I would like to use cond_timedwait, but am limited to 5.8.0. So I am trying to write the equivalent but the threads silently die during cond_wait

Thread1-

  lock($signal);
  eval {
    local $SIG{ALRM} = sub { die "alarm\n" };
    alarm 30;
    cond_wait($signal);
    alarm 0;
  };

  if ($@) {
     print "timed out\n";
  }else{
     print "did not time out";
  }


Thread 2;

cond_signal($signal);
[download]

If I substitute cond_timedwait($signal, time() + 30); for the alarm eval codeblock on 5.8.3 everything is well. Any help is much appreciated.

Best
Kevin