import java.util.concurrent.atomic.AtomicInteger;
import static java.lang.Float.*;

class AtomicFloat extends Number {

    private AtomicInteger bits;

    public AtomicFloat() {
        this(0f);
    }

    public AtomicFloat(float initialValue) {
        bits = new AtomicInteger(floatToIntBits(initialValue));
    }

    public final boolean compareAndSet(float expect, float update) {
        return bits.compareAndSet(floatToIntBits(expect),
                                  floatToIntBits(update));
    }

    public final void set(float newValue) {
        bits.set(floatToIntBits(newValue));
    }

    public final float get() {
        return intBitsToFloat(bits.get());
    }

    public float floatValue() {
        return get();
    }

    public final float getAndSet(float newValue) {
        return intBitsToFloat(bits.getAndSet(floatToIntBits(newValue)));
    }

    public final boolean weakCompareAndSet(float expect, float update) {
        return bits.weakCompareAndSet(floatToIntBits(expect),
                                      floatToIntBits(update));
    }

    public double doubleValue() { return (double) floatValue(); }
    public int intValue()       { return (int) get();           }
    public long longValue()     { return (long) get();          }

}

class AtomicDouble {
    private val value = new AtomicReference(java.lang.Double.valueOf(0.0))
    @tailrec
    final def getAndAdd(delta: Double): Double = {
        val currentValue = value.get
        val newValue = java.lang.Double.valueOf(currentValue.doubleValue + delta)
        if (value.compareAndSet(currentValue, newValue))
            currentValue.doubleValue
        else
            getAndAdd(delta)   // try, try again
    }
}

class AtomicDouble {
    private AtomicReference<Double> value = new AtomicReference(Double.valueOf(0.0));
    double getAndAdd(double delta) {
        while (true) {
            Double currentValue = value.get();
            Double newValue = Double.valueOf(currentValue.doubleValue() + delta);
            if (value.compareAndSet(currentValue, newValue))
                return currentValue.doubleValue();
        }
    }
}

average.set( average.get() > x ? dosomething(y) : y) ;

average.updateAndGet(new DoubleUnaryOperator() {
    @Override
    public double applyAsDouble( double previous ) {
           return previous > x ? dosomething(y) : y;
    }
});

import static java.lang.Double.doubleToLongBits;
import static java.lang.Double.longBitsToDouble;

import java.util.concurrent.atomic.AtomicLong;
import java.util.function.DoubleBinaryOperator;
import java.util.function.DoubleUnaryOperator;

public final class AtomicDouble extends Number {
        private static final long serialVersionUID = 12327722191124184L;

        private final AtomicLong bits;

        public AtomicDouble() {
                this(0.0d);
        }

        public AtomicDouble( double initialValue ) {
                bits = new AtomicLong( toLong(initialValue) );
        }

        /**
         * Atomically sets the value to the given updated value
         * if the current value {@code ==} the expected value.
         *
         * @param expect the expected value
         * @param update the new value
         * @return {@code true} if successful. False return indicates that
         * the actual value was not equal to the expected value.
         */
        public final boolean compareAndSet( double expect, double update ) {
                return bits.compareAndSet(toLong(expect), toLong(update));
        }

        /**
         * Sets to the given value.
         *
         * @param newValue the new value
         */
        public final void set( double newValue ) {
                bits.set(toLong(newValue));
        }

        public final double get() {
                return toDouble(bits.get());
        }

        /**
         * Atomically sets to the given value and returns the old value.
         *
         * @param newValue the new value
         * @return the previous value
         */
        public final double getAndSet( double newValue ) {
                return toDouble( bits.getAndSet(toLong(newValue)) );
        }

        /**
         * Atomically sets the value to the given updated value
         * if the current value {@code ==} the expected value.
         *
         * <p><a href="package-summary.html#weakCompareAndSet">May fail
         * spuriously and does not provide ordering guarantees</a>, so is
         * only rarely an appropriate alternative to {@code compareAndSet}.
         *
         * @param expect the expected value
         * @param update the new value
         * @return {@code true} if successful
         */
        public final boolean weakCompareAndSet( double expect, double update ) {
                return bits.weakCompareAndSet(toLong(expect), toLong(update));
        }

        /**
         * Atomically updates the current value 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 as its first argument,
         * and the given update as the second argument.
         *
         * @param x                   the update value
         * @param accumulatorFunction a side-effect-free function of two arguments
         * @return the updated value
         * @since 1.8
         */
        public final double accumulateAndGet( double x, DoubleBinaryOperator accumulatorFunction ) {
                double prev, next;
                do {
                        prev = get();
                        next = accumulatorFunction.applyAsDouble(prev, x);
                } while (!compareAndSet(prev, next));
                return next;
        }

        /**
         * Atomically adds the given value to the current value.
         *
         * @param delta the value to add
         * @return the updated value
         */
        public final double addAndGet( double delta ) {
                return toDouble(bits.addAndGet(toLong(delta)));
        }

        /**
         * Atomically decrements by one the current value.
         *
         * @return the updated value
         */
        public final double decrementAndGet() {
                return addAndGet(-1.0d);
        }

        /**
         * Atomically updates the current value 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 as its first argument,
         * and the given update as the second argument.
         *
         * @param x                   the update value
         * @param accumulatorFunction a side-effect-free function of two arguments
         * @return the previous value
         * @since 1.8
         */
        public final double getAndAccumulate( double x, DoubleBinaryOperator accumulatorFunction ) {
                double prev, next;
                do {
                        prev = get();
                        next = accumulatorFunction.applyAsDouble(prev, x);
                } while (!compareAndSet(prev, next));
                return prev;
        }

        /**
         * Atomically adds the given value to the current value.
         *
         * @param delta the value to add
         * @return the previous value
         */
        public final double getAndAdd( double delta ) {
                return toDouble(bits.getAndAdd(toLong(delta)));
        }

        public final double getAndDecrement() {
                return getAndAdd(-1.0d);
        }

        /**
         * Atomically increments by one the current value.
         *
         * @return the previous value
         */
        public final double getAndIncrement() {
                return getAndAdd(1.0d);
        }

        /**
         * Atomically increments by one the current value.
         *
         * @return the updated value
         */
        public final double incrementAndGet() {
                return addAndGet(1.0d);
        }

        /**
         * Atomically updates the current value 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.
         *
         * @param updateFunction a side-effect-free function
         * @return the previous value
         * @since 1.8
         */
        public final double getAndUpdate( DoubleUnaryOperator updateFunction ) {
                double prev, next;
                do {
                        prev = get();
                        next = updateFunction.applyAsDouble(prev);
                } while (!compareAndSet(prev, next));
                return prev;
        }


        /**
         * Eventually sets to the given value.
         *
         * @param newValue the new value
         * @since 1.6
         */
        public final void lazySet( double newValue ) {
                bits.lazySet(toLong(newValue));
                // unsafe.putOrderedLong(this, valueOffset, newValue);
        }

        /**
         * Returns the value of this {@code AtomicLong} as a {@code long}.
         */
        public long longValue() {
                return (long) get();
        }

        /**
         * Returns the String representation of the current value.
         *
         * @return the String representation of the current value
         */
        public String toString() {
                return Double.toString(get());
        }

        /**
         * Atomically updates the current value 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.
         *
         * @param updateFunction a side-effect-free function
         * @return the updated value
         * @since 1.8
         */
        public final double updateAndGet( DoubleUnaryOperator updateFunction ) {
                double prev, next;
                do {
                        prev = get();
                        next = updateFunction.applyAsDouble(prev);
                } while (!compareAndSet(prev, next));
                return next;
        }
        /**
         * Returns the value of this {@code AtomicLong} as an {@code int}
         * after a narrowing primitive conversion.
         *
         * @jls 5.1.3 Narrowing Primitive Conversions
         */
        public int intValue() {
                return (int) get();
        }

        /**
         * Returns the value of this {@code AtomicLong} as a {@code float}
         * after a widening primitive conversion.
         *
         * @jls 5.1.2 Widening Primitive Conversions
         */
        public float floatValue() {
                return (float) get();
        }

        /**
         * Returns the value of this {@code AtomicLong} as a {@code double}
         * after a widening primitive conversion.
         *
         * @jls 5.1.2 Widening Primitive Conversions
         */
        public double doubleValue() {
                return get();
        }

        private static double toDouble( long l ) {
                return longBitsToDouble(l);
        }

        private static long toLong( double delta ) {
                return doubleToLongBits(delta);
        }

}