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;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.lang.reflect.Field;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.taskdefs.ExecuteWatchdog;
  import org.apache.tools.ant.taskdefs.optional.junit.JUnitTask;
  import org.apache.tools.ant.util.Watchdog;
  
  public class JStackJUnitTask extends JUnitTask
  {
      private Integer timeout;
  
      public JStackJUnitTask() throws Exception
      {
      }
  
      @Override
      public void setTimeout(Integer timeout)
      {
          this.timeout = timeout;
          super.setTimeout(timeout);
      }
  
      @Override
      public ExecuteWatchdog createWatchdog() throws BuildException
      {
          return new JStackWatchDog(timeout);
      }
  
      private static class JStackWatchDog extends ExecuteWatchdog
      {
          private long pid;
  
          public JStackWatchDog(long timeout)
          {
              super(timeout);
          }
  
          public JStackWatchDog(int timeout)
          {
              super(timeout);
          }
  
          @Override
          public synchronized void start(Process process)
          {
              this.pid = getPid(process);
              super.start(process);
          }
  
          @Override
          public synchronized void timeoutOccured(Watchdog w)
          {
              if (pid > 0)
              {
                  ProcessBuilder pb = new ProcessBuilder("jstack","-l", String.valueOf(pid));
                  try
                  {
                      Process p = pb.start();
                      try (BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream())))
                      {
                          StringBuilder sb = new StringBuilder();
                          String line;
                          while((line = br.readLine()) != null)
                          {
                              sb.append(line).append("\n");
                          }
                          System.out.println(sb.toString());
                      }
                  }
                  catch (IOException e)
                  {
                      System.err.println("Could not get stack for "+pid);
                      e.printStackTrace();
                  }
              }
              super.timeoutOccured(w);
          }
  
          private long getPid(Process process)
          {
              if (process.getClass().getName().equals("java.lang.UNIXProcess"))
              {
                  try
                  {
                      Field f = process.getClass().getDeclaredField("pid");
                      f.setAccessible(true);
                      long pid = f.getLong(process);
                      f.setAccessible(false);
                      return pid;
                  }
                  catch (IllegalAccessException | NoSuchFieldException e)
                  {
                      System.err.println("Could not get PID");
                  }
              }
              return -1;
          }
      }
  
  }
  