Bug 1395922 - [P2] Make MediaFormatReader::SetCDMProxy asynchronously with a promise. r=cpearce,jya

MozReview-Commit-ID: 7RarmmlA0lo

--HG--
extra : rebase_source : 195f64f405aa19920ccf09ffeddb087877d653a4

dom/media/MediaFormatReader.cpp

@@ -1228,6 +1228,10 @@ MediaFormatReader::Shutdown()
   mMetadataPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
   mSeekPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
   mSkipRequest.DisconnectIfExists();
+  mSetCDMPromise.RejectIfExists(
+    MediaResult(NS_ERROR_DOM_INVALID_STATE_ERR,
+                "MediaFormatReader is shutting down"),
+    __func__);
 
   if (mAudio.HasPromise()) {
     mAudio.RejectPromise(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
@@ -1319,22 +1323,66 @@ MediaFormatReader::Init()
 }
 
 void
+MediaFormatReader::ResolveSetCDMPromiseIfDone(TrackType aTrack)
+{
+  // When a CDM proxy is set, MFR would shutdown the existing MediaDataDecoder
+  // and would create new one for specific track in the next Update.
+  MOZ_ASSERT(OnTaskQueue());
+
+  if (mSetCDMForTracks.contains(aTrack)) {
+    MOZ_ASSERT(!mSetCDMPromise.IsEmpty());
+
+    mSetCDMForTracks -= aTrack;
+    if (mSetCDMForTracks.isEmpty()) {
+      mSetCDMPromise.Resolve(/* aIgnored = */ true, __func__);
+    }
+  }
+}
+
+RefPtr<SetCDMPromise>
 MediaFormatReader::SetCDMProxy(CDMProxy* aProxy)
 {
-  RefPtr<CDMProxy> proxy = aProxy;
-  RefPtr<MediaFormatReader> self = this;
-  nsCOMPtr<nsIRunnable> r =
-    NS_NewRunnableFunction("MediaFormatReader::SetCDMProxy", [=]() {
-      MOZ_ASSERT(self->OnTaskQueue());
-      self->mCDMProxy = proxy;
-      if (HasAudio()) {
-        self->ScheduleUpdate(TrackInfo::kAudioTrack);
-      }
-      if (HasVideo()) {
-        self->ScheduleUpdate(TrackInfo::kVideoTrack);
-      }
-    });
-  OwnerThread()->Dispatch(r.forget());
+  MOZ_ASSERT(OnTaskQueue());
+  LOGV("SetCDMProxy (%p)", aProxy);
+
+  if (mShutdown) {
+    return SetCDMPromise::CreateAndReject(
+      MediaResult(NS_ERROR_DOM_INVALID_STATE_ERR,
+                  "MediaFormatReader is shutting down"),
+      __func__);
+  }
+
+  mSetCDMPromise.RejectIfExists(
+    MediaResult(NS_ERROR_DOM_INVALID_STATE_ERR,
+                "Another new CDM proxy is being set."),
+    __func__);
+
+  if (HasAudio()) {
+    mSetCDMForTracks += TrackInfo::kAudioTrack;
+    ScheduleUpdate(TrackInfo::kAudioTrack);
+  }
+  if (HasVideo()) {
+    mSetCDMForTracks += TrackInfo::kVideoTrack;
+    ScheduleUpdate(TrackInfo::kVideoTrack);
+  }
+
+  // Shutdown all decoders as switching CDM proxy indicates that it's
+  // inappropriate for the existing decoders to continue decoding via the old
+  // CDM proxy.
+  if (!mSetCDMForTracks.isEmpty()) {
+    ReleaseResources();
+  }
+
+  mCDMProxy = aProxy;
+
+  if (!mInitDone || mSetCDMForTracks.isEmpty()) {
+    // MFR is not initialized yet or demuxer is initialized without active
+    // audio and video, the promise can be resolved directly.
+    return SetCDMPromise::CreateAndResolve(/* aIgnored = */ true, __func__);
+  }
+
+  RefPtr<SetCDMPromise> p = mSetCDMPromise.Ensure(__func__);
+  return p;
 }
 
 bool
@@ -2243,6 +2291,8 @@ MediaFormatReader::Update(TrackType aTrack)
   auto& decoder = GetDecoderData(aTrack);
   decoder.mUpdateScheduled = false;
 
+  ResolveSetCDMPromiseIfDone(aTrack);
+
   if (!mInitDone) {
     return;
   }

dom/media/MediaFormatReader.h

@@ -18,6 +18,7 @@
 #include "MediaDataDemuxer.h"
 #include "MediaMetadataManager.h"
 #include "MediaPrefs.h"
+#include "MediaPromiseDefs.h"
 #include "nsAutoPtr.h"
 #include "PDMFactory.h"
 #include "SeekTarget.h"
@@ -91,7 +92,6 @@ class MediaFormatReader final
   static const bool IsExclusive = true;
   typedef TrackInfo::TrackType TrackType;
   typedef MozPromise<bool, MediaResult, IsExclusive> NotifyDataArrivedPromise;
-
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaFormatReader)
 
 public:
@@ -194,7 +194,8 @@ public:
   // cases like MSE.
   bool UseBufferingHeuristics() const { return mTrackDemuxersMayBlock; }
 
-  void SetCDMProxy(CDMProxy* aProxy);
+  void ResolveSetCDMPromiseIfDone(TrackType aTrack);
+  RefPtr<SetCDMPromise> SetCDMProxy(CDMProxy* aProxy);
 
   // Returns a string describing the state of the decoder data.
   // Used for debugging purposes.
@@ -792,6 +793,9 @@ private:
 
   // Used in bug 1393399 for telemetry.
   const MediaDecoderOwnerID mMediaDecoderOwnerID;
+
+  MozPromiseHolder<SetCDMPromise> mSetCDMPromise;
+  TrackSet mSetCDMForTracks{};
 };
 
 } // namespace mozilla

dom/media/MediaPromiseDefs.h

@@ -0,0 +1,19 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef MediaPromiseDefs_h_
+#define MediaPromiseDefs_h_
+
+#include "MediaResult.h"
+#include "mozilla/MozPromise.h"
+
+namespace mozilla {
+
+using SetCDMPromise =
+  MozPromise<bool /* aIgnored */, MediaResult, /* IsExclusive */ true>;
+
+} // namespace mozilla
+
+#endif

dom/media/moz.build

@@ -121,6 +121,7 @@ EXPORTS += [
     'MediaMetadataManager.h',
     'MediaMIMETypes.h',
     'MediaPrefs.h',
+    'MediaPromiseDefs.h',
     'MediaQueue.h',
     'MediaRecorder.h',
     'MediaResource.h',