//-------------------------------------------------------------------
//	2signals.cpp
//
//	This program demonstrates fork(), signal(), and setitimer().
//
//	programmer: ALLAN CRUSE
//	written on: 04 OCT 2004
//-------------------------------------------------------------------

#include <stdio.h>	// for printf() 
#include <stdlib.h>	// for exit() 
#include <unistd.h>	// for fork() 
#include <signal.h>	// for signal()
#include <sys/time.h>	// for setitimer()

int	count = 0, done = 0;

void upon_signal( int signum )
{
	++count;
	if (( count == 4 )||( signum == SIGCHLD )) done = 1;
	printf( "count=%d \n", count );
}

int main( int argc, char **argv )
{
	struct itimerval   it = { { 1, 0 }, { 1, 0 } };
	
	if ( fork() == 0 )
		{
		signal( SIGVTALRM, upon_signal );
		setitimer( ITIMER_VIRTUAL, &it, NULL );
		}
	else	{
		signal( SIGCHLD, upon_signal );
		}
	
	while( !done );
	exit(0);	
}