com.sun.faban.driver.util.timermeter
Class TimerMeter

java.lang.Object
  com.sun.faban.driver.util.timermeter.TimerMeter

All Implemented Interfaces:

Runnable

public class TimerMeter
extends Object
implements Runnable

The TimerMeter code in large is a modification from Michael Kuperberg's TimerMeter work. We thank him for this work.

Michael Kuperberg (mkuper@ipd.uka.de),
Chair for Software Design and Quality (SDQ),
Institute for Program Structures and Data Organisation (IPD),
Faculty of Informatics, University of Karlsruhe, Germany
http://sdq.ipd.uka.de

Field Summary

protected int	currentUpperLoopSizeBound not private because needed in obtainMeasurementsUsingDirectInvocation
int	increased Global variable used by the core algorithm.
protected int	iterationIncreaseStepWidth See class description.
protected long	methodReturnAtMeasurementFinish Protected because it must be set and read in subclasses' that override the obtainMeasurementsUsingDirectInvocation method
protected long	methodReturnAtMeasurementStart protected because it must be set and read in subclasses' that override the obtainMeasurementsUsingDirectInvocation method
protected int	numberOfIterationIncreaseSteps Actual maximum number of for loop iterations that are executed between two nanoTime invocations (cf.
protected int	numberOfMeasurements See class description.
protected int	numberOfProcessRepetitions Number of times the entire process is repeated.
protected int	numberOfWarmupTimerInvocations See class description.
protected static long	publicDummy This dummy variable is used for warmup; it is intentionally global because of JIT / dead code elimination prevention.
protected String	timerMethodName TODO document assumption: parameterless and no class/package name! --> no parentheses: (){}[]<> and no "."s and ";" s
protected String	warningOnNegativeDiff Warning message displayed when the timer value difference of two consecutive is negative.

Constructor Summary

TimerMeter(int warmupLoops, int repeats, int measurements, int increaseWidth, int increaseAfter, int clusterThreshold)

Method Summary

TimerCharacterisation	computeTimerCharacterization(long[][] timerMeterMeasurements, boolean logValues) TODO engineer for performance: use one-dimensional array and work with offsets?
static void	main(String[] args) Test main method.
protected long[][]	obtainMeasurementsUsingDirectInvocation() THIS METHOD MUST BE OVERRIDDEN IN SUBCLASSES.
String	printTimerCharacterization()
void	run()

Methods inherited from class java.lang.Object

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

Field Detail

publicDummy

protected static long publicDummy

This dummy variable is used for warmup; it is intentionally global because of JIT / dead code elimination prevention.

currentUpperLoopSizeBound

protected int currentUpperLoopSizeBound

not private because needed in obtainMeasurementsUsingDirectInvocation

increased

public int increased

Global variable used by the core algorithm.

iterationIncreaseStepWidth

protected int iterationIncreaseStepWidth

See class description.

methodReturnAtMeasurementFinish

protected long methodReturnAtMeasurementFinish

Protected because it must be set and read in subclasses' that override the obtainMeasurementsUsingDirectInvocation method

methodReturnAtMeasurementStart

protected long methodReturnAtMeasurementStart

protected because it must be set and read in subclasses' that override the obtainMeasurementsUsingDirectInvocation method

numberOfIterationIncreaseSteps

protected int numberOfIterationIncreaseSteps

Actual maximum number of for loop iterations that are executed between two nanoTime invocations (cf. class description)

numberOfMeasurements

protected int numberOfMeasurements

See class description.

numberOfProcessRepetitions

protected int numberOfProcessRepetitions

Number of times the entire process is repeated.

numberOfWarmupTimerInvocations

protected int numberOfWarmupTimerInvocations

See class description.

timerMethodName

protected String timerMethodName

TODO document assumption: parameterless and no class/package name! --> no parentheses: (){}[]<> and no "."s and ";" s

warningOnNegativeDiff

protected final String warningOnNegativeDiff

Warning message displayed when the timer value difference of two consecutive is negative.

Constructor Detail

TimerMeter

public TimerMeter(int warmupLoops,
                  int repeats,
                  int measurements,
                  int increaseWidth,
                  int increaseAfter,
                  int clusterThreshold)

Method Detail

main

public static void main(String[] args)

Test main method.

Parameters:

args - Command line arguments, unused.

computeTimerCharacterization

public final TimerCharacterisation computeTimerCharacterization(long[][] timerMeterMeasurements,
                                                                boolean logValues)

TODO engineer for performance: use one-dimensional array and work with offsets?

Parameters:

timerMeterMeasurements - The measurement results

logValues - Whether to log values or not

Returns:

The timer characterization

obtainMeasurementsUsingDirectInvocation

protected long[][] obtainMeasurementsUsingDirectInvocation()

THIS METHOD MUST BE OVERRIDDEN IN SUBCLASSES. Implementation is provided here as an example. Use it and replace the nanoTime. After "warming up" the timer method numberOfWarmupTimerInvocations times, this method measures the duration of a 'for' loop. The measurement is repeated numberOfMeasurements times for each loop iteration number from 0 to numberOfIterationIncreaseSteps.

Returns:

List of measurements

printTimerCharacterization

public String printTimerCharacterization()

run

public void run()

Specified by:

run in interface Runnable