sysdeps/unix/sysv/linux/sigpending.c

   1 /* Copyright (C) 1997, 1998 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 not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22
  23 extern int __syscall_sigpending (sigset_t *);
  24 extern int __syscall_rt_sigpending (sigset_t *, size_t);
  25
  26
  27 /* The variable is shared between all wrappers around signal handling
  28    functions which have RT equivalents.  */
  29 int __libc_missing_rt_sigs;
  30
  31
  32 /* Change the set of blocked signals to SET,
  33    wait until a signal arrives, and restore the set of blocked signals.  */
  34 int
  35 sigpending (set)
  36      sigset_t *set;
  37 {
  38   /* First try the RT signals.  */
  39   if (!__libc_missing_rt_sigs)
  40     {
  41       /* XXX The size argument hopefully will have to be changed to the
  42          real size of the user-level sigset_t.  */
  43       int result = __syscall_rt_sigpending (set, _NSIG / 8);
  44
  45       if (result >= 0 || errno != ENOSYS)
  46         return result;
  47
  48       __libc_missing_rt_sigs = 1;
  49     }
  50
  51   return __syscall_sigpending (set);
  52 }