js/xpconnect/tests/mochitest/test_weakRefs_collected_wrapper.html

   1 <!DOCTYPE HTML>
   2 <html>
   3   <head>
   4     <meta charset="utf-8">
   5     <title>Test WeakRefs with DOM wrappers that get cycle collected</title>
   6     <script src="/tests/SimpleTest/SimpleTest.js"></script>
   7     <script type="application/javascript">
   8       let weakrefs = [];
   9
  10       function go() {
  11         SimpleTest.waitForExplicitFinish();
  12
  13         // 1. nsISupports-derived object.
  14         let doc = document.implementation.createHTMLDocument();
  15         weakrefs.push(new WeakRef(doc));
  16
  17         // 2. non-nsISupports-derived object.
  18         let buffer = new AudioBuffer({length: 1, sampleRate: 8000});
  19         weakrefs.push(new WeakRef(buffer));
  20
  21         // 3. nsISupports non-wrapper-cached object.
  22         let image = new ImageData(1, 1);
  23         weakrefs.push(new WeakRef(image));
  24
  25         // 4. non-nsISupports non-wrapper-cached object.
  26         let iterator = document.fonts.values();
  27         weakrefs.push(new WeakRef(iterator));
  28
  29         for (let wr of weakrefs) {
  30           isnot(wr.deref(), undefined, "Check that live wrapper is returned");
  31         }
  32
  33         // setTimeout will call its callback in a new task.
  34         setTimeout(task2, 0);
  35       }
  36
  37       function task2() {
  38         // Trigger a GC and CC to collect the DOM objects, but no GC to
  39         // collect the wrappers.
  40         SpecialPowers.DOMWindowUtils.garbageCollect();
  41         SpecialPowers.DOMWindowUtils.cycleCollect();
  42
  43         for (let wr of weakrefs) {
  44           is(wr.deref(), undefined, "Check that stale wrapper is not exposed");
  45         }
  46
  47         SimpleTest.finish();
  48       }
  49     </script>
  50   </head>
  51   <body onload="go()"></body>
  52 </html>