content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.cassandra.utils;
  
  import static org.apache.cassandra.utils.Clock.Global.nanoTime;
  import static org.apache.cassandra.utils.MonotonicClock.Global.approxTime;
  import static org.junit.Assert.*;
  
  import org.junit.Test;
  
  public class MonotonicClockTest
  {
      @Test
      public void testTimestampOrdering() throws Exception
      {
          long nowNanos = nanoTime();
          long now = System.currentTimeMillis();
          long lastConverted = 0;
          for (long ii = 0; ii < 10000000; ii++)
          {
              now = Math.max(now, System.currentTimeMillis());
              if (ii % 10000 == 0)
              {
                  ((MonotonicClock.SampledClock) approxTime).refreshNow();
                  Thread.sleep(1);
              }
  
              nowNanos = Math.max(nowNanos, nanoTime());
              long convertedNow = approxTime.translate().toMillisSinceEpoch(nowNanos);
  
              int maxDiff = 1;
              assertTrue("convertedNow = " + convertedNow + " lastConverted = " + lastConverted + " in iteration " + ii,
                         convertedNow >= (lastConverted - maxDiff));
  
              maxDiff = 2;
              assertTrue("now = " + now + " convertedNow = " + convertedNow + " in iteration " + ii,
                         (maxDiff - 2) <= convertedNow);
  
              lastConverted = convertedNow;
          }
      }
  }
  