/* signals.c -- Signal processing source
   This file is part of Redshift.

   Redshift is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Redshift 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 for more details.

   You should have received a copy of the GNU General Public License
   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.

   Copyright (c) 2009-2015  Jon Lund Steffensen <jonlst@gmail.com>
   Copyright (c) 2015       Mattias Andrée <m@maandree.se>
*/
#include "common.h"


#ifndef WINDOWS

volatile sig_atomic_t exiting = 0;
volatile sig_atomic_t disable = 0;


/* Signal handler for exit signals */
static void
sigexit(int signo)
{
	exiting = 1;
}

/* Signal handler for disable signal */
static void
sigdisable(int signo)
{
	disable = 1;
}

#else

int disable = 0;
int exiting = 0;

#endif


int
signals_install_handlers(void)
{
#ifndef WINDOWS
	struct sigaction sigact;
	sigset_t sigset;

	/* Install signal handler for INT and TERM signals */
	memset(&sigact, 0, sizeof(sigact));
	sigemptyset(&sigset);
	sigact.sa_handler = sigexit;
	sigact.sa_mask = sigset;
	sigact.sa_flags = 0;

	if (sigaction(SIGINT, &sigact, NULL)) {
		perror("sigaction");
		return -1;
	}

	if (sigaction(SIGTERM, &sigact, NULL)) {
		perror("sigaction");
		return -1;
	}

	if (sigaction(SIGQUIT, &sigact, NULL)) {
		perror("sigaction");
		return -1;
	}

	/* Install signal handler for USR1 signal */
	sigact.sa_handler = sigdisable;
	sigact.sa_mask = sigset;
	sigact.sa_flags = 0;

	if (sigaction(SIGUSR1, &sigact, NULL)) {
		perror("sigaction");
		return -1;
	}

	/* Ignore CHLD signal. This causes child processes
	   (hooks) to be reaped automatically. */
	sigact.sa_handler = SIG_IGN;
	sigact.sa_mask = sigset;
	sigact.sa_flags = 0;

	if (sigaction(SIGCHLD, &sigact, NULL)) {
		perror("sigaction");
		return -1;
	}
#endif

	return 0;
}