public interface TxnFactoryBuilder
TxnFactory
and TxnExecutor
. This builder provides full control
on transaction settings.
Since the Txn
and TxnExecutor
are very closely integrated, both of them are created
by this TxnFactoryBuilder.
Instances of this class are considered immutable, so when you call one of the modifying methods, make sure that you use the resulting TxnFactoryBuilder. Normally with the builder implementation the same instance is returned. In this case this isn't true because a new instance is returned every time.
TxnFactory
,
TxnConfig
Modifier and Type | Method and Description |
---|---|
TxnFactoryBuilder |
addPermanentListener(TxnListener listener)
Adds a permanent
Txn TxnListener . |
TxnConfig |
getConfig()
Returns the
TxnConfig used by this TxnFactoryBuilder. |
TxnFactory |
newTransactionFactory()
Builds a new
TxnFactory . |
TxnExecutor |
newTxnExecutor()
Builds a new
TxnExecutor optimized for executing transactions created by this TxnFactoryBuilder. |
TxnFactoryBuilder |
setBackoffPolicy(BackoffPolicy backoffPolicy)
Sets the
Txn BackoffPolicy . |
TxnFactoryBuilder |
setBlockingAllowed(boolean blockingAllowed)
Sets if the
Txn is allowed to do an explicit retry (needed for a blocking operation). |
TxnFactoryBuilder |
setControlFlowErrorsReused(boolean reused)
Sets if the
ControlFlowError is reused. |
TxnFactoryBuilder |
setDirtyCheckEnabled(boolean dirtyCheckEnabled)
Sets if the
Txn dirty check is enabled. |
TxnFactoryBuilder |
setFamilyName(String familyName)
Sets the
Txn familyname. |
TxnFactoryBuilder |
setInterruptible(boolean interruptible)
Sets if the
Txn can be interrupted while doing blocking operations. |
TxnFactoryBuilder |
setIsolationLevel(IsolationLevel isolationLevel)
Sets the
IsolationLevel on the Txn . |
TxnFactoryBuilder |
setMaxRetries(int maxRetries)
Sets the the maximum count a
Txn can be retried. |
TxnFactoryBuilder |
setPropagationLevel(PropagationLevel propagationLevel)
Sets the
PropagationLevel used. |
TxnFactoryBuilder |
setReadLockMode(LockMode lockMode)
|
TxnFactoryBuilder |
setReadonly(boolean readonly)
Sets the readonly property on a
Txn . |
TxnFactoryBuilder |
setReadTrackingEnabled(boolean enabled)
Sets if the
Txn should automatically track all reads that have been done. |
TxnFactoryBuilder |
setSpeculative(boolean speculative)
|
TxnFactoryBuilder |
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. |
TxnFactoryBuilder |
setTimeoutNs(long timeoutNs)
Sets the timeout (the maximum time a
Txn is allowed to block. |
TxnFactoryBuilder |
setTraceLevel(TraceLevel traceLevel)
Sets the
Txn TraceLevel . |
TxnFactoryBuilder |
setWriteLockMode(LockMode lockMode)
|
TxnConfig getConfig()
TxnConfig
used by this TxnFactoryBuilder.TxnFactoryBuilder setControlFlowErrorsReused(boolean reused)
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.reused
- true if ControlFlowErrors should be reused.TxnConfig.isControlFlowErrorsReused()
TxnFactoryBuilder setFamilyName(String familyName)
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.familyName
- the familyName of the transaction.NullPointerException
- if familyName is null.TxnConfig.getFamilyName()
TxnFactoryBuilder setPropagationLevel(PropagationLevel propagationLevel)
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.propagationLevel
- the new PropagationLevelNullPointerException
- if propagationLevel is null.TxnConfig.getPropagationLevel()
,
PropagationLevel
TxnFactoryBuilder setReadLockMode(LockMode lockMode)
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.lockMode
- the LockMode to set.NullPointerException
- if lockMode is null.TxnConfig.getReadLockMode()
,
LockMode
TxnFactoryBuilder setWriteLockMode(LockMode lockMode)
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.
lockMode
- the LockMode to set.NullPointerException
- if lockMode is null.TxnConfig.getWriteLockMode()
,
LockMode
TxnFactoryBuilder addPermanentListener(TxnListener listener)
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.
listener
- the permanent listener to add.NullPointerException
- if listener is null.TxnConfig.getPermanentListeners()
TxnFactoryBuilder setTraceLevel(TraceLevel traceLevel)
Txn
TraceLevel
. With tracing it is possible to see what is happening inside a transaction.traceLevel
- the new traceLevel.NullPointerException
- if traceLevel is null.TxnConfig.getTraceLevel()
,
TraceLevel
TxnFactoryBuilder setTimeoutNs(long timeoutNs)
Txn
is allowed to block. Long.MAX_VALUE indicates that an
unbound timeout should be used.timeoutNs
- the timeout specified in nano secondsTxnConfig.getTimeoutNs()
,
Txn.getRemainingTimeoutNs()
TxnFactoryBuilder setInterruptible(boolean interruptible)
Txn
can be interrupted while doing blocking operations.interruptible
- if the transaction can be interrupted while doing blocking operations.TxnConfig.isInterruptible()
TxnFactoryBuilder setBackoffPolicy(BackoffPolicy backoffPolicy)
Txn
BackoffPolicy
. Policy is used to backoff when a transaction conflicts with another Txn
.
See the BackoffPolicy
for more information.backoffPolicy
- the backoff policy to use.NullPointerException
- if backoffPolicy is null.TxnConfig.getBackoffPolicy()
TxnFactoryBuilder setDirtyCheckEnabled(boolean dirtyCheckEnabled)
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.dirtyCheckEnabled
- true if dirty check should be executed, false otherwise.TxnConfig.isDirtyCheckEnabled()
TxnFactoryBuilder setSpinCount(int spinCount)
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.
spinCount
- the maximum number of spinsIllegalArgumentException
- if spinCount smaller than 0.TxnConfig.getSpinCount()
TxnFactoryBuilder setReadonly(boolean readonly)
Txn
. If a transaction is configured as readonly, no write operations
(also no construction of new transactional objects making use of that transaction) is allowedreadonly
- true if the transaction should be readonly, false otherwise.TxnConfig.isReadonly()
TxnFactoryBuilder setReadTrackingEnabled(boolean enabled)
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.
enabled
- true if read tracking enabled, false otherwise.TxnConfig.isReadTrackingEnabled()
TxnFactoryBuilder setSpeculative(boolean speculative)
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.
speculative
- indicates if speculative configuration should be enabled.TxnConfig.isSpeculative()
TxnFactoryBuilder setMaxRetries(int maxRetries)
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 (setSpeculative(boolean)
), a few retries
are done in the beginning to figure out the best settings.
maxRetries
- the maximum number of times a transaction can be tried.IllegalArgumentException
- if maxRetries smaller than 0.TxnConfig.getMaxRetries()
TxnFactoryBuilder setIsolationLevel(IsolationLevel isolationLevel)
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).
isolationLevel
- the new IsolationLevelNullPointerException
- if isolationLevel is null.TxnConfig.getIsolationLevel()
,
IsolationLevel
TxnFactoryBuilder setBlockingAllowed(boolean blockingAllowed)
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).blockingAllowed
- true if explicit retry is allowed, false otherwise.TxnFactory newTransactionFactory()
TxnFactory
.IllegalTxnFactoryException
- if the TxnFactory could not be build
because the configuration was not correct.TxnExecutor newTxnExecutor()
TxnExecutor
optimized for executing transactions created by this TxnFactoryBuilder.IllegalTxnFactoryException
- if the TxnFactory could not be build
because the configuration was not correct.Copyright © 2020. All rights reserved.