com.oracle.svm.core.util

Class Counter

java.lang.Object

com.oracle.svm.core.util.Counter

public final class Counter
extends Object

A counter that can be incremented. The counting code is only emitted when an option is enabled. Counters are grouped for printing. Currently there is no shutdown hook in Substrate VM that is invoked automatically, so Counter.logValues() needs to be called manually at the end of the application to print counter values. Use this class in the following way:

 @Option(help = "Count foo")//
 @RuntimeOption//
 public static final StableOptionValue<Boolean> FooCounters = new StableOptionValue<>(false);

 private static final Counter.Group fooCounters = new Counter.Group(FooCounters, "Foo Counters");
 private static final Counter fooCount = new Counter(fooCounters, "foo", "number of times foo was invoked");

 void foo() {
     fooCount.inc();
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Counter.Group A group of related counters.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	description
protected Counter.Group	group
protected String	name
protected long	value
static Field	VALUE_FIELD

Constructor Summary

Constructors

Constructor and Description
Counter(Counter.Group group, String name, String description) Creates a counter.

Method Summary

Modifier and Type	Method and Description
void	add(long increment) Increments the value of this counter.
String	getName()
long	getValue() Returns the value of this counter.
void	inc() Increments the value of this counter.
static void	logValues() Prints all counters of all enabled groups to the Log.
void	reset() Resets the value of this counter to 0.

Methods inherited from class java.lang.Object

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

Field Detail

group

protected final Counter.Group group

name

protected final String name

description

protected final String description

value

protected long value

VALUE_FIELD

public static final Field VALUE_FIELD

Constructor Detail

Counter

public Counter(Counter.Group group,
               String name,
               String description)

Creates a counter.

Parameters:

group - the group to which the counter belongs.

name - the name of the counter

description - a brief comment describing the metric represented by the counter

Method Detail

getValue

public long getValue()

Returns the value of this counter.

getName

public String getName()

inc

public void inc()

Increments the value of this counter.

add

public void add(long increment)

Increments the value of this counter.

reset

public void reset()

Resets the value of this counter to 0.

logValues

public static void logValues()

Prints all counters of all enabled groups to the Log.