Module io.vertx.core
Package 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
    Description
    Future<Long>
    addAndGet(long value)
    Add the value to the counter atomically and return the new count
    Future<Boolean>
    compareAndSet(long expected, long value)
    Set the counter to the specified value only if the current value is the expectec value.
    Future<Long>
    decrementAndGet()
    Decrement the counter atomically and return the new count
    Future<Long>
    get()
    Get the current value of the counter
    Future<Long>
    getAndAdd(long value)
    Add the value to the counter atomically and return the value before the add
    Future<Long>
    getAndIncrement()
    Increment the counter atomically and return the value before the increment.
    Future<Long>
    incrementAndGet()
    Increment the counter atomically and return the new count

  • Method Details

    • get

      Future<Long> get()
      Get the current value of the counter
      Returns:
      a future notified with the value

    • incrementAndGet

      Future<Long> incrementAndGet()
      Increment the counter atomically and return the new count
      Returns:
      a future notified with the value

    • getAndIncrement

      Future<Long> getAndIncrement()
      Increment the counter atomically and return the value before the increment.
      Returns:
      a future notified with the value

    • decrementAndGet

      Future<Long> decrementAndGet()
      Decrement the counter atomically and return the new count
      Returns:
      a future notified with the value

    • addAndGet

      Future<Long> addAndGet(long value)
      Add the value to the counter atomically and return the new count
      Parameters:
      value - the value to add
      Returns:
      a future notified with the value

    • getAndAdd

      Future<Long> getAndAdd(long value)
      Add the value to the counter atomically and return the value before the add
      Parameters:
      value - the value to add
      Returns:
      a future notified with the value

    • compareAndSet

      Future<Boolean> compareAndSet(long expected, long value)
      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
      Returns:
      a future notified with true on success