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 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25
  26 extern int __syscall_sigpending (sigset_t *);
  27 extern int __syscall_rt_sigpending (sigset_t *, size_t);
  28
  29
  30 /* The variable is shared between all wrappers around signal handling
  31    functions which have RT equivalents.  */
  32 int __libc_missing_rt_sigs;
  33
  34
  35 /* Change the set of blocked signals to SET,
  36    wait until a signal arrives, and restore the set of blocked signals.  */
  37 int
  38 sigpending (set)
  39      sigset_t *set;
  40 {
  41 #ifdef __NR_rt_pending
  42   /* First try the RT signals.  */
  43   if (!__libc_missing_rt_sigs)
  44     {
  45       /* XXX The size argument hopefully will have to be changed to the
  46          real size of the user-level sigset_t.  */
  47       int saved_errno = errno;
  48       int result = INLINE_SYSCALL (rt_sigpending, 2, set, _NSIG / 8);
  49
  50       if (result >= 0 || errno != ENOSYS)
  51         return result;
  52
  53       __set_errno (saved_errno);
  54       __libc_missing_rt_sigs = 1;
  55     }
  56 #endif
  57
  58   return INLINE_SYSCALL (sigpending, 1, set);
  59 }