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root/usr/lib/posix/signal/sigaction.c

DEFINITIONS

1. sigaction

   1 /*
   2  * Copyright (c) 2005, Kohsuke Ohtani
   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. Neither the name of the author nor the names of any co-contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  30 #include <sys/signal.h>
  32 #include <stddef.h>
  33 #include <signal.h>
  34 #include <errno.h>
  36 /*
  37  * If act is not NULL, set the action for signum.
  38  * If oact is not NULL. store the old action to oact.
  39  */
  40 int
sigaction(int signum, const struct sigaction *act, struct sigaction *oact)
  42 {
  43         struct sigaction *sa;
  45         if (signum <= 0 || signum >= NSIG ||
signum == SIGSTOP || signum == SIGKILL) {
errno = EINVAL;
  48                 return -1;
  49         }
SIGNAL_LOCK();
sa = &__sig_act[signum];
  55         if (oact != NULL)
  56                 *oact = *sa;
  58         if (act != NULL)
  59                 *sa = *act;
  61         /* Discard pending signal in some cases */
  62         if (sa->sa_handler == SIG_IGN ||
  63             (sa->sa_handler == SIG_DFL && signum == SIGCHLD))
__sig_pending &= ~sigmask(signum);
SIGNAL_UNLOCK();
  68         /* Process pending signal */
__sig_flush();
  71         return 0;
  72 }