com.threerings.util.MethodProfiler Maven / Gradle / Ivy
//
// $Id: MethodProfiler.java 6711 2011-09-28 23:23:34Z mdb $
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2011 Three Rings Design, Inc., All Rights Reserved
// http://code.google.com/p/narya/
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package com.threerings.util;
import java.util.Map;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.collect.Maps;
import com.samskivert.util.StringUtil;
import static com.threerings.NaryaLog.log;
/**
* Records the times that it takes to call methods. Allows one simultaneous method call per thread
* (no nested calls). Uses java's nano second timer. Results are logged by method name.
*/
public class MethodProfiler
{
/**
* The results of sampling for a single method.
*/
public static class Result
{
/**
* Creates a new result with the given values.
*/
Result (int numSamples, double average, double stdDev)
{
this.numSamples = numSamples;
this.averageTime = average;
this.standardDeviation = stdDev;
}
/** Number of method calls sampled. */
public final int numSamples;
/** Average time spent in the method. */
public final double averageTime;
/** Standard deviation from the average. */
public final double standardDeviation;
// from Object
@Override
public String toString ()
{
return StringUtil.fieldsToString(this);
}
}
/**
* Runs some very basic tests of the method profiler.
*/
public static void main (String args[])
throws InterruptedException
{
int testNum = 0;
if (args.length > 0) {
testNum = Integer.parseInt(args[0]);
}
switch (testNum) {
case 0: // rum some rpc threads
MethodProfiler test = new MethodProfiler();
Thread t1 = test.new TestThread("testm1", 100, 50);
Thread t2 = test.new TestThread("testm2", 100, 50);
t1.start();
t2.start();
t1.join();
t2.join();
for (Map.Entry method : test.getResults().entrySet()) {
log.info(method.getKey(), "result", method.getValue());
}
break;
case 1:
simpleSampleTest("Single", 100);
break;
case 2:
simpleSampleTest("Triple", 100, 0, 200);
break;
case 3:
simpleSampleTest("Multi", 0, 25, 50, 100, 125, 150, 175, 200, 112.5, 112.5, 112.5);
break;
case 4:
MethodProfiler test4 = new MethodProfiler();
test4.enter("L1a");
test4.enter("L2a");
test4.swap("L2b");
test4.enter("L3a");
test4.exit(null);
test4.exit(null);
test4.swap("L1b");
test4.swap("L1c");
test4.exit(null);
for (Map.Entry result : test4.getResults().entrySet()) {
log.info("Results", "name", result.getKey(), "value", result.getValue());
}
break;
}
}
/**
* Gets all method results so far.
*/
public Map getResults ()
{
Map cmap = _profiles.asMap();
Map results = Maps.newHashMapWithExpectedSize(cmap.size());
for (Map.Entry entry : cmap.entrySet()) {
synchronized (entry.getValue()) {
results.put(entry.getKey(), toResult(entry.getValue()));
}
}
return results;
}
/**
* Notes that the calling thread has entered the given method and records the time stamp.
*/
public void enter (String methodName)
{
Method method = _stack.get().push();
method.name = methodName;
method.entryTime = System.nanoTime();
}
/**
* Notes that the calling thread has exited the given method and records the time delta since
* entry. The method parameter is not strictly necessary but allows some error checking. If not
* null, it must match the most recent value given to {@link #enter} for the calling thread.
*/
public void exit (String methodName)
{
long nanos = System.nanoTime();
Method method = _stack.get().pop();
if (method == null || (methodName != null && !methodName.equals(method.name))) {
// TODO: warn, but only once
return;
}
long elapsed = nanos - method.entryTime;
recordTime(method.fullName(), (double)elapsed / 1000000);
method.name = null;
// Clear the ThreadLocal after we've profiled our whole stack to prevent our class loader
// from hanging around
if (_stack.get().size() == 0) {
_stack.remove();
}
}
/**
* Transition to a new method or segment. Exits the current one and enters the given one.
*/
public void swap (String methodName)
{
exit(null);
enter(methodName);
}
/**
* Clears out the profile for the current thread, and invokes the exit of the top-level method.
* This allows callers to use one try... finally block in their top-level method without skewing
* the results for nested methods that may have thrown exceptions and/or not called
* {@link #exit}.
*/
public void exitAndClear (String methodName)
{
Stack stack = _stack.get();
while (stack.size() > 1) {
stack.pop();
}
if (stack.size() > 0) {
exit(methodName);
}
}
/**
* Clears all recorded methods and times.
*/
public void reset ()
{
_profiles.invalidateAll();
}
/**
* Adds a sample to our profile of the given method.
*/
protected void recordTime (String method, double elapsedMs)
{
RunningStats stats = _profiles.getUnchecked(method);
synchronized (stats) {
stats.addSample(elapsedMs);
}
}
/**
* For testing, just calls the {@link #enter} and {@link #exit} methods at a fixed interval
* for a given number of times.
*/
protected class TestThread extends Thread
{
public TestThread (String method, int methodCount, long sleep)
{
_method = method;
_methodCount = methodCount;
_sleep = sleep;
}
// from Runnable
@Override public void run ()
{
try {
for (int ii = 0; ii < _methodCount; ++ii) {
MethodProfiler.this.enter(_method);
Thread.sleep(_sleep);
MethodProfiler.this.exit(_method);
}
} catch (InterruptedException ie) {
}
}
protected int _methodCount;
protected String _method;
protected long _sleep;
}
/**
* Describes what we know about an in-progress method call.
*/
protected static class Method
{
/** The name of the entered method. */
public String name;
/** The time the method was entered. */
public long entryTime;
/** The parent of the method. */
public Method caller;
/**
* Gets this method's name, prefixed with all parent method names separated by dots.
*/
public String fullName ()
{
if (caller != null) {
return caller.fullName() + "." + name;
}
return name;
}
}
/**
* Describes what we know about a nested set of in progress method calls. This is a fake stack
* that avoid reallocating entries, i.e. pop() == push() and push() == pop().
*/
protected static class Stack
{
public Method push ()
{
if (_size == _methods.length) {
Method []realloc = new Method[_size + 1];
System.arraycopy(_methods, 0, realloc, 0, _size);
_methods = realloc;
_methods[_size] = new Method();
}
_methods[_size].name = null;
_methods[_size].caller = _size > 0 ? _methods[_size - 1] : null;
return _methods[_size++];
}
public Method pop ()
{
if (_size == 0) {
return null;
}
return _methods[--_size];
}
public int size ()
{
return _size;
}
protected int _size;
protected Method[] _methods = {new Method()};
}
/**
* Runs the method profile stat collection with the given samples and logs the result.
*/
protected static void simpleSampleTest (String name, double... samples)
{
RunningStats stats = new RunningStats();
for (double sample : samples) {
stats.addSample(sample);
}
log.info(name, "results", toResult(stats));
}
/**
* Calculates the results of the the profile.
*/
protected static Result toResult (RunningStats stats)
{
return new Result(stats.getNumSamples(), stats.getMean(), stats.getStandardDeviation());
}
/** Set of active methods in the current thread. */
protected ThreadLocal _stack = new ThreadLocal() {
@Override protected Stack initialValue () {
return new Stack();
}
};
/** Stats by method name. */
protected final Cache _profiles = CacheBuilder.newBuilder()
.build(new CacheLoader() {
public RunningStats load (String key) {
return new RunningStats();
}
});
}
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