gecko-dev/dom/workers/test/WorkerDebugger_sharedWorker.js

"use strict";

self.onconnect = function(event) {
  event.ports[0].onmessage = function(e) {
    switch (e.data) {
      case "close":
        close();
        break;

      case "close_loop":
        close();
        // Let's loop forever.
        while (1) {}
        break;
    }
  };
};