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.test.microbench;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLongArray;
  import java.util.concurrent.atomic.LongAdder;
  
  import org.apache.cassandra.metrics.Counter;
  import org.apache.cassandra.metrics.ThreadLocalCounter;
  import org.openjdk.jmh.annotations.Benchmark;
  import org.openjdk.jmh.annotations.BenchmarkMode;
  import org.openjdk.jmh.annotations.Fork;
  import org.openjdk.jmh.annotations.Level;
  import org.openjdk.jmh.annotations.Measurement;
  import org.openjdk.jmh.annotations.Mode;
  import org.openjdk.jmh.annotations.OutputTimeUnit;
  import org.openjdk.jmh.annotations.Param;
  import org.openjdk.jmh.annotations.Scope;
  import org.openjdk.jmh.annotations.Setup;
  import org.openjdk.jmh.annotations.State;
  import org.openjdk.jmh.annotations.Threads;
  import org.openjdk.jmh.annotations.Warmup;
  
  @BenchmarkMode(Mode.AverageTime)
  @OutputTimeUnit(TimeUnit.NANOSECONDS)
  @Warmup(iterations = 4, time = 1, timeUnit = TimeUnit.SECONDS)
  @Measurement(iterations = 8, time = 2, timeUnit = TimeUnit.SECONDS)
  @Fork(value = 2,
        jvmArgsAppend = { "-Djmh.executor=CUSTOM", "-Djmh.executor.class=org.apache.cassandra.test.microbench.FastThreadExecutor"})
  @Threads(4)
  @State(Scope.Benchmark)
  public class ThreadLocalMetricsBench
  {
      @Param({"LongAdder", "PlainArray"})
      private String type;
  
      @Param({"50", "100"})
      private int metricsCount;
  
      private List<Counter> counters;
  
  
      @Setup(Level.Trial)
      public void setup() throws Throwable
      {
          counters = new ArrayList<>(metricsCount);
          for (int i = 0; i < metricsCount; i++)
          {
              Counter counter;
              switch (type)
              {
                  case "LongAdder":
                      counter = new LongAdderCounter();
                      break;
                  case "PlainArray":
                      counter = new ThreadLocalCounter();
                      break;
                  default:
                      throw new UnsupportedOperationException();
              }
              counters.add(counter);
          }
      }
  
      private final AtomicLongArray anotherMemory = new AtomicLongArray(256 * 1024);
  
      @Setup(Level.Invocation)
      public void polluteCpuCaches()
      {
          for (int i = 0; i < anotherMemory.length(); i++)
              anotherMemory.incrementAndGet(i);
      }
  
      @Benchmark
      public void increment()
      {
          for (Counter counter : counters)
              counter.inc();
      }
  
      public static class LongAdderCounter implements Counter
      {
          private final LongAdder counter = new LongAdder();
  
          @Override
          public void inc()
          {
              counter.increment();
          }
  
          @Override
          public void inc(long n)
          {
              counter.add(n);
          }
  
          @Override
          public void dec()
          {
              counter.decrement();
          }
  
          @Override
          public void dec(long n)
          {
              counter.add(-n);
          }
  
          @Override
          public long getCount()
          {
              return counter.sum();
          }
      }
  }
  