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.ambari.server.testing;
  
  import java.lang.management.ManagementFactory;
  import java.lang.management.ThreadInfo;
  import java.lang.management.ThreadMXBean;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.commons.lang.ArrayUtils;
  
  /**
   * 
   * Monitoring of deadlocks thread
   * Please note. This class can not be used outside of tests
   */
  public class DeadlockWarningThread extends Thread {
  
    private final List<String> errorMessages;
    private int MAX_STACK_DEPTH = 30;
    private int SLEEP_TIME_MS = 3000;
    private Collection<Thread> monitoredThreads = null;
    private boolean deadlocked = false;
    private static final ThreadMXBean mbean = ManagementFactory.getThreadMXBean();
  
    public List<String> getErrorMessages() {
      return errorMessages;
    }
  
    public boolean isDeadlocked() {
      return deadlocked;
    }
  
    public DeadlockWarningThread(Collection<Thread> monitoredThreads, int maxStackDepth, int sleepTimeMS) {
      this.errorMessages = new ArrayList<>();
      this.monitoredThreads = monitoredThreads;
      this.MAX_STACK_DEPTH = maxStackDepth;
      this.SLEEP_TIME_MS = sleepTimeMS;
      start();
    }
  
    public DeadlockWarningThread(Collection<Thread> monitoredThreads) {
      this(monitoredThreads, 30, 3000);
    }
  
    public String getThreadsStacktraces(Collection<Long> ids) {
      StringBuilder errBuilder = new StringBuilder();
        for (long id : ids) {
          ThreadInfo ti = mbean.getThreadInfo(id, MAX_STACK_DEPTH);
          errBuilder.append("Deadlocked Thread:\n").
                  append("------------------\n").
                  append(ti).append('\n');
          for (StackTraceElement ste : ti.getStackTrace()) {
            errBuilder.append('\t').append(ste);
          }
          errBuilder.append('\n');
        }
      return errBuilder.toString();
    }
   
    
    @Override
    public void run() {
      while (true) {
        try {
          Thread.sleep(SLEEP_TIME_MS);
        } catch (InterruptedException ex) {
        }
        long[] ids = mbean.findMonitorDeadlockedThreads();
        StringBuilder errBuilder = new StringBuilder();
        if (ids != null && ids.length > 0) {
            errBuilder.append(getThreadsStacktraces(Arrays.asList(ArrayUtils.toObject(ids))));
            errorMessages.add(errBuilder.toString());
            System.out.append(errBuilder.toString());
           //Exit if deadlocks have been found         
            deadlocked = true;
            break;
        } else {
          //Exit if all monitored threads were finished
          boolean hasLive = false;
          boolean hasRunning = false;
          for (Thread monTh : monitoredThreads) {
            State state = monTh.getState();
            if (state != State.TERMINATED && state != State.NEW) {
              hasLive = true;
            }
            if (state == State.RUNNABLE || state == State.TIMED_WAITING) {
              hasRunning = true;
              break;
            }
          }
  
          if (!hasLive) {
            deadlocked = false;
            break;
          } else if (!hasRunning) {
            List<Long> tIds = new ArrayList<>();
            for (Thread monitoredThread : monitoredThreads) {
              State state = monitoredThread.getState();
              if (state == State.WAITING || state == State.BLOCKED) {
                tIds.add(monitoredThread.getId());
              }
            }
            errBuilder.append(getThreadsStacktraces(tIds));
            errorMessages.add(errBuilder.toString());
            deadlocked = true;
            break;
          }
        }
      }
    }  
  }
  