org.mmtk.plan.generational.marksweep

Class GenMSMutator

java.lang.Object

org.mmtk.plan.MutatorContext

org.mmtk.plan.SimpleMutator

org.mmtk.plan.StopTheWorldMutator

org.mmtk.plan.generational.GenMutator

org.mmtk.plan.generational.marksweep.GenMSMutator

public class GenMSMutator
extends GenMutator

This class implements per-mutator thread behavior and state for the GenMS two-generational copying collector.

Specifically, this class defines mutator-time semantics specific to the mature generation (GenMutator defines nursery semantics). In particular the mature space allocator is defined (for mutator-time allocation into the mature space via pre-tenuring), and the mature space per-mutator thread collection time semantics are defined (rebinding the mature space allocator).

See GenMS for a description of the GenMS algorithm.

See Also:

GenMS, GenMSCollector, GenMutator, StopTheWorldMutator, MutatorContext

Field Summary

Fields

Modifier and Type	Field and Description
private MarkSweepLocal	mature The allocator for the mark-sweep mature space (the mutator may "pretenure" objects into this space which is otherwise used only by the collector)

Fields inherited from class org.mmtk.plan.generational.GenMutator

arrayRemset, nursery, remset

Fields inherited from class org.mmtk.plan.MutatorContext

immortal, lgcode, log, los, nonmove, smcode

Constructor Summary

Constructors

Constructor and Description
GenMSMutator() 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 mutator context, in response to a requestMutatorFlush.
Allocator	getAllocatorFromSpace(Space space) Return the allocator instance associated with a space space, for this plan instance.
private static GenMS	global()
void	postAlloc(ObjectReference ref, ObjectReference typeRef, int bytes, int allocator) Perform post-allocation actions.

Methods inherited from class org.mmtk.plan.generational.GenMutator

assertRemsetsFlushed, flushRememberedSets, objectReferenceBulkCopy, objectReferenceNonHeapWrite, objectReferenceTryCompareAndSwap, objectReferenceWrite

Methods inherited from class org.mmtk.plan.MutatorContext

addressBulkCopy, addressRead, addressTryCompareAndSwap, addressWrite, booleanBulkCopy, booleanRead, booleanWrite, byteBulkCopy, byteRead, byteWrite, charBulkCopy, charRead, charWrite, checkAllocator, deinitMutator, doubleBulkCopy, doubleRead, doubleWrite, extentBulkCopy, extentRead, extentWrite, floatBulkCopy, floatRead, floatWrite, getId, getLog, initMutator, intBulkCopy, intRead, intTryCompareAndSwap, intWrite, javaLangReferenceReadBarrier, longBulkCopy, longRead, longTryCompareAndSwap, longWrite, objectReferenceNonHeapRead, objectReferenceRead, 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

mature

private final MarkSweepLocal mature

The allocator for the mark-sweep mature space (the mutator may "pretenure" objects into this space which is otherwise used only by the collector)

Constructor Detail

GenMSMutator

public GenMSMutator()

Constructor

Method Detail

alloc

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

Allocate memory for an object.

Overrides:

alloc in class GenMutator

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

Description copied from class: MutatorContext

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

Overrides:

postAlloc in class GenMutator

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 GenMutator

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 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 GenMutator

Parameters:

phaseId - The unique phase identifier

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

flush

public void flush()

Description copied from class: MutatorContext

Flush mutator context, in response to a requestMutatorFlush. Also called by the default implementation of deinitMutator.

Overrides:

flush in class MutatorContext

global

private static GenMS global()

Returns:

The active global plan as a GenMS instance.