cc: Use BeginFrameArgs

cc/scheduler/scheduler.cc

Index: cc/scheduler/scheduler.cc
diff --git a/cc/scheduler/scheduler.cc b/cc/scheduler/scheduler.cc
index 8329e8e9601b823f1293d842f7e55ed4fe7a40fe..c5fa211a0d6e213fb8c76583805f978d6c3edf9c 100644
--- a/cc/scheduler/scheduler.cc
+++ b/cc/scheduler/scheduler.cc
@@ -4,6 +4,8 @@
 
 #include "cc/scheduler/scheduler.h"
 
+#include "base/strings/stringprintf.h"
+#include <algorithm>
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ -43,9 +45,12 @@ void Scheduler::SetCanDraw(bool can_draw) {
   ProcessScheduledActions();
 }
 
-void Scheduler::SetHasPendingTree(bool has_pending_tree) {
-  state_machine_.SetHasPendingTree(has_pending_tree);
+void Scheduler::SetHasTrees(bool has_pending_tree, bool active_tree_is_null) {
+  state_machine_.SetHasTrees(has_pending_tree, active_tree_is_null);
   ProcessScheduledActions();
+
+  if (state_machine_.ShouldTriggerBeginFrameDeadlineEarly())
+    PostBeginFrameDeadline(base::TimeTicks());
 }
 
 void Scheduler::SetNeedsCommit() {
@@ -83,6 +88,9 @@ void Scheduler::FinishCommit() {
   TRACE_EVENT0("cc", "Scheduler::FinishCommit");
   state_machine_.FinishCommit();
   ProcessScheduledActions();
+
+  if (state_machine_.ShouldTriggerBeginFrameDeadlineEarly())
+    PostBeginFrameDeadline(base::TimeTicks());
 }
 
 void Scheduler::BeginFrameAbortedByMainThread() {
@@ -113,12 +121,11 @@ base::TimeTicks Scheduler::AnticipatedDrawTime() {
       last_begin_frame_args_.interval <= base::TimeDelta())
     return base::TimeTicks();
 
-  // TODO(brianderson): Express this in terms of the deadline.
   base::TimeTicks now = base::TimeTicks::Now();
-  int64 intervals = 1 + ((now - last_begin_frame_args_.frame_time) /
-                         last_begin_frame_args_.interval);
-  return last_begin_frame_args_.frame_time +
-      (last_begin_frame_args_.interval * intervals);
+  base::TimeTicks timebase = std::max(last_begin_frame_args_.frame_time,
+                                      last_begin_frame_args_.deadline);
+  int64 intervals = 1 + ((now - timebase) / last_begin_frame_args_.interval);
+  return timebase + (last_begin_frame_args_.interval * intervals);
 }
 
 base::TimeTicks Scheduler::LastBeginFrameOnImplThreadTime() {
@@ -128,51 +135,74 @@ base::TimeTicks Scheduler::LastBeginFrameOnImplThreadTime() {
 void Scheduler::SetupNextBeginFrameIfNeeded() {
   bool needs_begin_frame_to_draw =
       state_machine_.BeginFrameNeededToDrawByImplThread();
-  // We want to avoid proactive begin frames with the synchronous compositor
-  // because every SetNeedsBeginFrame will force a redraw.
   bool proactive_begin_frame_wanted =
-      state_machine_.ProactiveBeginFrameWantedByImplThread() &&
-      !settings_.using_synchronous_renderer_compositor;
+      state_machine_.ProactiveBeginFrameWantedByImplThread();
+
+  // We want to avoid proactive begin frames with the synchronous
+  // compositor because every SetNeedsBeginFrame will force a redraw.s
   bool needs_begin_frame = needs_begin_frame_to_draw ||
                            proactive_begin_frame_wanted;
-  bool immediate_disables_needed =
-      settings_.using_synchronous_renderer_compositor;
+
+  bool should_call_set_needs_begin_frame =
+      // The synchronous renderer compositor needs immediate enables/disables.
+      (settings_.using_synchronous_renderer_compositor &&
+       needs_begin_frame != last_set_needs_begin_frame_) ||
+      // Always request the BeginFrame immediately if it wasn't needed before.
+      (needs_begin_frame && !last_set_needs_begin_frame_) ||
+      // Only disable the BeginFrame after a BeginFrame where we didn't swap.
+      (!needs_begin_frame && last_set_needs_begin_frame_ &&
+       has_pending_begin_frame_ && !state_machine_.InsideBeginFrame()) ||
+      // We did not draw and swap this BeginFrame,
+      // so we need to explicitly request another BeginFrame.
+      (needs_begin_frame && has_pending_begin_frame_ &&
+       state_machine_.InsideBeginFrame());
 
   if (needs_begin_frame_to_draw)
     safe_to_expect_begin_frame_ = true;
 
-  // Determine if we need BeginFrame notifications.
-  // If we do, always request the BeginFrame immediately.
-  // If not, only disable on the next BeginFrame to avoid unnecessary toggles.
-  // The synchronous renderer compositor requires immediate disables though.
-  if ((needs_begin_frame ||
-       state_machine_.inside_begin_frame() ||
-       immediate_disables_needed) &&
-      (needs_begin_frame != last_set_needs_begin_frame_)) {
+  if (should_call_set_needs_begin_frame) {
     has_pending_begin_frame_ = false;
     client_->SetNeedsBeginFrameOnImplThread(needs_begin_frame);
     if (safe_to_expect_begin_frame_)
       last_set_needs_begin_frame_ = needs_begin_frame;
   }
-
-  // Request another BeginFrame if we haven't drawn for now until we have
-  // deadlines implemented.
-  if (state_machine_.inside_begin_frame() && has_pending_begin_frame_) {
-    has_pending_begin_frame_ = false;
-    client_->SetNeedsBeginFrameOnImplThread(true);
-    return;
-  }
 }
 
 void Scheduler::BeginFrame(const BeginFrameArgs& args) {
   TRACE_EVENT0("cc", "Scheduler::BeginFrame");
   DCHECK(!has_pending_begin_frame_);
+  if (has_pending_begin_frame_) {
+    // TODO(brianderson): Fix contention with background ticking.
+    begin_frame_deadline_closure_.Cancel();
+    OnBeginFrameDeadline();
+  }
   has_pending_begin_frame_ = true;
   safe_to_expect_begin_frame_ = true;
   last_begin_frame_args_ = args;
-  state_machine_.DidEnterBeginFrame(args);
+  last_begin_frame_args_.AdjustDeadline(-client_->DrawDurationEstimate());
+  state_machine_.OnBeginFrame(last_begin_frame_args_);
   ProcessScheduledActions();
-  state_machine_.DidLeaveBeginFrame();
+
+  if (state_machine_.ShouldTriggerBeginFrameDeadlineEarly())
+    PostBeginFrameDeadline(base::TimeTicks());
+  else
+    PostBeginFrameDeadline(last_begin_frame_args_.deadline);
+}
+
+void Scheduler::PostBeginFrameDeadline(base::TimeTicks deadline) {
+  begin_frame_deadline_closure_.Cancel();
+  begin_frame_deadline_closure_.Reset(
+      base::Bind(&Scheduler::OnBeginFrameDeadline, weak_factory_.GetWeakPtr()));
+  client_->PostBeginFrameDeadline(
+      begin_frame_deadline_closure_.callback(), deadline);
+}
+
+void Scheduler::OnBeginFrameDeadline() {
+  TRACE_EVENT0("cc", "Scheduler::OnBeginFrameDeadline");
+  begin_frame_deadline_closure_.Cancel();
+  state_machine_.OnBeginFrameDeadline();
+  ProcessScheduledActions();
+  client_->DidFinishBeginFrameOnImplThread();
 }
 
 void Scheduler::DrawAndSwapIfPossible() {
@@ -198,8 +228,16 @@ void Scheduler::ProcessScheduledActions() {
 
   base::AutoReset<bool> mark_inside(&inside_process_scheduled_actions_, true);
 
-  SchedulerStateMachine::Action action = state_machine_.NextAction();
-  while (action != SchedulerStateMachine::ACTION_NONE) {
+  SchedulerStateMachine::Action action;
+  do {
+    std::string str;
+    base::StringAppendF(&str, "SchedulerStateMachine : ticks %s",
+                        state_machine_.ToString().c_str());
+    TRACE_EVENT0("cc", str.c_str());

[Sami, 2013/07/02 10:28:06]

Can we trace strings like this nowadays? I remember some trouble earlier because
the string got free'd before the trace event was written.

[danakj, 2013/07/02 13:24:24]

I believe there are COPY versions of the macros to save the string. 

+
+    //TRACE_EVENT1("cc", "SchedulerStateMachine",

[Sami, 2013/07/02 10:28:06]

We could also uncomment this and put it to the disabled-by-default category as
we do with tree dumps.

+    //             "state", state_machine_.ToString());
+    action = state_machine_.NextAction();
     state_machine_.UpdateState(action);
     switch (action) {
       case SchedulerStateMachine::ACTION_NONE:
@@ -229,8 +267,7 @@ void Scheduler::ProcessScheduledActions() {
         client_->ScheduledActionAcquireLayerTexturesForMainThread();
         break;
     }
-    action = state_machine_.NextAction();
-  }
+  } while (action != SchedulerStateMachine::ACTION_NONE);
 
   SetupNextBeginFrameIfNeeded();
   client_->DidAnticipatedDrawTimeChange(AnticipatedDrawTime());