openflowplugin-impl/src/test/java/org/opendaylight/openflowplugin/impl/statistics/TimeCounterTest.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.openflowplugin.impl.statistics;
  10
  11 import org.junit.Assert;
  12 import org.junit.Before;
  13 import org.junit.Test;
  14 import org.slf4j.Logger;
  15 import org.slf4j.LoggerFactory;
  16
  17 /**
  18  * Test for {@link TimeCounter}.
  19  */
  20 public class TimeCounterTest {
  21
  22     private static final Logger LOG = LoggerFactory.getLogger(TimeCounterTest.class);
  23     private TimeCounter timeCounter;
  24
  25     @Before
  26     public void setUp() throws Exception {
  27         timeCounter = new TimeCounter();
  28     }
  29
  30     /**
  31      * tm = time mark
  32      * - tm1 at time 2 ms
  33      * - tm2 at time 4 ms
  34      * - tm3 at time 9 ms
  35      *
  36      * awaited average time:
  37      * - tm1 = 2/1 = 2 ms
  38      * - tm2 = 4/2 = 2 ms
  39      * - tm3 = 9/3 = 3 ms
  40      *
  41      * But this times are only theoretical if whole test is executed without latency and atomically. Therefore awaited
  42      * average times can't be compared to exact values of awaited average time (therefore == was replaced with >=)
  43      * @throws Exception
  44      */
  45     @Test
  46     public void testGetAverageTimeBetweenMarks() throws Exception {
  47         Assert.assertEquals(0, timeCounter.getAverageTimeBetweenMarks());
  48         timeCounter.markStart();
  49         Assert.assertEquals(0, timeCounter.getAverageTimeBetweenMarks());
  50
  51         zzz(2L);
  52         timeCounter.addTimeMark();
  53         Assert.assertTrue(timeCounter.getAverageTimeBetweenMarks() >= 2);
  54
  55         zzz(2L);
  56         timeCounter.addTimeMark();
  57         Assert.assertTrue(timeCounter.getAverageTimeBetweenMarks() >= 2);
  58
  59         zzz(5L);
  60         timeCounter.addTimeMark();
  61         Assert.assertTrue(timeCounter.getAverageTimeBetweenMarks() >= 3);
  62     }
  63
  64     private void zzz(long length) {
  65         try {
  66             Thread.sleep(length);
  67         } catch (InterruptedException e) {
  68             LOG.error("processing sleep interrupted", e);
  69         }
  70     }
  71 }