Package org.openjdk.jmh.profile

Class WinPerfAsmProfiler

java.lang.Object

org.openjdk.jmh.profile.AbstractPerfAsmProfiler

org.openjdk.jmh.profile.WinPerfAsmProfiler

All Implemented Interfaces:

ExternalProfiler, Profiler

public class WinPerfAsmProfiler
extends AbstractPerfAsmProfiler

Windows performance profiler based on "xperf" utility.

You must install Windows Performance Toolkit. Once installed, locate directory with xperf.exe file and either add it to PATH environment variable, or assign it to xperf.dir parameter.

This profiler counts only SampledProfile events. To achieve this, we set xperf providers to loader+proc_thread+profile. You may optionally save xperf binary or parsed outputs using savePerfBin or savePerf parameters respectively. If you do so and want to log more events, you can use xperf.providers parameter to override providers. However, you must specify loader, proc_thread and profile providers anyway. Otherwise sample events will not be generated and profiler will show nothing.

By default JDK distributive do not have debug symbols. If you want to analyze JVM internals, you must build OpenJDK on your own. Once built, go to bin/server directory and unpack jvm.diz. Now you have jvm.pdb file with JVM debug symbols. Finally, you must assign debug symbols directory to symbol.dir parameter.

This profiler behaves differently comparing to it's Linux counterpart LinuxPerfAsmProfiler. Linux profiler employs perf utility which can be used to profile a single process. Therefore, Linux profiler wraps forked JVM command line. In contrast, xperf cannot profile only a single process. It have -PidNewProcess argument, but it's sole purpose is to start profiling before the process is started, so that one can be sure that none events generated by this process are missed. It does not filter events from other processes anyhow. For this reason, this profiler doesn't alter forked JVM startup command. Instead, it starts xperf recording in beforeTrial(BenchmarkParams) method, and stops in ExternalProfiler.afterTrial(org.openjdk.jmh.results.BenchmarkResult, long, java.io.File, java.io.File). This leaves possibility to run this profiler in conjunction with some other profiler requiring startup command alteration.

For this reason the profiler must know PID of forked JVM process.

Nested Class Summary

Nested classes/interfaces inherited from class org.openjdk.jmh.profile.AbstractPerfAsmProfiler

AbstractPerfAsmProfiler.PerfEvents

Field Summary

Fields inherited from class org.openjdk.jmh.profile.AbstractPerfAsmProfiler

hsLog, perfBinData, perfParsedData, requestedEventNames, set

Constructor Summary

Constructors

Constructor	Description
WinPerfAsmProfiler(String initLine)

Method Summary

Modifier and Type	Method	Description
Collection<String>	addJVMInvokeOptions(BenchmarkParams params)	Prepend JVM invocation with these commands.
protected void	addMyOptions(joptsimple.OptionParser parser)
Collection<? extends Result>	afterTrial(BenchmarkResult br, long pid, File stdOut, File stdErr)	Run this code after the trial is done.
void	beforeTrial(BenchmarkParams params)	Run this code before starting the trial.
String	getDescription()	Human-readable one-line description of the profiler.
protected void	parseEvents()	Parse profiler events from binary to text form.
protected String	perfBinaryExtension()	Get perf binary data extension (optional).
protected AbstractPerfAsmProfiler.PerfEvents	readEvents(double skipMs, double lenMs)	Read parsed events.

Methods inherited from class org.openjdk.jmh.profile.AbstractPerfAsmProfiler

addJVMOptions, allowPrintErr, allowPrintOut, stripEventNames

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

WinPerfAsmProfiler

public WinPerfAsmProfiler(String initLine)
                   throws ProfilerException

Throws:

ProfilerException

Method Details

addMyOptions

protected void addMyOptions(joptsimple.OptionParser parser)

Specified by:

addMyOptions in class AbstractPerfAsmProfiler

addJVMInvokeOptions

public Collection<String> addJVMInvokeOptions(BenchmarkParams params)

Description copied from interface: ExternalProfiler

Prepend JVM invocation with these commands.

Parameters:

params - benchmark parameters used for current launch

Returns:

commands to prepend for JVM launch

beforeTrial

public void beforeTrial(BenchmarkParams params)

Description copied from interface: ExternalProfiler

Run this code before starting the trial. This method will execute before starting the benchmark JVM.

Specified by:

beforeTrial in interface ExternalProfiler

Overrides:

beforeTrial in class AbstractPerfAsmProfiler

Parameters:

params - benchmark parameters used for current launch

afterTrial

public Collection<? extends Result> afterTrial(BenchmarkResult br,
 long pid,
 File stdOut,
 File stdErr)

Description copied from interface: ExternalProfiler

Run this code after the trial is done. This method will execute after benchmark JVM had stopped.

Specified by:

afterTrial in interface ExternalProfiler

Overrides:

afterTrial in class AbstractPerfAsmProfiler

Parameters:

br - benchmark result that was the result of the trial

pid - pid that the forked JVM had

stdOut - file containing the standard output from the benchmark JVM

stdErr - file containing the standard error from the benchmark JVM

Returns:

profiler results

getDescription

public String getDescription()

Description copied from interface: Profiler

Human-readable one-line description of the profiler.

Returns:

description

parseEvents

protected void parseEvents()

Description copied from class: AbstractPerfAsmProfiler

Parse profiler events from binary to text form.

Specified by:

parseEvents in class AbstractPerfAsmProfiler

readEvents

protected AbstractPerfAsmProfiler.PerfEvents readEvents(double skipMs,
 double lenMs)

Description copied from class: AbstractPerfAsmProfiler

Read parsed events.

Specified by:

readEvents in class AbstractPerfAsmProfiler

Parameters:

skipMs - Milliseconds to skip.

lenMs - Milliseconds to capture after skip

Returns:

Events.

perfBinaryExtension

protected String perfBinaryExtension()

Description copied from class: AbstractPerfAsmProfiler

Get perf binary data extension (optional).

Specified by:

perfBinaryExtension in class AbstractPerfAsmProfiler

Returns:

Extension.