lib/libpthread/thread/thr_kill.c

   1 /*
   2  * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
   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, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD$
  33  */
  34 #include <errno.h>
  35 #include <signal.h>
  36 #ifdef _THREAD_SAFE
  37 #include <pthread.h>
  38 #include "pthread_private.h"
  39
  40 int
  41 pthread_kill(pthread_t pthread, int sig)
  42 {
  43         int ret;
  44
  45         /* Check for invalid signal numbers: */
  46         if (sig < 0 || sig >= NSIG)
  47                 /* Invalid signal: */
  48                 ret = EINVAL;
  49
  50         /*
  51          * Ensure the thread is in the list of active threads, and the
  52          * signal is valid (signal 0 specifies error checking only) and
  53          * not being ignored:
  54          */
  55         else if (((ret = _find_thread(pthread)) == 0) && (sig > 0) &&
  56             (_thread_sigact[sig - 1].sa_handler != SIG_IGN)) {
  57                 /*
  58                  * Defer signals to protect the scheduling queues from
  59                  * access by the signal handler:
  60                  */
  61                 _thread_kern_sig_defer();
  62
  63                 switch (pthread->state) {
  64                 case PS_SIGSUSPEND:
  65                         /*
  66                          * Only wake up the thread if the signal is unblocked
  67                          * and there is a handler installed for the signal.
  68                          */
  69                         if (!sigismember(&pthread->sigmask, sig) &&
  70                             _thread_sigact[sig - 1].sa_handler != SIG_DFL) {
  71                                 /* Change the state of the thread to run: */
  72                                 PTHREAD_NEW_STATE(pthread,PS_RUNNING);
  73
  74                                 /* Return the signal number: */
  75                                 pthread->signo = sig;
  76                         }
  77                         /* Increment the pending signal count: */
  78                         sigaddset(&pthread->sigpend,sig);
  79                         break;
  80
  81                 case PS_SIGWAIT:
  82                         /* Wake up the thread if the signal is blocked. */
  83                         if (sigismember(pthread->data.sigwait, sig)) {
  84                                 /* Change the state of the thread to run: */
  85                                 PTHREAD_NEW_STATE(pthread,PS_RUNNING);
  86
  87                                 /* Return the signal number: */
  88                                 pthread->signo = sig;
  89                         } else
  90                                 /* Increment the pending signal count. */
  91                                 sigaddset(&pthread->sigpend,sig);
  92                         break;
  93
  94                 case PS_FDR_WAIT:
  95                 case PS_FDW_WAIT:
  96                 case PS_POLL_WAIT:
  97                 case PS_SLEEP_WAIT:
  98                 case PS_SELECT_WAIT:
  99                         if (!sigismember(&pthread->sigmask, sig) &&
 100                             (_thread_sigact[sig - 1].sa_handler != SIG_IGN)) {
 101                                 /* Flag the operation as interrupted: */
 102                                 pthread->interrupted = 1;
 103
 104                                 if (pthread->flags & PTHREAD_FLAGS_IN_WORKQ)
 105                                         PTHREAD_WORKQ_REMOVE(pthread);
 106
 107                                 /* Change the state of the thread to run: */
 108                                 PTHREAD_NEW_STATE(pthread,PS_RUNNING);
 109
 110                                 /* Return the signal number: */
 111                                 pthread->signo = sig;
 112                         } else {
 113                                 /* Increment the pending signal count: */
 114                                 sigaddset(&pthread->sigpend,sig);
 115                         }
 116                         break;
 117
 118                 default:
 119                         /* Increment the pending signal count: */
 120                         sigaddset(&pthread->sigpend,sig);
 121                         break;
 122                 }
 123
 124
 125                 /*
 126                  * Check that a custom handler is installed
 127                  * and if the signal is not blocked:
 128                  */
 129                 if (_thread_sigact[sig - 1].sa_handler != SIG_DFL &&
 130                     _thread_sigact[sig - 1].sa_handler != SIG_IGN &&
 131                     sigismember(&pthread->sigpend, sig) &&
 132                     !sigismember(&pthread->sigmask, sig)) {
 133                         pthread_t pthread_saved = _thread_run;
 134
 135                         /* Current thread inside critical region? */
 136                         if (_thread_run->sig_defer_count > 0)
 137                                 pthread->sig_defer_count++;
 138
 139                         _thread_run = pthread;
 140
 141                         /* Clear the pending signal: */
 142                         sigdelset(&pthread->sigpend, sig);
 143
 144                         /*
 145                          * Dispatch the signal via the custom signal
 146                          * handler:
 147                          */
 148                         (*(_thread_sigact[sig - 1].sa_handler))(sig);
 149
 150                         _thread_run = pthread_saved;
 151
 152                         if (_thread_run->sig_defer_count > 0)
 153                                 pthread->sig_defer_count--;
 154                 }
 155
 156                 /*
 157                  * Undefer and handle pending signals, yielding if
 158                  * necessary:
 159                  */
 160                 _thread_kern_sig_undefer();
 161         }
 162
 163         /* Return the completion status: */
 164         return (ret);
 165 }
 166 #endif