Module java.base

Class 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
    Author:
    Doug Lea
    See Also:
    Serialized Form
    • Constructor Detail

      • 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 Detail

      • 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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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.
      • 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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.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(java.lang.Object...).
        Parameters:
        i - the index
        expectedValue - the expected value
        newValue - the new value
        Returns:
        true if successful
        Since:
        9