hurd/preempt-sig.c

   1 /* Copyright (C) 1994 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <hurd/signal.h>
  20
  21 /* Initialize PREEMPTER with the information given and stick it in the
  22    chain of preempters for SIGNO.  */
  23
  24 int
  25 hurd_preempt_signals (struct hurd_signal_preempt *preempter,
  26                       int signo, int first_code, int last_code,
  27                       sighandler_t (*handler) (thread_t, int, long int, int))
  28 {
  29   if (signo <= 0 || signo >= NSIG)
  30     {
  31       errno = EINVAL;
  32       return -1;
  33     }
  34   preempter->first = first_code;
  35   preempter->last = last_code;
  36   preempter->handler = handler;
  37   __mutex_lock (&_hurd_signal_preempt_lock);
  38   preempter->next = _hurd_signal_preempt[signo];
  39   _hurd_signal_preempt[signo] = preempter;
  40   __mutex_unlock (&_hurd_signal_preempt_lock);
  41   return 0;
  42 }
  43
  44 /* Remove PREEMPTER from the chain for SIGNO.  */
  45
  46 int
  47 hurd_unpreempt_signals (struct hurd_signal_preempt *preempter, int signo)
  48 {
  49   struct hurd_signal_preempt *p, *lastp;
  50   if (signo <= 0 || signo >= NSIG)
  51     {
  52       errno = EINVAL;
  53       return -1;
  54     }
  55   __mutex_lock (&_hurd_signal_preempt_lock);
  56   for (p = _hurd_signal_preempt[signo], lastp = NULL;
  57        p != NULL; lastp = p, p = p->next)
  58     if (p == preempter)
  59       {
  60         (lastp == NULL ? _hurd_signal_preempt[signo] : lastp->next) = p->next;
  61         __mutex_unlock (&_hurd_signal_preempt_lock);
  62         return 0;
  63       }
  64   _hurd_signal_preempt[signo] = preempter;
  65   __mutex_unlock (&_hurd_signal_preempt_lock);
  66   errno = ENOENT;
  67   return -1;
  68 }