cc: Make PrepareToDraw return an enum for why it aborts

cc/scheduler/scheduler_state_machine.cc

 // 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.
 
 #include "cc/scheduler/scheduler_state_machine.h"
 
 #include "base/debug/trace_event.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "ui/gfx/frame_time.h"
 
 namespace cc {
 
 SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
     : settings_(settings),
       output_surface_state_(OUTPUT_SURFACE_LOST),
       begin_impl_frame_state_(BEGIN_IMPL_FRAME_STATE_IDLE),
       commit_state_(COMMIT_STATE_IDLE),
       texture_state_(LAYER_TEXTURE_STATE_UNLOCKED),
       forced_redraw_state_(FORCED_REDRAW_STATE_IDLE),
       readback_state_(READBACK_STATE_IDLE),
       commit_count_(0),
       current_frame_number_(0),
       last_frame_number_swap_performed_(-1),
       last_frame_number_begin_main_frame_sent_(-1),
       last_frame_number_update_visible_tiles_was_called_(-1),
       manage_tiles_funnel_(0),
-      consecutive_failed_draws_(0),
+      consecutive_checkerboard_animations_(0),
       needs_redraw_(false),
       needs_manage_tiles_(false),
       swap_used_incomplete_tile_(false),
       needs_commit_(false),
       main_thread_needs_layer_textures_(false),
       inside_poll_for_anticipated_draw_triggers_(false),
       visible_(false),
       can_start_(false),
       can_draw_(false),
       has_pending_tree_(false),
@@ skipping 192 matching lines @@
   minor_state->SetInteger("last_frame_number_swap_performed",
                           last_frame_number_swap_performed_);
   minor_state->SetInteger(
       "last_frame_number_begin_main_frame_sent",
       last_frame_number_begin_main_frame_sent_);
   minor_state->SetInteger(
       "last_frame_number_update_visible_tiles_was_called",
       last_frame_number_update_visible_tiles_was_called_);
 
   minor_state->SetInteger("manage_tiles_funnel", manage_tiles_funnel_);
-  minor_state->SetInteger("consecutive_failed_draws",
-                          consecutive_failed_draws_);
+  minor_state->SetInteger("consecutive_checkerboard_animations",
+                          consecutive_checkerboard_animations_);
   minor_state->SetBoolean("needs_redraw", needs_redraw_);
   minor_state->SetBoolean("needs_manage_tiles", needs_manage_tiles_);
   minor_state->SetBoolean("swap_used_incomplete_tile",
                           swap_used_incomplete_tile_);
   minor_state->SetBoolean("needs_commit", needs_commit_);
   minor_state->SetBoolean("main_thread_needs_layer_textures",
                           main_thread_needs_layer_textures_);
   minor_state->SetBoolean("visible", visible_);
   minor_state->SetBoolean("can_start", can_start_);
   minor_state->SetBoolean("can_draw", can_draw_);
@@ skipping 760 matching lines @@
 void SchedulerStateMachine::SetSwapUsedIncompleteTile(
     bool used_incomplete_tile) {
   swap_used_incomplete_tile_ = used_incomplete_tile;
 }
 
 void SchedulerStateMachine::SetSmoothnessTakesPriority(
     bool smoothness_takes_priority) {
   smoothness_takes_priority_ = smoothness_takes_priority;
 }
 
-void SchedulerStateMachine::DidDrawIfPossibleCompleted(bool success) {
-  draw_if_possible_failed_ = !success;
-  if (draw_if_possible_failed_) {
-    needs_redraw_ = true;
+void SchedulerStateMachine::DidDrawIfPossibleCompleted(
+    DrawSwapReadbackResult::DrawResult result) {
+  switch (result) {
+    case DrawSwapReadbackResult::INVALID_RESULT:
+      // Uninitialized DrawSwapReadbackResult.
+      NOTREACHED();
+      break;
+    case DrawSwapReadbackResult::DID_DRAW:
+      consecutive_checkerboard_animations_ = 0;
+      forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
+      break;
+    case DrawSwapReadbackResult::DRAW_ABORTED_CANT_DRAW:
+    case DrawSwapReadbackResult::DRAW_ABORTED_NO_TREE:
+    case DrawSwapReadbackResult::DRAW_ABORTED_NO_RENDERER:
+      // Nothing to do in these cases.  External state needs to change first.

[brianderson, 2014/01/29 01:31:22]

I suppose this is one of the few logic changes, but it makes more sense like
this.

+      break;
+    case DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS:
+      needs_redraw_ = true;
 
-    // If we're already in the middle of a redraw, we don't need to
-    // restart it.
-    if (forced_redraw_state_ != FORCED_REDRAW_STATE_IDLE)
-      return;
+      // If we're already in the middle of a redraw, we don't need to
+      // restart it.
+      if (forced_redraw_state_ != FORCED_REDRAW_STATE_IDLE)
+        return;
 
-    needs_commit_ = true;
-    consecutive_failed_draws_++;
-    if (settings_.timeout_and_draw_when_animation_checkerboards &&
-        consecutive_failed_draws_ >=
-            settings_.maximum_number_of_failed_draws_before_draw_is_forced_) {
-      consecutive_failed_draws_ = 0;
-      // We need to force a draw, but it doesn't make sense to do this until
-      // we've committed and have new textures.
-      forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
-    }
-  } else {
-    consecutive_failed_draws_ = 0;
-    forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
+      needs_commit_ = true;
+      consecutive_checkerboard_animations_++;
+      if (settings_.timeout_and_draw_when_animation_checkerboards &&
+          consecutive_checkerboard_animations_ >=
+              settings_.maximum_number_of_failed_draws_before_draw_is_forced_) {

[brianderson, 2014/01/29 01:31:22]

Should we change the name of this setting? Doesn't have to be part of this
patch.

+        consecutive_checkerboard_animations_ = 0;
+        // We need to force a draw, but it doesn't make sense to do this until
+        // we've committed and have new textures.
+        forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
+      }
+      break;
   }
 }
 
 void SchedulerStateMachine::SetNeedsCommit() { needs_commit_ = true; }
 
 void SchedulerStateMachine::SetNeedsForcedCommitForReadback() {
   // If this is called in READBACK_STATE_IDLE, this is a "first" readback
   // request.
   // If this is called in READBACK_STATE_WAITING_FOR_REPLACEMENT_COMMIT, this
   // is a back-to-back readback request that started before the replacement
@@ skipping 71 matching lines @@
     case OUTPUT_SURFACE_ACTIVE:
     case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
     case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
       return true;
   }
   NOTREACHED();
   return false;
 }
 
 }  // namespace cc