/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2000, 2012 Oracle and/or its affiliates.  All rights reserved.
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 * $Id$
 */

#include "db_config.h"

#include "db_int.h"

static int	interrupt;
static void	set_signal __P((int, int));
static void	signal_handler __P((int));

/*
 * signal_handler --
 *	Interrupt signal handler.
 */
static void
signal_handler(signo)
	int signo;
{
#ifndef HAVE_SIGACTION
	/* Assume signal() is unreliable and reset it, first thing. */
	set_signal(signo, 0);
#endif
	/* Some systems don't pass in the correct signal value -- check. */
	if ((interrupt = signo) == 0)
		interrupt = SIGINT;
}

/*
 * set_signal
 */
static void
set_signal(s, is_dflt)
	int s, is_dflt;
{
	/*
	 * Use sigaction if it's available, otherwise use signal().
	 */
#ifdef HAVE_SIGACTION
	struct sigaction sa, osa;

	sa.sa_handler = is_dflt ? SIG_DFL : signal_handler;
	(void)sigemptyset(&sa.sa_mask);
	sa.sa_flags = 0;
	(void)sigaction(s, &sa, &osa);
#else
	(void)signal(s, is_dflt ? SIG_DFL : signal_handler);
#endif
}

/*
 * __db_util_siginit --
 *
 * PUBLIC: void __db_util_siginit __P((void));
 */
void
__db_util_siginit()
{
	/*
	 * Initialize the set of signals for which we want to clean up.
	 * Generally, we try not to leave the shared regions locked if
	 * we can.
	 */
#ifdef SIGHUP
	set_signal(SIGHUP, 0);
#endif
#ifdef SIGINT
	set_signal(SIGINT, 0);
#endif
#ifdef SIGPIPE
	set_signal(SIGPIPE, 0);
#endif
#ifdef SIGTERM
	set_signal(SIGTERM, 0);
#endif
}

/*
 * __db_util_interrupted --
 *	Return if interrupted.
 *
 * PUBLIC: int __db_util_interrupted __P((void));
 */
int
__db_util_interrupted()
{
	return (interrupt != 0);
}

/*
 * __db_util_sigresend --
 *
 * PUBLIC: void __db_util_sigresend __P((void));
 */
void
__db_util_sigresend()
{
	/* Resend any caught signal. */
	if (interrupt != 0) {
		set_signal(interrupt, 1);

		(void)raise(interrupt);
		/* NOTREACHED */
	}
}