// Copyright 2015 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/surfaces/display_scheduler.h"

#include "base/logging.h"
#include "base/test/null_task_runner.h"
#include "base/test/simple_test_tick_clock.h"
#include "base/trace_event/trace_event.h"
#include "cc/output/begin_frame_args.h"
#include "cc/surfaces/display.h"
#include "cc/test/scheduler_test_common.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cc {
namespace {

const int kMaxPendingSwaps = 1;

class FakeDisplaySchedulerClient : public DisplaySchedulerClient {
 public:
  FakeDisplaySchedulerClient() : draw_and_swap_count_(0) {}

  ~FakeDisplaySchedulerClient() override {}

  bool DrawAndSwap() override {
    draw_and_swap_count_++;
    return true;
  }

  void Reset() { draw_and_swap_count_ = 0; }

  int draw_and_swap_count() const { return draw_and_swap_count_; }

 protected:
  int draw_and_swap_count_;
};

class TestDisplayScheduler : public DisplayScheduler {
 public:
  TestDisplayScheduler(DisplaySchedulerClient* client,
                       BeginFrameSource* begin_frame_source,
                       base::SingleThreadTaskRunner* task_runner,
                       int max_pending_swaps)
      : DisplayScheduler(client,
                         begin_frame_source,
                         task_runner,
                         max_pending_swaps),
        scheduler_begin_frame_deadline_count_(0) {}

  base::TimeTicks DesiredBeginFrameDeadlineTimeForTest() {
    return DesiredBeginFrameDeadlineTime();
  }

  void BeginFrameDeadlineForTest() { OnBeginFrameDeadline(); }

  void ScheduleBeginFrameDeadline() override {
    scheduler_begin_frame_deadline_count_++;
    DisplayScheduler::ScheduleBeginFrameDeadline();
  }

  int scheduler_begin_frame_deadline_count() {
    return scheduler_begin_frame_deadline_count_;
  }

 protected:
  int scheduler_begin_frame_deadline_count_;
};

class DisplaySchedulerTest : public testing::Test {
 public:
  DisplaySchedulerTest()
      : now_src_(new base::SimpleTestTickClock()),
        task_runner_(new base::NullTaskRunner),
        client_(new FakeDisplaySchedulerClient),
        scheduler_(new TestDisplayScheduler(client_.get(),
                                            &fake_begin_frame_source_,
                                            task_runner_.get(),
                                            kMaxPendingSwaps)) {
    now_src_->Advance(base::TimeDelta::FromMicroseconds(10000));
  }

  ~DisplaySchedulerTest() override {}

  void SetUp() override { scheduler_->SetRootSurfaceResourcesLocked(false); }

  void BeginFrameForTest() {
    base::TimeTicks frame_time = now_src_->NowTicks();
    base::TimeDelta interval = BeginFrameArgs::DefaultInterval();
    base::TimeTicks deadline = frame_time + interval;
    fake_begin_frame_source_.TestOnBeginFrame(
        BeginFrameArgs::Create(BEGINFRAME_FROM_HERE, frame_time, deadline,
                               interval, BeginFrameArgs::NORMAL));
  }

 protected:
  base::SimpleTestTickClock& now_src() { return *now_src_; }
  FakeDisplaySchedulerClient& client() { return *client_; }
  DisplayScheduler& scheduler() { return *scheduler_; }

  FakeBeginFrameSource fake_begin_frame_source_;

  scoped_ptr<base::SimpleTestTickClock> now_src_;
  scoped_refptr<base::NullTaskRunner> task_runner_;
  scoped_ptr<FakeDisplaySchedulerClient> client_;
  scoped_ptr<TestDisplayScheduler> scheduler_;
};

TEST_F(DisplaySchedulerTest, EntireDisplayDamagedDrawsImmediately) {
  SurfaceId root_surface_id(1);
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->EntireDisplayDamaged(root_surface_id);
  EXPECT_GE(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
}

TEST_F(DisplaySchedulerTest, SurfaceDamaged) {
  SurfaceId root_surface_id(0);
  SurfaceId sid1(1);
  SurfaceId sid2(2);

  // Set the root surface
  scheduler_->EntireDisplayDamaged(root_surface_id);

  // Get scheduler to detect surface 1 as active by drawing
  // two frames in a row with damage from surface 1.
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();

  // Damage only from surface 2 (inactive) does not trigger deadline early.
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid2);
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());

  // Damage from surface 1 triggers deadline early.
  scheduler_->SurfaceDamaged(sid1);
  EXPECT_GE(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->BeginFrameDeadlineForTest();

  // Make both surface 1 and 2 active.
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid2);
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();

  // Deadline doesn't trigger early until surface 1 and 2 are both damaged.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->SurfaceDamaged(sid1);
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->SurfaceDamaged(sid2);
  EXPECT_GE(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->BeginFrameDeadlineForTest();

  // Make the system idle
  BeginFrameForTest();
  scheduler_->BeginFrameDeadlineForTest();
  BeginFrameForTest();
  scheduler_->BeginFrameDeadlineForTest();

  // Deadline should trigger early if child surfaces are idle and
  // we get damage on the root surface.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->SurfaceDamaged(root_surface_id);
  EXPECT_GE(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->BeginFrameDeadlineForTest();
}

TEST_F(DisplaySchedulerTest, OutputSurfaceLost) {
  SurfaceId sid1(1);

  // DrawAndSwap normally.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  EXPECT_EQ(0, client_->draw_and_swap_count());
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(1, client_->draw_and_swap_count());

  // Deadline triggers immediately on OutputSurfaceLost.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->OutputSurfaceLost();
  EXPECT_GE(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());

  // Deadline does not DrawAndSwap after OutputSurfaceLost.
  EXPECT_EQ(1, client_->draw_and_swap_count());
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(1, client_->draw_and_swap_count());
}

TEST_F(DisplaySchedulerTest, RootSurfaceResourcesLocked) {
  SurfaceId sid1(1);
  base::TimeTicks late_deadline;

  // DrawAndSwap normally.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  EXPECT_EQ(0, client_->draw_and_swap_count());
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(1, client_->draw_and_swap_count());

  // Deadline triggers late while root resources are locked.
  late_deadline = now_src().NowTicks() + BeginFrameArgs::DefaultInterval();
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  EXPECT_GT(late_deadline, scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->SetRootSurfaceResourcesLocked(true);
  EXPECT_EQ(late_deadline, scheduler_->DesiredBeginFrameDeadlineTimeForTest());

  // Deadline does not DrawAndSwap while root resources are locked.
  EXPECT_EQ(1, client_->draw_and_swap_count());
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(1, client_->draw_and_swap_count());

  //  Deadline triggers normally when root resources are unlocked.
  late_deadline = now_src().NowTicks() + BeginFrameArgs::DefaultInterval();
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  EXPECT_EQ(late_deadline, scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  scheduler_->SetRootSurfaceResourcesLocked(false);
  EXPECT_EQ(base::TimeTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());

  EXPECT_EQ(1, client_->draw_and_swap_count());
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(2, client_->draw_and_swap_count());
}

TEST_F(DisplaySchedulerTest, DidSwapBuffers) {
  SurfaceId sid1(1);
  SurfaceId sid2(2);

  // Get scheduler to detect surface 1 and 2 as active.
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->SurfaceDamaged(sid2);
  scheduler_->BeginFrameDeadlineForTest();
  BeginFrameForTest();
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->SurfaceDamaged(sid2);
  scheduler_->BeginFrameDeadlineForTest();

  // DrawAndSwap normally.
  BeginFrameForTest();
  EXPECT_LT(now_src().NowTicks(),
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  EXPECT_EQ(2, client_->draw_and_swap_count());
  scheduler_->SurfaceDamaged(sid1);
  scheduler_->SurfaceDamaged(sid2);
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(3, client_->draw_and_swap_count());
  scheduler_->DidSwapBuffers();

  // Deadline triggers late when swap throttled.
  base::TimeTicks late_deadline =
      now_src().NowTicks() + BeginFrameArgs::DefaultInterval();
  BeginFrameForTest();
  // Damage surface 1, but not surface 2 so we avoid triggering deadline
  // early because all surfaces are ready.
  scheduler_->SurfaceDamaged(sid1);
  EXPECT_EQ(late_deadline, scheduler_->DesiredBeginFrameDeadlineTimeForTest());

  // Don't draw and swap in deadline while swap throttled.
  EXPECT_EQ(3, client_->draw_and_swap_count());
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(3, client_->draw_and_swap_count());

  // Deadline triggers normally once not swap throttled.
  // Damage from previous BeginFrame should cary over, so don't damage again.
  base::TimeTicks expected_deadline =
      fake_begin_frame_source_.TestLastUsedBeginFrameArgs().deadline -
      BeginFrameArgs::DefaultEstimatedParentDrawTime();
  scheduler_->DidSwapBuffersComplete();
  BeginFrameForTest();
  EXPECT_EQ(expected_deadline,
            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
  // Still waiting for surface 2. Once it updates, deadline should trigger
  // immediately again.
  scheduler_->SurfaceDamaged(sid2);
  EXPECT_EQ(scheduler_->DesiredBeginFrameDeadlineTimeForTest(),
            base::TimeTicks());
  // Draw and swap now that we aren't throttled.
  EXPECT_EQ(3, client_->draw_and_swap_count());
  scheduler_->BeginFrameDeadlineForTest();
  EXPECT_EQ(4, client_->draw_and_swap_count());
}

// This test verfies that we try to reschedule the deadline
// after any event that may change what deadline we want.
TEST_F(DisplaySchedulerTest, ScheduleBeginFrameDeadline) {
  SurfaceId root_surface_id(1);
  SurfaceId sid1(2);
  int count = 1;
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  BeginFrameForTest();
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->BeginFrameDeadlineForTest();
  scheduler_->DidSwapBuffers();
  BeginFrameForTest();
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->DidSwapBuffersComplete();
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->EntireDisplayDamaged(root_surface_id);
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->SurfaceDamaged(sid1);
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->SetRootSurfaceResourcesLocked(true);
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());

  scheduler_->OutputSurfaceLost();
  EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
}

}  // namespace
}  // namespace cc