javolution.test.Perfometer< T > Class Template Reference

Collaboration diagram for javolution.test.Perfometer< T >:

Public Member Functions
	Perfometer (String description)
double	getAvgTimeInSeconds ()
String	getDescription ()
T	getInput ()
int	getNbrOfIterations ()
double[]	getTimesInSeconds ()
Perfometer< T >	measure (T input, int nbrOfIterations)
void	print ()
void	printDetails ()
double	getWCETinSeconds ()
int	getWorstCaseNumber ()

Static Public Attributes
static final Configurable< Integer >	DURATION_MS
static final Configurable< Boolean >	SKIP

Protected Member Functions
abstract void	initialize () throws Exception
abstract void	run (boolean measure) throws Exception
void	validate ()

Private Member Functions
long[]	longArray (int length, long initialValue)

Private Attributes
final String	description
T	input
long[]	times

Detailed Description

Utility class to measure the worst case execution time and average execution time with high precision. Here an example measuring the worst case execution time of java.util.List#add(int, Object) for diverse list implementations.

[code] Perfometer<Class<? extends List>> insertPerf = new Perfometer<>("java.util.List#add(int, Object)") { List<Object> list; Random random; protected void initialize() throws Exception { list = getInput().newInstance(); random = new Random(-1); // Use seed to ensure same execution path. } protected void run(boolean measure) { Object obj = new Object(); int i = random.nextInt(list.size() + 1); if (measure) list.add(i, obj); } protected void validate() { // Optional. assert list.size() == getNbrOfIterations(); } } ... public void testExecutionTime() { insertPerf.measure(java.util.ArrayList.class, 10000).print(); insertPerf.measure(java.util.LinkedList.class, 10000).print(); insertPerf.measure(javolution.util.FastTable.class, 10000).print(); } ...

[INFO] java.util.List::add(int, Object) (10000) for java.util.ArrayList: 590.21450 ns (avg), 8443.0000 ns (wcet#9369) [INFO] java.util.List::add(int, Object) (10000) for java.util.LinkedList: 4849.8313 ns (avg), 26536.000 ns (wcet#9863) [INFO] java.util.List::add(int, Object) (10000) for javolution.util.FastTable: 217.26300 ns (avg), 534.00000 ns (wcet#8864)

[/code]

Parameters

<T>	the perfometer input type.

Definition at line 53 of file Perfometer.java.

Constructor & Destructor Documentation

Perfometer()

javolution.test.Perfometer< T >.Perfometer

(

String

description

)

Creates a perfometer having the specified description.

Parameters

description

the description of the code being measured.

Definition at line 100 of file Perfometer.java.

                                          {
        this.description = description;
    }

References javolution.test.Perfometer< T >.description.

Member Function Documentation

getAvgTimeInSeconds()

double javolution.test.Perfometer< T >.getAvgTimeInSeconds

(

)

Returns the average execution time in seconds.

Definition at line 107 of file Perfometer.java.

                                        {
        if (times == null) return Double.NaN;
        long sum = 0;
        for (long time : times) {
            sum += time;
        }
        return sum / 1e9 / times.length;
    }

References javolution.test.Perfometer< T >.times.

Referenced by javolution.test.Perfometer< T >.print().

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getDescription()

String javolution.test.Perfometer< T >.getDescription

(

)

Returns this perfometer description.

Definition at line 119 of file Perfometer.java.

                                   {
        return description;
    }

References javolution.test.Perfometer< T >.description.

getInput()

T javolution.test.Perfometer< T >.getInput

(

)

Returns this perfometer current inputs.

Definition at line 126 of file Perfometer.java.

                        {
        return input;
    }

References javolution.test.Perfometer< T >.input.

getNbrOfIterations()

int javolution.test.Perfometer< T >.getNbrOfIterations

(

)

Returns this perfometer current number of iterations performed.

Definition at line 133 of file Perfometer.java.

                                    {
        return (times != null) ? times.length : 0;
    }

References javolution.test.Perfometer< T >.times.

Referenced by javolution.test.Perfometer< T >.print().

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getTimesInSeconds()

double [] javolution.test.Perfometer< T >.getTimesInSeconds

(

)

Returns the execution times in seconds.

Definition at line 140 of file Perfometer.java.

                                        {
        if (times == null) return new double[0];
        double[] timesSec = new double[times.length];
        for (int i=0; i < times.length; i++) {
            timesSec[i] = times[i] / 1e9;
        }
        return timesSec;
    }

References javolution.test.Perfometer< T >.times.

getWCETinSeconds()

double javolution.test.Perfometer< T >.getWCETinSeconds

(

)

Returns the worst case execution time in seconds.

Definition at line 222 of file Perfometer.java.

                                     {
        if (times == null) return Double.NaN;
        long wcet = 0;
        for (long time : times) {
            if (time > wcet) wcet = time;
        }
        return wcet / 1e9;
    }

References javolution.test.Perfometer< T >.times.

Referenced by javolution.test.Perfometer< T >.print().

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getWorstCaseNumber()

int javolution.test.Perfometer< T >.getWorstCaseNumber

(

)

Returns the iteration number having the slowest execution time.

Definition at line 234 of file Perfometer.java.

                                    {
        if (times == null) return -1;
        long wcet = 0;
        int j = -1;
        for (int i=0; i < times.length; i++) {
            if (times[i] > wcet) {
                wcet = times[i];
                j = i;   
            }
        }
        return j;
    }

References javolution.test.Perfometer< T >.times.

Referenced by javolution.test.Perfometer< T >.print().

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initialize()

abstract void javolution.test.Perfometer< T >.initialize ( ) throws Exception

abstractprotected

Performs the initialization.

Referenced by javolution.test.Perfometer< T >.measure().

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longArray()

long [] javolution.test.Perfometer< T >.longArray ( int  length, long  initialValue  )

private

Definition at line 265 of file Perfometer.java.

                                                            {
        long[] array = new long[length];
        for (int i = 0; i < length; i++)
            array[i] = initialValue;
        return array;
    }

Referenced by javolution.test.Perfometer< T >.measure().

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measure()

Perfometer<T> javolution.test.Perfometer< T >.measure	(	T	input,
		int	nbrOfIterations
	)

Measures the worst case execution time and average execution time.

Parameters

input	the test input.
nbrOfIterations	the number of iterations performed on which the average will be calculated.

Definition at line 156 of file Perfometer.java.

                                                               {
        if (SKIP.get()) return this; // Skip.
        this.input = input;
        this.times = new long[nbrOfIterations];
        long[] calibrations = longArray(nbrOfIterations, Long.MAX_VALUE);
        long[] measures = longArray(nbrOfIterations, Long.MAX_VALUE);
        try {
            long exitTime = System.currentTimeMillis() + DURATION_MS.get();
            do {
                // Calibration.
                initialize();
                for (int i = 0; i < nbrOfIterations; i++) {
                    long start = System.nanoTime();
                    run(false);
                    long time = System.nanoTime() - start;
                    calibrations[i] = MathLib.min(calibrations[i], time);
                }
                // Measurement.
                initialize();
                for (int i = 0; i < nbrOfIterations; i++) {
                    long start = System.nanoTime();
                    run(true);
                    long time = System.nanoTime() - start;
                    measures[i] = MathLib.min(measures[i], time);
                }
            } while (System.currentTimeMillis() < exitTime);
            for (int i = 0; i < nbrOfIterations; i++) {
                times[i] = measures[i] - calibrations[i];
            }
            return this;
        } catch (Exception error) {
            throw new RuntimeException("Perfometer Exception", error);
        }
    }

References javolution.test.Perfometer< T >.DURATION_MS, javolution.lang.Configurable< T >.get(), javolution.test.Perfometer< T >.initialize(), javolution.test.Perfometer< T >.input, javolution.test.Perfometer< T >.longArray(), javolution.lang.MathLib.min(), javolution.test.Perfometer< T >.run(), javolution.test.Perfometer< T >.SKIP, and javolution.test.Perfometer< T >.times.

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print()

void javolution.test.Perfometer< T >.print

(

)

Outputs the result.

Definition at line 194 of file Perfometer.java.

                        {
        if (Perfometer.SKIP.get()) return;
        TextBuilder txt = new TextBuilder();
        txt.append(description).append(" (").append(getNbrOfIterations())
                .append(") for ").append(input).append(": ");
        while (txt.length() < 80)
            txt.append(' ');
        txt.append(getAvgTimeInSeconds() * 1E9, 8, false, true); // Nano-Seconds.
        txt.append(" ns (avg), ");
        txt.append(getWCETinSeconds() * 1E9, 8, false, true); // Nano-Seconds.
        txt.append(" ns (wcet#").append(getWorstCaseNumber()).append(")");
        LogContext.info(txt);
    }

References javolution.text.TextBuilder.append(), javolution.test.Perfometer< T >.description, javolution.lang.Configurable< T >.get(), javolution.test.Perfometer< T >.getAvgTimeInSeconds(), javolution.test.Perfometer< T >.getNbrOfIterations(), javolution.test.Perfometer< T >.getWCETinSeconds(), javolution.test.Perfometer< T >.getWorstCaseNumber(), javolution.context.LogContext.info(), javolution.test.Perfometer< T >.input, javolution.text.TextBuilder.length(), and javolution.test.Perfometer< T >.SKIP.

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printDetails()

void javolution.test.Perfometer< T >.printDetails

(

)

Outputs the measurements in nanoseconds.

Definition at line 211 of file Perfometer.java.

                               {
        if (Perfometer.SKIP.get()) return;
        FastTable<Long> measurements = new FastTable<Long>();
        for (long time : times)
            measurements.add(time);
        LogContext.debug(measurements);
    }

References javolution.util.FastTable< E >.add(), javolution.context.LogContext.debug(), javolution.lang.Configurable< T >.get(), javolution.test.Perfometer< T >.SKIP, and javolution.test.Perfometer< T >.times.

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run()

abstract void javolution.test.Perfometer< T >.run ( boolean  measure ) throws Exception

abstractprotected

Runs the code being benchmarked.

Parameters

measure

Referenced by javolution.test.Perfometer< T >.measure().

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validate()

void javolution.test.Perfometer< T >.validate ( )

protected

Validates the final result (after all iterations are completed).

Definition at line 263 of file Perfometer.java.

{}

Member Data Documentation

description

final String javolution.test.Perfometer< T >.description

private

Definition at line 91 of file Perfometer.java.

Referenced by javolution.test.Perfometer< T >.getDescription(), javolution.test.Perfometer< T >.Perfometer(), and javolution.test.Perfometer< T >.print().

DURATION_MS

final Configurable<Integer> javolution.test.Perfometer< T >.DURATION_MS

static

Initial value:

= new Configurable<Integer>() {
 
        @Override
        public String getName() { 
            return this.getClass().getEnclosingClass().getName()
                    + "#DURATION_MS";
        }
 
        @Override
        protected Integer getDefault() {
            return 1000;
        }
 
    }

Hold the measurement duration in milliseconds (default 1000 ms).

Definition at line 58 of file Perfometer.java.

Referenced by javolution.test.Perfometer< T >.measure().

input

T javolution.test.Perfometer< T >.input

private

Definition at line 92 of file Perfometer.java.

Referenced by javolution.test.Perfometer< T >.getInput(), javolution.test.Perfometer< T >.measure(), and javolution.test.Perfometer< T >.print().

SKIP

final Configurable<Boolean> javolution.test.Perfometer< T >.SKIP

static

Initial value:

= new Configurable<Boolean>() {
 
        @Override
        public String getName() { 
            return this.getClass().getEnclosingClass().getName() + "#SKIP";
        }
 
        @Override
        protected Boolean getDefault() {
            return false;
        }
    }

Indicates if perfometer measurements should be skipped ( e.g.

-Djavolution.test.Perfometer#SKIP=true 

to skip performance measurements). When skipped, measure and print don't do anything.

Definition at line 78 of file Perfometer.java.

Referenced by javolution.test.Perfometer< T >.measure(), javolution.test.Perfometer< T >.print(), and javolution.test.Perfometer< T >.printDetails().

times

long [] javolution.test.Perfometer< T >.times

private

Definition at line 93 of file Perfometer.java.

Referenced by javolution.test.Perfometer< T >.getAvgTimeInSeconds(), javolution.test.Perfometer< T >.getNbrOfIterations(), javolution.test.Perfometer< T >.getTimesInSeconds(), javolution.test.Perfometer< T >.getWCETinSeconds(), javolution.test.Perfometer< T >.getWorstCaseNumber(), javolution.test.Perfometer< T >.measure(), and javolution.test.Perfometer< T >.printDetails().

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The documentation for this class was generated from the following file:

• Perfometer.java