Delete a connection only if it has timed out on writing and not receiving for 10 seconds.

webrtc/p2p/base/port.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 783 matching lines @@
       last_ping_sent_(0),
       last_ping_received_(0),
       last_data_received_(0),
       last_ping_response_received_(0),
       recv_rate_tracker_(100u, 10u),
       send_rate_tracker_(100u, 10u),
       sent_packets_discarded_(0),
       sent_packets_total_(0),
       reported_(false),
       state_(STATE_WAITING),
-      receiving_timeout_(WEAK_CONNECTION_RECEIVE_TIMEOUT) {
+      receiving_timeout_(WEAK_CONNECTION_RECEIVE_TIMEOUT),
+      time_created_ms_(rtc::Time()) {
   // All of our connections start in WAITING state.
   // TODO(mallinath) - Start connections from STATE_FROZEN.
   // Wire up to send stun packets
   requests_.SignalSendPacket.connect(this, &Connection::OnSendStunPacket);
   LOG_J(LS_INFO, this) << "Connection created";
 }
 
 Connection::~Connection() {
 }
 
@@ skipping 27 matching lines @@
   return priority;
 }
 
 void Connection::set_write_state(WriteState value) {
   WriteState old_value = write_state_;
   write_state_ = value;
   if (value != old_value) {
     LOG_J(LS_VERBOSE, this) << "set_write_state from: " << old_value << " to "
                             << value;
     SignalStateChange(this);
-    CheckTimeout();
   }
 }
 
 void Connection::set_receiving(bool value) {
   if (value != receiving_) {
     LOG_J(LS_VERBOSE, this) << "set_receiving to " << value;
     receiving_ = value;
     SignalStateChange(this);
-    CheckTimeout();
   }
 }
 
 void Connection::set_state(State state) {
   State old_state = state_;
   state_ = state;
   if (state != old_state) {
     LOG_J(LS_VERBOSE, this) << "set_state";
   }
 }
@@ skipping 120 matching lines @@
   }
 }
 
 void Connection::OnReadyToSend() {
   if (write_state_ == STATE_WRITABLE) {
     SignalReadyToSend(this);
   }
 }
 
 void Connection::Prune() {
-  if (!pruned_) {
+  if (!pruned_ || active()) {
     LOG_J(LS_VERBOSE, this) << "Connection pruned";
     pruned_ = true;
     requests_.Clear();
     set_write_state(STATE_WRITE_TIMEOUT);
   }
 }
 
 void Connection::Destroy() {
   LOG_J(LS_VERBOSE, this) << "Connection destroyed";
   port_->thread()->Post(this, MSG_DELETE);
@@ skipping 69 matching lines @@
                          << now - pings_since_last_response_[0].sent_time
                          << " ms without a response"
                          << ", rtt=" << rtt;
     set_write_state(STATE_WRITE_TIMEOUT);
   }
 
   // Check the receiving state.
   uint32 last_recv_time = last_received();
   bool receiving = now <= last_recv_time + receiving_timeout_;
   set_receiving(receiving);
+  if (dead(now)) {
+    Destroy();
+  }
 }
 
 void Connection::Ping(uint32 now) {
   last_ping_sent_ = now;
   ConnectionRequest *req = new ConnectionRequest(this);
   pings_since_last_response_.push_back(SentPing(req->id(), now));
   LOG_J(LS_VERBOSE, this) << "Sending STUN ping "
                           << ", id=" << rtc::hex_encode(req->id());
   requests_.Send(req);
   state_ = STATE_INPROGRESS;
@@ skipping 10 matching lines @@
   // So if we're not already, become writable. We may be bringing a pruned
   // connection back to life, but if we don't really want it, we can always
   // prune it again.
   set_receiving(true);
   set_write_state(STATE_WRITABLE);
   set_state(STATE_SUCCEEDED);
   pings_since_last_response_.clear();
   last_ping_response_received_ = rtc::Time();
 }
 
+bool Connection::dead(uint32 now) const {
+  if (now < (time_created_ms_ + MIN_CONNECTION_LIFETIME)) {
+    // A connection that hasn't passed its minimum lifetime is still alive.
+    // We do this to prevent connections from being pruned too quickly
+    // during a network change event when two networks would be up
+    // simultaneously but only for a brief period.
+    return false;
+  }
+
+  if (receiving_) {
+    // A connection that is receiving is alive.
+    return false;
+  }
+
+  // A connection is alive until it is inactive.
+  return !active();
+
+  // TODO(honghaiz): Move from using the write state to using the receiving
+  // state with something like the following:
+  // return (now > (last_received() + DEAD_CONNECTION_RECEIVE_TIMEOUT));
+}
+
 std::string Connection::ToDebugId() const {
   std::stringstream ss;
   ss << std::hex << this;
   return ss.str();
 }
 
 std::string Connection::ToString() const {
   const char CONNECT_STATE_ABBREV[2] = {
     '-',  // not connected (false)
     'C',  // connected (true)
@@ skipping 91 matching lines @@
     // Recoverable error, retry
   } else if (error_code == STUN_ERROR_STALE_CREDENTIALS) {
     // Race failure, retry
   } else if (error_code == STUN_ERROR_ROLE_CONFLICT) {
     HandleRoleConflictFromPeer();
   } else {
     // This is not a valid connection.
     LOG_J(LS_ERROR, this) << "Received STUN error response, code="
                           << error_code << "; killing connection";
     set_state(STATE_FAILED);
-    set_write_state(STATE_WRITE_TIMEOUT);
+    Destroy();
   }
 }
 
 void Connection::OnConnectionRequestTimeout(ConnectionRequest* request) {
   // Log at LS_INFO if we miss a ping on a writable connection.
   rtc::LoggingSeverity sev = writable() ? rtc::LS_INFO : rtc::LS_VERBOSE;
   LOG_JV(sev, this) << "Timing-out STUN ping "
                     << rtc::hex_encode(request->id())
                     << " after " << request->Elapsed() << " ms";
 }
 
 void Connection::OnConnectionRequestSent(ConnectionRequest* request) {
   // Log at LS_INFO if we send a ping on an unwritable connection.
   rtc::LoggingSeverity sev = !writable() ? rtc::LS_INFO : rtc::LS_VERBOSE;
   bool use_candidate = use_candidate_attr();
   LOG_JV(sev, this) << "Sent STUN ping"
                     << ", id=" << rtc::hex_encode(request->id())
                     << ", use_candidate=" << use_candidate;
 }
 
-void Connection::CheckTimeout() {
-  // If write has timed out and it is not receiving, remove the connection.
-  if (!receiving_ && write_state_ == STATE_WRITE_TIMEOUT) {
-    Destroy();
-  }
-}
-
 void Connection::HandleRoleConflictFromPeer() {
   port_->SignalRoleConflict(port_);
 }
 
 void Connection::MaybeSetRemoteIceCredentials(const std::string& ice_ufrag,
                                               const std::string& ice_pwd) {
   if (remote_candidate_.username() == ice_ufrag &&
       remote_candidate_.password().empty()) {
     remote_candidate_.set_password(ice_pwd);
   }
@@ skipping 131 matching lines @@
     ASSERT(sent < 0);
     error_ = port_->GetError();
     sent_packets_discarded_++;
   } else {
     send_rate_tracker_.AddSamples(sent);
   }
   return sent;
 }
 
 }  // namespace cricket