lib/libthr/thread/thr_cancel.c

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