70 lines
2.1 KiB
C
70 lines
2.1 KiB
C
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/* Copyright (C) 1998-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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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<https://www.gnu.org/licenses/>. */
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#include <errno.h>
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#define __need_NULL
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#include <stddef.h>
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#include <signal.h>
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#include <string.h> /* For the real memset prototype. */
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#include <sigsetops.h>
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/* Set the disposition for SIG. */
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__sighandler_t
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sigset (int sig, __sighandler_t disp)
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{
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struct sigaction act;
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struct sigaction oact;
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sigset_t set;
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sigset_t oset;
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__sigemptyset (&set);
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if (sigaddset (&set, sig) < 0)
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return SIG_ERR;
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if (disp == SIG_HOLD)
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{
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/* Add the signal to the current signal mask. */
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if (__sigprocmask (SIG_BLOCK, &set, &oset) < 0)
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return SIG_ERR;
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/* If the signal was already blocked signal this to the caller. */
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if (__sigismember (&oset, sig))
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return SIG_HOLD;
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/* We need to determine whether a specific handler is installed. */
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if (__sigaction (sig, NULL, &oact) < 0)
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return SIG_ERR;
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return oact.sa_handler;
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}
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else
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{
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act.sa_handler = disp;
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__sigemptyset (&act.sa_mask);
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act.sa_flags = 0;
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if (__sigaction (sig, &act, &oact) < 0)
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return SIG_ERR;
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/* Remove the signal from the current signal mask. */
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if (__sigprocmask (SIG_UNBLOCK, &set, &oset) < 0)
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return SIG_ERR;
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/* If the signal was already blocked return SIG_HOLD. */
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return __sigismember (&oset, sig) ? SIG_HOLD : oact.sa_handler;
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}
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}
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