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.activemq.tool.sampler.plugins;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.StringTokenizer;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  public class LinuxCpuSamplerPlugin implements CpuSamplerPlugin, Runnable {
  
      private Process vmstatProcess;
      private String vmstat;
      private String result = "";
      private final Object mutex = new Object();
      private AtomicBoolean stop = new AtomicBoolean(false);
  
      public LinuxCpuSamplerPlugin(long intervalInMs) {
          vmstat = "vmstat -n " + (int)(intervalInMs / 1000);
      }
  
      public void start() {
          stop.set(false);
          Thread t = new Thread(this);
          t.start();
      }
  
      public void stop() {
          stop.set(true);
          try {
              vmstatProcess.waitFor();
          } catch (InterruptedException e) {
              e.printStackTrace();
          }
      }
  
      public void run() {
  
          try {
              vmstatProcess = Runtime.getRuntime().exec(vmstat);
              BufferedReader br = new BufferedReader(new InputStreamReader(vmstatProcess.getInputStream()), 1024);
  
              br.readLine(); // throw away the first line
  
              String header = br.readLine();
              String data;
  
              while (!stop.get()) {
                  data = br.readLine();
                  if (data != null) {
                      String csvData = convertToCSV(header, data);
                      synchronized (mutex) {
                          result = csvData;
                      }
                  }
              }
              br.close();
              vmstatProcess.destroy();
  
          } catch (IOException ioe) {
              ioe.printStackTrace();
          }
      }
  
      public String getCpuUtilizationStats() {
          String data;
          synchronized (mutex) {
              data = result;
              result = "";
          }
          return data;
      }
  
      public String getVmstat() {
          return vmstat;
      }
  
      public void setVmstat(String vmstat) {
          this.vmstat = vmstat;
      }
  
      protected String convertToCSV(String header, String data) {
          StringTokenizer headerTokens = new StringTokenizer(header, " ");
          StringTokenizer dataTokens = new StringTokenizer(data, " ");
  
          String csv = "";
          while (headerTokens.hasMoreTokens()) {
              csv += headerTokens.nextToken() + "=" + dataTokens.nextToken() + ",";
          }
  
          return csv;
      }
  }
  