org.mmtk.plan.refcount.generational

Class GenRC

java.lang.Object

org.mmtk.plan.Plan

org.mmtk.plan.Simple

org.mmtk.plan.StopTheWorld

org.mmtk.plan.refcount.RCBase

org.mmtk.plan.refcount.generational.GenRC

public class GenRC
extends RCBase

This class implements the global state of a a simple reference counting collector.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ALLOC_NURSERY
static int	ALLOC_RC
static int	NURSERY
static CopySpace	nurserySpace The nursery space is where all new objects are allocated by default

Fields inherited from class org.mmtk.plan.refcount.RCBase

backupTrace, BT_CLOSURE, BUILD_FOR_GENRC, CC_BACKUP_TRACE, CC_ENABLED, ccForceFull, decPool, genRCCollection, genRCCollectionPhase, genRCRootClosurePhase, modPool, newRootPool, oldRootPool, performCycleCollection, PROCESS_DECBUFFER, PROCESS_MODBUFFER, PROCESS_NEWROOTBUFFER, PROCESS_OLDROOTBUFFER, rcloSpace, rcSpace, REF_COUNT, REF_COUNT_LOS, refCountCollection, refCountCollectionPhase, refCountRootClosurePhase, rootTrace

Fields inherited from class org.mmtk.plan.StopTheWorld

postSanityPhase, preSanityPhase

Fields inherited from class org.mmtk.plan.Simple

CLOSURE, collection, collectionAttempt, COMPLETE, completeClosurePhase, FINALIZABLE, finishPhase, FORWARD, FORWARD_FINALIZABLE, FORWARD_REFS, forwardPhase, INITIATE, initPhase, PHANTOM_REFS, POST_SANITY_PLACEHOLDER, PRE_SANITY_PLACEHOLDER, PREPARE, PREPARE_STACKS, prepareStacks, refTypeClosurePhase, RELEASE, rootClosurePhase, ROOTS, SANITY_BUILD_TABLE, SANITY_CHECK_TABLE, SANITY_COPY_ROOTS, SANITY_PREPARE, SANITY_RELEASE, SANITY_ROOTS, SANITY_SET_POSTGC, SANITY_SET_PREGC, sanityBuildPhase, sanityCheckPhase, SET_COLLECTION_KIND, SOFT_REFS, STACK_ROOTS, WEAK_REFS, WEAK_TRACK_REFS

Fields inherited from class org.mmtk.plan.Plan

ALLOC_CODE, ALLOC_COLD_CODE, ALLOC_DEFAULT, ALLOC_GCSPY, ALLOC_HOT_CODE, ALLOC_IMMORTAL, ALLOC_LARGE_CODE, ALLOC_LOS, ALLOC_NON_MOVING, ALLOC_NON_REFERENCE, ALLOC_PRIMITIVE_LOS, ALLOC_STACK, allocationSiteCount, ALLOCATORS, concurrentWorkers, controlCollectorContext, DEFAULT_MAX_NURSERY, DEFAULT_MIN_NURSERY, DEFAULT_SITE, defaultCollectorContext, emergencyCollection, GATHER_WRITE_BARRIER_STATS, GC_PREPARE, GC_PROPER, IMMORTAL, immortalSpace, insideHarness, internalTriggeredCollection, LARGE_CODE, largeCodeSpace, lastInternalTriggeredCollection, LOS, loSpace, MAX_NON_LOS_COPY_BYTES, MAX_NON_LOS_DEFAULT_ALLOC_BYTES, MAX_NON_LOS_NONMOVING_ALLOC_BYTES, META, metaDataSpace, NEEDS_LOG_BIT_IN_HEADER, NON_MOVING, NON_PARTICIPANT, nonMovingSpace, NOT_IN_GC, parallelWorkers, pretenureThreshold, SANITY, sanityChecker, sanitySpace, SCAN_BOOT_IMAGE, SMALL_CODE, smallCodeSpace, stacksPrepared, totalTime, USE_CODE_SPACE, userTriggeredCollection, VM_SPACE, vmSpace

Constructor Summary

Constructors

Constructor and Description
GenRC()

Method Summary

Modifier and Type	Method and Description
void	collectionPhase(short phaseId) Perform a (global) collection phase.
boolean	collectionRequired(boolean spaceFull, Space space) This method controls the triggering of a GC.
void	fullyBooted()
int	getCollectionReserve() Return the number of pages reserved for copying.
int	getPagesAvail() Return the number of pages available for allocation, assuming all future allocation is to the nursery.
boolean	willNeverMove(ObjectReference object) Can this object ever move.

Methods inherited from class org.mmtk.plan.refcount.RCBase

getPagesUsed, isRCObject, lastCollectionFullHeap, processOptions, registerSpecializedMethods, sanityExpectedRC, sanityLinearScan, setBuildTimeGCByte

Methods inherited from class org.mmtk.plan.Simple

replacePhase, replacePlaceholderPhase, switchNurseryZeroingApproach

Methods inherited from class org.mmtk.plan.Plan

availableMemory, bootTimeWriteBarrier, concurrentCollectionRequired, determineThreadCount, enableAllocation, enableCollection, forceFullHeapCollection, freeMemory, gcInProgress, gcInProgressProper, getAllocationSite, getPagesReserved, getSpecializedScanClass, getTotalPages, handleUserCollectionRequest, harnessBegin, harnessEnd, insertPhaseAfter, isCurrentGCNursery, isEmergencyCollection, isInitialized, isInternalTriggeredCollection, isUserTriggeredCollection, lastCollectionWasExhaustive, loadObjectReference, logPoll, notifyExit, poll, preCollectorSpawn, printDetailedTiming, printPostStats, printPreStats, printUsedPages, reservedMemory, resetCollectionTrigger, setGCStatus, spawnCollectorThreads, stacksPrepared, startGCspyServer, storeObjectReference, stressTestGCRequired, totalMemory, triggerInternalCollectionRequest, usedMemory

Methods inherited from class java.lang.Object

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

Field Detail

ALLOC_NURSERY

public static final int ALLOC_NURSERY

See Also:

Constant Field Values

ALLOC_RC

public static final int ALLOC_RC

See Also:

Constant Field Values

nurserySpace

public static final CopySpace nurserySpace

The nursery space is where all new objects are allocated by default

NURSERY

public static final int NURSERY

Constructor Detail

GenRC

public GenRC()

Method Detail

collectionPhase

public final void collectionPhase(short phaseId)

Perform a (global) collection phase.

Overrides:

collectionPhase in class RCBase

Parameters:

phaseId - The unique id of the phase to perform.

collectionRequired

public final boolean collectionRequired(boolean spaceFull,
                                        Space space)

Description copied from class: Plan

This method controls the triggering of a GC. It is called periodically during allocation. Returns true to trigger a collection.

Overrides:

collectionRequired in class Plan

Parameters:

spaceFull - Space request failed, must recover pages within 'space'.

space - TODO

Returns:

true if a collection is requested by the plan.

getPagesAvail

public int getPagesAvail()

Return the number of pages available for allocation, assuming all future allocation is to the nursery.

Overrides:

getPagesAvail in class Plan

Returns:

The number of pages available for allocation, assuming all future allocation is to the nursery.

getCollectionReserve

public final int getCollectionReserve()

Return the number of pages reserved for copying.

Overrides:

getCollectionReserve in class Plan

Returns:

The number of pages reserved given the pending allocation, including space reserved for collection.

willNeverMove

public boolean willNeverMove(ObjectReference object)

Description copied from class: Plan

Can this object ever move. Used by the VM to make decisions about whether it needs to copy IO buffers etc.

Overrides:

willNeverMove in class Plan

Parameters:

object - The object in question

Returns:

true if it is not possible that the object will ever move.

fullyBooted

public void fullyBooted()

Overrides:

fullyBooted in class Plan