third_party/WebKit/LayoutTests/webaudio/scriptprocessornode-premature-death.html

   1 <!DOCTYPE html>
   2 <script src="../resources/js-test.js"></script>
   3 <script src="resources/compatibility.js"></script>
   4 <body>
   5 <script>
   6 description('Tests that a script processor node is not prematurely GCed');
   7 var jsTestIsAsync = true;
   8
   9 if (!window.internals) {
  10     testFailed('This test requires window.internals.');
  11     finishJSTest();
  12 }
  13
  14 var wasCalled, wasCollectedPrematurely, savedNode, savedCallback;
  15
  16 function test(saveReference, nextStep) {
  17     debug('Testing ' + (saveReference ? 'with' : 'without') + ' explicitly ' +
  18           'keeping a reference to the script processor node alive.');
  19
  20     // Create an audio context
  21     var context = new OfflineAudioContext(
  22         2,        // channels
  23         4096,     // length (frames)
  24         44100.0); // sample rate
  25
  26     // Set up a source, reading from an empty buffer
  27     var source = context.createBufferSource();
  28     source.buffer = context.createBuffer(
  29         2,        // source channels
  30         4096,     // length (frames)
  31         44100.0); // sample rate
  32
  33     // Set up a script processor node to generate something
  34     var node = context.createScriptProcessor(
  35         512, // buffer size
  36         0,   // input channels
  37         2);  // output channels
  38
  39     // source -> script processor node -> destination
  40     source.connect(node);
  41     node.connect(context.destination);
  42
  43     // Set up something which indicates whether we're called to
  44     // generate anything
  45
  46     wasCalled = false;
  47     var callback = function () { wasCalled = true; };
  48     node.onaudioprocess = callback;
  49
  50     if (saveReference) {
  51         savedNode = node;
  52         savedCallback = callback;
  53     }
  54
  55     // Watch the callback; if it dies, we're obviously not generating anything
  56
  57     var observation = internals.observeGC(callback);
  58     node = callback = null;
  59     gc();
  60     wasCollectedPrematurely = observation.wasCollected;
  61
  62     // Make some noise!
  63
  64     source.start(0);
  65     context.oncomplete = check(nextStep);
  66     context.startRendering();
  67 }
  68
  69 function check(nextStep) {
  70     return function () {
  71         shouldBeFalse('wasCollectedPrematurely');
  72         shouldBeTrue('wasCalled');
  73         nextStep();
  74     };
  75 }
  76
  77 function step1() {
  78   test(true, step2);
  79 }
  80
  81 function step2() {
  82   test(false, finishJSTest);
  83 }
  84
  85 step1();
  86
  87 var successfullyParsed = true;
  88 </script>