#! perl -slw
use strict;
use threads;

my @t = map async( sub {
    my $tid = threads->tid;
    my $worktime = shift;
    print "Thread $tid started with a worktime of $worktime";
    eval {
        local $SIG{ ALRM } = sub { die 'times up' };
        alarm 10;

        ## simulate doing work here
        sleep $worktime;

        print "Thread $tid: all done";
    };
    print "Thread $tid ended ",  $@ ?  " with error: $@" : 'normally';
}, 2*$_ + $ARGV[ 0 ] ), 1 .. 4;

$_->join for @t;

__END__
C:\test>junk78 5
Thread 1 started with a worktime of 7
Thread 2 started with a worktime of 9
Thread 3 started with a worktime of 11
Thread 4 started with a worktime of 13
Thread 1: all done
Thread 1 ended normally
Thread 2: all done
Thread 2 ended normally
Thread 4 ended  with error: times up at C:\test\junk78.pl line 10.
Thread 3 ended  with error: times up at C:\test\junk78.pl line 10.