Overview  Package   Class  Use  Tree  Serialized  Deprecated  Index  Help 
 PREV CLASS   NEXT CLASS FRAMES    NO FRAMES    
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD

org.mmtk.plan.generational.immix
Class GenImmixMatureDefragTraceLocal

java.lang.Object
  extended by org.mmtk.plan.TransitiveClosure
      extended by org.mmtk.plan.TraceLocal
          extended by org.mmtk.plan.generational.GenMatureTraceLocal
              extended by org.mmtk.plan.generational.immix.GenImmixMatureDefragTraceLocal
All Implemented Interfaces:
Constants
public final class GenImmixMatureDefragTraceLocal
extends GenMatureTraceLocal

This class implments the core functionality for a transitive closure over the heap graph, specifically in a defragmenting pass over a generational immix 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
GenImmixMatureDefragTraceLocal(Trace global, GenCollector plan)
          Constructor
 
Method Summary
 boolean isLive(ObjectReference object)
          Is the specified object live?
 ObjectReference precopyObject(ObjectReference object)
          Ensure that this object will not move for the rest of the GC.
protected  void scanObject(ObjectReference object)
          Collectors that move objects must override this method.
 ObjectReference traceObject(ObjectReference object)
          This method is the core method during the trace of the object graph.
 boolean willNotMoveInCurrentCollection(ObjectReference object)
          Return true if this object is guaranteed not to move during this collection (i.e. this object is defintely not an unforwarded object).
 
Methods inherited from class org.mmtk.plan.generational.GenMatureTraceLocal
processRememberedSets
 
Methods inherited from class org.mmtk.plan.TraceLocal
completeTrace, flush, getForwardedFinalizable, getForwardedReference, getForwardedReferenceType, getForwardedReferent, incrementalTrace, isReachable, isReferentLive, logMessage, prepare, processEdge, processInteriorEdge, processNode, processPrecopyEdge, processRootEdge, processRoots, readyToFinalize, release, reportDelayedRootEdge, retainForFinalize, retainReferent, 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

GenImmixMatureDefragTraceLocal

public GenImmixMatureDefragTraceLocal(Trace global,
                                      GenCollector plan)
Constructor

Method Detail

isLive

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

Overrides:
isLive in class GenMatureTraceLocal
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.

Overrides:
traceObject in class GenMatureTraceLocal
Parameters:
object - The object to be traced.
Returns:
The new reference to the same object instance.

precopyObject

public ObjectReference precopyObject(ObjectReference object)
Description copied from class: TraceLocal
Ensure that this object will not move for the rest of the GC.

Overrides:
precopyObject in class TraceLocal
Parameters:
object - The object that must not move
Returns:
The new object, guaranteed stable for the rest of the GC.

willNotMoveInCurrentCollection

public boolean willNotMoveInCurrentCollection(ObjectReference object)
Return true if this object is guaranteed not to move during this collection (i.e. this object is defintely not an unforwarded object).

Overrides:
willNotMoveInCurrentCollection in class GenMatureTraceLocal
Parameters:
object -
Returns:
True if this object is guaranteed not to move during this collection.

scanObject

protected void scanObject(ObjectReference object)
Collectors that move objects must override this method. It performs the deferred scanning of objects which are forwarded during bootstrap of each copying collection. Because of the complexities of the collection bootstrap (such objects are generally themselves gc-critical), the forwarding and scanning of the objects must be dislocated. It is an error for a non-moving collector to call this method.

Overrides:
scanObject in class TraceLocal
Parameters:
object - The forwarded object to be scanned
Overview  Package   Class  Use  Tree  Serialized  Deprecated  Index  Help 
 PREV CLASS   NEXT CLASS FRAMES    NO FRAMES    
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD