cc: Use BeginFrameArgs

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index 6446e8dcbb7a9b181676c62e84605a85ee1d2630..771c371ce407726fd41f052974942d3bf1165ef0 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -15,9 +15,11 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
       commit_state_(COMMIT_STATE_IDLE),
       commit_count_(0),
       current_frame_number_(0),

[Sami, 2013/06/21 10:27:43]

Nit: I think it's a little confusing to have two counters with similar names but
more or less uncorrelated values. Would it make sense to
s/current_frame_attempt_/current_draw_attempt_/ or maybe
current_activation_attempt_? I'm not too opposed to the current name either if
you think it's more consistent.

-      last_frame_number_where_draw_was_called_(-1),
-      last_frame_number_where_tree_activation_attempted_(-1),
-      last_frame_number_where_check_for_completed_tile_uploads_called_(-1),
+      current_frame_attempt_(0),
+      last_frame_number_draw_was_called_(-1),
+      last_frame_number_begin_frame_sent_to_main_thread_(-1),
+      last_frame_attempt_tree_activation_attempted_(-1),
+      last_frame_attempt_check_for_completed_tile_uploads_called_(-1),
       consecutive_failed_draws_(0),
       maximum_number_of_failed_draws_before_draw_is_forced_(3),
       needs_redraw_(false),
@@ -28,7 +30,9 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
       needs_forced_commit_(false),
       expect_immediate_begin_frame_for_main_thread_(false),
       main_thread_needs_layer_textures_(false),
-      inside_begin_frame_(false),
+      begin_frame_state_(BEGIN_FRAME_STATE_IDLE),
+      commit_tree_has_been_drawn_or_null_(true),
+      active_tree_has_been_drawn_or_null_(true),
       visible_(false),
       can_start_(false),
       can_draw_(false),
@@ -45,19 +49,21 @@ std::string SchedulerStateMachine::ToString() {
                       settings_.impl_side_painting);
   base::StringAppendF(&str, "commit_state_ = %d; ", commit_state_);
   base::StringAppendF(&str, "commit_count_ = %d; ", commit_count_);
-  base::StringAppendF(
-      &str, "current_frame_number_ = %d; ", current_frame_number_);
+  base::StringAppendF(&str, "current_frame_number_ = %d; ",
+                      current_frame_number_);
+  base::StringAppendF(&str, "current_frame_attempt_ = %d; ",
+                      current_frame_attempt_);
   base::StringAppendF(&str,
-                      "last_frame_number_where_draw_was_called_ = %d; ",
-                      last_frame_number_where_draw_was_called_);
+                      "last_frame_number_draw_was_called_ = %d; ",
+                      last_frame_number_draw_was_called_);
   base::StringAppendF(
       &str,
-      "last_frame_number_where_tree_activation_attempted_ = %d; ",
-      last_frame_number_where_tree_activation_attempted_);
+      "last_frame_attempt_tree_activation_attempted_ = %d; ",
+      last_frame_attempt_tree_activation_attempted_);
   base::StringAppendF(
       &str,
-      "last_frame_number_where_check_for_completed_tile_uploads_called_ = %d; ",
-      last_frame_number_where_check_for_completed_tile_uploads_called_);
+      "last_frame_attempt_check_for_completed_tile_uploads_called_ = %d; ",
+      last_frame_attempt_check_for_completed_tile_uploads_called_);
   base::StringAppendF(
       &str, "consecutive_failed_draws_ = %d; ", consecutive_failed_draws_);
   base::StringAppendF(
@@ -81,8 +87,7 @@ std::string SchedulerStateMachine::ToString() {
   base::StringAppendF(&str,
                       "main_thread_needs_layer_textures_ = %d; ",
                       main_thread_needs_layer_textures_);
-  base::StringAppendF(&str, "inside_begin_frame_ = %d; ",
-      inside_begin_frame_);
+  base::StringAppendF(&str, "begin_frame_state_ = %d; ", begin_frame_state_);
   base::StringAppendF(&str, "last_frame_time_ = %"PRId64"; ",
       (last_begin_frame_args_.frame_time - base::TimeTicks())
           .InMilliseconds());
@@ -96,6 +101,10 @@ std::string SchedulerStateMachine::ToString() {
   base::StringAppendF(
       &str, "draw_if_possible_failed_ = %d; ", draw_if_possible_failed_);
   base::StringAppendF(&str, "has_pending_tree_ = %d; ", has_pending_tree_);
+  base::StringAppendF(&str, "commit_tree_has_been_drawn_or_null_ = %d; ",
+      commit_tree_has_been_drawn_or_null_);
+  base::StringAppendF(&str, "active_tree_has_been_drawn_or_null_ = %d; ",
+      active_tree_has_been_drawn_or_null_);
   base::StringAppendF(&str, "texture_state_ = %d; ", texture_state_);
   base::StringAppendF(
       &str, "output_surface_state_ = %d; ", output_surface_state_);
@@ -103,17 +112,23 @@ std::string SchedulerStateMachine::ToString() {
 }
 
 bool SchedulerStateMachine::HasDrawnThisFrame() const {
-  return current_frame_number_ == last_frame_number_where_draw_was_called_;
+  return current_frame_number_ == last_frame_number_draw_was_called_;
 }
 
-bool SchedulerStateMachine::HasAttemptedTreeActivationThisFrame() const {
+bool SchedulerStateMachine::HasSentBeginFrameToMainThreadThisFrame() const {
   return current_frame_number_ ==
-         last_frame_number_where_tree_activation_attempted_;
+         last_frame_number_begin_frame_sent_to_main_thread_;
 }
 
-bool SchedulerStateMachine::HasCheckedForCompletedTileUploadsThisFrame() const {
-  return current_frame_number_ ==
-         last_frame_number_where_check_for_completed_tile_uploads_called_;
+bool SchedulerStateMachine::HasAttemptedTreeActivationThisFrameAttempt() const {
+  return current_frame_attempt_ ==
+         last_frame_attempt_tree_activation_attempted_;
+}
+
+bool SchedulerStateMachine::
+    HasCheckedForCompletedTileUploadsThisFrameAttempt() const {
+  return current_frame_attempt_ ==
+         last_frame_attempt_check_for_completed_tile_uploads_called_;
 }
 
 bool SchedulerStateMachine::DrawSuspendedUntilCommit() const {
@@ -140,7 +155,7 @@ bool SchedulerStateMachine::ShouldDraw() const {
 
   if (!ScheduledToDraw())
     return false;
-  if (!inside_begin_frame_)
+  if (begin_frame_state_ != BEGIN_FRAME_STATE_INSIDE_DEADLINE)
     return false;
   if (HasDrawnThisFrame())
     return false;
@@ -150,14 +165,18 @@ bool SchedulerStateMachine::ShouldDraw() const {
 }
 
 bool SchedulerStateMachine::ShouldAttemptTreeActivation() const {
-  return has_pending_tree_ && inside_begin_frame_ &&
-         !HasAttemptedTreeActivationThisFrame();
+  return active_tree_has_been_drawn_or_null_ &&
+         has_pending_tree_ &&
+         (begin_frame_state_ == BEGIN_FRAME_STATE_INSIDE_BEGIN_FRAME ||
+          begin_frame_state_ == BEGIN_FRAME_STATE_DEADLINE_PENDING ||
+          begin_frame_state_ == BEGIN_FRAME_STATE_INSIDE_DEADLINE) &&
+         !HasAttemptedTreeActivationThisFrameAttempt();
 }
 
 bool SchedulerStateMachine::ShouldCheckForCompletedTileUploads() const {
   if (!settings_.impl_side_painting)
     return false;
-  if (HasCheckedForCompletedTileUploadsThisFrame())
+  if (HasCheckedForCompletedTileUploadsThisFrameAttempt())
     return false;
 
   return ShouldAttemptTreeActivation() || ShouldDraw() ||
@@ -179,6 +198,44 @@ bool SchedulerStateMachine::ShouldAcquireLayerTexturesForMainThread() const {
   return false;
 }
 
+bool SchedulerStateMachine::ShouldSendBeginFrameToMainThread() const {
+  if (HasSentBeginFrameToMainThreadThisFrame())
+    return false;
+
+  // We only request a new commit while idle if we aren't already going
+  // to draw a new commit.
+  if (WillDrawNewTree() &&
+      (begin_frame_state_ == BEGIN_FRAME_STATE_IDLE ||
+       begin_frame_state_ == BEGIN_FRAME_STATE_INSIDE_DEADLINE))
+    return false;
+
+  // We can't accept a commit if we have a pending tree.
+  if (has_pending_tree_)
+    return false;
+
+  switch (commit_state_) {
+    case COMMIT_STATE_IDLE:
+      return (needs_commit_ && (needs_forced_commit_ ||
+          (visible_ && output_surface_state_ == OUTPUT_SURFACE_ACTIVE)));
+
+    // COMMIT_STATE_WAITING_FOR_ACTIVATION wants to enforce activation and
+    // eventually a draw.
+    // COMMIT_STATE_WAITING_FOR_FIRST_DRAW wants to enforce a draw.
+    // If can_draw_ is false or textures are not available, proceed to the
+    // next step (similar as in COMMIT_STATE_IDLE).
+    case COMMIT_STATE_WAITING_FOR_ACTIVATION:
+    case COMMIT_STATE_WAITING_FOR_FIRST_DRAW: {
+      bool can_commit = visible_ || needs_forced_commit_;

[Sami, 2013/06/21 10:27:43]

Nit: can_commit could be moved above this switch() and reused in the
COMMIT_STATE_IDLE state above.

+      return (needs_commit_ && can_commit && DrawSuspendedUntilCommit());
+    }
+
+    default:
+      return false;
+  }
+
+  return false;
+}
+
 SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
   if (ShouldAcquireLayerTexturesForMainThread())
     return ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD;
@@ -205,12 +262,9 @@ SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
         return needs_forced_redraw_ ? ACTION_DRAW_FORCED
                                     : ACTION_DRAW_IF_POSSIBLE;
       }
-      if (needs_commit_ &&
-          ((visible_ && output_surface_state_ == OUTPUT_SURFACE_ACTIVE)
-           || needs_forced_commit_))
+      if (ShouldSendBeginFrameToMainThread())

[Sami, 2013/06/21 10:27:43]

Nit: braces for multi-line 'if'.

         // TODO(enne): Should probably drop the active tree on force commit.
-        return has_pending_tree_ ? ACTION_NONE
-                                 : ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD;
+        return ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD;
       return ACTION_NONE;
 
     case COMMIT_STATE_FRAME_IN_PROGRESS:
@@ -227,6 +281,7 @@ SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
     case COMMIT_STATE_READY_TO_COMMIT:
       return ACTION_COMMIT;
 
+    case COMMIT_STATE_WAITING_FOR_ACTIVATION:
     case COMMIT_STATE_WAITING_FOR_FIRST_DRAW: {
       if (ShouldCheckForCompletedTileUploads())
         return ACTION_CHECK_FOR_COMPLETED_TILE_UPLOADS;
@@ -236,13 +291,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
         return needs_forced_redraw_ ? ACTION_DRAW_FORCED
                                     : ACTION_DRAW_IF_POSSIBLE;
       }
-      // COMMIT_STATE_WAITING_FOR_FIRST_DRAW wants to enforce a draw. If
-      // can_draw_ is false or textures are not available, proceed to the next
-      // step (similar as in COMMIT_STATE_IDLE).
-      bool can_commit = visible_ || needs_forced_commit_;
-      if (needs_commit_ && can_commit && DrawSuspendedUntilCommit())
-        return has_pending_tree_ ? ACTION_NONE
-                                 : ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD;
+      if (ShouldSendBeginFrameToMainThread())
+        return ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD;
       return ACTION_NONE;
     }
 
@@ -262,16 +312,22 @@ SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
 void SchedulerStateMachine::UpdateState(Action action) {
   switch (action) {
     case ACTION_NONE:
+      if (begin_frame_state_ == BEGIN_FRAME_STATE_INSIDE_BEGIN_FRAME)
+        begin_frame_state_ = BEGIN_FRAME_STATE_DEADLINE_PENDING;
+      if (begin_frame_state_ == BEGIN_FRAME_STATE_INSIDE_DEADLINE) {
+        begin_frame_state_ = BEGIN_FRAME_STATE_IDLE;
+        current_frame_number_++;
+      }
       return;
 
     case ACTION_CHECK_FOR_COMPLETED_TILE_UPLOADS:
-      last_frame_number_where_check_for_completed_tile_uploads_called_ =
-          current_frame_number_;
+      last_frame_attempt_check_for_completed_tile_uploads_called_ =
+          current_frame_attempt_;
       return;
 
     case ACTION_ACTIVATE_PENDING_TREE_IF_NEEDED:
-      last_frame_number_where_tree_activation_attempted_ =
-          current_frame_number_;
+      last_frame_attempt_tree_activation_attempted_ =
+          current_frame_attempt_;
       return;
 
     case ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD:
@@ -280,25 +336,29 @@ void SchedulerStateMachine::UpdateState(Action action) {
       commit_state_ = COMMIT_STATE_FRAME_IN_PROGRESS;
       needs_commit_ = false;
       needs_forced_commit_ = false;
+      last_frame_number_begin_frame_sent_to_main_thread_ =
+          current_frame_number_;
       return;
 
     case ACTION_COMMIT:
       commit_count_++;
       if (expect_immediate_begin_frame_for_main_thread_)
         commit_state_ = COMMIT_STATE_WAITING_FOR_FIRST_FORCED_DRAW;
+      else if (settings_.impl_side_painting)
+        commit_state_ = COMMIT_STATE_WAITING_FOR_ACTIVATION;
       else
         commit_state_ = COMMIT_STATE_WAITING_FOR_FIRST_DRAW;
       // When impl-side painting, we draw on activation instead of on commit.
       if (!settings_.impl_side_painting)
         needs_redraw_ = true;
       if (draw_if_possible_failed_)
-        last_frame_number_where_draw_was_called_ = -1;
+        last_frame_number_draw_was_called_ = -1;
 
       if (needs_forced_redraw_after_next_commit_) {
         needs_forced_redraw_after_next_commit_ = false;
         needs_forced_redraw_ = true;
       }
-
+      commit_tree_has_been_drawn_or_null_ = false;
       texture_state_ = LAYER_TEXTURE_STATE_ACQUIRED_BY_IMPL_THREAD;
       return;
 
@@ -308,8 +368,7 @@ void SchedulerStateMachine::UpdateState(Action action) {
       needs_forced_redraw_ = false;
       draw_if_possible_failed_ = false;
       swap_used_incomplete_tile_ = false;
-      if (inside_begin_frame_)
-        last_frame_number_where_draw_was_called_ = current_frame_number_;
+      last_frame_number_draw_was_called_ = current_frame_number_;
       if (commit_state_ == COMMIT_STATE_WAITING_FOR_FIRST_FORCED_DRAW) {
         DCHECK(expect_immediate_begin_frame_for_main_thread_);
         commit_state_ = COMMIT_STATE_FRAME_IN_PROGRESS;
@@ -319,6 +378,8 @@ void SchedulerStateMachine::UpdateState(Action action) {
       }
       if (texture_state_ == LAYER_TEXTURE_STATE_ACQUIRED_BY_IMPL_THREAD)
         texture_state_ = LAYER_TEXTURE_STATE_UNLOCKED;
+      active_tree_has_been_drawn_or_null_ = true;
+      commit_tree_has_been_drawn_or_null_ = true;
       return;
 
     case ACTION_BEGIN_OUTPUT_SURFACE_CREATION:
@@ -372,14 +433,32 @@ bool SchedulerStateMachine::ProactiveBeginFrameWantedByImplThread() const {
   return false;
 }
 
-void SchedulerStateMachine::DidEnterBeginFrame(const BeginFrameArgs& args) {
-  inside_begin_frame_ = true;
+void SchedulerStateMachine::OnBeginFrame(const BeginFrameArgs& args) {
+  current_frame_attempt_++;
   last_begin_frame_args_ = args;
+  begin_frame_state_ = BEGIN_FRAME_STATE_INSIDE_BEGIN_FRAME;
+}
+
+bool SchedulerStateMachine::ShouldTriggerBeginFrameDeadlineEarly() const {
+  return begin_frame_state_ == BEGIN_FRAME_STATE_DEADLINE_PENDING &&
+         WillDrawNewTree();
+}
+
+bool SchedulerStateMachine::InsideBeginFrame() const {
+  return begin_frame_state_ != BEGIN_FRAME_STATE_IDLE;
+}
+
+bool SchedulerStateMachine::WillDrawNewTree() const {
+  if (settings_.impl_side_painting)
+    return !active_tree_has_been_drawn_or_null_;
+  else
+    return !commit_tree_has_been_drawn_or_null_;
 }
 
-void SchedulerStateMachine::DidLeaveBeginFrame() {
-  current_frame_number_++;
-  inside_begin_frame_ = false;
+void SchedulerStateMachine::OnBeginFrameDeadline() {
+  current_frame_attempt_++;
+  if (begin_frame_state_ == BEGIN_FRAME_STATE_DEADLINE_PENDING)
+    begin_frame_state_ = BEGIN_FRAME_STATE_INSIDE_DEADLINE;
 }
 
 void SchedulerStateMachine::SetVisible(bool visible) { visible_ = visible; }
@@ -446,6 +525,14 @@ void SchedulerStateMachine::DidLoseOutputSurface() {
 }
 
 void SchedulerStateMachine::SetHasPendingTree(bool has_pending_tree) {
+  if (has_pending_tree_ && !has_pending_tree) {
+    // This is a new activation.
+    current_frame_attempt_++;
+    active_tree_has_been_drawn_or_null_ = false;
+    if (COMMIT_STATE_WAITING_FOR_ACTIVATION == commit_state_)
+      commit_state_ = COMMIT_STATE_IDLE;
+  }
+
   has_pending_tree_ = has_pending_tree;
 }