io.vertx.core.shareddata

Interface Counter

public interface Counter

An asynchronous counter that can be used to across the cluster to maintain a consistent count.

Author:

Tim Fox

Method Summary

Modifier and Type	Method and Description
void	addAndGet(long value, Handler<AsyncResult<Long>> resultHandler) Add the value to the counter atomically and return the new count
void	compareAndSet(long expected, long value, Handler<AsyncResult<Boolean>> resultHandler) Set the counter to the specified value only if the current value is the expectec value.
void	decrementAndGet(Handler<AsyncResult<Long>> resultHandler) Decrement the counter atomically and return the new count
void	get(Handler<AsyncResult<Long>> resultHandler) Get the current value of the counter
void	getAndAdd(long value, Handler<AsyncResult<Long>> resultHandler) Add the value to the counter atomically and return the value before the add
void	getAndIncrement(Handler<AsyncResult<Long>> resultHandler) Increment the counter atomically and return the value before the increment.
void	incrementAndGet(Handler<AsyncResult<Long>> resultHandler) Increment the counter atomically and return the new count

Method Detail

get

void get(Handler<AsyncResult<Long>> resultHandler)

Get the current value of the counter

Parameters:

resultHandler - handler which will be passed the value

incrementAndGet

void incrementAndGet(Handler<AsyncResult<Long>> resultHandler)

Increment the counter atomically and return the new count

Parameters:

resultHandler - handler which will be passed the value

getAndIncrement

void getAndIncrement(Handler<AsyncResult<Long>> resultHandler)

Increment the counter atomically and return the value before the increment.

Parameters:

resultHandler - handler which will be passed the value

decrementAndGet

void decrementAndGet(Handler<AsyncResult<Long>> resultHandler)

Decrement the counter atomically and return the new count

Parameters:

resultHandler - handler which will be passed the value

addAndGet

void addAndGet(long value,
               Handler<AsyncResult<Long>> resultHandler)

Add the value to the counter atomically and return the new count

Parameters:

value - the value to add

resultHandler - handler which will be passed the value

getAndAdd

void getAndAdd(long value,
               Handler<AsyncResult<Long>> resultHandler)

Add the value to the counter atomically and return the value before the add

Parameters:

value - the value to add

resultHandler - handler which will be passed the value

compareAndSet

void compareAndSet(long expected,
                   long value,
                   Handler<AsyncResult<Boolean>> resultHandler)

Set the counter to the specified value only if the current value is the expectec value. This happens atomically.

Parameters:

expected - the expected value

value - the new value

resultHandler - the handler will be passed true on success