org.apache.activemq.util.ThreadTracker Maven / Gradle / Ivy
/**
* 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:
* public void someMethod() {
* ThreadTracker.track("someMethod");
* ...
* }
* and at some stage call result 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 trackers = new HashMap();
/**
* 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 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 {
public void track() {
Trace current = new Trace();
synchronized(this) {
Trace exist = get(current.id);
if (exist != null) {
exist.count++;
} else {
put(current.id, current);
}
}
}
}