Quic: add unittests for reduced PING Timeout

net/quic/core/quic_connection_test.cc

 // Copyright (c) 2012 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 "net/quic/core/quic_connection.h"
 
 #include <errno.h>
 #include <memory>
 #include <ostream>
 #include <utility>
@@ skipping 2895 matching lines @@
 
   // Now recevie and ACK of the previous packet, which will move the
   // ping alarm forward.
   clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
   QuicAckFrame frame = InitAckFrame(1);
   EXPECT_CALL(visitor_, OnSuccessfulVersionNegotiation(_));
   EXPECT_CALL(*send_algorithm_, OnCongestionEvent(true, _, _, _));
   ProcessAckPacket(&frame);
   EXPECT_TRUE(connection_.GetPingAlarm()->IsSet());
   // The ping timer is set slightly less than 15 seconds in the future, because
-  // of the 1s ping timer alarm granularity.
+  // of the 1st ping timer alarm granularity.

[Ryan Hamilton, 2016/09/02 21:26:52]

this really mean 1 second, not first.

[Zhongyi Shi, 2016/09/02 21:44:45]

Sorry for misread the code.

   EXPECT_EQ(clock_.ApproximateNow() + QuicTime::Delta::FromSeconds(15) -
                 QuicTime::Delta::FromMilliseconds(5),
             connection_.GetPingAlarm()->deadline());
 
   writer_->Reset();
   clock_.AdvanceTime(QuicTime::Delta::FromSeconds(15));
   connection_.GetPingAlarm()->Fire();
   EXPECT_EQ(1u, writer_->frame_count());
   ASSERT_EQ(1u, writer_->ping_frames().size());
   writer_->Reset();
 
   EXPECT_CALL(visitor_, HasOpenDynamicStreams()).WillRepeatedly(Return(false));
   clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
   SendAckPacketToPeer();
 
   EXPECT_FALSE(connection_.GetPingAlarm()->IsSet());
 }
 
+TEST_P(QuicConnectionTest, ReducedPingTimeout) {
+  EXPECT_TRUE(connection_.connected());
+  EXPECT_CALL(visitor_, HasOpenDynamicStreams()).WillRepeatedly(Return(true));
+  EXPECT_FALSE(connection_.GetPingAlarm()->IsSet());
+
+  // Use a reduced ping timeout for this connection.
+  connection_.set_ping_timeout(QuicTime::Delta::FromSeconds(10));

[Ryan Hamilton, 2016/09/02 21:26:52]

To confirm, this test fails if you comment out this line, right?

[Zhongyi Shi, 2016/09/02 21:44:45]

Yes! I just ran the test with this setter commented and it fails. 

+
+  // Advance to 5ms, and send a packet to the peer, which will set
+  // the ping alarm.
+  clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
+  EXPECT_FALSE(connection_.GetRetransmissionAlarm()->IsSet());
+  SendStreamDataToPeer(kHeadersStreamId, "GET /", 0, kFin, nullptr);
+  EXPECT_TRUE(connection_.GetPingAlarm()->IsSet());
+  EXPECT_EQ(clock_.ApproximateNow() + QuicTime::Delta::FromSeconds(10),
+            connection_.GetPingAlarm()->deadline());
+
+  // Now recevie and ACK of the previous packet, which will move the
+  // ping alarm forward.
+  clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
+  QuicAckFrame frame = InitAckFrame(1);
+  EXPECT_CALL(visitor_, OnSuccessfulVersionNegotiation(_));
+  EXPECT_CALL(*send_algorithm_, OnCongestionEvent(true, _, _, _));
+  ProcessAckPacket(&frame);
+  EXPECT_TRUE(connection_.GetPingAlarm()->IsSet());
+  // The ping timer is set slightly less than 10 seconds in the future, because
+  // of the 1st ping timer alarm granularity.
+  EXPECT_EQ(clock_.ApproximateNow() + QuicTime::Delta::FromSeconds(10) -
+                QuicTime::Delta::FromMilliseconds(5),
+            connection_.GetPingAlarm()->deadline());
+
+  writer_->Reset();
+  clock_.AdvanceTime(QuicTime::Delta::FromSeconds(10));
+  connection_.GetPingAlarm()->Fire();
+  EXPECT_EQ(1u, writer_->frame_count());
+  ASSERT_EQ(1u, writer_->ping_frames().size());
+  writer_->Reset();
+
+  EXPECT_CALL(visitor_, HasOpenDynamicStreams()).WillRepeatedly(Return(false));
+  clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(5));
+  SendAckPacketToPeer();
+
+  EXPECT_FALSE(connection_.GetPingAlarm()->IsSet());
+}
+
 // Tests whether sending an MTU discovery packet to peer successfully causes the
 // maximum packet size to increase.
 TEST_P(QuicConnectionTest, SendMtuDiscoveryPacket) {
   EXPECT_TRUE(connection_.connected());
 
   // Send an MTU probe.
   const size_t new_mtu = kDefaultMaxPacketSize + 100;
   QuicByteCount mtu_probe_size;
   EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _))
       .WillOnce(DoAll(SaveArg<3>(&mtu_probe_size), Return(true)));
@@ skipping 2260 matching lines @@
   connection_.SendStreamDataWithString(3, "foo", 0, !kFin, nullptr);
   EXPECT_EQ(1u, writer_->frame_count());
   EXPECT_FALSE(writer_->connection_close_frames().empty());
   // Ack frame is not bundled in connection close packet.
   EXPECT_TRUE(writer_->ack_frames().empty());
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net