# HG changeset patch
# User Tommaso Pecorella <tommaso.pecorella@unifi.it>
# Date 1424677743 -3600
# Parent  4c6637fccb7b242f8731a0ce1d7228240057b6be
Bug 2067 - TCP performances drop when Advertised Window is larger than Sender Buffer size

diff --git a/src/applications/model/bulk-send-application.cc b/src/applications/model/bulk-send-application.cc
--- a/src/applications/model/bulk-send-application.cc
+++ b/src/applications/model/bulk-send-application.cc
@@ -224,7 +224,7 @@
 
   if (m_connected)
     { // Only send new data if the connection has completed
-      Simulator::ScheduleNow (&BulkSendApplication::SendData, this);
+      SendData ();
     }
 }
 
diff --git a/src/internet/model/tcp-newreno.cc b/src/internet/model/tcp-newreno.cc
--- a/src/internet/model/tcp-newreno.cc
+++ b/src/internet/model/tcp-newreno.cc
@@ -182,7 +182,10 @@
     { // Increase cwnd for every additional dupack (RFC2582, sec.3 bullet #3)
       m_cWnd += m_segmentSize;
       NS_LOG_INFO ("Dupack in fast recovery mode. Increase cwnd to " << m_cWnd);
-      SendPendingData (m_connected);
+      if (!m_sendPendingDataEvent.IsRunning ())
+        {
+          SendPendingData (m_connected);
+        }
     }
   else if (!m_inFastRec && m_limitedTx && m_txBuffer->SizeFromSequence (m_nextTxSequence) > 0)
     { // RFC3042 Limited transmit: Send a new packet for each duplicated ACK before fast retransmit
@@ -261,4 +264,10 @@
   m_ssThresh = m_initialSsThresh;
 }
 
+void
+TcpNewReno::ScaleSsThresh (uint8_t scaleFactor)
+{
+  m_ssThresh <<= scaleFactor;
+}
+
 } // namespace ns3
diff --git a/src/internet/model/tcp-newreno.h b/src/internet/model/tcp-newreno.h
--- a/src/internet/model/tcp-newreno.h
+++ b/src/internet/model/tcp-newreno.h
@@ -69,6 +69,8 @@
   virtual uint32_t GetInitialSSThresh (void) const;
   virtual void     SetInitialCwnd (uint32_t cwnd);
   virtual uint32_t GetInitialCwnd (void) const;
+  virtual void ScaleSsThresh (uint8_t scaleFactor);
+
 private:
   /**
    * \brief Set the congestion window when connection starts
diff --git a/src/internet/model/tcp-reno.cc b/src/internet/model/tcp-reno.cc
--- a/src/internet/model/tcp-reno.cc
+++ b/src/internet/model/tcp-reno.cc
@@ -164,7 +164,10 @@
     { // In fast recovery, inc cwnd for every additional dupack (RFC2581, sec.3.2)
       m_cWnd += m_segmentSize;
       NS_LOG_INFO ("Increased cwnd to " << m_cWnd);
-      SendPendingData (m_connected);
+      if (!m_sendPendingDataEvent.IsRunning ())
+        {
+          SendPendingData (m_connected);
+        }
     };
 }
 
@@ -236,4 +239,11 @@
   m_ssThresh = m_initialSsThresh;
 }
 
+void
+TcpReno::ScaleSsThresh (uint8_t scaleFactor)
+{
+  m_ssThresh <<= scaleFactor;
+}
+
+
 } // namespace ns3
diff --git a/src/internet/model/tcp-reno.h b/src/internet/model/tcp-reno.h
--- a/src/internet/model/tcp-reno.h
+++ b/src/internet/model/tcp-reno.h
@@ -71,6 +71,8 @@
   virtual uint32_t GetInitialSSThresh (void) const;
   virtual void     SetInitialCwnd (uint32_t cwnd);
   virtual uint32_t GetInitialCwnd (void) const;
+  virtual void ScaleSsThresh (uint8_t scaleFactor);
+
 private:
   /**
    * \brief Set the congestion window when connection starts
diff --git a/src/internet/model/tcp-rfc793.cc b/src/internet/model/tcp-rfc793.cc
--- a/src/internet/model/tcp-rfc793.cc
+++ b/src/internet/model/tcp-rfc793.cc
@@ -88,4 +88,19 @@
   return 0;
 }
 
+uint32_t
+TcpRfc793::Window ()
+{
+  NS_LOG_FUNCTION (this);
+  return m_rWnd;
+}
+
+void
+TcpRfc793::ScaleSsThresh (uint8_t scaleFactor)
+{
+  NS_LOG_WARN ("DoD TCP does not perform slow start");
+  return;
+}
+
+
 } // namespace ns3
diff --git a/src/internet/model/tcp-rfc793.h b/src/internet/model/tcp-rfc793.h
--- a/src/internet/model/tcp-rfc793.h
+++ b/src/internet/model/tcp-rfc793.h
@@ -62,6 +62,10 @@
   virtual uint32_t GetInitialSSThresh (void) const;
   virtual void     SetInitialCwnd (uint32_t cwnd);
   virtual uint32_t GetInitialCwnd (void) const;
+
+  virtual uint32_t Window (void);
+  virtual void ScaleSsThresh (uint8_t scaleFactor);
+
 };
 
 } // namespace ns3
diff --git a/src/internet/model/tcp-socket-base.cc b/src/internet/model/tcp-socket-base.cc
--- a/src/internet/model/tcp-socket-base.cc
+++ b/src/internet/model/tcp-socket-base.cc
@@ -600,7 +600,10 @@
       NS_LOG_LOGIC ("txBufSize=" << m_txBuffer->Size () << " state " << TcpStateName[m_state]);
       if (m_state == ESTABLISHED || m_state == CLOSE_WAIT)
         { // Try to send the data out
-          SendPendingData (m_connected);
+          if (!m_sendPendingDataEvent.IsRunning ())
+            {
+              m_sendPendingDataEvent = Simulator::Schedule ( TimeStep (1), &TcpSocketBase::SendPendingData, this, m_connected);
+            }
         }
       return p->GetSize ();
     }
@@ -947,8 +950,7 @@
       NS_LOG_LOGIC (this << " Leaving zerowindow persist state");
       m_persistEvent.Cancel ();
     }
-  m_rWnd = tcpHeader.GetWindowSize ();
-  m_rWnd <<= m_rcvScaleFactor;
+  m_rWnd = (uint32_t(tcpHeader.GetWindowSize ()) << m_rcvScaleFactor);
 
   // Discard fully out of range data packets
   if (packet->GetSize ()
@@ -1051,8 +1053,7 @@
       NS_LOG_LOGIC (this << " Leaving zerowindow persist state");
       m_persistEvent.Cancel ();
     }
-  m_rWnd = tcpHeader.GetWindowSize ();
-  m_rWnd <<= m_rcvScaleFactor;
+  m_rWnd = (uint32_t(tcpHeader.GetWindowSize ()) << m_rcvScaleFactor);
 
   // Discard fully out of range packets
   if (packet->GetSize ()
@@ -2063,7 +2064,6 @@
   if (m_txBuffer->Size () == 0)
     {
       return false;                           // Nothing to send
-
     }
   if (m_endPoint == 0 && m_endPoint6 == 0)
     {
@@ -2074,17 +2074,10 @@
   while (m_txBuffer->SizeFromSequence (m_nextTxSequence))
     {
       uint32_t w = AvailableWindow (); // Get available window size
-      NS_LOG_LOGIC ("TcpSocketBase " << this << " SendPendingData" <<
-                    " w " << w <<
-                    " rxwin " << m_rWnd <<
-                    " segsize " << m_segmentSize <<
-                    " nextTxSeq " << m_nextTxSequence <<
-                    " highestRxAck " << m_txBuffer->HeadSequence () <<
-                    " pd->Size " << m_txBuffer->Size () <<
-                    " pd->SFS " << m_txBuffer->SizeFromSequence (m_nextTxSequence));
       // Stop sending if we need to wait for a larger Tx window (prevent silly window syndrome)
       if (w < m_segmentSize && m_txBuffer->SizeFromSequence (m_nextTxSequence) > w)
         {
+          NS_LOG_LOGIC ("Preventing Silly Window Syndrome. Wait to send.");
           break; // No more
         }
       // Nagle's algorithm (RFC896): Hold off sending if there is unacked data
@@ -2095,6 +2088,14 @@
           NS_LOG_LOGIC ("Invoking Nagle's algorithm. Wait to send.");
           break;
         }
+      NS_LOG_LOGIC ("TcpSocketBase " << this << " SendPendingData" <<
+                    " w " << w <<
+                    " rxwin " << m_rWnd <<
+                    " segsize " << m_segmentSize <<
+                    " nextTxSeq " << m_nextTxSequence <<
+                    " highestRxAck " << m_txBuffer->HeadSequence () <<
+                    " pd->Size " << m_txBuffer->Size () <<
+                    " pd->SFS " << m_txBuffer->SizeFromSequence (m_nextTxSequence));
       uint32_t s = std::min (w, m_segmentSize);  // Send no more than window
       uint32_t sz = SendDataPacket (m_nextTxSequence, s, withAck);
       nPacketsSent++;                             // Count sent this loop
@@ -2119,13 +2120,6 @@
 }
 
 uint32_t
-TcpSocketBase::Window ()
-{
-  NS_LOG_FUNCTION (this);
-  return m_rWnd;
-}
-
-uint32_t
 TcpSocketBase::AvailableWindow ()
 {
   NS_LOG_FUNCTION_NOARGS ();
@@ -2313,7 +2307,10 @@
       m_retxEvent.Cancel ();
     }
   // Try to send more data
-  SendPendingData (m_connected);
+  if (!m_sendPendingDataEvent.IsRunning ())
+    {
+      m_sendPendingDataEvent = Simulator::Schedule ( TimeStep (1), &TcpSocketBase::SendPendingData, this, m_connected);
+    }
 }
 
 // Retransmit timeout
@@ -2450,6 +2447,7 @@
   m_delAckEvent.Cancel ();
   m_lastAckEvent.Cancel ();
   m_timewaitEvent.Cancel ();
+  m_sendPendingDataEvent.Cancel ();
 }
 
 /* Move TCP to Time_Wait state and schedule a transition to Closed state */
@@ -2604,6 +2602,7 @@
             {
               m_winScalingEnabled = true;
               ProcessOptionWScale (header.GetOption (TcpOption::WINSCALE));
+              ScaleSsThresh (m_sndScaleFactor);
             }
         }
     }
diff --git a/src/internet/model/tcp-socket-base.h b/src/internet/model/tcp-socket-base.h
--- a/src/internet/model/tcp-socket-base.h
+++ b/src/internet/model/tcp-socket-base.h
@@ -518,7 +518,7 @@
    * \brief Return the max possible number of unacked bytes
    * \returns the max possible number of unacked bytes
    */
-  virtual uint32_t Window (void);
+  virtual uint32_t Window (void) = 0;
 
   /**
    * \brief Return unfilled portion of window
@@ -675,6 +675,15 @@
    */
   void AddOptionTimestamp (TcpHeader& header);
 
+  /**
+   * \brief Scale the initial SsThresh value to the correct one
+   *
+   * Set the initial SsThresh to the largest possible advertised window
+   * according to the sender scale factor.
+   *
+   * \param scaleFactor the sender scale factor
+   */
+  virtual void ScaleSsThresh (uint8_t scaleFactor) = 0;
 
 protected:
   // Counters and events
@@ -736,6 +745,8 @@
 
   bool     m_timestampEnabled;    //!< Timestamp option enabled
   uint32_t m_timestampToEcho;     //!< Timestamp to echo
+
+  EventId m_sendPendingDataEvent; //!< micro-delay event to send pending data
 };
 
 } // namespace ns3
diff --git a/src/internet/model/tcp-tahoe.cc b/src/internet/model/tcp-tahoe.cc
--- a/src/internet/model/tcp-tahoe.cc
+++ b/src/internet/model/tcp-tahoe.cc
@@ -214,4 +214,11 @@
   m_ssThresh = m_initialSsThresh;
 }
 
+void
+TcpTahoe::ScaleSsThresh (uint8_t scaleFactor)
+{
+  m_ssThresh <<= scaleFactor;
+}
+
+
 } // namespace ns3
diff --git a/src/internet/model/tcp-tahoe.h b/src/internet/model/tcp-tahoe.h
--- a/src/internet/model/tcp-tahoe.h
+++ b/src/internet/model/tcp-tahoe.h
@@ -75,6 +75,7 @@
   virtual uint32_t GetInitialSSThresh (void) const;
   virtual void     SetInitialCwnd (uint32_t cwnd);
   virtual uint32_t GetInitialCwnd (void) const;
+  virtual void ScaleSsThresh (uint8_t scaleFactor);
 private:
   /**
    * \brief Set the congestion window when connection starts
diff --git a/src/internet/model/tcp-westwood.cc b/src/internet/model/tcp-westwood.cc
--- a/src/internet/model/tcp-westwood.cc
+++ b/src/internet/model/tcp-westwood.cc
@@ -292,7 +292,10 @@
     {// Increase cwnd for every additional DUPACK as in Reno
       m_cWnd += m_segmentSize;
       NS_LOG_INFO ("Dupack in fast recovery mode. Increase cwnd to " << m_cWnd);
-      SendPendingData (m_connected);
+      if (!m_sendPendingDataEvent.IsRunning ())
+        {
+          SendPendingData (m_connected);
+        }
     }
 }
 
@@ -425,4 +428,11 @@
   m_ssThresh = m_initialSsThresh;
 }
 
+void
+TcpWestwood::ScaleSsThresh (uint8_t scaleFactor)
+{
+  m_ssThresh <<= scaleFactor;
+}
+
+
 } // namespace ns3
diff --git a/src/internet/model/tcp-westwood.h b/src/internet/model/tcp-westwood.h
--- a/src/internet/model/tcp-westwood.h
+++ b/src/internet/model/tcp-westwood.h
@@ -126,6 +126,7 @@
   virtual uint32_t GetInitialSSThresh (void) const;
   virtual void     SetInitialCwnd (uint32_t cwnd);
   virtual uint32_t GetInitialCwnd (void) const;
+  virtual void ScaleSsThresh (uint8_t scaleFactor);
 
 private:
   /**