src/third_party/WebKit/LayoutTests/media/encrypted-media/encrypted-media-lifetime-mediakeysession-release.html

   1 <!DOCTYPE html>
   2 <html>
   3     <head>
   4         <title>Test MediaKeySession lifetime</title>
   5         <script src="../w3c-media-utils.js"></script>
   6         <script src="../../resources/testharness.js"></script>
   7         <script src="../../resources/testharnessreport.js"></script>
   8         <script src="../../resources/gc.js"></script>
   9     </head>
  10     <body>
  11         <div id="log"></div>
  12         <script>
  13             // Since MediaKeySession (but not MediaKeys) are ActiveDOMObjects,
  14             // we can determine when they are garbage collected.
  15             // MediaKeySessions remain as long as:
  16             //   JavaScript has a reference to it
  17             //   OR (MediaKeys is around AND the session has not received a close() event)
  18             async_test(function(test)
  19             {
  20                 var initData = new Uint8Array([0, 1, 2, 3, 4, 5, 6, 7]);
  21
  22                 gc();
  23                 var startingActiveDOMObjectCount = window.internals.activeDOMObjectCount(document);
  24
  25                 function numActiveDOMObjectsCreated()
  26                 {
  27                     gc();
  28                     return window.internals.activeDOMObjectCount(document) - startingActiveDOMObjectCount;
  29                 }
  30
  31                 // Create 2 sessions.
  32                 var mediaKeys = new MediaKeys("org.w3.clearkey");
  33                 var mediaKeySession1 = mediaKeys.createSession('video/webm', initData);
  34                 assert_equals(numActiveDOMObjectsCreated(), 1);
  35                 var mediaKeySession2 = mediaKeys.createSession('video/webm', initData);
  36                 assert_equals(numActiveDOMObjectsCreated(), 2);
  37                 var openSessions = 2;
  38
  39                 // Release the sessions. Once the close() event is received,
  40                 // only the JS reference to them keeps them around.
  41                 mediaKeySession1.release();
  42                 waitForEventAndRunStep("close", mediaKeySession1, onClose, test);
  43                 mediaKeySession2.release();
  44                 waitForEventAndRunStep("close", mediaKeySession2, onClose, test);
  45
  46                 function onClose(event)
  47                 {
  48                     --openSessions;
  49                     if (openSessions > 0)
  50                         return;
  51
  52                     // Delay to give time for close to complete since
  53                     // event.target is a reference to the MediaKeySession.
  54                     setTimeout(finish, 1);
  55                 }
  56
  57                 function finish()
  58                 {
  59                     // Since both sessions have been closed, dropping the
  60                     // reference to them from JS will result in the session
  61                     // being garbage-collected.
  62                     assert_equals(openSessions, 0);
  63                     assert_not_equals(mediaKeys, null);
  64                     assert_equals(numActiveDOMObjectsCreated(), 2);
  65
  66                     mediaKeySession1 = null;
  67                     gc();
  68                     assert_equals(numActiveDOMObjectsCreated(), 1, "mediaKeySession1 not collected");
  69
  70                     mediaKeySession2 = null;
  71                     gc();
  72                     assert_equals(numActiveDOMObjectsCreated(), 0, "mediaKeySession2 not collected");
  73
  74                     test.done();
  75                 }
  76             }, "MediaKeySession lifetime after release()");
  77         </script>
  78     </body>
  79 </html>