Track when QUIC connections are application limited. Protected by quic_enable_app_limited_check.

net/quic/core/quic_session_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_session.h"
 
 #include <set>
 #include <utility>
 
 #include "base/rand_util.h"
@@ skipping 474 matching lines @@
   EXPECT_CALL(*stream2, OnCanWrite())
       .WillOnce(DoAll(testing::IgnoreResult(Invoke(CreateFunctor(
                           &TestSession::SendLargeFakeData,
                           base::Unretained(&session_), stream2, 6000))),
                       Invoke(&stream2_blocker,
                              &StreamBlocker::MarkConnectionLevelWriteBlocked)));
   session_.OnCanWrite();
 }
 
 TEST_P(QuicSessionTestServer, OnCanWriteBundlesStreams) {
+  FLAGS_quic_enable_app_limited_check = true;
+
   // Encryption needs to be established before data can be sent.
   CryptoHandshakeMessage msg;
   session_.GetCryptoStream()->OnHandshakeMessage(msg);
 
   // Drive congestion control manually.
   MockSendAlgorithm* send_algorithm = new StrictMock<MockSendAlgorithm>;
   QuicConnectionPeer::SetSendAlgorithm(session_.connection(), kDefaultPathId,
                                        send_algorithm);
 
   TestStream* stream2 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
@@ skipping 21 matching lines @@
           Invoke(CreateFunctor(&TestSession::SendStreamData,
                                base::Unretained(&session_), stream6))));
 
   // Expect that we only send one packet, the writes from different streams
   // should be bundled together.
   MockPacketWriter* writer = static_cast<MockPacketWriter*>(
       QuicConnectionPeer::GetWriter(session_.connection()));
   EXPECT_CALL(*writer, WritePacket(_, _, _, _, _))
       .WillOnce(Return(WriteResult(WRITE_STATUS_OK, 0)));
   EXPECT_CALL(*send_algorithm, OnPacketSent(_, _, _, _, _));
+  EXPECT_CALL(*send_algorithm, OnApplicationLimited(_));
   session_.OnCanWrite();
   EXPECT_FALSE(session_.WillingAndAbleToWrite());
 }
 
 TEST_P(QuicSessionTestServer, OnCanWriteCongestionControlBlocks) {
+  FLAGS_quic_enable_app_limited_check = true;
+
   InSequence s;
 
   // Drive congestion control manually.
   MockSendAlgorithm* send_algorithm = new StrictMock<MockSendAlgorithm>;
   QuicConnectionPeer::SetSendAlgorithm(session_.connection(), kDefaultPathId,
                                        send_algorithm);
 
   TestStream* stream2 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
   TestStream* stream4 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
   TestStream* stream6 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
@@ skipping 20 matching lines @@
   EXPECT_CALL(*send_algorithm, TimeUntilSend(_, _))
       .WillOnce(Return(QuicTime::Delta::Infinite()));
   session_.OnCanWrite();
   EXPECT_TRUE(session_.WillingAndAbleToWrite());
 
   // stream4->OnCanWrite is called once the connection stops being
   // congestion-control blocked.
   EXPECT_CALL(*send_algorithm, TimeUntilSend(_, _))
       .WillOnce(Return(QuicTime::Delta::Zero()));
   EXPECT_CALL(*stream4, OnCanWrite());
+  EXPECT_CALL(*send_algorithm, OnApplicationLimited(_));
   session_.OnCanWrite();
   EXPECT_FALSE(session_.WillingAndAbleToWrite());
 }
 
+TEST_P(QuicSessionTestServer, OnCanWriteWriterBlocks) {
+  FLAGS_quic_enable_app_limited_check = true;
+
+  // Drive congestion control manually in order to ensure that
+  // application-limited signaling is handled correctly.
+  MockSendAlgorithm* send_algorithm = new StrictMock<MockSendAlgorithm>;
+  QuicConnectionPeer::SetSendAlgorithm(session_.connection(), kDefaultPathId,
+                                       send_algorithm);
+  EXPECT_CALL(*send_algorithm, TimeUntilSend(_, _))
+      .WillRepeatedly(Return(QuicTime::Delta::Zero()));
+
+  // Drive packet writer manually.
+  MockPacketWriter* writer = static_cast<MockPacketWriter*>(
+      QuicConnectionPeer::GetWriter(session_.connection()));
+  EXPECT_CALL(*writer, IsWriteBlocked()).WillRepeatedly(Return(true));
+  EXPECT_CALL(*writer, IsWriteBlockedDataBuffered())
+      .WillRepeatedly(Return(true));
+  EXPECT_CALL(*writer, WritePacket(_, _, _, _, _)).Times(0);
+
+  TestStream* stream2 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
+
+  session_.MarkConnectionLevelWriteBlocked(stream2->id());
+
+  EXPECT_CALL(*stream2, OnCanWrite()).Times(0);
+  EXPECT_CALL(*send_algorithm, OnApplicationLimited(_)).Times(0);
+
+  session_.OnCanWrite();
+  EXPECT_TRUE(session_.WillingAndAbleToWrite());
+}
+
 TEST_P(QuicSessionTestServer, BufferedHandshake) {
   EXPECT_FALSE(session_.HasPendingHandshake());  // Default value.
 
   // Test that blocking other streams does not change our status.
   TestStream* stream2 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
   StreamBlocker stream2_blocker(&session_, stream2->id());
   stream2_blocker.MarkConnectionLevelWriteBlocked();
   EXPECT_FALSE(session_.HasPendingHandshake());
 
   TestStream* stream3 = session_.CreateOutgoingDynamicStream(kDefaultPriority);
@@ skipping 42 matching lines @@
   CloseStream(stream6->id());
 
   InSequence s;
   EXPECT_CALL(*stream2, OnCanWrite());
   EXPECT_CALL(*stream4, OnCanWrite());
   session_.OnCanWrite();
   EXPECT_FALSE(session_.WillingAndAbleToWrite());
 }
 
 TEST_P(QuicSessionTestServer, OnCanWriteLimitsNumWritesIfFlowControlBlocked) {
+  FLAGS_quic_enable_app_limited_check = true;
+
+  // Drive congestion control manually in order to ensure that
+  // application-limited signaling is handled correctly.
+  MockSendAlgorithm* send_algorithm = new StrictMock<MockSendAlgorithm>;
+  QuicConnectionPeer::SetSendAlgorithm(session_.connection(), kDefaultPathId,
+                                       send_algorithm);
+  EXPECT_CALL(*send_algorithm, TimeUntilSend(_, _))
+      .WillRepeatedly(Return(QuicTime::Delta::Zero()));
+
   // Ensure connection level flow control blockage.
   QuicFlowControllerPeer::SetSendWindowOffset(session_.flow_controller(), 0);
   EXPECT_TRUE(session_.flow_controller()->IsBlocked());
   EXPECT_TRUE(session_.IsConnectionFlowControlBlocked());
   EXPECT_FALSE(session_.IsStreamFlowControlBlocked());
 
   // Mark the crypto and headers streams as write blocked, we expect them to be
   // allowed to write later.
   session_.MarkConnectionLevelWriteBlocked(kCryptoStreamId);
   session_.MarkConnectionLevelWriteBlocked(kHeadersStreamId);
 
   // Create a data stream, and although it is write blocked we never expect it
   // to be allowed to write as we are connection level flow control blocked.
   TestStream* stream = session_.CreateOutgoingDynamicStream(kDefaultPriority);
   session_.MarkConnectionLevelWriteBlocked(stream->id());
   EXPECT_CALL(*stream, OnCanWrite()).Times(0);
 
   // The crypto and headers streams should be called even though we are
   // connection flow control blocked.
   TestCryptoStream* crypto_stream = session_.GetCryptoStream();
   EXPECT_CALL(*crypto_stream, OnCanWrite());
   TestHeadersStream* headers_stream = new TestHeadersStream(&session_);
   QuicSpdySessionPeer::SetHeadersStream(&session_, headers_stream);
   EXPECT_CALL(*headers_stream, OnCanWrite());
 
+  // After the crypto and header streams perform a write, the connection will be
+  // blocked by the flow control, hence it should become application-limited.
+  EXPECT_CALL(*send_algorithm, OnApplicationLimited(_));
+
   session_.OnCanWrite();
   EXPECT_FALSE(session_.WillingAndAbleToWrite());
 }
 
 TEST_P(QuicSessionTestServer, SendGoAway) {
   MockPacketWriter* writer = static_cast<MockPacketWriter*>(
       QuicConnectionPeer::GetWriter(session_.connection()));
   EXPECT_CALL(*writer, WritePacket(_, _, _, _, _))
       .WillOnce(Return(WriteResult(WRITE_STATUS_OK, 0)));
   EXPECT_CALL(*connection_, SendGoAway(_, _, _))
@@ skipping 521 matching lines @@
   if (version() <= QUIC_VERSION_35) {
     EXPECT_FALSE(session_.force_hol_blocking());
   } else {
     EXPECT_TRUE(session_.force_hol_blocking());
   }
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net