org.mmtk.plan.markcompact

Class MCMutator

java.lang.Object

org.mmtk.plan.MutatorContext

org.mmtk.plan.SimpleMutator

org.mmtk.plan.StopTheWorldMutator

org.mmtk.plan.markcompact.MCMutator

public class MCMutator
extends StopTheWorldMutator

This class implements per-mutator thread behavior and state for the MC plan, which implements a full-heap mark-compact collector.

Specifically, this class defines MC mutator-time allocation and per-mutator thread collection semantics (flushing and restoring per-mutator allocator state).

See MC for an overview of the mark-compact algorithm.

See Also:

MC, MCCollector, StopTheWorldMutator, MutatorContext

Field Summary

Fields

Modifier and Type	Field and Description
private MarkCompactLocal	mc Instance fields

Fields inherited from class org.mmtk.plan.MutatorContext

immortal, lgcode, log, los, nonmove, smcode

Constructor Summary

Constructors

Constructor and Description
MCMutator() Constructor

Method Summary

Modifier and Type	Method and Description
Address	alloc(int bytes, int align, int offset, int allocator, int site) Allocate memory for an object.
void	collectionPhase(short phaseId, boolean primary) Perform a per-mutator collection phase.
void	flush() Flush the pages this mutator has allocated back to the global dirty page list, where the collectors can find them.
Allocator	getAllocatorFromSpace(Space space) Return the allocator instance associated with a space space, for this plan instance.
void	postAlloc(ObjectReference ref, ObjectReference typeRef, int bytes, int allocator) Perform post-allocation actions.

Methods inherited from class org.mmtk.plan.MutatorContext

addressBulkCopy, addressRead, addressTryCompareAndSwap, addressWrite, assertRemsetsFlushed, booleanBulkCopy, booleanRead, booleanWrite, byteBulkCopy, byteRead, byteWrite, charBulkCopy, charRead, charWrite, checkAllocator, deinitMutator, doubleBulkCopy, doubleRead, doubleWrite, extentBulkCopy, extentRead, extentWrite, floatBulkCopy, floatRead, floatWrite, flushRememberedSets, getId, getLog, initMutator, intBulkCopy, intRead, intTryCompareAndSwap, intWrite, javaLangReferenceReadBarrier, longBulkCopy, longRead, longTryCompareAndSwap, longWrite, objectReferenceBulkCopy, objectReferenceNonHeapRead, objectReferenceNonHeapWrite, objectReferenceRead, objectReferenceTryCompareAndSwap, objectReferenceWrite, offsetBulkCopy, offsetRead, offsetWrite, shortBulkCopy, shortRead, shortWrite, wordBulkCopy, wordRead, wordTryCompareAndSwap, wordWrite

Methods inherited from class java.lang.Object

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

Field Detail

mc

private final MarkCompactLocal mc

Instance fields

Constructor Detail

MCMutator

public MCMutator()

Constructor

Method Detail

alloc

public Address alloc(int bytes,
                     int align,
                     int offset,
                     int allocator,
                     int site)

Allocate memory for an object.

This class handles the default allocator from the mark sweep space, and delegates everything else to the superclass.

Overrides:

alloc in class MutatorContext

Parameters:

bytes - The number of bytes required for the object.

align - Required alignment for the object.

offset - Offset associated with the alignment.

allocator - The allocator associated with this request.

site - Allocation site

Returns:

The low address of the allocated chunk.

postAlloc

public void postAlloc(ObjectReference ref,
                      ObjectReference typeRef,
                      int bytes,
                      int allocator)

Perform post-allocation actions. For many allocators none are required.

Initialize the object header for objects in the mark-sweep space, and delegate to the superclass for other objects.

Overrides:

postAlloc in class MutatorContext

Parameters:

ref - 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 number to be used for this allocation

getAllocatorFromSpace

public Allocator getAllocatorFromSpace(Space space)

Description copied from class: MutatorContext

Return the allocator instance associated with a space space, for this plan instance.

Overrides:

getAllocatorFromSpace in class MutatorContext

Parameters:

space - The space for which the allocator instance is desired.

Returns:

The allocator instance associated with this plan instance which is allocating into space, or null if no appropriate allocator can be established.

collectionPhase

public final void collectionPhase(short phaseId,
                                  boolean primary)

Perform a per-mutator collection phase. This is executed by one collector thread on behalf of a mutator thread.

Overrides:

collectionPhase in class SimpleMutator

Parameters:

phaseId - The unique phase identifier

primary - Should this thread be used to execute any single-threaded local operations?

flush

public void flush()

Flush the pages this mutator has allocated back to the global dirty page list, where the collectors can find them.

Overrides:

flush in class MutatorContext