#! perl -slw
use strict;
use threads;
use threads::shared;

my $sem :shared = 0;

async {
    my $last = time;
    while( sleep 1 ) {
        my $now = time;
        if( $now - $last > 2 ) {
            $sem = 1;
        }
        $last = $now;
    }
}->detach;


while( sleep 1 ) {
    print "tum te tum";
    if( $sem ) {
        print "You snoozed me";
        $sem = 0;
    }
}

__END__
C:\test>junk96
tum te tum
tum te tum
tum te tum
tum te tum
tum te tum
tum te tum
tum te tum
tum te tum
tum te tum
You snoozed me
tum te tum
tum te tum
tum te tum
tum te tum
Terminating on signal SIGINT(2)