test_event_handler_cc.html

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<!DOCTYPE HTML>

<html>

<head>

  <meta charset="utf-8">

  <title>Test for cycle collection of event handlers</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <link rel="stylesheet" href="/tests/SimpleTest/test.css"/>

  <script>

    SimpleTest.waitForExplicitFinish();

    function listener() {}

    function make_weak_ref(obj) {

      let m = new WeakMap;

      m.set(obj, {});

      return m;

    function weak_ref_dead(r) {

      return !SpecialPowers.nondeterministicGetWeakMapKeys(r).length;

    function setupTarget1() {

      let ifr = document.getElementById("target1");

      let doc = ifr.contentDocument;

      let b = doc.createElement("button");

      doc.body.appendChild(b);

      b.onclick = listener;

      ifr.remove();

      return make_weak_ref(b);

    function setupTarget2() {

      let ifr = document.getElementById("target2");

      let doc = ifr.contentDocument;

      let b = doc.createElement("button");

      doc.body.appendChild(b);

      let setFunc = new ifr.contentWindow.Function(`

           var b = document.querySelector("button");

           var proto = parent.HTMLElement.prototype;

           var setter = Object.getOwnPropertyDescriptor(proto, "onclick").set;

           // Here the current global (and hence CallbackObject global) will be

           // the parent, the callback will be a known-live thing from the

           // parent, but the incumbent global will be the child.

           setter.call(b, parent.listener);

`);

      setFunc();

      ifr.remove();

      return make_weak_ref(b);

    var ref1;

    var ref2;

    var maxCounter = 20;

    function GCCCUntilCollected() {

      SpecialPowers.exactGC(function () {

        SpecialPowers.forceCC();

        SpecialPowers.forceGC();

        SpecialPowers.forceGC();

        if ((!weak_ref_dead(ref1) || !weak_ref_dead(ref2)) && --maxCounter > 0) {

          requestIdleCallback(GCCCUntilCollected, {timeout: 250});

          return;

        ok(weak_ref_dead(ref1),

           "Should collect cycle through callback global");

        ok(weak_ref_dead(ref2),

           "Should collect cycle through incumbent global");

        SimpleTest.finish();

});

    addLoadEvent(function() {

      ref1 = setupTarget1();

      ref2 = setupTarget2();

      GCCCUntilCollected();

});

  </script>

</head>

<body>

<p id="display"></p>

<div id="content" style="display: none"></div>

<iframe id="target1"></iframe>

<iframe id="target2"></iframe>

<pre id="test"></pre>

</body>

</html>