org.mmtk.plan

Class TransitiveClosure

java.lang.Object

org.mmtk.plan.TransitiveClosure

Direct Known Subclasses:

GenRCModifiedProcessor, ImmortalSpaceDriver.Closure, ObjectReferenceBuffer, RCModifiedProcessor, RCZero, TraceLocal, TraceWriteBuffer

public abstract class TransitiveClosure
extends Object

This abstract class is the fundamental mechanism for performing a transitive closure over an object graph.

Some mechanisms only operate on nodes or edges, but due to limitations of inheritance we have combined these two here.

See Also:

TraceLocal

Field Summary

Fields

Modifier and Type	Field and Description
protected int	specializedScan The specialized scan identifier
private static Class<?>[]	specializedScans Database of specialized scan classes.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TransitiveClosure()
protected	TransitiveClosure(int specializedScan) Constructor

Method Summary

Modifier and Type	Method and Description
static Class<?>	getSpecializedScanClass(int id) Get the specialized scan with the given id.
void	processEdge(ObjectReference source, Address slot) Trace an edge during GC.
void	processNode(ObjectReference object) Trace a node during GC.
static void	registerSpecializedScan(int id, Class<?> specializedScanClass) A transitive closure has been created that is designed to work with a specialized scan method.

Methods inherited from class java.lang.Object

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

Field Detail

specializedScans

private static final Class<?>[] specializedScans

Database of specialized scan classes.

specializedScan

protected final int specializedScan

The specialized scan identifier

Constructor Detail

TransitiveClosure

protected TransitiveClosure()

TransitiveClosure

protected TransitiveClosure(int specializedScan)

Constructor

Parameters:

specializedScan - The specialized scan for this trace.

Method Detail

registerSpecializedScan

public static void registerSpecializedScan(int id,
                                           Class<?> specializedScanClass)

A transitive closure has been created that is designed to work with a specialized scan method. We must register it here so the specializer can return the class when queried.

Parameters:

id - The method id to register.

specializedScanClass - The class to register.

getSpecializedScanClass

public static Class<?> getSpecializedScanClass(int id)

Get the specialized scan with the given id.

Parameters:

id - the id of the specialized scan

Returns:

the specialized scan class

processEdge

public void processEdge(ObjectReference source,
                        Address slot)

Trace an edge during GC.

Parameters:

source - The source of the reference.

slot - The location containing the object reference.

processNode

public void processNode(ObjectReference object)

Trace a node during GC.

Parameters:

object - The object to be processed.