changes QUIC negotiation about max open streams which effects server

net/quic/quic_session.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_session.h"
 
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "net/quic/crypto/proof_verifier.h"
@@ skipping 15 matching lines @@
 using net::SpdyPriority;
 
 namespace net {
 
 #define ENDPOINT \
   (perspective() == Perspective::IS_SERVER ? "Server: " : " Client: ")
 
 QuicSession::QuicSession(QuicConnection* connection, const QuicConfig& config)
     : connection_(connection),
       config_(config),
-      max_open_streams_(config_.MaxStreamsPerConnection()),
+      max_open_outgoing_streams_(config_.MaxStreamsPerConnection()),
+      max_open_incoming_streams_(config_.MaxStreamsPerConnection()),
       next_outgoing_stream_id_(perspective() == Perspective::IS_SERVER ? 2 : 3),
       largest_peer_created_stream_id_(
           perspective() == Perspective::IS_SERVER ? 1 : 0),
       num_dynamic_incoming_streams_(0),
       num_draining_incoming_streams_(0),
       num_locally_closed_incoming_streams_highest_offset_(0),
       error_(QUIC_NO_ERROR),
       flow_controller_(connection_.get(),
                        0,
                        perspective(),
                        kMinimumFlowControlSendWindow,
                        config_.GetInitialSessionFlowControlWindowToSend(),
                        false),
       currently_writing_stream_id_(0) {}
 
 void QuicSession::Initialize() {
   connection_->set_visitor(this);
   connection_->SetFromConfig(config_);
 
   DCHECK_EQ(kCryptoStreamId, GetCryptoStream()->id());
   static_stream_map_[kCryptoStreamId] = GetCryptoStream();
 }
 
 QuicSession::~QuicSession() {
   STLDeleteElements(&closed_streams_);
   STLDeleteValues(&dynamic_stream_map_);
 
   DLOG_IF(WARNING, num_locally_closed_incoming_streams_highest_offset() >
-                       max_open_streams_)
+                       max_open_incoming_streams_)
       << "Surprisingly high number of locally closed peer initiated streams"
          "still waiting for final byte offset: "
       << num_locally_closed_incoming_streams_highest_offset();
-  DLOG_IF(WARNING,
-          GetNumLocallyClosedOutgoingStreamsHighestOffset() > max_open_streams_)
+  DLOG_IF(WARNING, GetNumLocallyClosedOutgoingStreamsHighestOffset() >
+                       max_open_outgoing_streams_)
       << "Surprisingly high number of locally closed self initiated streams"
          "still waiting for final byte offset: "
       << GetNumLocallyClosedOutgoingStreamsHighestOffset();
 }
 
 void QuicSession::OnStreamFrame(const QuicStreamFrame& frame) {
   // TODO(rch) deal with the error case of stream id 0.
   QuicStreamId stream_id = frame.stream_id;
   ReliableQuicStream* stream = GetStream(stream_id);
   if (!stream) {
@@ skipping 283 matching lines @@
 
 bool QuicSession::IsCryptoHandshakeConfirmed() {
   return GetCryptoStream()->handshake_confirmed();
 }
 
 void QuicSession::OnConfigNegotiated() {
   connection_->SetFromConfig(config_);
 
   uint32_t max_streams = config_.MaxStreamsPerConnection();
   if (perspective() == Perspective::IS_SERVER) {
-    // A server should accept a small number of additional streams beyond the
-    // limit sent to the client. This helps avoid early connection termination
-    // when FIN/RSTs for old streams are lost or arrive out of order.
-    // Use a minimum number of additional streams, or a percentage increase,
-    // whichever is larger.
-    max_streams =
-        max(max_streams + kMaxStreamsMinimumIncrement,
-            static_cast<uint32_t>(max_streams * kMaxStreamsMultiplier));
+    if (!FLAGS_quic_different_max_num_open_streams) {
+      max_streams =
+          max(max_streams + kMaxStreamsMinimumIncrement,
+              static_cast<uint32_t>(max_streams * kMaxStreamsMultiplier));
+    }
 
     if (config_.HasReceivedConnectionOptions()) {
       if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kAFCW)) {
         // The following variations change the initial receive flow control
         // window sizes.
         if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW5)) {
           AdjustInitialFlowControlWindows(32 * 1024);
         }
         if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW6)) {
           AdjustInitialFlowControlWindows(64 * 1024);
         }
         if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW7)) {
           AdjustInitialFlowControlWindows(128 * 1024);
         }
         EnableAutoTuneReceiveWindow();
       }
     }
   }
-  set_max_open_streams(max_streams);
+
+  set_max_open_outgoing_streams(max_streams);
+
+  uint32_t max_incoming_streams = max_streams;
+  if (FLAGS_quic_different_max_num_open_streams) {
+    // A small number of additional incoming streams beyond the limit should be
+    // allowed. This helps avoid early connection termination when FIN/RSTs for
+    // old streams are lost or arrive out of order.
+    // Use a minimum number of additional streams, or a percentage increase,
+    // whichever is larger.
+    max_incoming_streams =
+        max(max_streams + kMaxStreamsMinimumIncrement,
+            static_cast<uint32_t>(max_streams * kMaxStreamsMultiplier));
+  }
+  set_max_open_incoming_streams(max_incoming_streams);
 
   if (config_.HasReceivedInitialStreamFlowControlWindowBytes()) {
     // Streams which were created before the SHLO was received (0-RTT
     // requests) are now informed of the peer's initial flow control window.
     OnNewStreamFlowControlWindow(
         config_.ReceivedInitialStreamFlowControlWindowBytes());
   }
   if (config_.HasReceivedInitialSessionFlowControlWindowBytes()) {
     OnNewSessionFlowControlWindow(
         config_.ReceivedInitialSessionFlowControlWindowBytes());
@@ skipping 191 matching lines @@
     return true;
   }
 
   // Check if the new number of available streams would cause the number of
   // available streams to exceed the limit.  Note that the peer can create
   // only alternately-numbered streams.
   size_t additional_available_streams =
       (stream_id - largest_peer_created_stream_id_) / 2 - 1;
   size_t new_num_available_streams =
       GetNumAvailableStreams() + additional_available_streams;
-  if (new_num_available_streams > get_max_available_streams()) {
+  if (new_num_available_streams > MaxAvailableStreams()) {
     DVLOG(1) << "Failed to create a new incoming stream with id:" << stream_id
              << ".  There are already " << GetNumAvailableStreams()
              << " streams available, which would become "
              << new_num_available_streams << ", which exceeds the limit "
-             << get_max_available_streams() << ".";
+             << MaxAvailableStreams() << ".";
     string details = IntToString(new_num_available_streams) + " above " +
-                     IntToString(get_max_available_streams());
+                     IntToString(MaxAvailableStreams());
     CloseConnectionWithDetails(QUIC_TOO_MANY_AVAILABLE_STREAMS,
                                details.c_str());
     return false;
   }
   for (QuicStreamId id = largest_peer_created_stream_id_ + 2; id < stream_id;
        id += 2) {
     available_streams_.insert(id);
   }
   largest_peer_created_stream_id_ = stream_id;
 
@@ skipping 29 matching lines @@
     return nullptr;
   }
 
   available_streams_.erase(stream_id);
 
   if (!MaybeIncreaseLargestPeerStreamId(stream_id)) {
     return nullptr;
   }
   // Check if the new number of open streams would cause the number of
   // open streams to exceed the limit.
-  size_t num_current_open_streams =
+  size_t num_open_incoming_streams =
       FLAGS_quic_distinguish_incoming_outgoing_streams
           ? GetNumOpenIncomingStreams()
           : dynamic_stream_map_.size() - draining_streams_.size() +
                 locally_closed_streams_highest_offset_.size();
-  if (num_current_open_streams >= get_max_open_streams()) {
+  if (num_open_incoming_streams >= max_open_incoming_streams()) {
     if (connection()->version() <= QUIC_VERSION_27) {
       CloseConnectionWithDetails(QUIC_TOO_MANY_OPEN_STREAMS,
                                  "Old style stream rejection");
     } else {
       // Refuse to open the stream.
       SendRstStream(stream_id, QUIC_REFUSED_STREAM, 0);
     }
     return nullptr;
   }
 
   ReliableQuicStream* stream = CreateIncomingDynamicStream(stream_id);
   if (stream == nullptr) {
     return nullptr;
   }
   ActivateStream(stream);
   return stream;
 }
 
-void QuicSession::set_max_open_streams(size_t max_open_streams) {
-  DVLOG(1) << "Setting max_open_streams_ to " << max_open_streams;
-  DVLOG(1) << "Setting get_max_available_streams() to "
-           << get_max_available_streams();
-  max_open_streams_ = max_open_streams;
+void QuicSession::set_max_open_incoming_streams(
+    size_t max_open_incoming_streams) {
+  DVLOG(1) << "Setting max_open_incoming_streams_ to "
+           << max_open_incoming_streams;
+  max_open_incoming_streams_ = max_open_incoming_streams;
+  DVLOG(1) << "MaxAvailableStreams() became " << MaxAvailableStreams();
+}
+
+void QuicSession::set_max_open_outgoing_streams(
+    size_t max_open_outgoing_streams) {
+  DVLOG(1) << "Setting max_open_outgoing_streams_ to "
+           << max_open_outgoing_streams;
+  max_open_outgoing_streams_ = max_open_outgoing_streams;
 }
 
 bool QuicSession::goaway_sent() const {
   return connection_->goaway_sent();
 }
 
 bool QuicSession::goaway_received() const {
   return connection_->goaway_received();
 }
 
@@ skipping 93 matching lines @@
     }
   }
   for (auto const& kv : dynamic_stream_map_) {
     if (kv.second->flow_controller()->IsBlocked()) {
       return true;
     }
   }
   return false;
 }
 
+size_t QuicSession::MaxAvailableStreams() const {
+  return max_open_incoming_streams_ * kMaxAvailableStreamsMultiplier;
+}
+
 bool QuicSession::IsIncomingStream(QuicStreamId id) const {
   return id % 2 != next_outgoing_stream_id_ % 2;
 }
 
 }  // namespace net