79 lines
2.5 KiB
C
79 lines
2.5 KiB
C
/* Handle real-time signal allocation. Generic version.
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Copyright (C) 1997-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <signal.h>
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/* Another sysdeps file can #define this and then #include this file. */
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#ifndef RESERVED_SIGRT
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# define RESERVED_SIGRT 0
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#endif
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/* In these variables we keep track of the used variables. If the
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platform does not support any real-time signals we will define the
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values to some unreasonable value which will signal failing of all
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the functions below. */
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#ifdef __SIGRTMIN
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static int current_rtmin = __SIGRTMIN + RESERVED_SIGRT;
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static int current_rtmax = __SIGRTMAX;
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#endif
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/* Return number of available real-time signal with highest priority. */
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int
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__libc_current_sigrtmin (void)
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{
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#ifdef __SIGRTMIN
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return current_rtmin;
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#else
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return -1;
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#endif
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}
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libc_hidden_def (__libc_current_sigrtmin)
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strong_alias (__libc_current_sigrtmin, __libc_current_sigrtmin_private)
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/* Return number of available real-time signal with lowest priority. */
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int
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__libc_current_sigrtmax (void)
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{
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#ifdef __SIGRTMIN
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return current_rtmax;
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#else
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return -1;
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#endif
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}
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libc_hidden_def (__libc_current_sigrtmax)
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strong_alias (__libc_current_sigrtmax, __libc_current_sigrtmax_private)
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/* Allocate real-time signal with highest/lowest available
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priority. Please note that we don't use a lock since we assume
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this function to be called at program start. */
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int
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__libc_allocate_rtsig (int high)
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{
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#ifndef __SIGRTMIN
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return -1;
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#else
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if (current_rtmin == -1 || current_rtmin > current_rtmax)
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/* We don't have any more signals available. */
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return -1;
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return high ? current_rtmin++ : current_rtmax--;
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#endif
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}
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strong_alias (__libc_allocate_rtsig, __libc_allocate_rtsig_private)
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