third_party/WebKit/LayoutTests/fast/dom/gc-12.html

   1 <p>
   2 This test verifies that DOM nodes are not garbage collected as long as a node in the
   3 tree is referenced from JavaScript.
   4 </p>
   5
   6 <pre id="console"></pre>
   7
   8 <script>
   9 function log(s)
  10 {
  11     document.getElementById("console").appendChild(document.createTextNode(s + "\n"));
  12 }
  13
  14 function shouldBeNode(a, aDescription)
  15 {
  16     if (!(a instanceof Node)) {
  17         log("FAIL: " + aDescription + " should be a Node but instead is " + a + ".");
  18         return;
  19     }
  20
  21     log("PASS: " + aDescription + " should be a Node and is.");
  22 }
  23
  24 function gc()
  25 {
  26     if (window.GCController)
  27         return GCController.collect();
  28
  29     for (var i = 0; i < 10000; i++)
  30         var s = new String("");
  31 }
  32
  33 (function () {
  34     if (window.testRunner) {
  35         testRunner.dumpAsText();
  36     }
  37
  38     (function() {
  39         // Try to create an orphan tree by removal.
  40         var p = document.createElement("p");
  41         document.body.appendChild(p);
  42         p.innerHTML ='<div><span id="span"><br></span></div>';
  43         var span = document.getElementById("span");
  44         p.innerHTML = "";
  45
  46         gc();
  47
  48         shouldBeNode(span, "span");
  49         shouldBeNode(span.parentNode, "span.parentNode");
  50         shouldBeNode(span.firstChild, "span.firstChild");
  51     })();
  52
  53     (function() {
  54         // Try to create an orphan tree by insertion.
  55         var p = document.createElement("p");
  56         var span = document.createElement("span");
  57         p.appendChild(span);
  58         p = null;
  59
  60         gc();
  61
  62         shouldBeNode(span, "span");
  63         shouldBeNode(span.parentNode, "span.parentNode");
  64     })();
  65 })();
  66 </script>