RTT Estimator Test Code

src/internet/test/rtt-test.cc

@@ -0,0 +1,108 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include "ns3/test.h"
+#include "ns3/core-module.h"
+#include "ns3/internet-module.h"
+#include "ns3/rtt-estimator.h"
+#include "ns3/log.h"
+
+NS_LOG_COMPONENT_DEFINE ("RttTestSuite");
+
+using namespace ns3;
+
+class RttTestCase : public TestCase
+{
+public:
+  RttTestCase (double mean,
+               double variance,
+               double gain);
+
+private:
+  virtual void DoRun (void);
+  virtual void DoTeardown (void);
+
+  double m_mean;
+  double m_variance;
+  double m_gain;
+
+};
+
+RttTestCase::RttTestCase (double mean,
+                          double variance,
+                          double gain)
+  : TestCase ("Rtt Estimate Test"),
+    m_mean (mean),
+    m_variance (variance),
+    m_gain (gain)
+{
+}
+
+void
+RttTestCase::DoRun (void)
+{
+  Config::SetDefault ("ns3::RttEstimator::InitialEstimation", TimeValue (MilliSeconds (m_mean)));
+  Config::SetDefault ("ns3::RttMeanDeviation::Gain", DoubleValue (m_gain));
+  Config::SetDefault ("ns3::RttEstimator::MinRTO", TimeValue (Seconds (0)));
+
+  Ptr<RttMeanDeviation> rtt = CreateObject<RttMeanDeviation> ();
+  Ptr<NormalRandomVariable> nv = CreateObject<NormalRandomVariable> ();
+  nv->SetAttribute ("Mean", DoubleValue (m_mean));
+  nv->SetAttribute ("Variance", DoubleValue (m_variance));
+
+  NS_TEST_EXPECT_MSG_EQ (m_mean, rtt->GetCurrentEstimate ().GetMilliSeconds (), "Initial estimate should match mean");
+
+  double a, v, g;
+  a = v = m_mean;
+  g = m_gain;
+
+  for (uint32_t i = 0; i < 10000; ++i)
+    {
+      int measurement = nv->GetInteger ();
+      rtt->Measurement (Time::FromInteger (measurement, Time::MS));
+      double err = (measurement - a);
+      a = a + g * err;
+      v = v + g * (std::abs (err) - v);
+    }
+
+  //5% tolerance
+  double tolerance = m_mean * .05;
+
+  NS_TEST_ASSERT_MSG_EQ_TOL (m_mean, rtt->GetCurrentEstimate ().GetMilliSeconds (), tolerance, "Unexpected estimate");
+
+  int expectedTimeout = (int)a + 4 * (int)v;
+
+  NS_TEST_EXPECT_MSG_EQ (rtt->RetransmitTimeout ().GetMilliSeconds (), expectedTimeout, "Timeout values do not match");
+}
+void
+RttTestCase::DoTeardown (void)
+{
+}
+
+
+static class RttTestSuite : public TestSuite
+{
+public:
+  RttTestSuite ()
+    : TestSuite ("rtt", UNIT)
+  {
+    AddTestCase (new RttTestCase (150.0, 10.0, .1), TestCase::QUICK);
+    AddTestCase (new RttTestCase (5000.0, 5.0, .5), TestCase::QUICK);
+    AddTestCase (new RttTestCase (200.0, 25.0, .7), TestCase::QUICK);
+  }
+
+} g_tcpTestSuite;

src/internet/wscript

@@ -208,8 +208,8 @@ def build(bld):
         'test/ipv6-dual-stack-test-suite.cc',
         'test/ipv6-fragmentation-test.cc',
         'test/ipv6-address-helper-test-suite.cc',
+        'test/rtt-test.cc',
         ]
-
     headers = bld(features='ns3header')
     headers.module = 'internet'
     headers.source = [