001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2006-2010 Sun Microsystems, Inc.
015 * Portions Copyright 2014-2016 ForgeRock AS.
016 */
017package org.opends.server.monitors;
018
019import java.util.ArrayList;
020import java.util.Collection;
021import java.util.Map;
022import java.util.TreeMap;
023
024import org.forgerock.opendj.config.server.ConfigException;
025import org.opends.server.api.MonitorData;
026import org.forgerock.opendj.server.config.server.StackTraceMonitorProviderCfg;
027import org.opends.server.api.MonitorProvider;
028import org.opends.server.types.InitializationException;
029
030/**
031 * This class defines a Directory Server monitor provider that can be used to
032 * obtain a stack trace from all server threads that are currently defined in
033 * the JVM.
034 */
035public class StackTraceMonitorProvider
036       extends MonitorProvider<StackTraceMonitorProviderCfg>
037{
038  @Override
039  public void initializeMonitorProvider(
040                   StackTraceMonitorProviderCfg configuration)
041         throws ConfigException, InitializationException
042  {
043    // No initialization is required.
044  }
045
046  @Override
047  public String getMonitorInstanceName()
048  {
049    return "JVM Stack Trace";
050  }
051
052  @Override
053  public MonitorData getMonitorData()
054  {
055    Map<Thread,StackTraceElement[]> threadStacks = Thread.getAllStackTraces();
056
057    // Re-arrange all of the elements by thread ID so that there is some logical order.
058    TreeMap<Long,Map.Entry<Thread,StackTraceElement[]>> orderedStacks = new TreeMap<>();
059    for (Map.Entry<Thread,StackTraceElement[]> e : threadStacks.entrySet())
060    {
061      orderedStacks.put(e.getKey().getId(), e);
062    }
063
064    Collection<String> jvmThreads = new ArrayList<>();
065    for (Map.Entry<Thread,StackTraceElement[]> e : orderedStacks.values())
066    {
067      Thread t                          = e.getKey();
068      StackTraceElement[] stackElements = e.getValue();
069
070      long tid = t.getId();
071      jvmThreads.add("id=" + tid + " ---------- " + t.getName() + " ----------");
072
073      // Create an attribute for the stack trace.
074      if (stackElements != null)
075      {
076        for (int j = 0; j < stackElements.length; j++)
077        {
078          jvmThreads.add(toString(tid, j, stackElements[j]));
079        }
080      }
081    }
082
083    MonitorData result = new MonitorData(1);
084    result.add("jvmThread", jvmThreads);
085    return result;
086  }
087
088  private String toString(long tid, int frame, StackTraceElement stackElement)
089  {
090    StringBuilder buffer = new StringBuilder();
091    buffer.append("id=").append(tid);
092    buffer.append(" frame[").append(frame).append("]=");
093
094    buffer.append(stackElement.getClassName());
095    buffer.append(".");
096    buffer.append(stackElement.getMethodName());
097    buffer.append("(");
098    buffer.append(stackElement.getFileName());
099    buffer.append(":");
100    if (stackElement.isNativeMethod())
101    {
102      buffer.append("native");
103    }
104    else
105    {
106      buffer.append(stackElement.getLineNumber());
107    }
108    buffer.append(")");
109    return buffer.toString();
110  }
111}