/* Copyright (c) 1997-2000 Miller Puckette.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

/* This file is compiled into the separate program, "pd-watchdog," which
tries to prevent Pd from locking up the processor if it's at realtime
priority.  Linux only.  Invoked from s_inter.c. */

#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>

int main(int argc, char **argv)
{
    int happy = 1;
    while (1)
    {
    	struct timeval timout;
    	fd_set readset;
	if (happy)
	{
    	    timout.tv_sec = 5;
    	    timout.tv_usec = 0;
	}
	else
	{
    	    timout.tv_sec = 2;
    	    timout.tv_usec = 0;
	}
	FD_ZERO(&readset);
    	FD_SET(0, &readset);
    	select(1, &readset, 0, 0, &timout);
    	if (FD_ISSET(0, &readset))
	{
	    char buf[100];
	    happy = 1;
	    if (read(0, &buf, 100) <= 0)
		return (0);
	    else continue;
	}
	happy = 0;
	kill(getppid(), SIGHUP);
	fprintf(stderr, "watchdog: signaling pd...\n"); 
    }
}

