QUIC - disable QUIC under recent pathological connection errors.

net/quic/quic_client_session.h

 // 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.
 //
 // A client specific QuicSession subclass.  This class owns the underlying
 // QuicConnection and QuicConnectionHelper objects.  The connection stores
 // a non-owning pointer to the helper so this session needs to ensure that
 // the helper outlives the connection.
 
 #ifndef NET_QUIC_QUIC_CLIENT_SESSION_H_
@@ skipping 26 matching lines @@
 class SSLInfo;
 class TransportSecurityState;
 
 namespace test {
 class QuicClientSessionPeer;
 }  // namespace test
 
 class NET_EXPORT_PRIVATE QuicClientSession : public QuicClientSessionBase,
                                              public QuicPacketReader::Visitor {
  public:
+  // Reasons we may disable QUIC, that is under certain pathological

[Ryan Hamilton, 2015/07/07 03:09:37]

nit: Please don't use the first person in comments.

[Buck, 2015/07/07 18:38:48]

Done.

+  // connection errors.  Note: these values must be kept in sync with
+  // the corresponding values of QuicDisabledReason in:
+  // tools/metrics/histograms/histograms.xml
+  enum QuicDisabledReason {
+    QUIC_DISABLED_NOT = 0,  // default, not disabled
+    QUIC_DISABLED_PUBLIC_RESET_POST_HANDSHAKE = 1,
+    QUIC_DISABLED_TIMEOUT_WITH_OPEN_STREAMS = 2,
+    QUIC_DISABLED_BAD_PACKET_LOSS_RATE = 3,
+    QUIC_DISABLED_MAX = 4,
+  };
+
   // An interface for observing events on a session.
   class NET_EXPORT_PRIVATE Observer {
    public:
     virtual ~Observer() {}
     virtual void OnCryptoHandshakeConfirmed() = 0;
     virtual void OnSessionClosed(int error) = 0;
   };
 
   // A helper class used to manage a request to create a stream.
   class NET_EXPORT_PRIVATE StreamRequest {
@@ skipping 130 matching lines @@
   // than the number of round-trips needed for the handshake.
   int GetNumSentClientHellos() const;
 
   // Returns true if |hostname| may be pooled onto this session.  If this
   // is a secure QUIC session, then |hostname| must match the certificate
   // presented during the handshake.
   bool CanPool(const std::string& hostname, PrivacyMode privacy_mode) const;
 
   const QuicServerId& server_id() const { return server_id_; }
 
+  const QuicDisabledReason disabled_reason() const { return disabled_reason_; }

[Alexei Svitkine (slow), 2015/07/07 15:15:29]

Nit: No need for leading const.

[Buck, 2015/07/07 18:38:48]

Done.

+
  protected:
   // QuicSession methods:
   QuicDataStream* CreateIncomingDynamicStream(QuicStreamId id) override;
 
  private:
   friend class test::QuicClientSessionPeer;
 
   typedef std::set<Observer*> ObserverSet;
   typedef std::list<StreamRequest*> StreamRequestQueue;
 
@@ skipping 47 matching lines @@
   size_t num_total_streams_;
   base::TaskRunner* task_runner_;
   BoundNetLog net_log_;
   QuicPacketReader packet_reader_;
   base::TimeTicks dns_resolution_end_time_;
   base::TimeTicks handshake_start_;  // Time the handshake was started.
   scoped_ptr<QuicConnectionLogger> logger_;
   // True when the session is going away, and streams may no longer be created
   // on this session. Existing stream will continue to be processed.
   bool going_away_;
+  QuicDisabledReason disabled_reason_;
   base::WeakPtrFactory<QuicClientSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicClientSession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CLIENT_SESSION_H_