org.mmtk.plan.poisoned

Class PoisonedMutator

java.lang.Object

org.mmtk.plan.MutatorContext

org.mmtk.plan.SimpleMutator

org.mmtk.plan.StopTheWorldMutator

org.mmtk.plan.marksweep.MSMutator

org.mmtk.plan.poisoned.PoisonedMutator

public class PoisonedMutator
extends MSMutator

This class implements a poisoned collector, that is essentially a test case for read and write barriers in the VM.

Field Summary

Fields inherited from class org.mmtk.plan.marksweep.MSMutator

ms

Fields inherited from class org.mmtk.plan.MutatorContext

immortal, lgcode, log, los, nonmove, smcode

Constructor Summary

Constructors

Constructor and Description
PoisonedMutator()

Method Summary

Modifier and Type	Method and Description
ObjectReference	objectReferenceRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) Read an object reference.
boolean	objectReferenceTryCompareAndSwap(ObjectReference src, Address slot, ObjectReference old, ObjectReference tgt, Word metaDataA, Word metaDataB, int mode) Attempt to atomically exchange the value in the given slot with the passed replacement value.
void	objectReferenceWrite(ObjectReference src, Address slot, ObjectReference tgt, Word metaDataA, Word metaDataB, int mode) Write an object reference.

Methods inherited from class org.mmtk.plan.marksweep.MSMutator

alloc, collectionPhase, flush, getAllocatorFromSpace, postAlloc

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, 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

Constructor Detail

PoisonedMutator

public PoisonedMutator()

Method Detail

objectReferenceWrite

public void objectReferenceWrite(ObjectReference src,
                                 Address slot,
                                 ObjectReference tgt,
                                 Word metaDataA,
                                 Word metaDataB,
                                 int mode)

Write an object reference. Take appropriate write barrier actions.

By default do nothing, override if appropriate.

Overrides:

objectReferenceWrite in class MutatorContext

Parameters:

src - The object into which the new reference will be stored

slot - The address into which the new reference will be stored.

tgt - The value of the new reference

metaDataA - A value that assists the host VM in creating a store

metaDataB - A value that assists the host VM in creating a store

mode - The context in which the store occurred

objectReferenceTryCompareAndSwap

public boolean objectReferenceTryCompareAndSwap(ObjectReference src,
                                                Address slot,
                                                ObjectReference old,
                                                ObjectReference tgt,
                                                Word metaDataA,
                                                Word metaDataB,
                                                int mode)

Description copied from class: MutatorContext

Attempt to atomically exchange the value in the given slot with the passed replacement value. If a new reference is created, we must then take appropriate write barrier actions.

By default do nothing, override if appropriate.

Overrides:

objectReferenceTryCompareAndSwap in class MutatorContext

Parameters:

src - The object into which the new reference will be stored

slot - The address into which the new reference will be stored.

old - The old reference to be swapped out

tgt - The target of the new reference

metaDataA - A value that assists the host VM in creating a store

metaDataB - A value that assists the host VM in creating a store

mode - The context in which the store occurred

Returns:

True if the swap was successful.

objectReferenceRead

public ObjectReference objectReferenceRead(ObjectReference src,
                                           Address slot,
                                           Word metaDataA,
                                           Word metaDataB,
                                           int mode)

Description copied from class: MutatorContext

Read an object reference. Take appropriate read barrier action, and return the value that was read.

This is a substituting barrier. The call to this barrier takes the place of a load.

Overrides:

objectReferenceRead in class MutatorContext

Parameters:

src - The object reference holding the field being read.

slot - The address of the slot being read.

metaDataA - A value that assists the host VM in creating a load

metaDataB - A value that assists the host VM in creating a load

mode - The context in which the load occurred

Returns:

The reference that was read.