glibc/sysdeps/posix/sigpause.c

/* Copyright (C) 1991-2013 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#define sigpause __rename_sigpause
#include <errno.h>
#include <signal.h>
#include <stddef.h>		/* For NULL.  */
#include <sysdep-cancel.h>
#undef sigpause

#include <sigset-cvt-mask.h>

/* Set the mask of blocked signals to MASK,
   wait for a signal to arrive, and then restore the mask.  */
static int
do_sigpause (int sig_or_mask, int is_sig)
{
  sigset_t set;

  if (is_sig != 0)
    {
      /* The modern X/Open implementation is requested.  */
      if (__sigprocmask (0, NULL, &set) < 0
	  || sigdelset (&set, sig_or_mask) < 0)
	return -1;
    }
  else if (sigset_set_old_mask (&set, sig_or_mask) < 0)
    return -1;

  /* Note the sigpause() is a cancellation point.  But since we call
     sigsuspend() which itself is a cancellation point we do not have
     to do anything here.  */
  return __sigsuspend (&set);
}

int
__sigpause (int sig_or_mask, int is_sig)
{
  if (SINGLE_THREAD_P)
    return do_sigpause (sig_or_mask, is_sig);

  int oldtype = LIBC_CANCEL_ASYNC ();

  int result = do_sigpause (sig_or_mask, is_sig);

  LIBC_CANCEL_RESET (oldtype);

  return result;
}
libc_hidden_def (__sigpause)

/* We have to provide a default version of this function since the
   standards demand it.  The version which is a bit more reasonable is
   the BSD version.  So make this the default.  */
int
__attribute__ ((weak))
__default_sigpause (int mask)
{
  return __sigpause (mask, 0);
}
#undef sigpause
weak_alias (__default_sigpause, sigpause)
strong_alias (__default_sigpause, __libc_sigpause)


/* We have to provide a default version of this function since the
   standards demand it.  The version which is a bit more reasonable is
   the BSD version.  So make this the default.  */
int
__attribute__ ((weak))
__xpg_sigpause (int sig)
{
  return __sigpause (sig, 1);
}
strong_alias (__xpg_sigpause, __libc___xpg_sigpause)