org.mmtk.plan.markcompact

Class MCForwardTraceLocal

java.lang.Object

org.mmtk.plan.TransitiveClosure

org.mmtk.plan.TraceLocal

org.mmtk.plan.markcompact.MCForwardTraceLocal

public final class MCForwardTraceLocal
extends TraceLocal

This class implements the thread-local functionality for a transitive closure over a mark-compact space during the forwarding phase.

Field Summary

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
MCForwardTraceLocal(Trace trace)

Method Summary

Modifier and Type	Method and Description
boolean	isLive(ObjectReference object) Is the specified object live?
ObjectReference	traceObject(ObjectReference object) This method is the core method during the trace of the object graph.
boolean	willNotMoveInCurrentCollection(ObjectReference object) Will this object move from this point on, during the current trace ?

Methods inherited from class org.mmtk.plan.TraceLocal

completeTrace, flush, getForwardedFinalizable, getForwardedReference, getForwardedReferenceType, getForwardedReferent, incrementalTrace, isReachable, isReferentLive, logMessage, overwriteReferenceDuringTrace, prepare, processEdge, processInteriorEdge, processNode, processRememberedSets, 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

Constructor Detail

MCForwardTraceLocal

public MCForwardTraceLocal(Trace trace)

Parameters:

trace - the associated global trace

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)

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.

In this instance, we refer objects in the mark-sweep space to the msSpace for tracing, and defer to the superclass for all others.

Overrides:

traceObject in class TraceLocal

Parameters:

object - The object to be traced.

Returns:

The new reference to the same object instance.

willNotMoveInCurrentCollection

public boolean willNotMoveInCurrentCollection(ObjectReference object)

Will this object move from this point on, during the current trace ?

Overrides:

willNotMoveInCurrentCollection in class TraceLocal

Parameters:

object - The object to query.

Returns:

true if the object will not move.