QUIC - disable QUIC if packet loss rate is bad for a connection.

net/quic/quic_stream_factory.h

Index: net/quic/quic_stream_factory.h
diff --git a/net/quic/quic_stream_factory.h b/net/quic/quic_stream_factory.h
index c55059002be1edb4185c311b53eb601d59f0a3b4..1c310f287e8d5f231f192777be9c562a543f5657 100644
--- a/net/quic/quic_stream_factory.h
+++ b/net/quic/quic_stream_factory.h
@@ -108,6 +108,8 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
       bool enable_connection_racing,
       bool enable_non_blocking_io,
       bool disable_disk_cache,
+      int max_number_of_lossy_connections,
+      float packet_loss_threshold,
       int socket_receive_buffer_size,
       const QuicTagVector& connection_options);
   ~QuicStreamFactory() override;
@@ -124,6 +126,18 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
              const BoundNetLog& net_log,
              QuicStreamRequest* request);
 
+  // Returns false if |packet_loss_rate| is less than |packet_loss_threshold_|
+  // otherwise it returns true and closes the session and marks QUIC as recently
+  // broken for the given |server_id|. Increments |number_of_lossy_connections_|
+  // for the server_id's port.
+  bool OnBadPacketLoss(QuicClientSession* session,
+                       const QuicServerId& server_id,

[Ryan Hamilton, 2015/03/24 03:43:00]

I think |session| has a server_id() method so perhaps you can drop the
|server_id| argument.

[ramant (doing other things), 2015/03/24 17:19:24]

Done.

+                       float packet_loss_rate);
+
+  // Returns true if the |number_of_lossy_connections_| for the given port is
+  // greater than |max_number_of_lossy_connections_|.

[Ryan Hamilton, 2015/03/24 03:43:00]

I think I would simply say
  // Returns true if QUIC is disabled for this port.
Typically it's best to document the interface here, and the implementation in
the method in the .cc file if it needs to be documented.

[ramant (doing other things), 2015/03/24 17:19:23]

Done.

+  bool IsQuicDisabled(uint16 port);
+
   // Called by a session when it becomes idle.
   void OnIdleSession(QuicClientSession* session);
 
@@ -327,6 +341,12 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
   // Set if we do not want to load server config from the disk cache.
   bool disable_disk_cache_;
 
+  // Set if we want to disable QUIC when there is high packet loss rate.
+  int max_number_of_lossy_connections_;
+  float packet_loss_threshold_;
+  // Count number of lossy connections by port.
+  std::map<uint16, int> number_of_lossy_connections_;
+
   // Size of the UDP receive buffer.
   int socket_receive_buffer_size_;