[MSE] ManagedMediaSource isn't usable in a DedicatedWorker

https://bugs.webkit.org/show_bug.cgi?id=270891 rdar://124499286 Reviewed by Youenn Fablet. The HTMLMediaElement was never attached to the MediaSource (or ManagedMediaSource) running in the dedicated worker. While this didn't prevent MediaSource to work, it would have caused the ManagedMediaSource to never move to the `Open` readyState as the MMS need to check the HTMLMediaElement if an AirPlay alternative is present. The MediaSourceHandle uses the ensureOnDispatcher utility to dispatch to the MediaSource dispatcher, which will not run the function should MediaSource::isClosed() return true. We need to force the function to run when we attach the HTMLMediaElement which in turn will move the readyState to `open`. Added test. * LayoutTests/media/media-source/worker/media-managedmse-worker-expected.txt: Added. * LayoutTests/media/media-source/worker/media-managedmse-worker.html: Added. * LayoutTests/media/media-source/worker/worker.js: Added. (logToMain): (onmessage): * LayoutTests/platform/glib/TestExpectations: * Source/WebCore/Modules/mediasource/MediaSourceHandle.cpp: (WebCore::MediaSourceHandle::ensureOnDispatcher const): * Source/WebCore/Modules/mediasource/MediaSourceHandle.h: * Source/WebCore/Modules/mediasource/MediaSourceInterfaceWorker.cpp: (WebCore::MediaSourceInterfaceWorker::attachToElement): Canonical link: https://commits.webkit.org/276140@main
WebKit · Mar 15, 2024 · 321003e · 321003e
1 parent 2773206
commit 321003e
Show file tree

Hide file tree

Showing 7 changed files with 64 additions and 4 deletions.
diff --git a/LayoutTests/media/media-source/worker/media-managedmse-worker-expected.txt b/LayoutTests/media/media-source/worker/media-managedmse-worker-expected.txt
@@ -0,0 +1,6 @@
+
+RUN(video.disableRemotePlayback = true)
+received handle message: [object MediaSourceHandle] OK
+info message from worker: sourceopen event received OK
+END OF TEST
+
diff --git a/LayoutTests/media/media-source/worker/media-managedmse-worker.html b/LayoutTests/media/media-source/worker/media-managedmse-worker.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html> <!-- webkit-test-runner [ ManagedMediaSourceEnabled=true MediaSourceEnabled=true ] -->
+<html>
+<head>
+    <title>managedmediasource in worker</title>
+    <script src="../../../media/video-test.js"></script>
+    <script>
+    window.addEventListener('load', async event => {
+        findMediaElement();
+
+        const worker = new Worker('worker.js');
+        worker.onmessage = msg => {
+            switch (msg.data.topic) {
+                case 'handle':
+                logResult(true, 'received handle message: ' + msg.data.arg);
+                video.srcObject = msg.data.arg;
+                break;
+                case 'info':
+                logResult(true, 'info message from worker: ' + msg.data.arg);
+                endTest();
+                break;
+                default:
+                logResult(false, 'error: Unrecognized topic in message from worker');
+                break;
+            }
+        };
+        run('video.disableRemotePlayback = true');
+        worker.postMessage({ });
+    });
+    </script>
+</head>
+<body>
+    <video controls></video>
+</body>
+</html>
diff --git a/LayoutTests/media/media-source/worker/worker.js b/LayoutTests/media/media-source/worker/worker.js
@@ -0,0 +1,16 @@
+function logToMain(msg) {
+    postMessage({topic: 'info', arg: msg});
+}
+
+onmessage = (e) => {
+    const ms = new ManagedMediaSource();
+    const handle = ms.handle;
+
+    ms.onsourceopen = () => {
+        logToMain("sourceopen event received");
+    };
+    // Transfer the MediaSourceHandle to the main thread for use in attaching to
+    // the main thread media element that will play the content being buffered
+    // here in the worker.
+    postMessage({topic: 'handle', arg: handle}, [handle]);
+};
diff --git a/LayoutTests/platform/glib/TestExpectations b/LayoutTests/platform/glib/TestExpectations
@@ -1084,6 +1084,9 @@ media/media-source/media-managedmse-memorypressure.html [ Timeout ]
 media/media-source/media-managedmse-memorypressure-inactive.html [ Timeout ]
 media/media-source/media-managedmse-eviction.html [ Timeout ]
 
+# No MSE in a worker on glib platforms for now (requires GPU process).
+media/media-source/worker/media-managedmse-worker.html [ Timeout ]
+
 webkit.org/b/211995 fast/images/animated-image-mp4.html [ Failure Timeout ]
 
 webkit.org/b/214038 imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/track/track-element/track-cues-cuechange.html [ Missing Failure ]

diff --git a/Source/WebCore/Modules/mediasource/MediaSourceHandle.cpp b/Source/WebCore/Modules/mediasource/MediaSourceHandle.cpp
@@ -120,9 +120,9 @@ bool MediaSourceHandle::isManaged() const
     return m_private->m_isManaged;
 }
 
-void MediaSourceHandle::ensureOnDispatcher(MediaSourceHandle::TaskType&& task) const
+void MediaSourceHandle::ensureOnDispatcher(MediaSourceHandle::TaskType&& task, bool forceRun) const
 {
-    m_private->dispatch(WTFMove(task));
+    m_private->dispatch(WTFMove(task), forceRun);
 }
 
 Ref<DetachedMediaSourceHandle> MediaSourceHandle::detach()

diff --git a/Source/WebCore/Modules/mediasource/MediaSourceHandle.h b/Source/WebCore/Modules/mediasource/MediaSourceHandle.h
@@ -55,7 +55,7 @@ class MediaSourceHandle
     bool isManaged() const;
 
     using TaskType = Function<void(MediaSource&)>;
-    void ensureOnDispatcher(TaskType&&) const;
+    void ensureOnDispatcher(TaskType&&, bool forceRun = false) const;
 
     RefPtr<MediaSourcePrivateClient> mediaSourcePrivateClient() const;
     RefPtr<MediaSourcePrivate> mediaSourcePrivate() const;

diff --git a/Source/WebCore/Modules/mediasource/MediaSourceInterfaceWorker.cpp b/Source/WebCore/Modules/mediasource/MediaSourceInterfaceWorker.cpp
@@ -96,9 +96,10 @@ bool MediaSourceInterfaceWorker::attachToElement(WeakPtr<HTMLMediaElement>&& ele
     if (m_handle->hasEverBeenAssignedAsSrcObject())
         return false;
     m_handle->setHasEverBeenAssignedAsSrcObject();
+    bool forceRun = true;
     m_handle->ensureOnDispatcher([element = WTFMove(element)](MediaSource& mediaSource) mutable {
         mediaSource.attachToElement(WTFMove(element));
-    });
+    }, forceRun);
     return true;
 }