org.multiverse.api.references
Interface TxnDouble

All Superinterfaces:

TxnObject

All Known Implementing Classes:

GammaTxnDouble

public interface TxnDouble
extends TxnObject

A Transactional Reference comparable to the Clojure Ref. If a method is prefixed with atomic, the call will always run under its own txn, no matter if there already is a txn available (so the propagation level is PropagationLevel.RequiresNew). For the other methods, always an txn needs to be available, else you will get the TxnMandatoryException.

ControlFlowError

All non atomic methods are able to throw a (subclass) of the ControlFlowError. This error should not be caught, it is task of the TxnExecutor to deal with.

TransactionExecutionException

Most of the methods can throw a TxnExecutionException. This exception can be caught, but in most cases you want to figure out what the cause is (e.g. because there are too many retries) and solve that problem.

Threadsafe

All methods are threadsafe.

Author:

Peter Veentjer.

Method Summary

double	alterAndGet(DoubleFunction function) Alters the value stored in this Ref using the provided function and returns the result.
double	alterAndGet(Txn txn, DoubleFunction function) Alters the value stored in this Ref using the provided function and lifting on the provided txn.
double	atomicAlterAndGet(DoubleFunction function) Atomically applies the function to the current value in this ref and returns the new value.
boolean	atomicCompareAndSet(double expectedValue, double newValue) Executes a compare and set atomically.
double	atomicGet() Atomically gets the value.
double	atomicGetAndAlter(DoubleFunction function) Atomically applies the function to alter the value stored in this ref and returns the old value.
double	atomicGetAndIncrement(double amount) Atomically increments the value and returns the old value.
double	atomicGetAndSet(double newValue) Atomically sets the value and returns the previous value.
double	atomicIncrementAndGet(double amount) Atomically increments the value and returns the old value.
double	atomicSet(double newValue) Atomically sets the value and returns the new value.
double	atomicWeakGet() Atomically gets the value without providing any ordering guarantees.
void	await(double value) Awaits for the value to become the given value.
void	await(DoublePredicate predicate) Awaits until the predicate holds.
void	await(Txn txn, double value) Awaits for the reference to become the given value.
void	await(Txn txn, DoublePredicate predicate) Awaits until the predicate holds using the provided txn.
void	commute(DoubleFunction function) Applies the function on the ref in a commuting manner.
void	commute(Txn txn, DoubleFunction function) Applies the function on the ref in a commuting manner.
double	get() Gets the value using the provided txn.
double	get(Txn txn) Gets the value using the provided txn.
double	getAndAlter(DoubleFunction function) Alters the value stored in this Ref using the provided function amd returns the old value.
double	getAndAlter(Txn txn, DoubleFunction function) Alters the value stored in this Ref using the function and returns the old value, using the provided txn.
double	getAndIncrement(double amount) Increments the value and returns the old value.
double	getAndIncrement(Txn txn, double amount) Increments the value and returns the old value using the provided txn.
double	getAndLock(LockMode lockMode) Gets the value and applies the lock.
double	getAndLock(Txn txn, LockMode lockMode) Gets the value using the provided txn and acquired the lock with the specified LockMode.
double	getAndSet(double value) Sets the value the value and returns the new value.
double	getAndSet(Txn txn, double value) Sets the value using the provided txn.
double	getAndSetAndLock(double value, LockMode lockMode) Sets the value, acquired the Lock with the specified Lockmode and returns the previous value.
double	getAndSetAndLock(Txn txn, double value, LockMode lockMode) Sets the value and acquired the Lock with the provided LockMode.
double	incrementAndGet(double amount) Increments and gets the new value.
double	incrementAndGet(Txn txn, double amount) Increments and gets the new value using the provided txn.
double	set(double value) Sets the new value.
double	set(Txn txn, double value) Sets the new value using the provided txn.
double	setAndLock(double value, LockMode lockMode) Sets the new value and applies the lock.
double	setAndLock(Txn txn, double value, LockMode lockMode) Sets the new value using the provided txn.

Methods inherited from interface org.multiverse.api.TxnObject

atomicToString, ensure, ensure, getLock, getStm, getVersion, toDebugString, toString, toString

Method Detail

get

double get()

Gets the value using the provided txn.

Returns:

the current value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

See Also:

atomicGet()

getAndLock

double getAndLock(LockMode lockMode)

Gets the value and applies the lock. If the current lockMode already is higher than the provided lockMode the Lock is not upgraded to a higher value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

lockMode - the LockMode applied.

Returns:

the current value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

See Also:

atomicGet()

get

double get(Txn txn)

Gets the value using the provided txn.

Parameters:

txn - the Txn used for this operation.

Returns:

the value stored in the ref.

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndLock

double getAndLock(Txn txn,
                  LockMode lockMode)

Gets the value using the provided txn and acquired the lock with the specified LockMode.

Parameters:

txn - the Txn used for this operation.

lockMode - the LockMode used

Returns:

the value stored in the ref.

Throws:

NullPointerException - if txn is null or if lockMode is null. If LockMode is null and a running txn is available it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

set

double set(double value)

Sets the new value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the new value.

Returns:

the new value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

setAndLock

double setAndLock(double value,
                  LockMode lockMode)

Sets the new value and applies the lock.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the new value.

lockMode - the used LockMode.

Returns:

the new value.

Throws:

NullPointerException - if lockMode is null (if the txn is alive, it will also be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

set

double set(Txn txn,
           double value)

Sets the new value using the provided txn.

Parameters:

txn - the Txn used for this operation.

value - the new value

Returns:

the old value

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

setAndLock

double setAndLock(Txn txn,
                  double value,
                  LockMode lockMode)

Sets the new value using the provided txn.

Parameters:

txn - the Txn used for this operation.

value - the new value

lockMode - the lockMode used.

Returns:

the old value

Throws:

NullPointerException - if txn is null or lockMode is null. If the lockMode is null and the txn is alive, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndSet

double getAndSet(double value)

Sets the value the value and returns the new value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the new value.

Returns:

the old value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndSetAndLock

double getAndSetAndLock(double value,
                        LockMode lockMode)

Sets the value, acquired the Lock with the specified Lockmode and returns the previous value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the new value.

lockMode - the LockMode used.

Returns:

the old value.

Throws:

NullPointerException - if LockMode is null. If a running txn is available, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndSet

double getAndSet(Txn txn,
                 double value)

Sets the value using the provided txn.

Parameters:

value - the new value.

txn - the Txn used for this operation.

Returns:

the old value.

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndSetAndLock

double getAndSetAndLock(Txn txn,
                        double value,
                        LockMode lockMode)

Sets the value and acquired the Lock with the provided LockMode.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the new value.

txn - the Txn used for this operation.

lockMode - the LockMode used.

Returns:

the old value.

Throws:

NullPointerException - if txn or LockMode is null. If the txn is running, and the LockMode is null, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

atomicGet

double atomicGet()

Atomically gets the value. The value could be stale as soon as it is returned. This method doesn't care about any running txns. It could be that this call fails e.g. when a ref is locked. If you don't care about correct orderings, see the atomicWeakGet().

Returns:

the current value.

Throws:

TxnExecutionException

atomicWeakGet

double atomicWeakGet()

Atomically gets the value without providing any ordering guarantees. This method is extremely cheap and will never fail. So even if the ref is privatized, this call will still complete.

It is the best method to call if you just want to get the current value stored.

Returns:

the value.

atomicSet

double atomicSet(double newValue)

Atomically sets the value and returns the new value. This method doesn't care about any running txns.

Parameters:

newValue - the new value.

Returns:

the new value.

Throws:

TxnExecutionException

atomicGetAndSet

double atomicGetAndSet(double newValue)

Atomically sets the value and returns the previous value. This method doesn't care about any running txns.

Parameters:

newValue - the new value.

Returns:

the old value.

Throws:

TxnExecutionException

commute

void commute(DoubleFunction function)

Applies the function on the ref in a commuting manner. So if there are no dependencies, the function will commute. If somehow there already is a dependency or a dependency is formed on the result of the commuting function, the function will not commute and will be exactly the same as an alter.

This is different than the behavior in Clojure where the commute will be re-applied at the end of the txn, even though some dependency is introduced, which can lead to inconsistencies.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

function - the function to apply to this reference.

Throws:

NullPointerException - if function is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

commute

void commute(Txn txn,
             DoubleFunction function)

Applies the function on the ref in a commuting manner. So if there are no dependencies, the function will commute. If somehow there already is a dependency or a dependency is formed on the result of the commuting function, the function will not commute and will be exactly the same as an alter.

This is different than the behavior in Clojure where the commute will be re-applied at the end of the txn, even though some dependency is introduced, which can lead to inconsistencies.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

txn - the Txn used for this operation.

function - the function to apply to this reference.

Throws:

NullPointerException - if function is null. If there is an active txn, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

atomicAlterAndGet

double atomicAlterAndGet(DoubleFunction function)

Atomically applies the function to the current value in this ref and returns the new value. This method doesn't care about any running txns.

Parameters:

function - the Function used

Returns:

the new value.

Throws:

NullPointerException - if function is null.

alterAndGet

double alterAndGet(DoubleFunction function)

Alters the value stored in this Ref using the provided function and returns the result.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

function - the function that alters the value stored in this Ref.

Returns:

the new value.

Throws:

NullPointerException - if function is null. The Txn will also be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

alterAndGet

double alterAndGet(Txn txn,
                   DoubleFunction function)

Alters the value stored in this Ref using the provided function and lifting on the provided txn.

Parameters:

function - the function that alters the value stored in this Ref.

txn - the Txn used for this operation.

Returns:

the new value.

Throws:

NullPointerException - if function or txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

atomicGetAndAlter

double atomicGetAndAlter(DoubleFunction function)

Atomically applies the function to alter the value stored in this ref and returns the old value. This method doesn't care about any running txns.

Parameters:

function - the Function used

Returns:

the old value.

Throws:

NullPointerException - if function is null.

TxnExecutionException

getAndAlter

double getAndAlter(DoubleFunction function)

Alters the value stored in this Ref using the provided function amd returns the old value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

function - the function that alters the value stored in this Ref.

Returns:

the old value.

Throws:

NullPointerException - if function is null. The txn will be aborted as well.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndAlter

double getAndAlter(Txn txn,
                   DoubleFunction function)

Alters the value stored in this Ref using the function and returns the old value, using the provided txn.

Parameters:

function - the function that alters the value stored in this Ref.

txn - the Txn used for this operation.

Returns:

the old value

Throws:

NullPointerException - if function or txn is null. The txn will be aborted as well.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

atomicCompareAndSet

boolean atomicCompareAndSet(double expectedValue,
                            double newValue)

Executes a compare and set atomically. This method doesn't care about any running txns.

Parameters:

expectedValue - the expected value.

newValue - the new value.

Returns:

true if the compareAndSwap was a success, false otherwise.

Throws:

TxnExecutionException

atomicGetAndIncrement

double atomicGetAndIncrement(double amount)

Atomically increments the value and returns the old value. This method doesn't care about any running txns.

Parameters:

amount - the amount to increase with.

Returns:

the old value.

Throws:

TxnExecutionException

getAndIncrement

double getAndIncrement(double amount)

Increments the value and returns the old value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

amount - the amount to increment with.

Returns:

the old value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

getAndIncrement

double getAndIncrement(Txn txn,
                       double amount)

Increments the value and returns the old value using the provided txn.

Parameters:

txn - the Txn used for this operation.

amount - the amount to increment with.

Returns:

the old value.

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

atomicIncrementAndGet

double atomicIncrementAndGet(double amount)

Atomically increments the value and returns the old value. This method doesn't care about any running txns.

Parameters:

amount - the amount to increment with.

Returns:

the new value.

Throws:

TxnExecutionException

incrementAndGet

double incrementAndGet(double amount)

Increments and gets the new value.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

amount - the amount to increment with.

Returns:

the new value.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

incrementAndGet

double incrementAndGet(Txn txn,
                       double amount)

Increments and gets the new value using the provided txn.

Parameters:

txn - the Txn used for this operation.

amount - the amount to increment with.

Returns:

the new value.

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

await

void await(double value)

Awaits for the value to become the given value. If the value already has the the specified value, the call continues, else a retry is done.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

value - the value to wait for.

Throws:

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

await

void await(Txn txn,
           double value)

Awaits for the reference to become the given value. If the value already has the the specified value, the call continues, else a retry is done.

Parameters:

txn - the Txn used for this operation.

value - the value to wait for.

Throws:

NullPointerException - if txn is null.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

await

void await(DoublePredicate predicate)

Awaits until the predicate holds. If the value already evaluates to true, the call continues else a retry is done. If the predicate throws an exception, the txn is aborted and the throwable is propagated.

This call lifts on the Txn stored in the TxnThreadLocal.

Parameters:

predicate - the predicate to evaluate.

Throws:

NullPointerException - if predicate is null. When there is a non dead txn, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.

await

void await(Txn txn,
           DoublePredicate predicate)

Awaits until the predicate holds using the provided txn. If the value already evaluates to true, the call continues else a retry is done. If the predicate throws an exception, the txn is aborted and the throwable is propagated.

Parameters:

txn - the Txn used for this operation.

predicate - the predicate to evaluate.

Throws:

NullPointerException - if predicate is null or txn is null. When there is a non dead txn, it will be aborted.

TxnExecutionException - if something failed while using the txn. The txn is guaranteed to have been aborted.

ControlFlowError - if the Stm needs to control the flow in a different way than normal returns of exceptions. The txn is guaranteed to have been aborted.