[cc] Calculate the correct latest_confirmed_sequence_number in cc::Scheduler.

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/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "base/values.h"
+#include "cc/output/begin_frame_args.h"
 
 namespace cc {
 
 namespace {
 // Surfaces and CompositorTimingHistory don't support more than 1 pending swap.
 const int kMaxPendingSubmitFrames = 1;
 }  // namespace
 
 SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
     : settings_(settings),
       compositor_frame_sink_state_(COMPOSITOR_FRAME_SINK_NONE),
       begin_impl_frame_state_(BEGIN_IMPL_FRAME_STATE_IDLE),
       begin_main_frame_state_(BEGIN_MAIN_FRAME_STATE_IDLE),
       forced_redraw_state_(FORCED_REDRAW_STATE_IDLE),
+      begin_frame_source_id_(0),
+      begin_frame_sequence_number_(BeginFrameArgs::kInvalidFrameNumber),
+      last_begin_frame_sequence_number_begin_main_frame_sent_(
+          BeginFrameArgs::kInvalidFrameNumber),
+      last_begin_frame_sequence_number_pending_tree_was_fresh_(
+          BeginFrameArgs::kInvalidFrameNumber),
+      last_begin_frame_sequence_number_active_tree_was_fresh_(
+          BeginFrameArgs::kInvalidFrameNumber),
+      last_begin_frame_sequence_number_compositor_frame_was_fresh_(
+          BeginFrameArgs::kInvalidFrameNumber),
       commit_count_(0),
       current_frame_number_(0),
       last_frame_number_submit_performed_(-1),
       last_frame_number_draw_performed_(-1),
       last_frame_number_begin_main_frame_sent_(-1),
       last_frame_number_invalidate_compositor_frame_sink_performed_(-1),
       draw_funnel_(false),
       send_begin_main_frame_funnel_(true),
       invalidate_compositor_frame_sink_funnel_(false),
       prepare_tiles_funnel_(0),
@@ skipping 170 matching lines @@
 
   state->BeginDictionary("minor_state");
   state->SetInteger("commit_count", commit_count_);
   state->SetInteger("current_frame_number", current_frame_number_);
   state->SetInteger("last_frame_number_submit_performed",
                     last_frame_number_submit_performed_);
   state->SetInteger("last_frame_number_draw_performed",
                     last_frame_number_draw_performed_);
   state->SetInteger("last_frame_number_begin_main_frame_sent",
                     last_frame_number_begin_main_frame_sent_);
+  state->SetInteger("begin_frame_source_id", begin_frame_source_id_);
+  state->SetInteger("begin_frame_sequence_number",
+                    begin_frame_sequence_number_);
+  state->SetInteger("last_begin_frame_sequence_number_begin_main_frame_sent",
+                    last_begin_frame_sequence_number_begin_main_frame_sent_);
+  state->SetInteger("last_begin_frame_sequence_number_pending_tree_was_fresh",
+                    last_begin_frame_sequence_number_pending_tree_was_fresh_);
+  state->SetInteger("last_begin_frame_sequence_number_active_tree_was_fresh",
+                    last_begin_frame_sequence_number_active_tree_was_fresh_);
+  state->SetInteger(
+      "last_begin_frame_sequence_number_compositor_frame_was_fresh",
+      last_begin_frame_sequence_number_compositor_frame_was_fresh_);
   state->SetBoolean("funnel: draw_funnel", draw_funnel_);
   state->SetBoolean("funnel: send_begin_main_frame_funnel",
                     send_begin_main_frame_funnel_);
   state->SetInteger("funnel: prepare_tiles_funnel", prepare_tiles_funnel_);
   state->SetBoolean("funnel: invalidate_compositor_frame_sink_funnel",
                     invalidate_compositor_frame_sink_funnel_);
   state->SetInteger("consecutive_checkerboard_animations",
                     consecutive_checkerboard_animations_);
   state->SetInteger("pending_submit_frames_", pending_submit_frames_);
   state->SetInteger("submit_frames_with_current_compositor_frame_sink",
@@ skipping 340 matching lines @@
 
 void SchedulerStateMachine::WillSendBeginMainFrame() {
   DCHECK(!has_pending_tree_ || settings_.main_frame_before_activation_enabled);
   DCHECK(visible_);
   DCHECK(!begin_frame_source_paused_);
   DCHECK(!send_begin_main_frame_funnel_);
   begin_main_frame_state_ = BEGIN_MAIN_FRAME_STATE_SENT;
   needs_begin_main_frame_ = false;
   send_begin_main_frame_funnel_ = true;
   last_frame_number_begin_main_frame_sent_ = current_frame_number_;
+  last_begin_frame_sequence_number_begin_main_frame_sent_ =
+      begin_frame_sequence_number_;
 }
 
 void SchedulerStateMachine::WillCommit(bool commit_has_no_updates) {
   DCHECK(!has_pending_tree_ ||
          (settings_.main_frame_before_activation_enabled &&
           commit_has_no_updates));
   commit_count_++;
   last_commit_had_no_updates_ = commit_has_no_updates;
   begin_main_frame_state_ = BEGIN_MAIN_FRAME_STATE_IDLE;
 
-  if (!commit_has_no_updates) {
-    // Pending tree only exists if commit had updates.
+  if (commit_has_no_updates) {
+    // Pending tree might still exist from prior commit.
+    if (has_pending_tree_) {
+      DCHECK(settings_.main_frame_before_activation_enabled);
+      last_begin_frame_sequence_number_pending_tree_was_fresh_ =
+          last_begin_frame_sequence_number_begin_main_frame_sent_;
+    } else {
+      if (last_begin_frame_sequence_number_compositor_frame_was_fresh_ ==
+          last_begin_frame_sequence_number_active_tree_was_fresh_) {
+        // Assuming that SetNeedsRedraw() is only called at the beginning of
+        // a BeginFrame, we can update the compositor frame freshness.
+        last_begin_frame_sequence_number_compositor_frame_was_fresh_ =
+            last_begin_frame_sequence_number_begin_main_frame_sent_;
+      }
+      last_begin_frame_sequence_number_active_tree_was_fresh_ =
+          last_begin_frame_sequence_number_begin_main_frame_sent_;
+    }
+  } else {
+    // We have a new pending tree.
     has_pending_tree_ = true;
     pending_tree_is_ready_for_activation_ = false;
+    last_begin_frame_sequence_number_pending_tree_was_fresh_ =
+        last_begin_frame_sequence_number_begin_main_frame_sent_;
     wait_for_ready_to_draw_ = settings_.commit_to_active_tree;
   }
 
   // Update state related to forced draws.
   if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_COMMIT) {
     forced_redraw_state_ = has_pending_tree_
                                ? FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION
                                : FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
   }
 
@@ skipping 11 matching lines @@
       COMPOSITOR_FRAME_SINK_WAITING_FOR_FIRST_ACTIVATION)
     compositor_frame_sink_state_ = COMPOSITOR_FRAME_SINK_ACTIVE;
 
   if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION)
     forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
 
   has_pending_tree_ = false;
   pending_tree_is_ready_for_activation_ = false;
   active_tree_needs_first_draw_ = true;
   needs_redraw_ = true;
+  last_begin_frame_sequence_number_active_tree_was_fresh_ =
+      last_begin_frame_sequence_number_pending_tree_was_fresh_;
 }
 
 void SchedulerStateMachine::WillDrawInternal() {
   // If a new active tree is pending after the one we are about to draw,
   // the main thread is in a high latency mode.
   // main_thread_missed_last_deadline_ is here in addition to
   // OnBeginImplFrameIdle for cases where the scheduler aborts draws outside
   // of the deadline.
   main_thread_missed_last_deadline_ = CommitPending() || has_pending_tree_;
 
@@ skipping 14 matching lines @@
   switch (draw_result) {
     case INVALID_RESULT:
     case DRAW_ABORTED_CANT_DRAW:
     case DRAW_ABORTED_CONTEXT_LOST:
       NOTREACHED() << "Invalid return DrawResult:" << draw_result;
       break;
     case DRAW_ABORTED_DRAINING_PIPELINE:
     case DRAW_SUCCESS:
       consecutive_checkerboard_animations_ = 0;
       forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
+      // The draw either didn't have damage or had damage and submitted a

[Eric Seckler, 2017/02/17 00:07:27]

To cover successful draws with and without damages, I moved the update of
compositor frame freshness from DidSubmitCompositorFrame into DidDraw:

Brian mentioned that successful draw doesn't always produce a CompositorFrame.
If a successful draw produces no damage, then no CompositorFrame will be
submitted. On the other hand, judging by ProxyImpl::DrawInternal /
SingleThreadProxy::DoComposite, when SchedulerStateMachine::DidDraw() is called,
DidSubmitCompositorFrame() would have already been called if the draw was
successful and produced damages.

[brianderson, 2017/02/22 23:27:05]

Glad we found that!

+      // CompositorFrame. In either case, the compositor frame freshness should
+      // be updated to match the active tree.
+      last_begin_frame_sequence_number_compositor_frame_was_fresh_ =
+          last_begin_frame_sequence_number_active_tree_was_fresh_;
       break;
     case DRAW_ABORTED_CHECKERBOARD_ANIMATIONS:
       DCHECK(!did_submit_in_last_frame_);
       needs_begin_main_frame_ = true;
       needs_redraw_ = true;
       consecutive_checkerboard_animations_++;
 
       if (consecutive_checkerboard_animations_ >=
               settings_.maximum_number_of_failed_draws_before_draw_is_forced &&
           forced_redraw_state_ == FORCED_REDRAW_STATE_IDLE &&
@@ skipping 142 matching lines @@
     return true;
 
   // If the last commit was aborted because of early out (no updates), we should
   // still want a begin frame in case there is a commit coming again.
   if (last_commit_had_no_updates_)
     return true;
 
   return false;
 }
 
-void SchedulerStateMachine::OnBeginImplFrame() {
+void SchedulerStateMachine::OnBeginFrameDroppedNotObserving(
+    uint32_t source_id,
+    uint64_t sequence_number) {
+  DCHECK(!BeginFrameNeeded());
+  DCHECK_EQ(BEGIN_IMPL_FRAME_STATE_IDLE, begin_impl_frame_state_);
+
+  // Confirms the dropped BeginFrame, since we don't have updates.
+  UpdateBeginFrameSequenceNumbersForBeginFrame(source_id, sequence_number);
+  UpdateBeginFrameSequenceNumbersForBeginFrameDeadline();
+}
+
+void SchedulerStateMachine::UpdateBeginFrameSequenceNumbersForBeginFrame(
+    uint32_t source_id,
+    uint64_t sequence_number) {
+  if (source_id != begin_frame_source_id_) {
+    begin_frame_source_id_ = source_id;
+    begin_frame_sequence_number_ = sequence_number;
+
+    // Reset freshness sequence numbers.
+    last_begin_frame_sequence_number_begin_main_frame_sent_ =
+        BeginFrameArgs::kInvalidFrameNumber;
+    last_begin_frame_sequence_number_active_tree_was_fresh_ =
+        BeginFrameArgs::kInvalidFrameNumber;
+    last_begin_frame_sequence_number_pending_tree_was_fresh_ =
+        BeginFrameArgs::kInvalidFrameNumber;
+    last_begin_frame_sequence_number_compositor_frame_was_fresh_ =
+        BeginFrameArgs::kInvalidFrameNumber;
+  } else {
+    DCHECK_GT(sequence_number, begin_frame_sequence_number_);
+    begin_frame_sequence_number_ = sequence_number;
+  }
+}
+
+void SchedulerStateMachine::
+    UpdateBeginFrameSequenceNumbersForBeginFrameDeadline() {
+  // Update frame numbers for freshness in case no updates were necessary.
+  if (begin_main_frame_state_ != BEGIN_MAIN_FRAME_STATE_IDLE ||
+      needs_begin_main_frame_) {
+    return;
+  }
+
+  if (has_pending_tree_) {
+    last_begin_frame_sequence_number_pending_tree_was_fresh_ =
+        begin_frame_sequence_number_;
+    return;
+  }
+
+  last_begin_frame_sequence_number_active_tree_was_fresh_ =
+      begin_frame_sequence_number_;
+
+  if (!needs_redraw_)

[brianderson, 2017/02/22 23:27:05]

{}

+    last_begin_frame_sequence_number_compositor_frame_was_fresh_ =
+        begin_frame_sequence_number_;
+}
+
+void SchedulerStateMachine::OnBeginImplFrame(uint32_t source_id,
+                                             uint64_t sequence_number) {
+  UpdateBeginFrameSequenceNumbersForBeginFrame(source_id, sequence_number);
+
   begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME;
   current_frame_number_++;
 
   last_commit_had_no_updates_ = false;
   did_draw_in_last_frame_ = false;
   did_submit_in_last_frame_ = false;
   needs_one_begin_impl_frame_ = false;
 
   // Clear funnels for any actions we perform during the frame.
   send_begin_main_frame_funnel_ = false;
   invalidate_compositor_frame_sink_funnel_ = false;
 
   // "Drain" the PrepareTiles funnel.
   if (prepare_tiles_funnel_ > 0)
     prepare_tiles_funnel_--;
 }
 
 void SchedulerStateMachine::OnBeginImplFrameDeadline() {
   begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE;
 
   // Clear funnels for any actions we perform during the deadline.
   draw_funnel_ = false;
 
   // Allow one PrepareTiles per draw for synchronous compositor.
   if (settings_.using_synchronous_renderer_compositor) {
     if (prepare_tiles_funnel_ > 0)
       prepare_tiles_funnel_--;
   }
+
+  UpdateBeginFrameSequenceNumbersForBeginFrameDeadline();
 }
 
 void SchedulerStateMachine::OnBeginImplFrameIdle() {
   begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_IDLE;
 
   skip_next_begin_main_frame_to_reduce_latency_ = false;
 
   // If a new or undrawn active tree is pending after the deadline,
   // then the main thread is in a high latency mode.
   main_thread_missed_last_deadline_ =
@@ skipping 246 matching lines @@
     case COMPOSITOR_FRAME_SINK_ACTIVE:
     case COMPOSITOR_FRAME_SINK_WAITING_FOR_FIRST_COMMIT:
     case COMPOSITOR_FRAME_SINK_WAITING_FOR_FIRST_ACTIVATION:
       return true;
   }
   NOTREACHED();
   return false;
 }
 
 }  // namespace cc