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