Class AtomicIntegerArray

java.lang.Object
java.util.concurrent.atomic.AtomicIntegerArray
All Implemented Interfaces:
Serializable
public class AtomicIntegerArray extends Object implements Serializable
An int array in which elements may be updated atomically. See the VarHandle specification for descriptions of the properties of atomic accesses.
Since:
1.5
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    AtomicIntegerArray(int length)
    Creates a new AtomicIntegerArray of the given length, with all elements initially zero.
    AtomicIntegerArray(int[] array)
    Creates a new AtomicIntegerArray with the same length as, and all elements copied from, the given array.

  • Method Summary

    Modifier and Type
    Method
    Description
    final int
    accumulateAndGet(int i, int x, IntBinaryOperator accumulatorFunction)
    Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function to the current and given values, returning the updated value.
    final int
    addAndGet(int i, int delta)
    Atomically adds the given value to the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final int
    compareAndExchange(int i, int expectedValue, int newValue)
    Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchange(Object...).
    final int
    compareAndExchangeAcquire(int i, int expectedValue, int newValue)
    Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeAcquire(Object...).
    final int
    compareAndExchangeRelease(int i, int expectedValue, int newValue)
    Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeRelease(Object...).
    final boolean
    compareAndSet(int i, int expectedValue, int newValue)
    Atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.compareAndSet(Object...).
    final int
    decrementAndGet(int i)
    Atomically decrements the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final int
    get(int i)
    Returns the current value of the element at index i, with memory effects as specified by VarHandle.getVolatile(Object...).
    final int
    getAcquire(int i)
    Returns the current value of the element at index i, with memory effects as specified by VarHandle.getAcquire(Object...).
    final int
    getAndAccumulate(int i, int x, IntBinaryOperator accumulatorFunction)
    Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function to the current and given values, returning the previous value.
    final int
    getAndAdd(int i, int delta)
    Atomically adds the given value to the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final int
    getAndDecrement(int i)
    Atomically decrements the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final int
    getAndIncrement(int i)
    Atomically increments the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final int
    getAndSet(int i, int newValue)
    Atomically sets the element at index i to newValue and returns the old value, with memory effects as specified by VarHandle.getAndSet(Object...).
    final int
    getAndUpdate(int i, IntUnaryOperator updateFunction)
    Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function, returning the previous value.
    final int
    getOpaque(int i)
    Returns the current value of the element at index i, with memory effects as specified by VarHandle.getOpaque(Object...).
    final int
    getPlain(int i)
    Returns the current value of the element at index i, with memory semantics of reading as if the variable was declared non-volatile.
    final int
    incrementAndGet(int i)
    Atomically increments the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
    final void
    lazySet(int i, int newValue)
    Sets the element at index i to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
    final int
    length()
    Returns the length of the array.
    final void
    set(int i, int newValue)
    Sets the element at index i to newValue, with memory effects as specified by VarHandle.setVolatile(Object...).
    final void
    setOpaque(int i, int newValue)
    Sets the element at index i to newValue, with memory effects as specified by VarHandle.setOpaque(Object...).
    final void
    setPlain(int i, int newValue)
    Sets the element at index i to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.
    final void
    setRelease(int i, int newValue)
    Sets the element at index i to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
    String
    toString()
    Returns the String representation of the current values of array.
    final int
    updateAndGet(int i, IntUnaryOperator updateFunction)
    Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function, returning the updated value.
    final boolean
    weakCompareAndSet(int i, int expectedValue, int newValue)
    Deprecated.
    This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange(int, int, int) and compareAndSet(int, int, int)).
    final boolean
    weakCompareAndSetAcquire(int i, int expectedValue, int newValue)
    Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetAcquire(Object...).
    final boolean
    weakCompareAndSetPlain(int i, int expectedValue, int newValue)
    Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
    final boolean
    weakCompareAndSetRelease(int i, int expectedValue, int newValue)
    Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetRelease(Object...).
    final boolean
    weakCompareAndSetVolatile(int i, int expectedValue, int newValue)
    Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSet(Object...).

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • AtomicIntegerArray

      public AtomicIntegerArray(int length)
      Creates a new AtomicIntegerArray of the given length, with all elements initially zero.
      Parameters:
      length - the length of the array

    • AtomicIntegerArray

      public AtomicIntegerArray(int[] array)
      Creates a new AtomicIntegerArray with the same length as, and all elements copied from, the given array.
      Parameters:
      array - the array to copy elements from
      Throws:
      NullPointerException - if array is null

  • Method Details

    • length

      public final int length()
      Returns the length of the array.
      Returns:
      the length of the array

    • get

      public final int get(int i)
      Returns the current value of the element at index i, with memory effects as specified by VarHandle.getVolatile(Object...).
      Parameters:
      i - the index
      Returns:
      the current value

    • set

      public final void set(int i, int newValue)
      Sets the element at index i to newValue, with memory effects as specified by VarHandle.setVolatile(Object...).
      Parameters:
      i - the index
      newValue - the new value

    • lazySet

      public final void lazySet(int i, int newValue)
      Sets the element at index i to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
      Parameters:
      i - the index
      newValue - the new value
      Since:
      1.6

    • getAndSet

      public final int getAndSet(int i, int newValue)
      Atomically sets the element at index i to newValue and returns the old value, with memory effects as specified by VarHandle.getAndSet(Object...).
      Parameters:
      i - the index
      newValue - the new value
      Returns:
      the previous value

    • compareAndSet

      public final boolean compareAndSet(int i, int expectedValue, int newValue)
      Atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.compareAndSet(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful. False return indicates that the actual value was not equal to the expected value.

    • weakCompareAndSet

      @Deprecated(since="9") public final boolean weakCompareAndSet(int i, int expectedValue, int newValue)
      Deprecated.
      This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange(int, int, int) and compareAndSet(int, int, int)). To avoid confusion over plain or volatile memory effects it is recommended that the method weakCompareAndSetPlain(int, int, int) be used instead.
      Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      See Also:

    • weakCompareAndSetPlain

      public final boolean weakCompareAndSetPlain(int i, int expectedValue, int newValue)
      Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • getAndIncrement

      public final int getAndIncrement(int i)
      Atomically increments the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).

      Equivalent to getAndAdd(i, 1).

      Parameters:
      i - the index
      Returns:
      the previous value

    • getAndDecrement

      public final int getAndDecrement(int i)
      Atomically decrements the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).

      Equivalent to getAndAdd(i, -1).

      Parameters:
      i - the index
      Returns:
      the previous value

    • getAndAdd

      public final int getAndAdd(int i, int delta)
      Atomically adds the given value to the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
      Parameters:
      i - the index
      delta - the value to add
      Returns:
      the previous value

    • incrementAndGet

      public final int incrementAndGet(int i)
      Atomically increments the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).

      Equivalent to addAndGet(i, 1).

      Parameters:
      i - the index
      Returns:
      the updated value

    • decrementAndGet

      public final int decrementAndGet(int i)
      Atomically decrements the value of the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).

      Equivalent to addAndGet(i, -1).

      Parameters:
      i - the index
      Returns:
      the updated value

    • addAndGet

      public final int addAndGet(int i, int delta)
      Atomically adds the given value to the element at index i, with memory effects as specified by VarHandle.getAndAdd(Object...).
      Parameters:
      i - the index
      delta - the value to add
      Returns:
      the updated value

    • getAndUpdate

      public final int getAndUpdate(int i, IntUnaryOperator updateFunction)
      Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.
      Parameters:
      i - the index
      updateFunction - a side-effect-free function
      Returns:
      the previous value
      Since:
      1.8

    • updateAndGet

      public final int updateAndGet(int i, IntUnaryOperator updateFunction)
      Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.
      Parameters:
      i - the index
      updateFunction - a side-effect-free function
      Returns:
      the updated value
      Since:
      1.8

    • getAndAccumulate

      public final int getAndAccumulate(int i, int x, IntBinaryOperator accumulatorFunction)
      Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value of the element at index i as its first argument, and the given update as the second argument.
      Parameters:
      i - the index
      x - the update value
      accumulatorFunction - a side-effect-free function of two arguments
      Returns:
      the previous value
      Since:
      1.8

    • accumulateAndGet

      public final int accumulateAndGet(int i, int x, IntBinaryOperator accumulatorFunction)
      Atomically updates (with memory effects as specified by VarHandle.compareAndSet(Object...)) the element at index i with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value of the element at index i as its first argument, and the given update as the second argument.
      Parameters:
      i - the index
      x - the update value
      accumulatorFunction - a side-effect-free function of two arguments
      Returns:
      the updated value
      Since:
      1.8

    • toString

      public String toString()
      Returns the String representation of the current values of array.
      Overrides:
      toString in class Object
      Returns:
      the String representation of the current values of array

    • getPlain

      public final int getPlain(int i)
      Returns the current value of the element at index i, with memory semantics of reading as if the variable was declared non-volatile.
      Parameters:
      i - the index
      Returns:
      the value
      Since:
      9

    • setPlain

      public final void setPlain(int i, int newValue)
      Sets the element at index i to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.
      Parameters:
      i - the index
      newValue - the new value
      Since:
      9

    • getOpaque

      public final int getOpaque(int i)
      Returns the current value of the element at index i, with memory effects as specified by VarHandle.getOpaque(Object...).
      Parameters:
      i - the index
      Returns:
      the value
      Since:
      9

    • setOpaque

      public final void setOpaque(int i, int newValue)
      Sets the element at index i to newValue, with memory effects as specified by VarHandle.setOpaque(Object...).
      Parameters:
      i - the index
      newValue - the new value
      Since:
      9

    • getAcquire

      public final int getAcquire(int i)
      Returns the current value of the element at index i, with memory effects as specified by VarHandle.getAcquire(Object...).
      Parameters:
      i - the index
      Returns:
      the value
      Since:
      9

    • setRelease

      public final void setRelease(int i, int newValue)
      Sets the element at index i to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
      Parameters:
      i - the index
      newValue - the new value
      Since:
      9

    • compareAndExchange

      public final int compareAndExchange(int i, int expectedValue, int newValue)
      Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchange(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeAcquire

      public final int compareAndExchangeAcquire(int i, int expectedValue, int newValue)
      Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeAcquire(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeRelease

      public final int compareAndExchangeRelease(int i, int expectedValue, int newValue)
      Atomically sets the element at index i to newValue if the element's current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeRelease(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • weakCompareAndSetVolatile

      public final boolean weakCompareAndSetVolatile(int i, int expectedValue, int newValue)
      Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSet(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetAcquire

      public final boolean weakCompareAndSetAcquire(int i, int expectedValue, int newValue)
      Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetAcquire(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetRelease

      public final boolean weakCompareAndSetRelease(int i, int expectedValue, int newValue)
      Possibly atomically sets the element at index i to newValue if the element's current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetRelease(Object...).
      Parameters:
      i - the index
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9