cc: Use BeginFrameArgs

cc/scheduler/scheduler_state_machine.h

 // Copyright 2011 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 CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 #define CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 13 matching lines @@
 // requested, while external state includes things like the current time being
 // near to the vblank time.
 //
 // The scheduler seperates "what to do next" from the updating of its internal
 // state to make testing cleaner.
 class CC_EXPORT SchedulerStateMachine {
  public:
   // settings must be valid for the lifetime of this class.
   explicit SchedulerStateMachine(const SchedulerSettings& settings);
 
+  enum BeginFrameState {

[brianderson, 2013/06/21 01:27:20]

Note: This version of the patch enforces the rule that the BeginFrameState will
always cycle through all the states in order, whether or not it actually waits
or draws. It will at least *try* to wait or *try* to draw in those states.

I found it easier to reason about than the branching state sequence of the first
patch.

I will add a comment about this.

+    BEGIN_FRAME_IDLE,
+    BEGIN_FRAME_STARTING,
+    BEGIN_FRAME_WAITING,
+    BEGIN_FRAME_DRAWING,
+  };
+
   enum CommitState {
     COMMIT_STATE_IDLE,
     COMMIT_STATE_FRAME_IN_PROGRESS,
     COMMIT_STATE_READY_TO_COMMIT,
+    COMMIT_STATE_WAITING_FOR_ACTIVATION,
     COMMIT_STATE_WAITING_FOR_FIRST_DRAW,
     COMMIT_STATE_WAITING_FOR_FIRST_FORCED_DRAW,
   };
 
   enum TextureState {
     LAYER_TEXTURE_STATE_UNLOCKED,
     LAYER_TEXTURE_STATE_ACQUIRED_BY_MAIN_THREAD,
     LAYER_TEXTURE_STATE_ACQUIRED_BY_IMPL_THREAD,
   };
 
@@ skipping 25 matching lines @@
   void UpdateState(Action action);
 
   // Indicates whether the main thread needs a begin frame callback in order to
   // make progress.
   bool BeginFrameNeededToDrawByImplThread() const;
   bool ProactiveBeginFrameWantedByImplThread() const;
 
   // Indicates that the system has entered and left a BeginFrame callback.
   // The scheduler will not draw more than once in a given BeginFrame
   // callback.
-  void DidEnterBeginFrame(const BeginFrameArgs& args);
-  void DidLeaveBeginFrame();
-  bool inside_begin_frame() const { return inside_begin_frame_; }
+  void OnBeginFrame(const BeginFrameArgs& args);
+  void OnBeginFrameDeadline();
+  bool ShouldTriggerBeginFrameDeadlineEarly() const;
+  bool InsideBeginFrame() const;
 
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool visible);
 
   // Indicates that a redraw is required, either due to the impl tree changing
   // or the screen being damaged and simply needing redisplay.
   void SetNeedsRedraw();
 
   // As SetNeedsRedraw(), but ensures the draw will definitely happen even if
   // we are not visible.
@@ skipping 58 matching lines @@
 
   // False if drawing is not being prevented, true if drawing won't happen
   // for some reason, such as not being visible.
   bool DrawSuspendedUntilCommit() const;
 
   std::string ToString();
 
  protected:
   bool ShouldDrawForced() const;
   bool ScheduledToDraw() const;
+  bool WillDrawNewTree() const;
   bool ShouldDraw() const;
+  bool ShouldDrawInternal(BeginFrameState begin_frame_state) const;
   bool ShouldAttemptTreeActivation() const;
   bool ShouldAcquireLayerTexturesForMainThread() const;
   bool ShouldCheckForCompletedTileUploads() const;
+  bool ShouldSendBeginFrameToMainThread() const;
   bool HasDrawnThisFrame() const;
-  bool HasAttemptedTreeActivationThisFrame() const;
-  bool HasCheckedForCompletedTileUploadsThisFrame() const;
+  bool HasAttemptedTreeActivationThisFrameAttempt() const;
+  bool HasCheckedForCompletedTileUploadsThisFrameAttempt() const;
+  bool HasSentBeginFrameToMainThreadThisFrame() const;
 
   const SchedulerSettings settings_;
 
   CommitState commit_state_;
   int commit_count_;
 
   int current_frame_number_;
-  int last_frame_number_where_draw_was_called_;
-  int last_frame_number_where_tree_activation_attempted_;
-  int last_frame_number_where_check_for_completed_tile_uploads_called_;
+  int current_frame_attempt_;
+  int last_frame_number_draw_was_called_;
+  int last_frame_number_begin_frame_sent_to_main_thread_;
+  int last_frame_attempt_tree_activation_attempted_;
+  int last_frame_attempt_check_for_completed_tile_uploads_called_;
   int consecutive_failed_draws_;
   int maximum_number_of_failed_draws_before_draw_is_forced_;
   bool needs_redraw_;
   bool swap_used_incomplete_tile_;
   bool needs_forced_redraw_;
   bool needs_forced_redraw_after_next_commit_;
   bool needs_commit_;
   bool needs_forced_commit_;
   bool expect_immediate_begin_frame_for_main_thread_;
   bool main_thread_needs_layer_textures_;
-  bool inside_begin_frame_;
+  BeginFrameState begin_frame_state_;
+  bool commit_tree_has_been_drawn_or_null_;
+  bool active_tree_has_been_drawn_or_null_;
   BeginFrameArgs last_begin_frame_args_;
   bool visible_;
   bool can_start_;
   bool can_draw_;
   bool has_pending_tree_;
   bool draw_if_possible_failed_;
   TextureState texture_state_;
   OutputSurfaceState output_surface_state_;
   bool did_create_and_initialize_first_output_surface_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_