/* Handle real-time signal allocation.  Generic version.

   Copyright (C) 1997-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.

   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/>.  */

#include <signal.h>

/* Another sysdeps file can #define this and then #include this file.  */

#ifndef RESERVED_SIGRT

# define RESERVED_SIGRT 0

#endif

/* In these variables we keep track of the used variables.  If the

   platform does not support any real-time signals we will define the

   values to some unreasonable value which will signal failing of all

   the functions below.  */

#ifdef __SIGRTMIN

static int current_rtmin = __SIGRTMIN + RESERVED_SIGRT;

static int current_rtmax = __SIGRTMAX;

#endif

/* Return number of available real-time signal with highest priority.  */

int

__libc_current_sigrtmin (void)

{

#ifdef __SIGRTMIN

  return current_rtmin;

#else

  return -1;

#endif

}

libc_hidden_def (__libc_current_sigrtmin)

strong_alias (__libc_current_sigrtmin, __libc_current_sigrtmin_private)

/* Return number of available real-time signal with lowest priority.  */

int

__libc_current_sigrtmax (void)

{

#ifdef __SIGRTMIN

  return current_rtmax;

#else

  return -1;

#endif

}

libc_hidden_def (__libc_current_sigrtmax)

strong_alias (__libc_current_sigrtmax, __libc_current_sigrtmax_private)

/* Allocate real-time signal with highest/lowest available

   priority.  Please note that we don't use a lock since we assume

   this function to be called at program start.  */

int

__libc_allocate_rtsig (int high)

{

#ifndef __SIGRTMIN

  return -1;

#else

  if (current_rtmin == -1 || current_rtmin > current_rtmax)

    /* We don't have any more signals available.  */

    return -1;

  return high ? current_rtmin++ : current_rtmax--;

#endif

}

strong_alias (__libc_allocate_rtsig, __libc_allocate_rtsig_private)