org.mmtk.plan.concurrent.marksweep

Class CMS

java.lang.Object

org.mmtk.plan.Plan

org.mmtk.plan.Simple

org.mmtk.plan.concurrent.Concurrent

org.mmtk.plan.concurrent.marksweep.CMS

public class CMS
extends Concurrent

This class implements the global state of a concurrent mark-sweep collector.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MARK_SWEEP
static MarkSweepSpace	msSpace
Trace	msTrace

Fields inherited from class org.mmtk.plan.concurrent.Concurrent

CLEAR_BARRIER_ACTIVE, CONCURRENT_CLOSURE, concurrentClosure, FLUSH_COLLECTOR, FLUSH_MUTATOR, postSanityPhase, preemptConcurrentClosure, preSanityPhase, SET_BARRIER_ACTIVE

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
CMS()

Method Summary

Modifier and Type	Method and Description
void	collectionPhase(short phaseId) Perform a (global) collection phase.
int	getPagesUsed() Return the number of pages reserved for use given the pending allocation.
boolean	willNeverMove(ObjectReference object) Can this object ever move.

Methods inherited from class org.mmtk.plan.concurrent.Concurrent

concurrentCollectionRequired, lastCollectionFullHeap, processOptions

Methods inherited from class org.mmtk.plan.Simple

replacePhase, replacePlaceholderPhase, switchNurseryZeroingApproach

Methods inherited from class org.mmtk.plan.Plan

availableMemory, bootTimeWriteBarrier, collectionRequired, determineThreadCount, enableAllocation, enableCollection, forceFullHeapCollection, freeMemory, fullyBooted, gcInProgress, gcInProgressProper, getAllocationSite, getCollectionReserve, getPagesAvail, getPagesReserved, getSpecializedScanClass, getTotalPages, handleUserCollectionRequest, harnessBegin, harnessEnd, insertPhaseAfter, isCurrentGCNursery, isEmergencyCollection, isInitialized, isInternalTriggeredCollection, isUserTriggeredCollection, lastCollectionWasExhaustive, loadObjectReference, logPoll, notifyExit, poll, preCollectorSpawn, printDetailedTiming, printPostStats, printPreStats, printUsedPages, registerSpecializedMethods, reservedMemory, resetCollectionTrigger, sanityExpectedRC, sanityLinearScan, setBuildTimeGCByte, 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

msSpace

public static final MarkSweepSpace msSpace

MARK_SWEEP

public static final int MARK_SWEEP

msTrace

public final Trace msTrace

Constructor Detail

CMS

public CMS()

Method Detail

collectionPhase

public void collectionPhase(short phaseId)

Perform a (global) collection phase.

Overrides:

collectionPhase in class Concurrent

Parameters:

phaseId - The unique id of the phase to perform.

getPagesUsed

public int getPagesUsed()

Return the number of pages reserved for use given the pending allocation. The superclass accounts for its spaces, we just augment this with the mark-sweep space's contribution.

Overrides:

getPagesUsed in class Plan

Returns:

The number of pages reserved given the pending allocation, excluding space reserved for copying.

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.