Package org.multiverse.stms.gamma

Class GammaStm.GammaTxnFactoryBuilderImpl

java.lang.Object

org.multiverse.stms.gamma.GammaStm.GammaTxnFactoryBuilderImpl

All Implemented Interfaces:

TxnFactoryBuilder, GammaTxnFactoryBuilder

Enclosing class:

GammaStm

private final class GammaStm.GammaTxnFactoryBuilderImpl
extends java.lang.Object
implements GammaTxnFactoryBuilder

Field Summary

Fields

Modifier and Type	Field	Description
private GammaTxnConfig	config

Constructor Summary

Constructors

Constructor	Description
GammaTxnFactoryBuilderImpl(GammaTxnConfig config)

Method Summary

Modifier and Type	Method	Description
GammaTxnFactoryBuilder	addPermanentListener(TxnListener listener)	Adds a permanent Txn TxnListener.
GammaTxnConfig	getConfig()	Returns the TxnConfig used by this TxnFactoryBuilder.
private boolean	isLean()
GammaTxnFactory	newTransactionFactory()	Builds a new TxnFactory.
GammaTxnExecutor	newTxnExecutor()	Builds a new TxnExecutor optimized for executing transactions created by this TxnFactoryBuilder.
GammaTxnFactoryBuilder	setBackoffPolicy(BackoffPolicy backoffPolicy)	Sets the Txn BackoffPolicy.
GammaTxnFactoryBuilder	setBlockingAllowed(boolean blockingAllowed)	Sets if the Txn is allowed to do an explicit retry (needed for a blocking operation).
GammaTxnFactoryBuilder	setControlFlowErrorsReused(boolean reused)	Sets if the ControlFlowError is reused.
GammaTxnFactoryBuilder	setDirtyCheckEnabled(boolean dirtyCheckEnabled)	Sets if the Txn dirty check is enabled.
GammaTxnFactoryBuilder	setFamilyName(java.lang.String familyName)	Sets the Txn familyname.
GammaTxnFactoryBuilder	setFat()
GammaTxnFactoryBuilder	setInterruptible(boolean interruptible)	Sets if the Txn can be interrupted while doing blocking operations.
GammaTxnFactoryBuilder	setIsolationLevel(IsolationLevel isolationLevel)	Sets the IsolationLevel on the Txn.
GammaTxnFactoryBuilder	setMaxRetries(int maxRetries)	Sets the the maximum count a Txn can be retried.
GammaTxnFactoryBuilder	setPropagationLevel(PropagationLevel level)	Sets the PropagationLevel used.
GammaTxnFactoryBuilder	setReadLockMode(LockMode lockMode)	Sets the Txn LockMode for all reads.
GammaTxnFactoryBuilder	setReadonly(boolean readonly)	Sets the readonly property on a Txn.
GammaTxnFactoryBuilder	setReadTrackingEnabled(boolean enabled)	Sets if the Txn should automatically track all reads that have been done.
GammaTxnFactoryBuilder	setSpeculative(boolean enabled)	With the speculative configuration enabled, the Stm is allowed to determine optimal settings for a Txn.
GammaTxnFactoryBuilder	setSpinCount(int spinCount)	Sets the maximum number of spins that are allowed when a Txn can't be read/written/locked because it is locked by another transaction.
GammaTxnFactoryBuilder	setTimeoutNs(long timeoutNs)	Sets the timeout (the maximum time a Txn is allowed to block.
GammaTxnFactoryBuilder	setTraceLevel(TraceLevel traceLevel)	Sets the Txn TraceLevel.
GammaTxnFactoryBuilder	setWriteLockMode(LockMode lockMode)	Sets the Txn LockMode for all writes.

Methods inherited from class java.lang.Object

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

Field Detail

config

private final GammaTxnConfig config

Constructor Detail

GammaTxnFactoryBuilderImpl

GammaTxnFactoryBuilderImpl(GammaTxnConfig config)

Method Detail

setFat

public final GammaTxnFactoryBuilder setFat()

Specified by:

setFat in interface GammaTxnFactoryBuilder

getConfig

public final GammaTxnConfig getConfig()

Description copied from interface: TxnFactoryBuilder

Returns the TxnConfig used by this TxnFactoryBuilder.

Specified by:

getConfig in interface GammaTxnFactoryBuilder

Specified by:

getConfig in interface TxnFactoryBuilder

Returns:

the used TxnConfig.

addPermanentListener

public GammaTxnFactoryBuilder addPermanentListener(TxnListener listener)

Description copied from interface: TxnFactoryBuilder

Adds a permanent Txn TxnListener. All permanent listeners are always executed after all normal listeners are executed. If the same listener is added multiple times, it will be executed multiple times.

This method is very useful for integrating Multiverse in other JVM based environments because with this approach you have a callback when transaction aborts/commit and can add your own logic. See the TxnListener for more information about normal vs permanent listeners.

Specified by:

addPermanentListener in interface GammaTxnFactoryBuilder

Specified by:

addPermanentListener in interface TxnFactoryBuilder

Parameters:

listener - the permanent listener to add.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.getPermanentListeners()

setControlFlowErrorsReused

public final GammaTxnFactoryBuilder setControlFlowErrorsReused(boolean reused)

Description copied from interface: TxnFactoryBuilder

Sets if the ControlFlowError is reused. Normally you don't want to reuse them because they can be expensive to create (especially the stacktrace) and they could be created very often. But for debugging purposes it can be quite annoying because you want to see the stacktrace.

Specified by:

setControlFlowErrorsReused in interface GammaTxnFactoryBuilder

Specified by:

setControlFlowErrorsReused in interface TxnFactoryBuilder

Parameters:

reused - true if ControlFlowErrors should be reused.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.isControlFlowErrorsReused()

setReadLockMode

public final GammaTxnFactoryBuilder setReadLockMode(LockMode lockMode)

Description copied from interface: TxnFactoryBuilder

Sets the Txn LockMode for all reads. If a LockMode is set higher than LockMode.None, this transaction will locks all reads (and writes since a read is needed for a write) and the transaction automatically becomes serialized.

Specified by:

setReadLockMode in interface GammaTxnFactoryBuilder

Specified by:

setReadLockMode in interface TxnFactoryBuilder

Parameters:

lockMode - the LockMode to set.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.getReadLockMode(), LockMode

setWriteLockMode

public final GammaTxnFactoryBuilder setWriteLockMode(LockMode lockMode)

Description copied from interface: TxnFactoryBuilder

Sets the Txn LockMode for all writes. For a write, always a read needs to be done, so if the read LockMode is

Freshly constructed objects that are not committed, automatically are locked with LockMode.Exclusive.

If the write LockMode is set after the read LockMode and the write LockMode is lower than the read LockMode, an IllegalTxnFactoryException will be thrown when a TxnFactory is created.

If the write LockMode is set before the read LockMode and the write LockMode is lower than the read LockMode, the write LockMode automatically is upgraded to that of the read LockMode. This makes setting the readLock mode less of a nuisance.

Specified by:

setWriteLockMode in interface GammaTxnFactoryBuilder

Specified by:

setWriteLockMode in interface TxnFactoryBuilder

Parameters:

lockMode - the LockMode to set.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.getWriteLockMode(), LockMode

setFamilyName

public final GammaTxnFactoryBuilder setFamilyName(java.lang.String familyName)

Description copied from interface: TxnFactoryBuilder

Sets the Txn familyname. If an TxnExecutor is used inside a method, a useful familyname could be the full name of the class and the method.

The transaction familyName is useful debugging purposes, but has not other meaning.

Specified by:

setFamilyName in interface GammaTxnFactoryBuilder

Specified by:

setFamilyName in interface TxnFactoryBuilder

Parameters:

familyName - the familyName of the transaction.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getFamilyName()

setPropagationLevel

public final GammaTxnFactoryBuilder setPropagationLevel(PropagationLevel level)

Description copied from interface: TxnFactoryBuilder

Sets the PropagationLevel used. With the PropagationLevel you have control on how the transaction deals with transaction nesting. The default is PropagationLevel.Requires which automatically starts a transaction is one is missing, or lifts on a transaction if available.

Specified by:

setPropagationLevel in interface GammaTxnFactoryBuilder

Specified by:

setPropagationLevel in interface TxnFactoryBuilder

Parameters:

level - the new PropagationLevel

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getPropagationLevel(), PropagationLevel

setBlockingAllowed

public final GammaTxnFactoryBuilder setBlockingAllowed(boolean blockingAllowed)

Description copied from interface: TxnFactoryBuilder

Sets if the Txn is allowed to do an explicit retry (needed for a blocking operation). One use case for disallowing it, it when the transaction is used inside an actor, and you don't want that inside the logic executed by the agent a blocking operations is done (e.g. taking an item of a blocking queue).

Specified by:

setBlockingAllowed in interface GammaTxnFactoryBuilder

Specified by:

setBlockingAllowed in interface TxnFactoryBuilder

Parameters:

blockingAllowed - true if explicit retry is allowed, false otherwise.

Returns:

the updated TxnFactoryBuilder

setIsolationLevel

public final GammaTxnFactoryBuilder setIsolationLevel(IsolationLevel isolationLevel)

Description copied from interface: TxnFactoryBuilder

Sets the IsolationLevel on the Txn.

The Txn is free to upgraded to a higher IsolationLevel. This is essentially the same behavior you get when Oracle is used, where a read uncommitted is upgraded to a read committed and a repeatable read is upgraded to the Oracle version of serialized (so with the writeskew problem still there).

Specified by:

setIsolationLevel in interface GammaTxnFactoryBuilder

Specified by:

setIsolationLevel in interface TxnFactoryBuilder

Parameters:

isolationLevel - the new IsolationLevel

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getIsolationLevel(), IsolationLevel

setTraceLevel

public final GammaTxnFactoryBuilder setTraceLevel(TraceLevel traceLevel)

Description copied from interface: TxnFactoryBuilder

Sets the Txn TraceLevel. With tracing it is possible to see what is happening inside a transaction.

Specified by:

setTraceLevel in interface GammaTxnFactoryBuilder

Specified by:

setTraceLevel in interface TxnFactoryBuilder

Parameters:

traceLevel - the new traceLevel.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.getTraceLevel(), TraceLevel

setTimeoutNs

public final GammaTxnFactoryBuilder setTimeoutNs(long timeoutNs)

Description copied from interface: TxnFactoryBuilder

Sets the timeout (the maximum time a Txn is allowed to block. Long.MAX_VALUE indicates that an unbound timeout should be used.

Specified by:

setTimeoutNs in interface GammaTxnFactoryBuilder

Specified by:

setTimeoutNs in interface TxnFactoryBuilder

Parameters:

timeoutNs - the timeout specified in nano seconds

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getTimeoutNs(), Txn.getRemainingTimeoutNs()

setInterruptible

public final GammaTxnFactoryBuilder setInterruptible(boolean interruptible)

Description copied from interface: TxnFactoryBuilder

Sets if the Txn can be interrupted while doing blocking operations.

Specified by:

setInterruptible in interface GammaTxnFactoryBuilder

Specified by:

setInterruptible in interface TxnFactoryBuilder

Parameters:

interruptible - if the transaction can be interrupted while doing blocking operations.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.isInterruptible()

setBackoffPolicy

public final GammaTxnFactoryBuilder setBackoffPolicy(BackoffPolicy backoffPolicy)

Description copied from interface: TxnFactoryBuilder

Sets the Txn BackoffPolicy. Policy is used to backoff when a transaction conflicts with another Txn. See the BackoffPolicy for more information.

Specified by:

setBackoffPolicy in interface GammaTxnFactoryBuilder

Specified by:

setBackoffPolicy in interface TxnFactoryBuilder

Parameters:

backoffPolicy - the backoff policy to use.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getBackoffPolicy()

setDirtyCheckEnabled

public final GammaTxnFactoryBuilder setDirtyCheckEnabled(boolean dirtyCheckEnabled)

Description copied from interface: TxnFactoryBuilder

Sets if the Txn dirty check is enabled. Dirty check is that something only needs to be written, if there really is a change (else it will be interpreted as a read). If it is disabled, it will always write, and this could prevent the aba isolation anomaly, but causes more conflicts so more contention. In most cases enabling it is the best option.

Specified by:

setDirtyCheckEnabled in interface GammaTxnFactoryBuilder

Specified by:

setDirtyCheckEnabled in interface TxnFactoryBuilder

Parameters:

dirtyCheckEnabled - true if dirty check should be executed, false otherwise.

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.isDirtyCheckEnabled()

setSpinCount

public final GammaTxnFactoryBuilder setSpinCount(int spinCount)

Description copied from interface: TxnFactoryBuilder

Sets the maximum number of spins that are allowed when a Txn can't be read/written/locked because it is locked by another transaction.

Setting the value to a very high value, could lead to more an increased chance of a live locking.

Specified by:

setSpinCount in interface GammaTxnFactoryBuilder

Specified by:

setSpinCount in interface TxnFactoryBuilder

Parameters:

spinCount - the maximum number of spins

Returns:

the updated TxnFactoryBuilder.

See Also:

TxnConfig.getSpinCount()

setSpeculative

public final GammaTxnFactoryBuilder setSpeculative(boolean enabled)

Description copied from interface: TxnFactoryBuilder

With the speculative configuration enabled, the Stm is allowed to determine optimal settings for a Txn.

Some behavior like readonly or the need for tracking reads can be determined runtime. The system can start with a readonly non readtracking transaction and upgrade to an update or a read tracking once a write or retry happens.

It depends on the Stm implementation on which properties it is going to speculate.

Enabling it can cause a few unexpected 'retries' of transactions, but it can seriously improve performance.

Specified by:

setSpeculative in interface GammaTxnFactoryBuilder

Specified by:

setSpeculative in interface TxnFactoryBuilder

Parameters:

enabled - indicates if speculative configuration should be enabled.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.isSpeculative()

setReadonly

public final GammaTxnFactoryBuilder setReadonly(boolean readonly)

Description copied from interface: TxnFactoryBuilder

Sets the readonly property on a Txn. If a transaction is configured as readonly, no write operations (also no construction of new transactional objects making use of that transaction) is allowed

Specified by:

setReadonly in interface GammaTxnFactoryBuilder

Specified by:

setReadonly in interface TxnFactoryBuilder

Parameters:

readonly - true if the transaction should be readonly, false otherwise.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.isReadonly()

setReadTrackingEnabled

public final GammaTxnFactoryBuilder setReadTrackingEnabled(boolean enabled)

Description copied from interface: TxnFactoryBuilder

Sets if the Txn should automatically track all reads that have been done. This is needed for blocking operations, but also for other features like writeskew detection.

Tracking reads puts more pressure on the transaction since it needs to store all reads, but it reduces the chance of read conflicts, since once read from main memory, it can be retrieved from the transaction. The transaction is free to track reads even though this property is disabled.

Specified by:

setReadTrackingEnabled in interface GammaTxnFactoryBuilder

Specified by:

setReadTrackingEnabled in interface TxnFactoryBuilder

Parameters:

enabled - true if read tracking enabled, false otherwise.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.isReadTrackingEnabled()

setMaxRetries

public final GammaTxnFactoryBuilder setMaxRetries(int maxRetries)

Description copied from interface: TxnFactoryBuilder

Sets the the maximum count a Txn can be retried. The default is 1000. Setting it to a very low value could mean that a transaction can't complete. Setting it to a very high value could lead to live-locking.

If the speculative configuration mechanism is enabled (TxnFactoryBuilder.setSpeculative(boolean)), a few retries are done in the beginning to figure out the best settings.

Specified by:

setMaxRetries in interface GammaTxnFactoryBuilder

Specified by:

setMaxRetries in interface TxnFactoryBuilder

Parameters:

maxRetries - the maximum number of times a transaction can be tried.

Returns:

the updated TxnFactoryBuilder

See Also:

TxnConfig.getMaxRetries()

newTxnExecutor

public final GammaTxnExecutor newTxnExecutor()

Description copied from interface: TxnFactoryBuilder

Builds a new TxnExecutor optimized for executing transactions created by this TxnFactoryBuilder.

Specified by:

newTxnExecutor in interface GammaTxnFactoryBuilder

Specified by:

newTxnExecutor in interface TxnFactoryBuilder

Returns:

the created TxnExecutor.

isLean

private boolean isLean()

newTransactionFactory

public GammaTxnFactory newTransactionFactory()

Description copied from interface: TxnFactoryBuilder

Builds a new TxnFactory.

Specified by:

newTransactionFactory in interface GammaTxnFactoryBuilder

Specified by:

newTransactionFactory in interface TxnFactoryBuilder

Returns:

the build TxnFactory.