cc: Allow the main thread to cancel commits

cc/scheduler/scheduler_state_machine_unittest.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 "cc/scheduler/scheduler.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
@@ skipping 700 matching lines @@
   // Begin the frame while visible.
   state.UpdateState(
       SchedulerStateMachine::ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_FRAME_IN_PROGRESS,
             state.CommitState());
   EXPECT_FALSE(state.NeedsCommit());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   // Become invisible and abort the main thread's begin frame.
   state.SetVisible(false);
-  state.BeginFrameAbortedByMainThread();
+  state.BeginFrameAbortedByMainThread(false);
 
   // We should now be back in the idle state as if we didn't start a frame at
   // all.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   // Become visible again.
   state.SetVisible(true);
 
-  // We should be beginning a frame now.
+  // Although we have aborted on this frame and haven't cancelled the commit
+  // (i.e. need another), don't send another begin frame yet.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
+  EXPECT_TRUE(state.NeedsCommit());
+
+  // Start a new frame.
+  state.DidEnterBeginFrame(BeginFrameArgs::CreateForTesting());
   EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD,
             state.NextAction());
 
   // Begin the frame.
   state.UpdateState(state.NextAction());
 
   // We should be starting the commit now.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_FRAME_IN_PROGRESS,
             state.CommitState());
 }
 
+TEST(SchedulerStateMachineTest, AbortBeginFrameAndCancelCommit) {
+  SchedulerSettings default_scheduler_settings;
+  StateMachine state(default_scheduler_settings);
+  state.SetCanStart();
+  state.UpdateState(state.NextAction());
+  state.DidCreateAndInitializeOutputSurface();
+  state.SetVisible(true);
+  state.SetCanDraw(true);
+
+  // Get into a begin frame / commit state.
+  state.SetNeedsCommit();
+  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD,
+            state.NextAction());
+  state.UpdateState(
+      SchedulerStateMachine::ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD);
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_FRAME_IN_PROGRESS,
+            state.CommitState());
+  EXPECT_FALSE(state.NeedsCommit());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
+
+  // Abort the commit, cancelling future commits.
+  state.BeginFrameAbortedByMainThread(true);
+
+  // Verify that another commit doesn't start on the same frame.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
+  EXPECT_FALSE(state.NeedsCommit());
+
+  // Start a new frame.
+  state.DidEnterBeginFrame(BeginFrameArgs::CreateForTesting());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
+  state.DidLeaveBeginFrame();
+
+  // Verify another commit doesn't start on another frame either.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
+  EXPECT_FALSE(state.NeedsCommit());
+
+  // Verify another commit can start if requested, though.
+  state.SetNeedsCommit();
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD,
+            state.NextAction());
+}
+
 TEST(SchedulerStateMachineTest, TestFirstContextCreation) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
   state.UpdateState(state.NextAction());
@@ skipping 431 matching lines @@
   state.UpdateState(state.NextAction());
   state.DidDrawIfPossibleCompleted(true);
   state.DidLeaveBeginFrame();
 
   // Should be waiting for the main thread's begin frame.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_FRAME_IN_PROGRESS,
             state.CommitState()) << state.ToString();
 
   // Become invisible and abort the main thread's begin frame.
   state.SetVisible(false);
-  state.BeginFrameAbortedByMainThread();
+  state.BeginFrameAbortedByMainThread(false);
 
   // Should be back in the idle state, but needing a commit.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_TRUE(state.NeedsCommit());
 }
 
 TEST(SchedulerStateMachineTest, ImmediateFinishCommitWhileCantDraw) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
@@ skipping 84 matching lines @@
   EXPECT_TRUE(state.DrawSuspendedUntilCommit());
 
   EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());
 
   state.UpdateState(state.NextAction());
   EXPECT_FALSE(state.DrawSuspendedUntilCommit());
 }
 
 }  // namespace
 }  // namespace cc