 case PTHREAD_CANCEL_ASYNCHRONOUS: 121 atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 122 testcancel(curthread); 123 ret = 0; 124 break; 125 case PTHREAD_CANCEL_DEFERRED: 126 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 127 ret = 0; 128 break; 129 default: 130 ret = EINVAL; 131 } 132 133 return (ret); 134 } 135 136 void 137 _pthread_testcancel(void) 138 { 139 testcancel(tls_get_curthread()); 140 } 141 142 int 143 _thr_cancel_enter(struct pthread *curthread) 144 { 145 int oldval; 146 147 oldval = curthread->cancelflags; 148 if (!(oldval & THR_CANCEL_AT_POINT)) { 149 atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 150 testcancel(curthread); 151 } 152 return (oldval); 153 } 154 155 void 156 _thr_cancel_leave(struct pthread *curthread, int previous) 157 { 158 if (!(previous & THR_CANCEL_AT_POINT)) 159 atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT); 160 } 161 162 __strong_reference(_pthread_cancel, pthread_cancel); 163 __strong_reference(_pthread_setcancelstate, pthread_setcancelstate); 164 __strong_reference(_pthread_setcanceltype, pthread_setcanceltype); 165 __strong_reference(_pthread_testcancel, pthread_testcancel); 166 167