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

   1 <!DOCTYPE html>
   2 <html>
   3     <head>
   4         <title>Test multiple MediaKeys lifetimes</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 to each
  15             // MediaKeys object so 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 several MediaKeys (each with a
  26             // MediaKeySession object so they can be counted) and verify
  27             // lifetime.
  28             async_test(function(test)
  29             {
  30                 var mediaKeys;
  31                 var initDataType = getInitDataType();
  32                 var initData = getInitData(initDataType);
  33
  34                 var startingActiveDOMObjectCount = window.internals.activeDOMObjectCount(document);
  35
  36                 function numActiveDOMObjectsCreated()
  37                 {
  38                     return window.internals.activeDOMObjectCount(document) - startingActiveDOMObjectCount;
  39                 }
  40
  41                 // Create a MediaKeys object and an associated MediaKeySession
  42                 // object. |mediaKeys| is updated to refer to the new MediaKeys
  43                 // object. Returns a promise that resolves with the new
  44                 // MediaKeySession object.
  45                 function createMediaKeyWithMediaKeySession()
  46                 {
  47                     return MediaKeys.create('org.w3.clearkey').then(function(result) {
  48                         mediaKeys = result;
  49                         var mediaKeySession = mediaKeys.createSession();
  50                         return mediaKeySession.generateRequest(initDataType, initData).then(function() {
  51                             return mediaKeySession;
  52                         });
  53                     });
  54                 }
  55
  56                 // Create a few MediaKeys + MediaKeySession objects. Only keep
  57                 // a reference to the last one created.
  58                 createMediaKeyWithMediaKeySession().then(function(mediaKeySession) {
  59                     // Should be 1 MediaKeySession.
  60                     assert_equals(numActiveDOMObjectsCreated(), 1);
  61                     return createMediaKeyWithMediaKeySession();
  62                 }).then(function(mediaKeySession) {
  63                     // Should be 2 MediaKeySessions.
  64                     assert_equals(numActiveDOMObjectsCreated(), 2);
  65                     return createMediaKeyWithMediaKeySession();
  66                 }).then(function(mediaKeySession) {
  67                     // Should be 3 MediaKeySessions.
  68                     assert_equals(numActiveDOMObjectsCreated(), 3);
  69                     return createMediaKeyWithMediaKeySession();
  70                 }).then(function(mediaKeySession) {
  71                     // Should be 4 MediaKeySessions.
  72                     assert_equals(numActiveDOMObjectsCreated(), 4);
  73                     return createMediaKeyWithMediaKeySession();
  74                 }).then(function(mediaKeySession) {
  75                     // Should be 5 MediaKeySessions.
  76                     assert_equals(numActiveDOMObjectsCreated(), 5);
  77
  78                     // |mediaKeys| refers to the most recently created MediaKeys
  79                     // object.
  80                     //
  81                     // In order for the MediaKeySession objects to have no
  82                     // outstanding activity so that they can be garbage
  83                     // collected, it needs time to process any pending events.
  84                     // As a "message" event is generated when a new session is
  85                     // created, we need to allow the event to run (we're not
  86                     // doing anything with the event in this test).
  87                     return delayToAllowEventProcessingPromise();
  88                 }).then(function(result) {
  89                     // Should be just 5 MediaKeySessions.
  90                     assert_equals(numActiveDOMObjectsCreated(), 5);
  91
  92                     // As we only have a reference (|mediaKeys|) to the last
  93                     // created MediaKeys object, the other 4 MediaKeys objects
  94                     // are available to be garbage collected.
  95                     //
  96                     // Since MediaKeySessions remain alive as long as MediaKeys
  97                     // is around, it is possible that gc() checks the
  98                     // MediaKeySession object first, and doesn't collect it
  99                     // since MediaKeys hasn't been collected yet. Thus run gc()
 100                     // twice, to ensure that the unreferenced MediaKeySession
 101                     // objects get collected.
 102                     return createGCPromise();
 103                 }).then(function(result) {
 104                     return createGCPromise();
 105                 }).then(function(result) {
 106                     // Should be 1 MediaKeySession, the session for |mediaKeys|.
 107                     assert_equals(numActiveDOMObjectsCreated(), 1);
 108                     assert_equals(mediaKeys.keySystem, 'org.w3.clearkey');
 109
 110                     // Release the last MediaKeys object created.
 111                     mediaKeys = null;
 112
 113                     // Run gc() again to reclaim the remaining MediaKeys object
 114                     // and the last MediaKeySession. gc() run twice in case
 115                     // MediaKeySession checked first and not collected in the
 116                     // first pass.
 117                     return createGCPromise();
 118                 }).then(function(result) {
 119                     return createGCPromise();
 120                 }).then(function(result) {
 121                     assert_equals(numActiveDOMObjectsCreated(), 0);
 122                     test.done();
 123                 }).catch(function(error) {
 124                     forceTestFailureFromPromise(test, error);
 125                 });
 126             }, 'Multiple MediaKeys lifetime');
 127         </script>
 128     </body>
 129 </html>