Throttle media decoding after excessive Android media server crashes

content/browser/media/android/browser_media_player_manager.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_PLAYER_MANAGER_H_
 #define CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_PLAYER_MANAGER_H_
 
+#include <map>
+
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/time/time.h"
 #include "content/browser/android/content_video_view.h"
 #include "content/browser/media/android/media_session_observer.h"
 #include "content/common/content_export.h"
 #include "content/common/media/media_player_messages_enums_android.h"
 #include "content/public/browser/android/content_view_core.h"
@@ skipping 123 matching lines @@
   // Removes the player with the specified id.
   void RemovePlayer(int player_id);
 
   // Replaces a player with the specified id with a given MediaPlayerAndroid
   // object. This will also return the original MediaPlayerAndroid object that
   // was replaced.
   scoped_ptr<media::MediaPlayerAndroid> SwapPlayer(
       int player_id,
       media::MediaPlayerAndroid* player);
 
+  // Called to request decoder resources. Returns true if the request is
+  // permitted, or false otherwise. The manager object maintains an array

[Ted C, 2015/10/01 02:19:57]

"an array" seems a bit too specific.  maybe a list or mapping to avoid the usage
of a actual datatype

[qinmin, 2015/10/01 18:14:02]

Done.

+  // of active MediaPlayerAndroid objects and releases the inactive resources
+  // when needed. If |temporary| is true, the request is short lived
+  // and it will not be cleaned up when handling other requests.
+  // On the contrary, requests with false |temporary| value are subject to
+  // clean up if their players are idle.
+  virtual bool RequestDecoderResources(int player_id, bool temporary);
+
+  // MediaPlayerAndroid must call this to inform the manager that it has
+  // released the decoder resources. This can be triggered by the
+  // ReleasePlayer() call below, or when meta data is extracted, or when player
+  // is stuck in an error.
+  virtual void OnDecoderResourcesReleased(int player_id);
+
   int RoutingID();
 
   // Helper function to send messages to RenderFrameObserver.
   bool Send(IPC::Message* msg);
 
  private:
   // Constructs a MediaPlayerAndroid object.
   media::MediaPlayerAndroid* CreateMediaPlayer(
       const MediaPlayerHostMsg_Initialize_Params& media_player_params,
       bool hide_url_log,
       BrowserDemuxerAndroid* demuxer);
 
-  // MediaPlayerAndroid must call this before it is going to decode
-  // media streams. This helps the manager object maintain an array
-  // of active MediaPlayerAndroid objects and release the resources
-  // when needed. Currently we only count video resources as they are
-  // constrained by hardware and memory limits.
-  virtual void OnMediaResourcesRequested(int player_id);
+  // Instructs |player| to release its java player. This will not remove the
+  // player from |players_|.
+  void ReleasePlayer(media::MediaPlayerAndroid* player);
 
-  // Called when a player releases all decoding resources.
-  void ReleaseMediaResources(int player_id);
+  // Called when user approves media playback after being throttled.
+  void OnPlaybackPermissionGranted(int player_id, bool granted);
 
-  // Releases the player. However, don't remove it from |players_|.
-  void ReleasePlayer(media::MediaPlayerAndroid* player);
+  // Helper method to start playback.
+  void StartInternal(int player_id);
 
 #if defined(VIDEO_HOLE)
   void ReleasePlayerOfExternalVideoSurfaceIfNeeded(int future_player);
   void OnRequestExternalSurface(int player_id, const gfx::RectF& rect);
+  void ReleaseExternalSurface(int player_id);
 #endif  // defined(VIDEO_HOLE)
 
   RenderFrameHost* const render_frame_host_;
 
   // An array of managed players.
   ScopedVector<media::MediaPlayerAndroid> players_;
 
+  typedef std::map<int, bool> ActivePlayerMap;
+  // Players that have requested decoding resources. Even though resource is
+  // requested, a player may be in a paused or error state and the manager
+  // will release its resources later.
+  ActivePlayerMap active_players_;
+
   // The fullscreen video view object or NULL if video is not played in
   // fullscreen.
   scoped_ptr<ContentVideoView> video_view_;
 
 #if defined(VIDEO_HOLE)
   scoped_ptr<ExternalVideoSurfaceContainer> external_video_surface_container_;
 #endif
 
   // Player ID of the fullscreen media player.
   int fullscreen_player_id_;
 
   // Whether the fullscreen player has been Release()-d.
   bool fullscreen_player_is_released_;
 
   WebContents* const web_contents_;
 
   // Object for retrieving resources media players.
   scoped_ptr<media::MediaResourceGetter> media_resource_getter_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<BrowserMediaPlayerManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMediaPlayerManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_PLAYER_MANAGER_H_