| /** |
| * 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.util; |
| |
| import java.util.HashMap; |
| import java.util.Map.Entry; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Debugging tool to track entry points through code, useful to see runtime call paths |
| * To use, add to a method as follows:<code> |
| * public void someMethod() { |
| * ThreadTracker.track("someMethod"); |
| * ... |
| * }</code> |
| * and at some stage call <code>result</code> to get a LOG |
| * output of the callers with an associated call count |
| * |
| */ |
| public class ThreadTracker { |
| |
| static final Logger LOG = LoggerFactory.getLogger(ThreadTracker.class); |
| static HashMap<String, Tracker> trackers = new HashMap<String, Tracker>(); |
| |
| /** |
| * track the stack trace of callers |
| * @param name the method being tracked |
| */ |
| public static void track(final String name) { |
| Tracker t; |
| final String key = name.intern(); |
| synchronized(trackers) { |
| t = trackers.get(key); |
| if (t == null) { |
| t = new Tracker(); |
| trackers.put(key, t); |
| } |
| } |
| t.track(); |
| } |
| |
| /** |
| * output the result of stack trace capture to the log |
| */ |
| public static void result() { |
| synchronized(trackers) { |
| for (Entry<String, Tracker> t: trackers.entrySet()) { |
| LOG.info("Tracker: " + t.getKey() + ", " + t.getValue().size() + " entry points..."); |
| for (Trace trace : t.getValue().values()) { |
| LOG.info("count: " + trace.count, trace); |
| } |
| LOG.info("Tracker: " + t.getKey() + ", done."); |
| } |
| } |
| } |
| |
| } |
| |
| @SuppressWarnings("serial") |
| class Trace extends Throwable { |
| public int count = 1; |
| public final long id; |
| Trace() { |
| super(); |
| id = calculateIdentifier(); |
| } |
| private long calculateIdentifier() { |
| int len = 0; |
| for (int i=0; i<this.getStackTrace().length; i++) { |
| len += this.getStackTrace()[i].toString().intern().hashCode(); |
| } |
| return len; |
| } |
| } |
| |
| @SuppressWarnings("serial") |
| class Tracker extends HashMap<Long, Trace> { |
| public void track() { |
| Trace current = new Trace(); |
| synchronized(this) { |
| Trace exist = get(current.id); |
| if (exist != null) { |
| exist.count++; |
| } else { |
| put(current.id, current); |
| } |
| } |
| } |
| } |