sysdeps/unix/sysv/linux/sigpending.c

   1 /* Copyright (C) 1997,1998,1999,2000,2003,2006
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25 #include <bp-checks.h>
  26
  27 #include <kernel-features.h>
  28
  29
  30 /* The variable is shared between all wrappers around signal handling
  31    functions which have RT equivalents.  The definition is in sigaction.c.  */
  32 extern 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 #if __ASSUME_REALTIME_SIGNALS > 0
  42   return INLINE_SYSCALL (rt_sigpending, 2, CHECK_SIGSET (set), _NSIG / 8);
  43 #else
  44 # ifdef __NR_rt_sigpending
  45   /* First try the RT signals.  */
  46   if (!__libc_missing_rt_sigs)
  47     {
  48       /* XXX The size argument hopefully will have to be changed to the
  49          real size of the user-level sigset_t.  */
  50       int saved_errno = errno;
  51       int result = INLINE_SYSCALL (rt_sigpending, 2, CHECK_SIGSET (set), _NSIG / 8);
  52
  53       if (result >= 0 || errno != ENOSYS)
  54         return result;
  55
  56       __set_errno (saved_errno);
  57       __libc_missing_rt_sigs = 1;
  58     }
  59 # endif
  60
  61   return INLINE_SYSCALL (sigpending, 1, CHECK_SIGSET (set));
  62 #endif
  63 }