org.multiverse.stms.alpha.transactions.update
Class MapUpdateAlphaTransaction

java.lang.Object
  org.multiverse.stms.AbstractTransaction<C,S>
      org.multiverse.stms.alpha.transactions.AbstractAlphaTransaction<UpdateConfiguration,org.multiverse.stms.AbstractTransactionSnapshot>
          org.multiverse.stms.alpha.transactions.update.AbstractUpdateAlphaTransaction
              org.multiverse.stms.alpha.transactions.update.MapUpdateAlphaTransaction

All Implemented Interfaces:

org.multiverse.api.Transaction, org.multiverse.MultiverseConstants, AlphaTransaction

public final class MapUpdateAlphaTransaction
extends AbstractUpdateAlphaTransaction

A AbstractUpdateAlphaTransaction implementation where the AlphaTranlocals are stored in an IdentityHashMap (to prevent unwanted equals/hashcode calls on AlphaTransactionalObjects.

This implementation is good for larger transaction sizes and is able to grow. In the future certain parts of this implementation (like writing, conflict detection etc) could be executed in parallel (e.g. by using the fork join framework).

Author:

Peter Veentjer.

Nested Class Summary

static class

MapUpdateAlphaTransaction.Factory

Field Summary

Fields inherited from class org.multiverse.stms.alpha.transactions.update.AbstractUpdateAlphaTransaction

updateTransactionStatus

Fields inherited from class org.multiverse.stms.AbstractTransaction

config

Fields inherited from interface org.multiverse.MultiverseConstants

___SANITY_CHECKS_ENABLED

Constructor Summary

MapUpdateAlphaTransaction(UpdateConfiguration config)

Method Summary

protected void	attach(AlphaTranlocal tranlocal) Attaches the tranlocal to this Transaction.
protected void	dodoClear()
protected boolean	dodoRegisterRetryLatch(org.multiverse.api.latches.Latch latch, long wakeupVersion)
protected void	doReleaseWriteLocksForFailure() Releases all the locks on the transactional objects of the attached tranlocals that have been acquired.
protected void	doReleaseWriteLocksForSuccess(long writeVersion) Releases the locks on the tranlocal objects of the attached tranlocals with the given writeVersion.
protected AlphaTranlocal	findAttached(AlphaTransactionalObject txObject) Finds the tranlocal for the given transactional object in the set of attached tranlocals.
protected boolean	hasReadConflict() Checks if the reads don't have conflicts.
protected boolean	hasWriteConflict() Checks if attached updated-items have a conflict.
protected boolean	isDirty() Returns the state of the attached tranlocals.
protected org.multiverse.api.Listeners[]	makeChangesPermanent(long writeVersion) Writes the tranlocals that need to be written to their transactional objects.
protected boolean	tryWriteLocks(org.multiverse.api.commitlock.CommitLockFilter commitLockFilter) Locks the writeset.

Methods inherited from class org.multiverse.stms.alpha.transactions.update.AbstractUpdateAlphaTransaction

doAbortPrepared, doClear, doOpenForCommutingWrite, doOpenForConstruction, doOpenForRead, doOpenForWrite, doOpenForWritePreviousCommittedAndAttach, doPrepare, doReleaseWriteLockForSuccess, doReleaseWriteSetLocksForFailure, hasReadConflict, hasWriteConflict, isDirty, makeChangesPermanent, makePermanent

Methods inherited from class org.multiverse.stms.alpha.transactions.AbstractAlphaTransaction

doRegisterRetryLatch, load, openForCommutingWrite, openForConstruction, openForRead, openForWrite

Methods inherited from class org.multiverse.stms.AbstractTransaction

abort, commit, doAbortActive, doInit, endOr, endOrAndStartElse, getAttempt, getConfiguration, getReadVersion, getRemainingTimeoutNs, getSnapshot, getStatus, init, prepare, registerLifecycleListener, registerRetryLatch, restart, setAttempt, setRemainingTimeoutNs, startOr, storeSnapshot, takeSnapshot

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.multiverse.api.Transaction

abort, commit, getAttempt, getConfiguration, getReadVersion, getRemainingTimeoutNs, getStatus, prepare, registerLifecycleListener, registerRetryLatch, restart, setAttempt, setRemainingTimeoutNs

Constructor Detail

MapUpdateAlphaTransaction

public MapUpdateAlphaTransaction(UpdateConfiguration config)

Method Detail

dodoClear

protected void dodoClear()

Specified by:

dodoClear in class AbstractUpdateAlphaTransaction

attach

protected void attach(AlphaTranlocal tranlocal)

Description copied from class: AbstractUpdateAlphaTransaction

Attaches the tranlocal to this Transaction. The tranlocal will never be null and this call is only made when no read for the transactional object of the readonly has been made. It is important that an implementation doesn't ignore this call.

Specified by:

attach in class AbstractUpdateAlphaTransaction

Parameters:

tranlocal - the opened AlphaTranlocal to attach.

findAttached

protected AlphaTranlocal findAttached(AlphaTransactionalObject txObject)

Description copied from class: AbstractUpdateAlphaTransaction

Finds the tranlocal for the given transactional object in the set of attached tranlocals.

Specified by:

findAttached in class AbstractUpdateAlphaTransaction

Parameters:

txObject - the transactional object to find the tranlocal for.

Returns:

the found tranlocal. If no tranlocal was found in the set of attached tranlocals, null is returned.

tryWriteLocks

protected boolean tryWriteLocks(org.multiverse.api.commitlock.CommitLockFilter commitLockFilter)

Description copied from class: AbstractUpdateAlphaTransaction

Locks the writeset. If the locks could not be obtained, false is returned.

todo: in the future the dirty check could be added. If something is an update, but not dirty there is no need to lock it under certain conditions (it causes the aba problem).

Specified by:

tryWriteLocks in class AbstractUpdateAlphaTransaction

Returns:

true if the writeset was locked successfully, false otherwise.

doReleaseWriteLocksForFailure

protected void doReleaseWriteLocksForFailure()

Description copied from class: AbstractUpdateAlphaTransaction

Releases all the locks on the transactional objects of the attached tranlocals that have been acquired. This call is made when the commit was not a success (so the writeversion still isn't set).

It is important that this call doesn't fail, because else it could leave transactional objects locked forever.

Specified by:

doReleaseWriteLocksForFailure in class AbstractUpdateAlphaTransaction

doReleaseWriteLocksForSuccess

protected void doReleaseWriteLocksForSuccess(long writeVersion)

Description copied from class: AbstractUpdateAlphaTransaction

Releases the locks on the tranlocal objects of the attached tranlocals with the given writeVersion. This call is made when the commit was a success.

It is important that this call doesn't fail, because else it could leave transactional objects locked forever.

Specified by:

doReleaseWriteLocksForSuccess in class AbstractUpdateAlphaTransaction

Parameters:

writeVersion - the writeVersion of the tranlocals to release.

isDirty

protected boolean isDirty()

Description copied from class: AbstractUpdateAlphaTransaction

Returns the state of the attached tranlocals. This information is needed for the transaction to decide what to do (write changes etc). It is important that the implementation should not stop after it finds one element that is dirty, it should check all attached objects. This is because the isDirty flag on each tranlocal needs to be cached for later use.

Specified by:

isDirty in class AbstractUpdateAlphaTransaction

Returns:

the AttachedState.

hasWriteConflict

protected boolean hasWriteConflict()

Description copied from class: AbstractUpdateAlphaTransaction

Checks if attached updated-items have a conflict. Call is made after the locks on the updates have been acquired. A conflict means that a new version of the tranlocal (that itself is a update) already is stored in in the transactional object.

Specified by:

hasWriteConflict in class AbstractUpdateAlphaTransaction

Returns:

true if at least 1 attached tranlocal has a conflict.

hasReadConflict

protected boolean hasReadConflict()

Description copied from class: AbstractUpdateAlphaTransaction

Checks if the reads don't have conflicts. The writes are neglected because they will be checked with the hasWriteConflict.

Specified by:

hasReadConflict in class AbstractUpdateAlphaTransaction

Returns:

true if there are conflict, false otherwise.

makeChangesPermanent

protected org.multiverse.api.Listeners[] makeChangesPermanent(long writeVersion)

Description copied from class: AbstractUpdateAlphaTransaction

Writes the tranlocals that need to be written to their transactional objects.

It is important that a store always completes. If it doesn't it could cause partially committed transactions.

Specified by:

makeChangesPermanent in class AbstractUpdateAlphaTransaction

Parameters:

writeVersion - the version of the commit.

Returns:

the array of listeners that need to be notified of the write (array is allowed to be null to prevent object creation).

dodoRegisterRetryLatch

protected boolean dodoRegisterRetryLatch(org.multiverse.api.latches.Latch latch,
                                         long wakeupVersion)

Specified by:

dodoRegisterRetryLatch in class AbstractAlphaTransaction<UpdateConfiguration,org.multiverse.stms.AbstractTransactionSnapshot>