org.mmtk.plan.copyms
Class CopyMSTraceLocal

java.lang.Object
  extended by org.mmtk.plan.TransitiveClosure
      extended by org.mmtk.plan.TraceLocal
          extended by org.mmtk.plan.copyms.CopyMSTraceLocal
All Implemented Interfaces:
Constants

public final class CopyMSTraceLocal
extends TraceLocal

This class implements the thread-local functionality for a transitive closure over a coping/mark-sweep hybrid collector.


Field Summary
 
Fields inherited from class org.mmtk.plan.TraceLocal
rootLocations, values
 
Fields inherited from class org.mmtk.plan.TransitiveClosure
specializedScan
 
Fields inherited from interface org.mmtk.utility.Constants
ALIGNMENT_VALUE, ARRAY_ELEMENT, BITS_IN_ADDRESS, BITS_IN_BYTE, BITS_IN_CHAR, BITS_IN_INT, BITS_IN_PAGE, BITS_IN_SHORT, BITS_IN_WORD, BYTES_IN_ADDRESS, BYTES_IN_BYTE, BYTES_IN_CHAR, BYTES_IN_INT, BYTES_IN_KBYTE, BYTES_IN_MBYTE, BYTES_IN_PAGE, BYTES_IN_SHORT, BYTES_IN_WORD, CARD_MASK, CARD_META_PAGES_PER_REGION, INSTANCE_FIELD, LOG_BITS_IN_ADDRESS, LOG_BITS_IN_BYTE, LOG_BITS_IN_CHAR, LOG_BITS_IN_INT, LOG_BITS_IN_PAGE, LOG_BITS_IN_SHORT, LOG_BITS_IN_WORD, LOG_BYTES_IN_ADDRESS, LOG_BYTES_IN_ADDRESS_SPACE, LOG_BYTES_IN_BYTE, LOG_BYTES_IN_CHAR, LOG_BYTES_IN_INT, LOG_BYTES_IN_KBYTE, LOG_BYTES_IN_MBYTE, LOG_BYTES_IN_PAGE, LOG_BYTES_IN_SHORT, LOG_BYTES_IN_WORD, LOG_CARD_BYTES, LOG_CARD_GRAIN, LOG_CARD_META_BYTES, LOG_CARD_META_PAGES, LOG_CARD_META_SIZE, LOG_CARD_UNITS, LOG_MIN_ALIGNMENT, MAX_ALIGNMENT, MAX_BYTES_PADDING, MAX_INT, MIN_ALIGNMENT, MIN_INT, SUPPORT_CARD_SCANNING
 
Constructor Summary
CopyMSTraceLocal(Trace trace)
          Constructor
 
Method Summary
 boolean isLive(ObjectReference object)
          Is the specified object reachable?
 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 collection ?
 
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

CopyMSTraceLocal

public CopyMSTraceLocal(Trace trace)
Constructor

Method Detail

isLive

public boolean isLive(ObjectReference object)
Is the specified object reachable?

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 collection ?

Overrides:
willNotMoveInCurrentCollection in class TraceLocal
Parameters:
object - The object to query.
Returns:
true If the object will not move during collection