Send PING to check the status of the SPDY connection.

net/spdy/spdy_session.h

Index: net/spdy/spdy_session.h
===================================================================
--- net/spdy/spdy_session.h	(revision 104856)
+++ net/spdy/spdy_session.h	(working copy)
@@ -104,6 +104,9 @@
   // NOTE:  This function can have false negatives on some platforms.
   bool VerifyDomainAuthentication(const std::string& domain);
 
+  // Send the PING frame for |stream_id|.
+  int WritePingFrame(spdy::SpdyStreamId stream_id);
+
   // Send the SYN frame for |stream_id|.
   int WriteSynStream(
       spdy::SpdyStreamId stream_id,
@@ -195,6 +198,14 @@
     return !active_streams_.empty();
   }
 
+  // Returns true if we have received a ping response from server for the ping
+  // message we had sent.
+  bool DidLastPingWork() const {
+    if (sent_ping_)

[willchan no longer on Chromium, 2011/10/12 05:41:06]

This isn't good enough, you're going to need to track multiple pings in flight.

[ramant (doing other things), 2011/10/13 21:41:14]

Done.

+      return received_ping_;
+    return true;
+  }
+
   // Access to the number of active and pending streams.  These are primarily
   // available for testing and diagnostics.
   size_t num_active_streams() const { return active_streams_.size(); }
@@ -271,6 +282,7 @@
                  const linked_ptr<spdy::SpdyHeaderBlock>& headers);
   void OnRst(const spdy::SpdyRstStreamControlFrame& frame);
   void OnGoAway(const spdy::SpdyGoAwayControlFrame& frame);
+  void OnPing(const spdy::SpdyPingControlFrame& frame);
   void OnSettings(const spdy::SpdySettingsControlFrame& frame);
   void OnWindowUpdate(const spdy::SpdyWindowUpdateControlFrame& frame);
 
@@ -431,6 +443,9 @@
                             // frame.
   int stalled_streams_;     // Count of streams that were ever stalled.
 
+  bool sent_ping_;          // Did this session send a ping message.
+  bool received_ping_;      // Did this session receive a ping message.
+
   // Initial send window size for the session; can be changed by an
   // arriving SETTINGS frame; newly created streams use this value for the
   // initial send window size.