org.mmtk.plan.semispace
Class SSCollector

java.lang.Object
  extended by org.mmtk.plan.CollectorContext
      extended by org.mmtk.plan.ParallelCollector
          extended by org.mmtk.plan.SimpleCollector
              extended by org.mmtk.plan.StopTheWorldCollector
                  extended by org.mmtk.plan.semispace.SSCollector
All Implemented Interfaces:
Constants
Direct Known Subclasses:
GCTraceCollector, SSGCspyCollector, UsePrimitiveWriteBarriersCollector

public class SSCollector
extends StopTheWorldCollector

This class implements per-collector thread behavior and state for the SS plan, which implements a full-heap semi-space collector.

Specifically, this class defines SS collection behavior (through trace and the collectionPhase method), and collection-time allocation (copying of objects).

See SS for an overview of the semi-space algorithm.

See Also:
SS, SSMutator, StopTheWorldCollector, CollectorContext

Field Summary
protected  LargeObjectLocal los
           
protected  CopyLocal ss
           
protected  SSTraceLocal trace
           
 
Fields inherited from class org.mmtk.plan.SimpleCollector
sanityLocal
 
Fields inherited from class org.mmtk.plan.ParallelCollector
group
 
Fields inherited from class org.mmtk.plan.CollectorContext
log
 
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
  SSCollector()
          Constructor
protected SSCollector(SSTraceLocal tr)
          Constructor
 
Method Summary
 Address allocCopy(ObjectReference original, int bytes, int align, int offset, int allocator)
          Allocate space for copying an object (this method does not copy the object, it only allocates space)
 void collectionPhase(short phaseId, boolean primary)
          Perform a (local, i.e.per-collector) collection phase.
 TraceLocal getCurrentTrace()
           
private static SS global()
           
static boolean isSemiSpaceObject(ObjectReference object)
          Return true if the given reference is to an object that is within one of the semi-spaces.
 void postCopy(ObjectReference object, ObjectReference typeRef, int bytes, int allocator)
          Perform any post-copy actions.
 
Methods inherited from class org.mmtk.plan.StopTheWorldCollector
collect, concurrentCollect, concurrentCollectionPhase
 
Methods inherited from class org.mmtk.plan.ParallelCollector
parallelWorkerCount, parallelWorkerOrdinal, park, rendezvous, run
 
Methods inherited from class org.mmtk.plan.CollectorContext
copyCheckAllocator, getId, getLog, initCollector
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

trace

protected final SSTraceLocal trace

ss

protected final CopyLocal ss

los

protected final LargeObjectLocal los
Constructor Detail

SSCollector

public SSCollector()
Constructor


SSCollector

protected SSCollector(SSTraceLocal tr)
Constructor

Parameters:
tr - The trace to use
Method Detail

allocCopy

public Address allocCopy(ObjectReference original,
                         int bytes,
                         int align,
                         int offset,
                         int allocator)
Allocate space for copying an object (this method does not copy the object, it only allocates space)

Overrides:
allocCopy in class CollectorContext
Parameters:
original - The object that is being copied.
bytes - The size of the space to be allocated (in bytes)
align - Required alignment for the copy
offset - Offset associated with the alignment.
allocator - The allocator associated with this request
Returns:
The address of the first byte of the allocated region

postCopy

public void postCopy(ObjectReference object,
                     ObjectReference typeRef,
                     int bytes,
                     int allocator)
Description copied from class: CollectorContext
Perform any post-copy actions.

Overrides:
postCopy in class CollectorContext
Parameters:
object - The newly allocated object.
typeRef - the type reference for the instance being created.
bytes - The size of the space to be allocated (in bytes).
allocator - The allocator statically assigned to this allocation.

collectionPhase

public void collectionPhase(short phaseId,
                            boolean primary)
Perform a (local, i.e.per-collector) collection phase.

Overrides:
collectionPhase in class SimpleCollector
Parameters:
phaseId - The unique phase identifier
primary - Should this thread be used to execute any single-threaded local operations?

isSemiSpaceObject

public static boolean isSemiSpaceObject(ObjectReference object)
Return true if the given reference is to an object that is within one of the semi-spaces.

Parameters:
object - The object in question
Returns:
true if the given reference is to an object that is within one of the semi-spaces.

global

private static SS global()
Returns:
The active global plan as an SS instance.

getCurrentTrace

public TraceLocal getCurrentTrace()
Overrides:
getCurrentTrace in class ParallelCollector
Returns:
The current trace instance.