Avoiding ThreadDeath with env.js

At Appcelerator we use John Resig's "simulated browser environment for Rhino" as part of our IDE. I'd had intermittent problems with a ThreadDeath error being thrown, which would then cause any other thread running Rhino to hang.

I wasn't sure if the problem was in my Java code, my JavaScript, Rhino's Java code, or Aptana's Java code (we built our IDE atop their HTML/CSS/JS editor). Turns out it wasn't any of those! It was in that "simulated browser environment" code, in window.clearInterval where the thread spawned with setInterval is killed. I puzzled for a moment over why Mr.Resig was using multiple threads rather than a single one for setIntervals (expediency I assume), and then changed two lines so that it doesn't kill the thread, but allows it to die of natural causes.

 window.setInterval = function(fn, time){
  var num = timers.length;
  
  timers[num] = new java.lang.Thread(new java.lang.Runnable({
   run: function(){
    while (true) {
    while (timers[num]) {
     java.lang.Thread.currentThread().sleep(time);
     fn();
    }
   }
  }));
  
  timers[num].start();
 
  return num;
 };
 
 window.clearInterval = function(num){
  if ( timers[num] ) {
   timers[num].stop();
   delete timers[num];
  }
 };

Another example of a day of debugging yielding a two line fix. Ugh.