org.mmtk.plan.generational

Class GenNurseryTraceLocal

java.lang.Object

org.mmtk.plan.TransitiveClosure

org.mmtk.plan.TraceLocal

org.mmtk.plan.generational.GenNurseryTraceLocal

public final class GenNurseryTraceLocal
extends TraceLocal

This class implements the core functionality for a transitive closure over the heap graph.

Field Summary

Fields

Modifier and Type	Field and Description
private AddressPairDeque	arrayRemset
private ObjectReferenceDeque	modbuf
private AddressDeque	remset

Fields inherited from class org.mmtk.plan.TraceLocal

rootLocations, values

Fields inherited from class org.mmtk.plan.TransitiveClosure

specializedScan

Constructor Summary

Constructors

Constructor and Description
GenNurseryTraceLocal(Trace trace, GenCollector plan)

Method Summary

Modifier and Type	Method and Description
boolean	isLive(ObjectReference object) Is the specified object live?
protected void	processRememberedSets() Process any remembered set entries.
ObjectReference	traceObject(ObjectReference object) This method is the core method during the trace of the object graph.
boolean	willNotMoveInCurrentCollection(ObjectReference object) Will the object move from now on during the collection.

Methods inherited from class org.mmtk.plan.TraceLocal

completeTrace, flush, getForwardedFinalizable, getForwardedReference, getForwardedReferenceType, getForwardedReferent, incrementalTrace, isReachable, isReferentLive, logMessage, overwriteReferenceDuringTrace, prepare, processEdge, processInteriorEdge, processNode, processRootEdge, processRoots, readyToFinalize, release, reportDelayedRootEdge, retainForFinalize, retainReferent, scanObject, traceObject

Methods inherited from class org.mmtk.plan.TransitiveClosure

getSpecializedScanClass, registerSpecializedScan

Methods inherited from class java.lang.Object

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

Field Detail

modbuf

private final ObjectReferenceDeque modbuf

remset

private final AddressDeque remset

arrayRemset

private final AddressPairDeque arrayRemset

Constructor Detail

GenNurseryTraceLocal

public GenNurseryTraceLocal(Trace trace,
                            GenCollector plan)

Parameters:

trace - the global trace class to use

plan - the state of the generational collector

Method Detail

isLive

public boolean isLive(ObjectReference object)

Is the specified object live?

Overrides:

isLive in class TraceLocal

Parameters:

object - The object.

Returns:

true if the object is live.

traceObject

public ObjectReference traceObject(ObjectReference object)

Description copied from class: TraceLocal

This method is the core method during the trace of the object graph. The role of this method is to:

1. Ensure the traced object is not collected.
2. If this is the first visit to the object enqueue it to be scanned.
3. Return the forwarded reference to the object.

Overrides:

traceObject in class TraceLocal

Parameters:

object - The object to be traced.

Returns:

The new reference to the same object instance.

processRememberedSets

protected void processRememberedSets()

Process any remembered set entries.

Overrides:

processRememberedSets in class TraceLocal

willNotMoveInCurrentCollection

public boolean willNotMoveInCurrentCollection(ObjectReference object)

Will the object move from now on during the collection.

Overrides:

willNotMoveInCurrentCollection in class TraceLocal

Parameters:

object - The object to query.

Returns:

true if the object is guaranteed not to move.