src/third_party/WebKit/LayoutTests/media/encrypted-media/encrypted-media-lifetime-mediakeys-with-session.html

   1 <!DOCTYPE html>
   2 <html>
   3     <head>
   4         <title>Test MediaKeys lifetime when adding a session</title>
   5         <script src="encrypted-media-utils.js"></script>
   6         <script src="../../resources/testharness.js"></script>
   7         <script src="../../resources/testharnessreport.js"></script>
   8     </head>
   9     <body>
  10         <div id="log"></div>
  11         <script>
  12             // Since MediaKeys are not ActiveDOMObjects, it is hard to
  13             // determine when they are garbage collected. For the test below
  14             // a MediaKeySession (which is an ActiveDOMObject) is added so
  15             // there is something to count.
  16
  17             // MediaKeySessions remain as long as:
  18             //   JavaScript has a reference to it
  19             //   OR (MediaKeys is around
  20             //       AND the session has not received a close() event)
  21             // In the tests below, we do not close any session nor keep a
  22             // Javascript reference to any session, so MediaKeySessions remain
  23             // as long as the associated MediaKeys object is around.
  24
  25             // For this test, create a MediaKeySession (which is an
  26             // ActiveDOMObject) and verify lifetime.
  27             async_test(function(test)
  28             {
  29                 var mediaKeys;
  30                 var startingActiveDOMObjectCount = window.internals.activeDOMObjectCount(document);
  31
  32                 function numActiveDOMObjectsCreated()
  33                 {
  34                     return window.internals.activeDOMObjectCount(document) - startingActiveDOMObjectCount;
  35                 }
  36
  37                 // Create a MediaKeys object with a session.
  38                 navigator.requestMediaKeySystemAccess('org.w3.clearkey').then(function(access) {
  39                     assert_equals(access.keySystem, 'org.w3.clearkey');
  40                     return access.createMediaKeys();
  41                 }).then(function(result) {
  42                     mediaKeys = result;
  43
  44                     // Verify MediaKeys are not an ActiveDOMObject.
  45                     assert_equals(numActiveDOMObjectsCreated(), 0, 'MediaKeys.create()');
  46
  47                     var initDataType = getInitDataType();
  48                     var mediaKeySession = mediaKeys.createSession();
  49                     return mediaKeySession.generateRequest(initDataType, getInitData(initDataType));
  50                 }).then(function() {
  51                     // 1 MediaKeySession.
  52                     assert_equals(numActiveDOMObjectsCreated(), 1, 'MediaKeys.createSession()');
  53
  54                     // Run gc(), should not affect MediaKeys object nor the
  55                     // session since we still have a reference to it.
  56                     return createGCPromise();
  57                 }).then(function(result) {
  58                     assert_equals(typeof mediaKeys.createSession, 'function');
  59                     // Ensure that MediaKeySession (but not PromiseResolver) is
  60                     // still around.
  61                     assert_equals(numActiveDOMObjectsCreated(), 1, 'After gc()');
  62
  63                     // Drop reference to the MediaKeys object and run gc()
  64                     // again. Object should be collected this time. Since
  65                     // MediaKeySessions remain alive as long as MediaKeys is
  66                     // around, it is possible that gc() checks the
  67                     // MediaKeySession object first, and doesn't collect it
  68                     // since MediaKeys hasn't been collected yet. Thus run gc()
  69                     // twice, to ensure that the unreferenced MediaKeySession
  70                     // object get collected.
  71                     mediaKeys = null;
  72                     return createGCPromise();
  73                 }).then(function(result) {
  74                     return createGCPromise();
  75                 }).then(function(result) {
  76                     assert_equals(numActiveDOMObjectsCreated(), 0);
  77                     test.done();
  78                 }).catch(function(error) {
  79                     forceTestFailureFromPromise(test, error);
  80                 });
  81             }, 'MediaKeys lifetime with session');
  82         </script>
  83     </body>
  84 </html>