org.multiverse.stms.gamma.transactions.lean
Class LeanFixedLengthGammaTxn

java.lang.Object
  org.multiverse.stms.gamma.transactions.GammaTxn
      org.multiverse.stms.gamma.transactions.lean.LeanFixedLengthGammaTxn

All Implemented Interfaces:

Txn, MultiverseConstants, GammaConstants

public final class LeanFixedLengthGammaTxn
extends GammaTxn

A Lean GammaTxn that is optimized for a fixed number of GammaTxnRefs.

Field Summary

boolean	hasReads
Tranlocal	head
Listeners[]	listenersArray
int	size

Fields inherited from class org.multiverse.stms.gamma.transactions.GammaTxn

abortOnly, attempt, commitConflict, config, evaluatingCommute, hasWrites, listeners, pool, remainingTimeoutNs, retryListener, richmansMansConflictScan, status, transactionType

Fields inherited from interface org.multiverse.stms.gamma.GammaConstants

FAILURE, MASK_CONFLICT, MASK_SUCCESS, MASK_UNREGISTERED, REGISTRATION_DONE, REGISTRATION_NONE, REGISTRATION_NOT_NEEDED, TRANLOCAL_COMMUTING, TRANLOCAL_CONSTRUCTING, TRANLOCAL_READ, TRANLOCAL_WRITE, TRANSACTIONTYPE_FAT_FIXED_LENGTH, TRANSACTIONTYPE_FAT_MONO, TRANSACTIONTYPE_FAT_VARIABLE_LENGTH, TRANSACTIONTYPE_LEAN_FIXED_LENGTH, TRANSACTIONTYPE_LEAN_MONO, TX_ABORTED, TX_ACTIVE, TX_COMMITTED, TX_PREPARED, TYPE_BOOLEAN, TYPE_DOUBLE, TYPE_INT, TYPE_LONG, TYPE_REF, VERSION_UNCOMMITTED

Fields inherited from interface org.multiverse.MultiverseConstants

LOCKMODE_EXCLUSIVE, LOCKMODE_NONE, LOCKMODE_READ, LOCKMODE_WRITE, SHAKE_BUGS, SPIN_YIELD, TRACING_ENABLED

Constructor Summary

LeanFixedLengthGammaTxn(GammaStm stm)

LeanFixedLengthGammaTxn(GammaTxnConfig config)

Method Summary

void	abort() Aborts this Txn.
void	commit() Commits this Txn.
Tranlocal	getRefTranlocal(BaseGammaTxnRef ref) Gets the Tranlocal for a specific AbstractGammaTxnRef.
void	hardReset() Does a hard reset of an aborted/committed transaction.
void	initLocalConflictCounter() Initializes the local conflict counter if the transaction has a need for it.
boolean	isReadConsistent(Tranlocal justAdded)
Tranlocal	locate(BaseGammaTxnRef o)
void	prepare() Prepares this transaction to be committed.
void	retry() Retries the transaction.
void	shiftInFront(Tranlocal newHead)
boolean	softReset() Does a soft reset of an aborted/committed transaction.

Methods inherited from class org.multiverse.stms.gamma.transactions.GammaTxn

abortAcquireOnNullLockMode, abortCommitOnAbortOnly, abortCommitOnBadStatus, abortCommuteOnBadStatus, abortCommuteOnBadStm, abortCommuteOnCommuteDetected, abortCommuteOnNullFunction, abortCommuteOnReadonly, abortEnsureOnBadStatus, abortEnsureOnEnsureDetected, abortIfAlive, abortLocateOnBadStatus, abortLocateOnNullArgument, abortOnOpenForCommuteWhileEvaluatingCommute, abortOnOpenForConstructionWhileEvaluatingCommute, abortOnOpenForReadWhileEvaluatingCommute, abortOnReadWriteConflict, abortOnRichmanConflictScanDetected, abortOnTransactionTooSmall, abortOpenForConstructionOnBadReference, abortOpenForConstructionOnBadStatus, abortOpenForConstructionOnBadStm, abortOpenForConstructionOnReadonly, abortOpenForConstructionRequired, abortOpenForReadOnBadStatus, abortOpenForReadOnBadStm, abortOpenForReadOnNonRefTypeDetected, abortOpenForReadOnNullLockMode, abortOpenForReadOrWriteOnExplicitLockingDetected, abortOpenForWriteOnReadonly, abortPrepareOnAbortOnly, abortPrepareOnBadStatus, abortRegisterOnListenerRequired, abortRetryOnBadStatus, abortRetryOnNoBlockingAllowed, abortRetryOnNoRetryPossible, awaitUpdate, copyForSpeculativeFailure, failAbortOnAlreadyCommitted, getAttempt, getConfig, getRemainingTimeoutNs, getStatus, hasWrites, init, isAbortOnly, isAlive, isLean, newRetryError, notifyListeners, register, setAbortOnly, skipPrepare

Methods inherited from class java.lang.Object

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

Field Detail

head

public Tranlocal head

size

public int size

hasReads

public boolean hasReads

listenersArray

public final Listeners[] listenersArray

Constructor Detail

LeanFixedLengthGammaTxn

public LeanFixedLengthGammaTxn(GammaStm stm)

LeanFixedLengthGammaTxn

public LeanFixedLengthGammaTxn(GammaTxnConfig config)

Method Detail

isReadConsistent

public final boolean isReadConsistent(Tranlocal justAdded)

Specified by:

isReadConsistent in class GammaTxn

commit

public final void commit()

Description copied from interface: Txn

Commits this Txn. If the Txn is:

1. active: it is prepared for commit and then committed
2. prepared: it is committed. Once it is prepared, the commit is guaranteed to succeed.
3. aborted: a DeadTxnException is thrown
4. committed: the call is ignored

Txn will always be aborted if the commit does not succeed.

Commit will not throw a ReadWriteConflict after the transaction is prepared. So if prepared successfully, a commit will always succeed.

If there are TxnListeners (either normal ones or permanent ones) and they thrown a RuntimeException or Error, this will be re-thrown. If a listener fails after the prepare/commit the transaction still is committed.

Specified by:

commit in interface Txn

Specified by:

commit in class GammaTxn

prepare

public final void prepare()

Description copied from interface: Txn

Prepares this transaction to be committed. It can lock resources to make sure that no conflicting changes are made after the transaction has been prepared. If the transaction already is prepared, the call is ignored. If the prepare fails, the transaction automatically is aborted. Once a transaction is prepared, the commit will always succeed.

It is very important that the transaction eventually commits or aborts, if it doesn't no other transaction reading/writing the committed resources, can't commit.

abort

public final void abort()

Description copied from interface: Txn

Aborts this Txn. This means that the changes made in this transaction are not committed. It depends on the implementation if this operation is simple (ditching objects for example), or if changes need to be rolled back. If an exception is thrown while executing the abort, the transaction is still aborted. And example of such a situation is a pre-abort task that fails. So the transaction always is aborted (unless it is committed).

If the Txn already is aborted, the call is ignored.

Specified by:

abort in interface Txn

Specified by:

abort in class GammaTxn

getRefTranlocal

public final Tranlocal getRefTranlocal(BaseGammaTxnRef ref)

Description copied from class: GammaTxn

Gets the Tranlocal for a specific AbstractGammaTxnRef. This method doesn't care about the state of a transaction.

Specified by:

getRefTranlocal in class GammaTxn

Parameters:

ref - the AbstractGammaTxnRef

Returns:

the found Tranlocal or null if not found.

retry

public final void retry()

Description copied from interface: Txn

Retries the transaction. This call doesn't block, but if all goes well a RetryError is thrown which is caught by the TxnExecutor.

locate

public final Tranlocal locate(BaseGammaTxnRef o)

Specified by:

locate in class GammaTxn

hardReset

public final void hardReset()

Description copied from class: GammaTxn

Does a hard reset of an aborted/committed transaction. This means that it is made ready to be used by another transaction configuration.

Specified by:

hardReset in class GammaTxn

softReset

public final boolean softReset()

Description copied from class: GammaTxn

Does a soft reset of an aborted/committed transaction. This method is called when the execution of a transaction fails, but needs to be retried again.

Specified by:

softReset in class GammaTxn

Returns:

if another attempt can be made, false otherwise.

shiftInFront

public final void shiftInFront(Tranlocal newHead)

initLocalConflictCounter

public void initLocalConflictCounter()

Description copied from class: GammaTxn

Initializes the local conflict counter if the transaction has a need for it. It should only be initialized if there are no reads.

Specified by:

initLocalConflictCounter in class GammaTxn