Track the RTT via histograms for PING messages sent from client.

BUG=100651
R=jar,willchan
TEST=network unittests

Review URL: http://codereview.chromium.org/8333008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106020 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 18 insertions, 0 deletions

diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 62db0f7..bc8a100 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -1386,6 +1386,10 @@ void SpdySession::OnPing(const spdy::SpdyPingControlFrame& frame) {
   if (pings_in_flight_ > 0)
     return;
 
+  // We will record RTT in histogram when there are no more client sent
+  // pings_in_flight_.
+  RecordPingRTTHistogram(base::TimeTicks::Now() - last_ping_sent_time_);
+
   if (!need_to_send_ping_)
     return;
 
@@ -1584,6 +1588,7 @@ void SpdySession::WritePingFrame(uint32 unique_id) {
     ++pings_in_flight_;
     need_to_send_ping_ = false;
     PlanToCheckPingStatus();
+    last_ping_sent_time_ = base::TimeTicks::Now();
   }
 }
 
@@ -1616,6 +1621,10 @@ void SpdySession::CheckPingStatus(base::TimeTicks last_check_time) {
 
   if (delay.InMilliseconds() < 0 || received_data_time_ < last_check_time) {
     CloseSessionOnError(net::ERR_SPDY_PING_FAILED, true);
+    // Track all failed PING messages in a separate bucket.
+    const base::TimeDelta kFailedPing =
+        base::TimeDelta::FromInternalValue(INT_MAX);
+    RecordPingRTTHistogram(kFailedPing);
     return;
   }
 
@@ -1626,6 +1635,10 @@ void SpdySession::CheckPingStatus(base::TimeTicks last_check_time) {
       delay.InMilliseconds());
 }
 
+void SpdySession::RecordPingRTTHistogram(base::TimeDelta duration) {
+  UMA_HISTOGRAM_TIMES("Net.SpdyPing.RTT", duration);
+}
+
 void SpdySession::RecordHistograms() {
   UMA_HISTOGRAM_CUSTOM_COUNTS("Net.SpdyStreamsPerSession",
                               streams_initiated_count_,
diff --git a/net/spdy/spdy_session.h b/net/spdy/spdy_session.h
index ac92b5e..e1bdd69 100644
--- a/net/spdy/spdy_session.h
+++ b/net/spdy/spdy_session.h
@@ -363,6 +363,8 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   bool Respond(const spdy::SpdyHeaderBlock& headers,
                const scoped_refptr<SpdyStream> stream);
 
+
+  void RecordPingRTTHistogram(base::TimeDelta duration);
   void RecordHistograms();
 
   // Closes all streams.  Used as part of shutdown.
@@ -514,6 +516,9 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // This is the next ping_id (unique_id) to be sent in PING frame.
   uint32 next_ping_id_;
 
+  // This is the last time we have sent a PING.
+  base::TimeTicks last_ping_sent_time_;
+
   // This is the last time we have received data.
   base::TimeTicks received_data_time_;