Emit session-level WINDOW_UPDATEs less frequently.

net/spdy/spdy_session.h

 // 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.
 
 #ifndef NET_SPDY_SPDY_SESSION_H_
 #define NET_SPDY_SPDY_SESSION_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 227 matching lines @@
   // |session| is the HttpNetworkSession.  |net_log| is the NetLog that we log
   // network events to.
   SpdySession(const SpdySessionKey& spdy_session_key,
               const base::WeakPtr<HttpServerProperties>& http_server_properties,
               TransportSecurityState* transport_security_state,
               bool verify_domain_authentication,
               bool enable_sending_initial_data,
               bool enable_compression,
               bool enable_ping_based_connection_checking,
               NextProto default_protocol,
+              size_t session_max_recv_window_size,
               size_t stream_initial_recv_window_size,
               size_t initial_max_concurrent_streams,
               size_t max_concurrent_streams_limit,
               TimeFunc time_func,
               const HostPortPair& trusted_spdy_proxy,
               NetLog* net_log);
 
   ~SpdySession() override;
 
   const HostPortPair& host_port_pair() const {
@@ skipping 847 matching lines @@
   // Indicate if we have already scheduled a delayed task to check the ping
   // status.
   bool check_ping_status_pending_;
 
   // Whether to send the (HTTP/2) connection header prefix.
   bool send_connection_header_prefix_;
 
   // The (version-dependent) flow control state.
   FlowControlState flow_control_state_;
 
+  // Current send window size.  Zero unless session flow control is turned on.
+  int32 session_send_window_size_;
+
+  // Maximum receive window size.  Each time a WINDOW_UPDATE is sent, it
+  // restores the receive window size to this value.  Zero unless session flow
+  // control is turned on.
+  int32 session_max_recv_window_size_;
+
+  // Sum of |session_unacked_recv_window_bytes_| and current receive window
+  // size.  Zero unless session flow control is turned on.
+  // TODO(bnc): Rename or change semantics so that |window_size_| is actual
+  // window size.
+  int32 session_recv_window_size_;
+
+  // Number of octets that are consumed and thus not stored in a buffer owned by

[Ryan Hamilton, 2015/04/07 14:56:40]

s/octets/bytes/

[Bence, 2015/04/07 20:21:38]

Done.

+  // SpdySession any more, but for which no corresponding WINDOW_UPDATEs have
+  // been sent yet.  Zero unless session flow control is turned on.

[Ryan Hamilton, 2015/04/07 14:56:40]

Can you explain where these bytes are living and how they will eventually be
accounted for? (The SpdyIOBuffer destructor calls back to the SpdySession when
the caller is finished with them. So you can probably paraphrase that)

[Bence, 2015/04/07 20:21:38]

Done.

[Ryan Hamilton, 2015/04/08 03:51:10]

Nice! Looks great.

+  int32 session_unacked_recv_window_bytes_;
+
   // Initial send window size for this session's streams. Can be
   // changed by an arriving SETTINGS frame. Newly created streams use
   // this value for the initial send window size.
   int32 stream_initial_send_window_size_;
 
   // Initial receive window size for this session's streams. There are
   // plans to add a command line switch that would cause a SETTINGS
   // frame with window size announcement to be sent on startup. Newly
   // created streams will use this value for the initial receive
   // window size.
   int32 stream_initial_recv_window_size_;
 
-  // Session flow control variables. All zero unless session flow
-  // control is turned on.
-  int32 session_send_window_size_;
-  int32 session_recv_window_size_;
-  int32 session_unacked_recv_window_bytes_;
-
   // A queue of stream IDs that have been send-stalled at some point
   // in the past.
   std::deque<SpdyStreamId> stream_send_unstall_queue_[NUM_PRIORITIES];
 
   BoundNetLog net_log_;
 
   // Outside of tests, these should always be true.
   bool verify_domain_authentication_;
   bool enable_sending_initial_data_;
   bool enable_compression_;
@@ skipping 34 matching lines @@
   // Used for posting asynchronous IO tasks.  We use this even though
   // SpdySession is refcounted because we don't need to keep the SpdySession
   // alive if the last reference is within a RunnableMethod.  Just revoke the
   // method.
   base::WeakPtrFactory<SpdySession> weak_factory_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_SESSION_H_