Tell JS heap that audio player object uses lot of native memory.

BUG=http://code.google.com/p/chromium/issues/detail?id=61293
BUG=http://code.google.com/p/chromium/issues/detail?id=78992
BUG=http://code.google.com/p/chromium/issues/detail?id=95230

Review URL: http://codereview.chromium.org/7923019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@101918 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 73 insertions, 0 deletions

diff --git a/webkit/glue/webmediaplayer_impl.cc b/webkit/glue/webmediaplayer_impl.cc
index e77ed36..76e6437 100644
--- a/webkit/glue/webmediaplayer_impl.cc
+++ b/webkit/glue/webmediaplayer_impl.cc
@@ -28,6 +28,7 @@
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebSize.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURL.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebVideoFrame.h"
+#include "v8/include/v8.h"
 #include "webkit/glue/media/buffered_data_source.h"
 #include "webkit/glue/media/simple_data_source.h"
 #include "webkit/glue/media/media_stream_client.h"
@@ -43,6 +44,16 @@ using media::PipelineStatus;
 
 namespace {
 
+// Amount of extra memory used by each player instance reported to V8.
+// It is not exact number -- first, it differs on different platforms,
+// and second, it is very hard to calculate. Instead, use some arbitrary
+// value that will cause garbage collection from time to time. We don't want
+// it to happen on every allocation, but don't want 5k players to sit in memory
+// either. Looks that chosen constant achieves both goals, at least for audio
+// objects. (Do not worry about video objects yet, JS programs do not create
+// thousands of them...)
+const int kPlayerExtraMemory = 1024 * 1024;
+
 // Limits the range of playback rate.
 //
 // TODO(kylep): Revisit these.
@@ -123,6 +134,19 @@ bool WebMediaPlayerImpl::Initialize(
     return false;
   }
 
+  // Let V8 know we started new thread if we did not did it yet.
+  // Made separate task to avoid deletion of player currently being created.
+  // Also, delaying GC until after player starts gets rid of starting lag --
+  // collection happens in parallel with playing.
+  // TODO(enal): remove when we get rid of per-audio-stream thread.
+  if (destructor_or_task_had_run_.get() == NULL) {
+    destructor_or_task_had_run_ = new DestructorOrTaskHadRun();
+    main_loop_->PostTask(
+        FROM_HERE,
+        NewRunnableFunction(WebMediaPlayerImpl::UsesExtraMemoryTask,
+                            destructor_or_task_had_run_));
+  }
+
   pipeline_ = new media::PipelineImpl(pipeline_message_loop, media_log_);
 
   // Also we want to be notified of |main_loop_| destruction.
@@ -817,6 +841,15 @@ void WebMediaPlayerImpl::Destroy() {
     media::PipelineStatusNotification note;
     pipeline_->Stop(note.Callback());
     note.Wait();
+
+    // Let V8 know we are not using extra resources anymore.
+    if (destructor_or_task_had_run_.get() != NULL) {
+      if (destructor_or_task_had_run_->value())
+        v8::V8::AdjustAmountOfExternalAllocatedMemory(-kPlayerExtraMemory);
+      else
+        destructor_or_task_had_run_->set_value(true);
+    }
+    destructor_or_task_had_run_ = NULL;
   }
 
   message_loop_factory_.reset();
@@ -835,4 +868,12 @@ WebKit::WebMediaPlayerClient* WebMediaPlayerImpl::GetClient() {
   return client_;
 }
 
+void WebMediaPlayerImpl::UsesExtraMemoryTask(
+    scoped_refptr<DestructorOrTaskHadRun> destructor_or_task_had_run) {
+  if (!destructor_or_task_had_run->value()) {
+    v8::V8::AdjustAmountOfExternalAllocatedMemory(kPlayerExtraMemory);
+    destructor_or_task_had_run->set_value(true);
+  }
+}
+
 }  // namespace webkit_glue
diff --git a/webkit/glue/webmediaplayer_impl.h b/webkit/glue/webmediaplayer_impl.h
index 1b2d8be..7d0ce41 100644
--- a/webkit/glue/webmediaplayer_impl.h
+++ b/webkit/glue/webmediaplayer_impl.h
@@ -196,6 +196,32 @@ class WebMediaPlayerImpl
   void OnDemuxerOpened();
 
  private:
+  // Class used to avoid race condition:
+  // * We added task UsesExtraMemoryTask to tell the V8 we are using extra
+  //   memory.
+  // * Meanwhile, WebMediaPlayerImpl is being deleted. We want to let V8 know
+  //   we are not using that extra memory anymore -- but we cannot be sure
+  //   UsesExtraMemoryTask was yet completed. We cannot add task doing that to
+  //   the message loop either, because we will break shutodown of some tests
+  //   that wait till queue is empty and don't expect destructor to add new
+  //   tasks.
+  // We also don't want to delay destruction of WebMediaPlayerImpl till
+  // UsesExtraMemoryTask finishes, as object is big and uses lot of resources.
+  //
+  // Solution is to use small ref counted object that usually has 2 references
+  // to it -- one from WebMediaPlayerImpl, and one from message loop. Destructor
+  // and UsesExtraMemoryTask can communicate through it.
+  class DestructorOrTaskHadRun:
+      public base::RefCounted<DestructorOrTaskHadRun> {
+   public:
+    DestructorOrTaskHadRun() : value_(false) { }
+    bool value() const { return value_; }
+    void set_value(bool value) { value_ = value; }
+
+   private:
+    bool value_;
+  };
+
   // Helpers that set the network/ready state and notifies the client if
   // they've changed.
   void SetNetworkState(WebKit::WebMediaPlayer::NetworkState state);
@@ -207,6 +233,10 @@ class WebMediaPlayerImpl
   // Getter method to |client_|.
   WebKit::WebMediaPlayerClient* GetClient();
 
+  // Lets V8 know that player uses extra resources not managed by V8.
+  static void UsesExtraMemoryTask(
+      scoped_refptr<DestructorOrTaskHadRun> destructor_or_task_had_run);
+
   // TODO(hclam): get rid of these members and read from the pipeline directly.
   WebKit::WebMediaPlayer::NetworkState network_state_;
   WebKit::WebMediaPlayer::ReadyState ready_state_;
@@ -260,6 +290,8 @@ class WebMediaPlayerImpl
 
   scoped_refptr<media::MediaLog> media_log_;
 
+  scoped_refptr<DestructorOrTaskHadRun> destructor_or_task_had_run_;
+
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };