Notfiy NQE of QUIC RTT

net/quic/quic_connection.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/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 1810 matching lines @@
   visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
 }
 
 void QuicConnection::OnRttChange() {
   // Uses the connection's smoothed RTT. If zero, uses initial_rtt.
   QuicTime::Delta rtt = sent_packet_manager_.GetRttStats()->smoothed_rtt();
   if (rtt.IsZero()) {
     rtt = QuicTime::Delta::FromMicroseconds(
         sent_packet_manager_.GetRttStats()->initial_rtt_us());
   }
+  if (debug_visitor_ != nullptr)

[Ryan Sleevi, 2015/09/18 17:36:45]

if (debug_visitor_)

It's cleaner that way, plus works across all pointer and smart pointer types :)

[tbansal1, 2015/09/18 17:59:59]

Done.

+    debug_visitor_->OnRttChanged(rtt);

[Ryan Sleevi, 2015/09/18 17:36:45]

It doesn't seem like it really makes sense to couple this with the the debug
visitor - this isn't necessarily a debug event. Shouldn't this have a proper
interface from the Quicconnection?

[tbansal1, 2015/09/18 17:59:59]

Not sure what is the right design here. Initially, I had the plumbing in
QuicConnection. rch@ mentioned it is discouraged to have Chromium specific code
in QuicConnection because it needs to be synced with the backend implementation.
wdyt?

[Ryan Hamilton, 2015/09/18 22:01:26]

I think this current approach is correct. The "real" visitor is used to
implement the core QUIC protocol, i.e. things which the QuicSession needs to
implement. The debug visitor is for pulling various metrics out of the
Connection. Some of these metrics may end up having "real" effects, but I'm fine
with this being tied to the debug visitor.

   packet_generator_.OnRttChange(rtt);
 }
 
 void QuicConnection::OnHandshakeComplete() {
   sent_packet_manager_.SetHandshakeConfirmed();
   // The client should immediately ack the SHLO to confirm the handshake is
   // complete with the server.
   if (perspective_ == Perspective::IS_CLIENT && !ack_queued_) {
     ack_alarm_->Cancel();
     ack_alarm_->Set(clock_->ApproximateNow());
@@ skipping 610 matching lines @@
       packet_number_of_last_sent_packet_ + packets_between_mtu_probes_ + 1;
   ++mtu_probe_count_;
 
   DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
   SendMtuDiscoveryPacket(mtu_discovery_target_);
 
   DCHECK(!mtu_discovery_alarm_->IsSet());
 }
 
 }  // namespace net