Implement video frame acknowledgements in the chromoting protocol.

remoting/host/capture_scheduler_unittest.cc

Index: remoting/host/capture_scheduler_unittest.cc
diff --git a/remoting/host/capture_scheduler_unittest.cc b/remoting/host/capture_scheduler_unittest.cc
index 477741a8d1016775726a8ff98a24daffdbecfdea..2cc57e1c398787ae0e207026c6695cb3cba31730 100644
--- a/remoting/host/capture_scheduler_unittest.cc
+++ b/remoting/host/capture_scheduler_unittest.cc
@@ -18,9 +18,10 @@ class CaptureSchedulerTest : public testing::Test {
  public:
   CaptureSchedulerTest() : capture_called_(false) {}
 
-  void InitScheduler() {
+  void InitScheduler(bool acks_supported) {
     scheduler_.reset(new CaptureScheduler(
-        base::Bind(&CaptureSchedulerTest::DoCapture, base::Unretained(this))));
+        base::Bind(&CaptureSchedulerTest::DoCapture, base::Unretained(this)),
+        acks_supported));
     scheduler_->set_minimum_interval(
         base::TimeDelta::FromMilliseconds(kMinumumFrameIntervalMs));
     tick_clock_ = new base::SimpleTestTickClock();
@@ -49,6 +50,7 @@ class CaptureSchedulerTest : public testing::Test {
     scheduler_->OnCaptureCompleted();
     scheduler_->OnFrameEncoded(encode_delay);
     scheduler_->OnFrameSent();
+    scheduler_->OnFrameAck();
 
     EXPECT_TRUE(capture_timer_->IsRunning());
     EXPECT_EQ(std::max(base::TimeDelta(),
@@ -78,7 +80,7 @@ TEST_F(CaptureSchedulerTest, SingleSampleSameTimes) {
 
   for (size_t i = 0; i < arraysize(kTestResults); ++i) {
     for (size_t j = 0; j < arraysize(kTestInputs); ++j) {
-      InitScheduler();
+      InitScheduler(true);
       scheduler_->set_num_of_processors_for_tests(1 << i);
 
       SimulateSingleFrameCapture(
@@ -99,7 +101,7 @@ TEST_F(CaptureSchedulerTest, SingleSampleDifferentTimes) {
 
   for (size_t i = 0; i < arraysize(kTestResults); ++i) {
     for (size_t j = 0; j < arraysize(kTestInputs); ++j) {
-      InitScheduler();
+      InitScheduler(true);
       scheduler_->set_num_of_processors_for_tests(1 << i);
 
       SimulateSingleFrameCapture(
@@ -120,7 +122,7 @@ TEST_F(CaptureSchedulerTest, RollingAverageDifferentTimes) {
   };
 
   for (size_t i = 0; i < arraysize(kTestResults); ++i) {
-    InitScheduler();
+    InitScheduler(true);
     scheduler_->set_num_of_processors_for_tests(1 << i);
     for (size_t j = 0; j < arraysize(kTestInputs); ++j) {
       SimulateSingleFrameCapture(
@@ -132,9 +134,9 @@ TEST_F(CaptureSchedulerTest, RollingAverageDifferentTimes) {
   }
 }
 
-// Verify that we never have more than 2 pending frames.
-TEST_F(CaptureSchedulerTest, MaximumPendingFrames) {
-  InitScheduler();
+// Verify that we never have more than 2 encoding frames.
+TEST_F(CaptureSchedulerTest, MaximumEncodingFrames) {
+  InitScheduler(true);
 
   capture_timer_->Fire();
   CheckCaptureCalled();
@@ -145,11 +147,52 @@ TEST_F(CaptureSchedulerTest, MaximumPendingFrames) {
   scheduler_->OnCaptureCompleted();
 
   EXPECT_FALSE(capture_timer_->IsRunning());
+  scheduler_->OnFrameEncoded(base::TimeDelta());
+  EXPECT_TRUE(capture_timer_->IsRunning());
+}
+
+// Verify that the scheduler doesn't exceed maximum number of pending frames.
+TEST_F(CaptureSchedulerTest, MaximumPendingFrames) {
+  InitScheduler(true);
+
+  scheduler_->set_maximum_pending_frames(2);
+
+  capture_timer_->Fire();
+  CheckCaptureCalled();
+  scheduler_->OnCaptureCompleted();
+  scheduler_->OnFrameEncoded(base::TimeDelta());
 
+  capture_timer_->Fire();

[Wez, 2015/02/03 00:54:32]

Should you be checking that the timer is running before firing it?

[Sergey Ulanov, 2015/02/09 19:14:54]

No. MockTimer::Fire() DCHECKs if the timer is not running.

+  CheckCaptureCalled();
+  scheduler_->OnCaptureCompleted();
   scheduler_->OnFrameEncoded(base::TimeDelta());
-  scheduler_->OnFrameSent();
 
+  EXPECT_FALSE(capture_timer_->IsRunning());
+  scheduler_->OnFrameSent();
+  EXPECT_FALSE(capture_timer_->IsRunning());
+  scheduler_->OnFrameAck();
   EXPECT_TRUE(capture_timer_->IsRunning());
 }
 
+// Verify that the scheduler doesn't exceed maximum number of pending frames
+// when acks are not supported.
+TEST_F(CaptureSchedulerTest, MaximumPendingFramesNoAcks) {
+  InitScheduler(false);
+
+  scheduler_->set_maximum_pending_frames(2);
+
+  capture_timer_->Fire();
+  CheckCaptureCalled();
+  scheduler_->OnCaptureCompleted();
+  scheduler_->OnFrameEncoded(base::TimeDelta());
+
+  capture_timer_->Fire();
+  CheckCaptureCalled();
+  scheduler_->OnCaptureCompleted();
+  scheduler_->OnFrameEncoded(base::TimeDelta());
+
+  EXPECT_FALSE(capture_timer_->IsRunning());
+  scheduler_->OnFrameSent();
+  EXPECT_TRUE(capture_timer_->IsRunning());
+}
 }  // namespace remoting