Adding the logic for releasing decoder resources in WebMediaPlayerManagerAndroid

webkit/media/android/webmediaplayer_manager_android.cc

Index: webkit/media/android/webmediaplayer_manager_android.cc
diff --git a/webkit/media/android/webmediaplayer_manager_android.cc b/webkit/media/android/webmediaplayer_manager_android.cc
index 93c9733d20d0be68aac4b2738da7b0620203bd4e..017c44c10ab8baf8e63817f10276fddd08b8574b 100644
--- a/webkit/media/android/webmediaplayer_manager_android.cc
+++ b/webkit/media/android/webmediaplayer_manager_android.cc
@@ -6,10 +6,14 @@
 
 #include "webkit/media/android/webmediaplayer_android.h"
 
+// The number of maximum active player allowed in a renderer.
+static const int kMaxMediaPlayerLimit = 2;
+
 namespace webkit_media {
 
 WebMediaPlayerManagerAndroid::WebMediaPlayerManagerAndroid()
-    : next_media_player_id_(0) {
+    : next_media_player_id_(0),
+      num_active_players_(0) {
 }
 
 WebMediaPlayerManagerAndroid::~WebMediaPlayerManagerAndroid() {}
@@ -17,6 +21,7 @@ WebMediaPlayerManagerAndroid::~WebMediaPlayerManagerAndroid() {}
 int WebMediaPlayerManagerAndroid::RegisterMediaPlayer(
     WebMediaPlayerAndroid* player) {
   MediaPlayerInfo info;
+  info.is_active_ = false;
   info.player = player;
   media_players_[next_media_player_id_] = info;
   return next_media_player_id_++;
@@ -27,15 +32,48 @@ void WebMediaPlayerManagerAndroid::UnregisterMediaPlayer(int player_id) {
       media_players_.find(player_id);
   DCHECK(iter != media_players_.end());
 
+  if ((iter->second).is_active_)
+    num_active_players_--;
   media_players_.erase(player_id);
 }
 
+void WebMediaPlayerManagerAndroid::RequestMediaResources(int player_id) {
+  std::map<int32, MediaPlayerInfo>::iterator iter =
+      media_players_.find(player_id);
+  DCHECK(iter != media_players_.end());
+
+  if ((iter->second).is_active_)
+    return;
+
+  // Release active players that are paused. Because we only release paused
+  // players, the number of running players could go beyond the limit.
+  // TODO(qinmin): we should use LRU to release the oldest player if we are
+  // reaching hardware limit.
+  if (num_active_players_ >= kMaxMediaPlayerLimit) {
+    std::map<int32, MediaPlayerInfo>::iterator player_it;
+    for (player_it = media_players_.begin();
+        player_it != media_players_.end(); ++player_it) {
+      if ((player_it->second).is_active_
+          && (player_it->second).player->paused()) {
+        (player_it->second).player->ReleaseMediaResources();
+        (player_it->second).is_active_ = false;

[scherkus (not reviewing), 2012/06/07 19:33:17]

do we need to track this state externally? doesn't a WMPA know whether it has
media resources or not based on the presence of a media_player_ object?

[qinmin, 2012/06/07 20:58:22]

Not necessarily. I made the change to use WMPA::IsInitialized() to replace the
is_active_ logic here.
 

On 2012/06/07 19:33:17, scherkus wrote:

+        num_active_players_--;
+      }
+    }
+  }
+
+  (iter->second).is_active_ = true;
+  num_active_players_++;
+}
+
 void WebMediaPlayerManagerAndroid::ReleaseMediaResources() {
   std::map<int32, MediaPlayerInfo>::iterator player_it;
   for (player_it = media_players_.begin();
       player_it != media_players_.end(); ++player_it) {
+    (player_it->second).is_active_ = false;
     (player_it->second).player->ReleaseMediaResources();
   }
+  num_active_players_ = 0;
 }
 
 WebMediaPlayerAndroid* WebMediaPlayerManagerAndroid::GetMediaPlayer(