#!/usr/bin/env perl
use threads;

##kill -10 handle
$SIG{USR1}=\&usr_kill_handler;
    
my @sons = ("Son1","Son2","Son3");
my @childs = ();
#Start fork
foreach my $son (@sons){
    my $pid = fork();
    if ($pid) {
        # parent
        push(@childs, $pid);
    }elsif($pid == 0) {
        # child
        my $results = new testProcess($son);
        exit 0;
    }else {
        print "\nerror : couldnt fork: $!\n";
        exit 1;
    }
}

#Wait for to end
foreach my $child (@childs) {
    my $tmp = waitpid($child, 0);
    print "\ninfo : done with pid $tmp\n";
}
    
sub usr_kill_handler{
    #Send SIGUSR1 to all childs (started with fork)
    kill SIGUSR1 => @childs;
	
    print "\n\n Stoped due to user request!\n\n";
    #Wait to all childs to exit
    foreach my $child (@childs) {
        my $tmp = waitpid($child, 0);
        print "\ndone with pid $tmp\n";
    }
    # After all child ended kill  father
    exit 1;
}

package testProcess;

sub new{
    my $class = shift;
    my ($son) = @_;
    
    ##kill -10 handle
    $SIG{USR1}=sub {
        print "\n Got signal to son $son with pid ".$$." \n";
        threads->exit;
    };

    print "\nSon $son with PID ".$$." Started\n";
    my %hash_results = ();
    
    my @grand_sons = ("Grand son 1","Grand son 2","Grand son 3");
    my @threads = ();
    
    #Start new thread
    foreach my $grand_son (@grand_sons){
        my $t = threads->create (\&start_threads,$son,$grand_son);
        push(@threads,$t);
    }
     
    my $index=0;
    foreach my $thread (@threads) #wait for all threads untill the end and insert results to hash
    {
       $hash_results{$index}=$thread->join;
       $index++;
    }
    print "\nSon $son with PID ".$$." Finished\n";
}

sub start_threads{
    my ($son,$grand_son) = @_;
    print "\nSon $son grand son $grand_son started\n";
    my $random_number = int(rand(100));
    my $msg = "Son $son grand son $grand_son returns random number $random_number";
    print "\n$msg\n";
    sleep 100;
    return $random_number;
}
1;