QUIC - disable QUIC under recent pathological connection errors.

net/quic/quic_client_session.h

Index: net/quic/quic_client_session.h
diff --git a/net/quic/quic_client_session.h b/net/quic/quic_client_session.h
index 414b9069b105cbdfdbbf5f2927d9857475d2f1f1..4156f6bda18aed3a9640b01045f88c5267cb4b5d 100644
--- a/net/quic/quic_client_session.h
+++ b/net/quic/quic_client_session.h
@@ -41,6 +41,18 @@ namespace test {
 class QuicClientSessionPeer;
 }  // namespace test
 
+// Epitaphs will be used to track the most recent departed sessions,

[Ryan Hamilton, 2015/06/30 18:55:31]

Can you define "epitath" in this context?

[Buck, 2015/07/01 19:06:19]

I've dropped epitaph everywhere, and switched to DisabledReason.

+// to enable certain policies for when to disable QUIC, based on K
+// of N type thresholds.
+// Note: these values must be kept in sync with the corresponding values
+// of QuicDisabledReason in: tools/metrics/histograms/histograms.xml
+enum QuicClientSessionEpitaph {

[Ryan Hamilton, 2015/06/30 18:55:31]

nit: might as well nest this enum inside of QuicClientSession as
QuicClientSession::Epitath.

[Buck, 2015/07/01 19:06:19]

I've moved it (enum QuicDisabledReason) to quic_types.h, as it's referenced from
both QuicClientSession and QuicStreamFactory.

[Ryan Hamilton, 2015/07/06 18:25:41]

quic_types.h is part of the shared code. Since these enums are
chromium-specific, we should probably keep them in chromium-specific code. I
recommend QuicClientSession::DisabledReason or perhaps
QuicStreamFactory::DisabledReason?

[Buck, 2015/07/06 21:39:32]

Ok, QuicClientSession::DisabledReason it is.

+  QUIC_EPITAPH_RIP = 0,

[Ryan Hamilton, 2015/06/30 18:55:31]

What does "RIP" mean in this context? Perhaps add a comment?

[Buck, 2015/07/01 19:06:19]

Corresponding entry in QuicDisabledReason has a comment now.

+  QUIC_EPITAPH_PUBLIC_RESET_POST_HANDSHAKE = 1,
+  QUIC_EPITAPH_TIMEOUT_STREAMS_OPEN = 2,
+  QUIC_EPITAPH_MAX = 3,

[Ryan Hamilton, 2015/06/30 18:55:31]

Could the packet loss code take advantage of this, or does that live up in the
Factory, not down here in the Session?

[Buck, 2015/07/01 19:06:19]

Somewhat.  As per above, I've moved it and also added a
QUIC_DISABLED_BAD_PACKET_LOSS to the revised enum.

+};
+
 class NET_EXPORT_PRIVATE QuicClientSession : public QuicClientSessionBase,
                                              public QuicPacketReader::Visitor {
  public:
@@ -194,6 +206,8 @@ class NET_EXPORT_PRIVATE QuicClientSession : public QuicClientSessionBase,
 
   const QuicServerId& server_id() const { return server_id_; }
 
+  const QuicClientSessionEpitaph epitaph() const { return epitaph_; }
+
  protected:
   // QuicSession methods:
   QuicDataStream* CreateIncomingDynamicStream(QuicStreamId id) override;
@@ -261,6 +275,7 @@ class NET_EXPORT_PRIVATE QuicClientSession : public QuicClientSessionBase,
   // 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_;
+  QuicClientSessionEpitaph epitaph_;
   base::WeakPtrFactory<QuicClientSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicClientSession);