Legacy EME WebKitMediaKeys createSessions unknown error

https://bugs.webkit.org/show_bug.cgi?id=262874
rdar://116689080

Reviewed by Jer Noble.

If a media resource protected with the legacy EME API loads very quickly, the media player
in GPU process may try to generate a key request before the HTMLMediaElement in the web
process has signaled it is OK to continue after a key request. Have HTMLMediaElement
call player->setShouldContinueAfterKeyNeeded as soon as the media player is allocaged so
it will know before media data loading begins.

No new test added because the problem is extremely timing dependent and I was never able
to reproduce in a layout test.

* Source/WebCore/html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::createMediaPlayer): Call updateShouldContinueAfterNeedKey.

* Source/WebCore/platform/graphics/MediaPlayer.cpp:
(WebCore::MediaPlayer::loadWithNextMediaEngine): Call shouldWaitForLoadingOfResource.
(WebCore::MediaPlayer::setShouldContinueAfterKeyNeeded):

* Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.h:
* Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
(WebCore::MediaPlayerPrivateAVFoundationObjC::MediaPlayerPrivateAVFoundationObjC): Add logging.
(WebCore::MediaPlayerPrivateAVFoundationObjC::shouldWaitForLoadingOfResource): Check
m_shouldContinueAfterKeyNeeded instead of calling up to the player.
(WebCore::MediaPlayerPrivateAVFoundationObjC::didCancelLoadingRequest): Add logging.
(WebCore::MediaPlayerPrivateAVFoundationObjC::didStopLoadingRequest): Ditto.
(WebCore::MediaPlayerPrivateAVFoundationObjC::setShouldContinueAfterKeyNeeded): Check
m_shouldContinueAfterKeyNeeded instead of calling up to the player.
(WebCore::MediaPlayerPrivateAVFoundationObjC::keyAdded): Add logging.

Canonical link: https://commits.webkit.org/275647@main

Source/WebCore/html/HTMLMediaElement.cpp

@@ -7536,6 +7536,9 @@ void HTMLMediaElement::createMediaPlayer() WTF_IGNORES_THREAD_SAFETY_ANALYSIS
     player->setPageIsVisible(!m_elementIsHidden, page ? page->sceneIdentifier() : ""_s);
     player->setVisibleInViewport(isVisibleInViewport());
     schedulePlaybackControlsManagerUpdate();
+#if ENABLE(LEGACY_ENCRYPTED_MEDIA) && ENABLE(ENCRYPTED_MEDIA)
+    updateShouldContinueAfterNeedKey();
+#endif
 
 #if ENABLE(WEB_AUDIO)
     if (m_audioSourceNode) {

Source/WebCore/platform/graphics/MediaPlayer.cpp

@@ -639,6 +639,10 @@ void MediaPlayer::loadWithNextMediaEngine(const MediaPlayerFactory* current)
                 m_private->startVideoFrameMetadataGathering();
             if (m_processIdentity)
                 m_private->setResourceOwner(m_processIdentity);
+#if ENABLE(LEGACY_ENCRYPTED_MEDIA) && ENABLE(ENCRYPTED_MEDIA)
+            if (m_shouldContinueAfterKeyNeeded)
+                m_private->setShouldContinueAfterKeyNeeded(m_shouldContinueAfterKeyNeeded);
+#endif
             m_private->prepareForPlayback(m_privateBrowsing, m_preload, m_preservesPitch, m_shouldPrepareToRender);
         }
     }
@@ -764,7 +768,7 @@ void MediaPlayer::attemptToDecryptWithInstance(CDMInstance& instance)
 void MediaPlayer::setShouldContinueAfterKeyNeeded(bool should)
 {
     m_shouldContinueAfterKeyNeeded = should;
-    m_private->setShouldContinueAfterKeyNeeded(should);
+    m_private->setShouldContinueAfterKeyNeeded(m_shouldContinueAfterKeyNeeded);
 }
 #endif
 

Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.h

@@ -98,6 +98,7 @@ class MediaPlayerPrivateAVFoundationObjC final : public MediaPlayerPrivateAVFoun
 
 #if ENABLE(LEGACY_ENCRYPTED_MEDIA)
     RetainPtr<AVAssetResourceLoadingRequest> takeRequestForKeyURI(const String&);
+    void setShouldContinueAfterKeyNeeded(bool) final;
 #endif
 
     void playerItemStatusDidChange(int);
@@ -435,6 +436,7 @@ class MediaPlayerPrivateAVFoundationObjC final : public MediaPlayerPrivateAVFoun
 
 #if ENABLE(LEGACY_ENCRYPTED_MEDIA)
     WeakPtr<CDMSessionAVFoundationObjC> m_session;
+    bool m_shouldContinueAfterKeyNeeded { false };
 #endif
 
 #if ENABLE(ENCRYPTED_MEDIA)

Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm

@@ -446,6 +446,7 @@ static WallTime toSystemClockTime(NSDate *date)
     , m_loaderDelegate(adoptNS([[WebCoreAVFLoaderDelegate alloc] initWithPlayer:*this]))
     , m_cachedItemStatus(MediaPlayerAVPlayerItemStatusDoesNotExist)
 {
+    ALWAYS_LOG(LOGIDENTIFIER);
     m_muted = player->muted();
 }
 
@@ -2149,7 +2150,7 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
         auto initData = SharedBuffer::create(Vector<uint8_t> { static_cast<uint8_t*>(initDataBuffer->data()), byteLength });
         player->keyNeeded(initData);
 #if ENABLE(ENCRYPTED_MEDIA)
-        if (!player->shouldContinueAfterKeyNeeded())
+        if (!m_shouldContinueAfterKeyNeeded)
             return true;
 #endif
 #endif
@@ -2166,6 +2167,7 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
         player->initializationDataEncountered("skd"_s, m_keyID->tryCreateArrayBuffer());
         setWaitingForKey(true);
 #endif
+
         m_keyURIToRequestMap.set(keyURI, avRequest);
 
         return true;
@@ -2185,7 +2187,7 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
 
         player->keyNeeded(initData);
 
-        if (!player->shouldContinueAfterKeyNeeded())
+        if (!m_shouldContinueAfterKeyNeeded)
             return false;
 
         m_keyURIToRequestMap.set(keyID, avRequest);
@@ -2204,6 +2206,8 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
 void MediaPlayerPrivateAVFoundationObjC::didCancelLoadingRequest(AVAssetResourceLoadingRequest* avRequest)
 {
     ASSERT(isMainThread());
+
+    ALWAYS_LOG(LOGIDENTIFIER);
     if (RefPtr resourceLoader = m_resourceLoaderMap.get((__bridge CFTypeRef)avRequest)) {
         m_targetQueue->dispatch([resourceLoader = WTFMove(resourceLoader)] { resourceLoader->stopLoading();
         });
@@ -2213,6 +2217,8 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
 void MediaPlayerPrivateAVFoundationObjC::didStopLoadingRequest(AVAssetResourceLoadingRequest *avRequest)
 {
     ASSERT(isMainThread());
+
+    ALWAYS_LOG(LOGIDENTIFIER);
     if (RefPtr resourceLoader = m_resourceLoaderMap.take((__bridge CFTypeRef)avRequest))
         m_targetQueue->dispatch([resourceLoader = WTFMove(resourceLoader)] { });
 }
@@ -2892,6 +2898,12 @@ void determineChangedTracksFromNewTracksAndOldItems(MediaSelectionGroupAVFObjC*
 
 #if ENABLE(LEGACY_ENCRYPTED_MEDIA)
 
+void MediaPlayerPrivateAVFoundationObjC::setShouldContinueAfterKeyNeeded(bool shouldContinue)
+{
+    ALWAYS_LOG(LOGIDENTIFIER, shouldContinue);
+    m_shouldContinueAfterKeyNeeded = shouldContinue;
+}
+
 RetainPtr<AVAssetResourceLoadingRequest> MediaPlayerPrivateAVFoundationObjC::takeRequestForKeyURI(const String& keyURI)
 {
     return m_keyURIToRequestMap.take(keyURI);
@@ -2905,6 +2917,7 @@ void determineChangedTracksFromNewTracksAndOldItems(MediaSelectionGroupAVFObjC*
 
     Vector<String> fulfilledKeyIds;
 
+    ALWAYS_LOG(LOGIDENTIFIER);
     for (auto& pair : m_keyURIToRequestMap) {
         const String& keyId = pair.key;
         const RetainPtr<AVAssetResourceLoadingRequest>& request = pair.value;