com.google.common.util.concurrent

## Class AtomicDoubleArray

- java.lang.Object
- - com.google.common.util.concurrent.AtomicDoubleArray

- All Implemented Interfaces:
    java.io.Serializable

      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
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and 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

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `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` | `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.
    `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)` Sets the element at position `i` to the given value.
    `java.lang.String` | `toString()` Returns the String representation of the current values of array.
    `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)

      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

          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

          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

    - #### 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