Package org.jgroups.blocks.atomic

Interface SyncCounter

All Known Subinterfaces:

Counter

All Known Implementing Classes:

COUNTER.SyncCounterImpl

public interface SyncCounter

A synchronous counter interface

Since:

5.2

Method Summary

Modifier and Type	Method	Description
long	addAndGet(long delta)	Atomically adds the given value to the current value.
AsyncCounter	async()
default boolean	compareAndSet(long expect, long update)	Atomically updates the counter using a CAS operation
long	compareAndSwap(long expect, long update)	Atomically updates the counter using a compare-and-swap operation.
default long	decrementAndGet()	Atomically decrements the counter and returns the new value
long	get()	Gets the current value of the counter
java.lang.String	getName()
default long	incrementAndGet()	Atomically increments the counter and returns the new value
void	set(long new_value)	Sets the counter to a new value
default <T extends Streamable> T	update(CounterFunction<T> updateFunction)	Atomically updates the counter's value.

Method Detail

getName

java.lang.String getName()

get

long get()

Gets the current value of the counter

Returns:

The current value

set

void set(long new_value)

Sets the counter to a new value

Parameters:

new_value - The new value

compareAndSet

default boolean compareAndSet(long expect,
                              long update)

Atomically updates the counter using a CAS operation

Parameters:

expect - The expected value of the counter

update - The new value of the counter

Returns:

True if the counter could be updated, false otherwise

compareAndSwap

long compareAndSwap(long expect,
                    long update)

Atomically updates the counter using a compare-and-swap operation.

Parameters:

expect - The expected value of the counter

update - The new value of the counter

Returns:

The previous value of the counter

incrementAndGet

default long incrementAndGet()

Atomically increments the counter and returns the new value

Returns:

The new value

decrementAndGet

default long decrementAndGet()

Atomically decrements the counter and returns the new value

Returns:

The new value

addAndGet

long addAndGet(long delta)

Atomically adds the given value to the current value.

Parameters:

delta - the value to add

Returns:

the updated value

update

default <T extends Streamable> T update(CounterFunction<T> updateFunction)

Atomically updates the counter's value.

Both CounterFunction and return value must implement Streamable to be sent over the network. The function should not block thread since it can cause deadlocks neither invoke any operation over the SyncCounter.

The CounterView is a copy of the counter's value and the last CounterView.set(long) will be applied to the counter.

Type Parameters:

T - The return value type.

Parameters:

updateFunction - The update CounterFunction.

Returns:

The function's return value.

See Also:

CounterFunction, CounterView, LongSizeStreamable

async

AsyncCounter async()

Returns:

an asynchronous wrapper around this instance.