Class AtomicDoubleArray

  • All Implemented Interfaces:
    java.io.Serializable

    @GwtIncompatible
    public class AtomicDoubleArray
    extends java.lang.Object
    implements java.io.Serializable
    A double array in which elements may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables.

    This class compares primitive double values in methods such as compareAndSet(int, double, double) by comparing their bitwise representation using Double.doubleToRawLongBits(double), which differs from both the primitive double == operator and from Double.equals(java.lang.Object), as if implemented by:

    
     static boolean bitEquals(double x, double y) {
       long xBits = Double.doubleToRawLongBits(x);
       long yBits = Double.doubleToRawLongBits(y);
       return xBits == yBits;
     }
     
    Since:
    11.0
    Author:
    Doug Lea, Martin Buchholz
    See Also:
    Serialized Form
    • Constructor Summary

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

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      double accumulateAndGet​(int i, double x, java.util.function.DoubleBinaryOperator accumulatorFunction)
      Atomically updates the element at index i with the results of applying the given function to the current and given values.
      double addAndGet​(int i, double delta)
      Atomically adds the given value to the element at index i.
      boolean compareAndSet​(int i, double expect, double update)
      Atomically sets the element at position i to the given updated value if the current value is bitwise equal to the expected value.
      double get​(int i)
      Gets the current value at position i.
      double getAndAccumulate​(int i, double x, java.util.function.DoubleBinaryOperator accumulatorFunction)
      Atomically updates the element at index i with the results of applying the given function to the current and given values.
      double getAndAdd​(int i, double delta)
      Atomically adds the given value to the element at index i.
      double getAndSet​(int i, double newValue)
      Atomically sets the element at position i to the given value and returns the old value.
      double getAndUpdate​(int i, java.util.function.DoubleUnaryOperator updaterFunction)
      Atomically updates the element at index i with the results of applying the given function to the current value.
      void lazySet​(int i, double newValue)
      Eventually sets the element at position i to the given value.
      int length()
      Returns the length of the array.
      void set​(int i, double newValue)
      Atomically sets the element at position i to the given value.
      java.lang.String toString()
      Returns the String representation of the current values of array.
      double updateAndGet​(int i, java.util.function.DoubleUnaryOperator updaterFunction)
      Atomically updates the element at index i with the results of applying the given function to the current value.
      boolean weakCompareAndSet​(int i, double expect, double update)
      Atomically sets the element at position i to the given updated value if the current value is bitwise equal to the expected value.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • AtomicDoubleArray

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

        public AtomicDoubleArray​(double[] array)
        Creates a new AtomicDoubleArray with the same length as, and all elements copied from, the given array.
        Parameters:
        array - the array to copy elements from
        Throws:
        java.lang.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 double get​(int i)
        Gets the current value at position i.
        Parameters:
        i - the index
        Returns:
        the current value
      • set

        public final void set​(int i,
                              double newValue)
        Atomically sets the element at position i to the given value.
        Parameters:
        i - the index
        newValue - the new value
      • lazySet

        public final void lazySet​(int i,
                                  double newValue)
        Eventually sets the element at position i to the given value.
        Parameters:
        i - the index
        newValue - the new value
      • getAndSet

        public final double getAndSet​(int i,
                                      double newValue)
        Atomically sets the element at position i to the given value and returns the old value.
        Parameters:
        i - the index
        newValue - the new value
        Returns:
        the previous value
      • compareAndSet

        public final boolean compareAndSet​(int i,
                                           double expect,
                                           double update)
        Atomically sets the element at position i to the given updated value if the current value is bitwise equal to the expected value.
        Parameters:
        i - the index
        expect - the expected value
        update - the new value
        Returns:
        true if successful. False return indicates that the actual value was not equal to the expected value.
      • weakCompareAndSet

        public final boolean weakCompareAndSet​(int i,
                                               double expect,
                                               double update)
        Atomically sets the element at position i to the given updated value if the current value is bitwise equal to the expected value.

        May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

        Parameters:
        i - the index
        expect - the expected value
        update - the new value
        Returns:
        true if successful
      • getAndAdd

        @CanIgnoreReturnValue
        public final double getAndAdd​(int i,
                                      double delta)
        Atomically adds the given value to the element at index i.
        Parameters:
        i - the index
        delta - the value to add
        Returns:
        the previous value
      • addAndGet

        @CanIgnoreReturnValue
        public double addAndGet​(int i,
                                double delta)
        Atomically adds the given value to the element at index i.
        Parameters:
        i - the index
        delta - the value to add
        Returns:
        the updated value
      • getAndAccumulate

        @CanIgnoreReturnValue
        public final double getAndAccumulate​(int i,
                                             double x,
                                             java.util.function.DoubleBinaryOperator accumulatorFunction)
        Atomically updates the element at index i with the results of applying the given function to the current and given values.
        Parameters:
        i - the index to update
        x - the update value
        accumulatorFunction - the accumulator function
        Returns:
        the previous value
        Since:
        31.1
      • accumulateAndGet

        @CanIgnoreReturnValue
        public final double accumulateAndGet​(int i,
                                             double x,
                                             java.util.function.DoubleBinaryOperator accumulatorFunction)
        Atomically updates the element at index i with the results of applying the given function to the current and given values.
        Parameters:
        i - the index to update
        x - the update value
        accumulatorFunction - the accumulator function
        Returns:
        the updated value
        Since:
        31.1
      • getAndUpdate

        @CanIgnoreReturnValue
        public final double getAndUpdate​(int i,
                                         java.util.function.DoubleUnaryOperator updaterFunction)
        Atomically updates the element at index i with the results of applying the given function to the current value.
        Parameters:
        i - the index to update
        updaterFunction - the update function
        Returns:
        the previous value
        Since:
        31.1
      • updateAndGet

        @CanIgnoreReturnValue
        public final double updateAndGet​(int i,
                                         java.util.function.DoubleUnaryOperator updaterFunction)
        Atomically updates the element at index i with the results of applying the given function to the current value.
        Parameters:
        i - the index to update
        updaterFunction - the update function
        Returns:
        the updated value
        Since:
        31.1
      • toString

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