feat(jdk8): move files to new folder to avoid resources compiled.

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicBoolean.java

@@ -0,0 +1,164 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import sun.misc.Unsafe;
+
+/**
+ * A {@code boolean} value that may be updated atomically. See the
+ * {@link java.util.concurrent.atomic} package specification for
+ * description of the properties of atomic variables. An
+ * {@code AtomicBoolean} is used in applications such as atomically
+ * updated flags, and cannot be used as a replacement for a
+ * {@link java.lang.Boolean}.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ */
+public class AtomicBoolean implements java.io.Serializable {
+    private static final long serialVersionUID = 4654671469794556979L;
+    // setup to use Unsafe.compareAndSwapInt for updates
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final long valueOffset;
+
+    static {
+        try {
+            valueOffset = unsafe.objectFieldOffset
+                (AtomicBoolean.class.getDeclaredField("value"));
+        } catch (Exception ex) { throw new Error(ex); }
+    }
+
+    private volatile int value;
+
+    /**
+     * Creates a new {@code AtomicBoolean} with the given initial value.
+     *
+     * @param initialValue the initial value
+     */
+    public AtomicBoolean(boolean initialValue) {
+        value = initialValue ? 1 : 0;
+    }
+
+    /**
+     * Creates a new {@code AtomicBoolean} with initial value {@code false}.
+     */
+    public AtomicBoolean() {
+    }
+
+    /**
+     * Returns the current value.
+     *
+     * @return the current value
+     */
+    public final boolean get() {
+        return value != 0;
+    }
+
+    /**
+     * 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(boolean expect, boolean update) {
+        int e = expect ? 1 : 0;
+        int u = update ? 1 : 0;
+        return unsafe.compareAndSwapInt(this, valueOffset, e, u);
+    }
+
+    /**
+     * 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 boolean weakCompareAndSet(boolean expect, boolean update) {
+        int e = expect ? 1 : 0;
+        int u = update ? 1 : 0;
+        return unsafe.compareAndSwapInt(this, valueOffset, e, u);
+    }
+
+    /**
+     * Unconditionally sets to the given value.
+     *
+     * @param newValue the new value
+     */
+    public final void set(boolean newValue) {
+        value = newValue ? 1 : 0;
+    }
+
+    /**
+     * Eventually sets to the given value.
+     *
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(boolean newValue) {
+        int v = newValue ? 1 : 0;
+        unsafe.putOrderedInt(this, valueOffset, v);
+    }
+
+    /**
+     * Atomically sets to the given value and returns the previous value.
+     *
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public final boolean getAndSet(boolean newValue) {
+        boolean prev;
+        do {
+            prev = get();
+        } while (!compareAndSet(prev, newValue));
+        return prev;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return Boolean.toString(get());
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicInteger.java

@@ -0,0 +1,336 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.IntUnaryOperator;
+import java.util.function.IntBinaryOperator;
+import sun.misc.Unsafe;
+
+/**
+ * An {@code int} value that may be updated atomically.  See the
+ * {@link java.util.concurrent.atomic} package specification for
+ * description of the properties of atomic variables. An
+ * {@code AtomicInteger} is used in applications such as atomically
+ * incremented counters, and cannot be used as a replacement for an
+ * {@link java.lang.Integer}. However, this class does extend
+ * {@code Number} to allow uniform access by tools and utilities that
+ * deal with numerically-based classes.
+ *
+ * @since 1.5
+ * @author Doug Lea
+*/
+public class AtomicInteger extends Number implements java.io.Serializable {
+    private static final long serialVersionUID = 6214790243416807050L;
+
+    // setup to use Unsafe.compareAndSwapInt for updates
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final long valueOffset;
+
+    static {
+        try {
+            valueOffset = unsafe.objectFieldOffset
+                (AtomicInteger.class.getDeclaredField("value"));
+        } catch (Exception ex) { throw new Error(ex); }
+    }
+
+    private volatile int value;
+
+    /**
+     * Creates a new AtomicInteger with the given initial value.
+     *
+     * @param initialValue the initial value
+     */
+    public AtomicInteger(int initialValue) {
+        value = initialValue;
+    }
+
+    /**
+     * Creates a new AtomicInteger with initial value {@code 0}.
+     */
+    public AtomicInteger() {
+    }
+
+    /**
+     * Gets the current value.
+     *
+     * @return the current value
+     */
+    public final int get() {
+        return value;
+    }
+
+    /**
+     * Sets to the given value.
+     *
+     * @param newValue the new value
+     */
+    public final void set(int newValue) {
+        value = newValue;
+    }
+
+    /**
+     * Eventually sets to the given value.
+     *
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(int newValue) {
+        unsafe.putOrderedInt(this, valueOffset, newValue);
+    }
+
+    /**
+     * Atomically sets to the given value and returns the old value.
+     *
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public final int getAndSet(int newValue) {
+        return unsafe.getAndSetInt(this, valueOffset, newValue);
+    }
+
+    /**
+     * 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(int expect, int update) {
+        return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
+    }
+
+    /**
+     * 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(int expect, int update) {
+        return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
+    }
+
+    /**
+     * Atomically increments by one the current value.
+     *
+     * @return the previous value
+     */
+    public final int getAndIncrement() {
+        return unsafe.getAndAddInt(this, valueOffset, 1);
+    }
+
+    /**
+     * Atomically decrements by one the current value.
+     *
+     * @return the previous value
+     */
+    public final int getAndDecrement() {
+        return unsafe.getAndAddInt(this, valueOffset, -1);
+    }
+
+    /**
+     * Atomically adds the given value to the current value.
+     *
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public final int getAndAdd(int delta) {
+        return unsafe.getAndAddInt(this, valueOffset, delta);
+    }
+
+    /**
+     * Atomically increments by one the current value.
+     *
+     * @return the updated value
+     */
+    public final int incrementAndGet() {
+        return unsafe.getAndAddInt(this, valueOffset, 1) + 1;
+    }
+
+    /**
+     * Atomically decrements by one the current value.
+     *
+     * @return the updated value
+     */
+    public final int decrementAndGet() {
+        return unsafe.getAndAddInt(this, valueOffset, -1) - 1;
+    }
+
+    /**
+     * Atomically adds the given value to the current value.
+     *
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public final int addAndGet(int delta) {
+        return unsafe.getAndAddInt(this, valueOffset, delta) + delta;
+    }
+
+    /**
+     * 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 int getAndUpdate(IntUnaryOperator updateFunction) {
+        int prev, next;
+        do {
+            prev = get();
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 int updateAndGet(IntUnaryOperator updateFunction) {
+        int prev, next;
+        do {
+            prev = get();
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * 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 int getAndAccumulate(int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        int prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 int accumulateAndGet(int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        int prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return Integer.toString(get());
+    }
+
+    /**
+     * Returns the value of this {@code AtomicInteger} as an {@code int}.
+     */
+    public int intValue() {
+        return get();
+    }
+
+    /**
+     * Returns the value of this {@code AtomicInteger} as a {@code long}
+     * after a widening primitive conversion.
+     * @jls 5.1.2 Widening Primitive Conversions
+     */
+    public long longValue() {
+        return (long)get();
+    }
+
+    /**
+     * Returns the value of this {@code AtomicInteger} 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 AtomicInteger} as a {@code double}
+     * after a widening primitive conversion.
+     * @jls 5.1.2 Widening Primitive Conversions
+     */
+    public double doubleValue() {
+        return (double)get();
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicIntegerArray.java

@@ -0,0 +1,364 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.IntUnaryOperator;
+import java.util.function.IntBinaryOperator;
+import sun.misc.Unsafe;
+
+/**
+ * An {@code int} array in which elements may be updated atomically.
+ * See the {@link java.util.concurrent.atomic} package
+ * specification for description of the properties of atomic
+ * variables.
+ * @since 1.5
+ * @author Doug Lea
+ */
+public class AtomicIntegerArray implements java.io.Serializable {
+    private static final long serialVersionUID = 2862133569453604235L;
+
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final int base = unsafe.arrayBaseOffset(int[].class);
+    private static final int shift;
+    private final int[] array;
+
+    static {
+        int scale = unsafe.arrayIndexScale(int[].class);
+        if ((scale & (scale - 1)) != 0)
+            throw new Error("data type scale not a power of two");
+        shift = 31 - Integer.numberOfLeadingZeros(scale);
+    }
+
+    private long checkedByteOffset(int i) {
+        if (i < 0 || i >= array.length)
+            throw new IndexOutOfBoundsException("index " + i);
+
+        return byteOffset(i);
+    }
+
+    private static long byteOffset(int i) {
+        return ((long) i << shift) + base;
+    }
+
+    /**
+     * Creates a new AtomicIntegerArray of the given length, with all
+     * elements initially zero.
+     *
+     * @param length the length of the array
+     */
+    public AtomicIntegerArray(int length) {
+        array = new int[length];
+    }
+
+    /**
+     * Creates a new AtomicIntegerArray with the same length as, and
+     * all elements copied from, the given array.
+     *
+     * @param array the array to copy elements from
+     * @throws NullPointerException if array is null
+     */
+    public AtomicIntegerArray(int[] array) {
+        // Visibility guaranteed by final field guarantees
+        this.array = array.clone();
+    }
+
+    /**
+     * Returns the length of the array.
+     *
+     * @return the length of the array
+     */
+    public final int length() {
+        return array.length;
+    }
+
+    /**
+     * Gets the current value at position {@code i}.
+     *
+     * @param i the index
+     * @return the current value
+     */
+    public final int get(int i) {
+        return getRaw(checkedByteOffset(i));
+    }
+
+    private int getRaw(long offset) {
+        return unsafe.getIntVolatile(array, offset);
+    }
+
+    /**
+     * Sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     */
+    public final void set(int i, int newValue) {
+        unsafe.putIntVolatile(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Eventually sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(int i, int newValue) {
+        unsafe.putOrderedInt(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given
+     * value and returns the old value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public final int getAndSet(int i, int newValue) {
+        return unsafe.getAndSetInt(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given
+     * updated value if the current value {@code ==} the expected value.
+     *
+     * @param i the index
+     * @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(int i, int expect, int update) {
+        return compareAndSetRaw(checkedByteOffset(i), expect, update);
+    }
+
+    private boolean compareAndSetRaw(long offset, int expect, int update) {
+        return unsafe.compareAndSwapInt(array, offset, expect, update);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} 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 i the index
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     */
+    public final boolean weakCompareAndSet(int i, int expect, int update) {
+        return compareAndSet(i, expect, update);
+    }
+
+    /**
+     * Atomically increments by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the previous value
+     */
+    public final int getAndIncrement(int i) {
+        return getAndAdd(i, 1);
+    }
+
+    /**
+     * Atomically decrements by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the previous value
+     */
+    public final int getAndDecrement(int i) {
+        return getAndAdd(i, -1);
+    }
+
+    /**
+     * Atomically adds the given value to the element at index {@code i}.
+     *
+     * @param i the index
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public final int getAndAdd(int i, int delta) {
+        return unsafe.getAndAddInt(array, checkedByteOffset(i), delta);
+    }
+
+    /**
+     * Atomically increments by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the updated value
+     */
+    public final int incrementAndGet(int i) {
+        return getAndAdd(i, 1) + 1;
+    }
+
+    /**
+     * Atomically decrements by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the updated value
+     */
+    public final int decrementAndGet(int i) {
+        return getAndAdd(i, -1) - 1;
+    }
+
+    /**
+     * Atomically adds the given value to the element at index {@code i}.
+     *
+     * @param i the index
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public final int addAndGet(int i, int delta) {
+        return getAndAdd(i, delta) + delta;
+    }
+
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final int getAndUpdate(int i, IntUnaryOperator updateFunction) {
+        long offset = checkedByteOffset(i);
+        int prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final int updateAndGet(int i, IntUnaryOperator updateFunction) {
+        long offset = checkedByteOffset(i);
+        int prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final int getAndAccumulate(int i, int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        int prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final int accumulateAndGet(int i, int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        int prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current values of array.
+     * @return the String representation of the current values of array
+     */
+    public String toString() {
+        int iMax = array.length - 1;
+        if (iMax == -1)
+            return "[]";
+
+        StringBuilder b = new StringBuilder();
+        b.append('[');
+        for (int i = 0; ; i++) {
+            b.append(getRaw(byteOffset(i)));
+            if (i == iMax)
+                return b.append(']').toString();
+            b.append(',').append(' ');
+        }
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicIntegerFieldUpdater.java

@@ -0,0 +1,543 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Objects;
+import java.util.function.IntBinaryOperator;
+import java.util.function.IntUnaryOperator;
+import sun.reflect.CallerSensitive;
+import sun.reflect.Reflection;
+
+/**
+ * A reflection-based utility that enables atomic updates to
+ * designated {@code volatile int} fields of designated classes.
+ * This class is designed for use in atomic data structures in which
+ * several fields of the same node are independently subject to atomic
+ * updates.
+ *
+ * <p>Note that the guarantees of the {@code compareAndSet}
+ * method in this class are weaker than in other atomic classes.
+ * Because this class cannot ensure that all uses of the field
+ * are appropriate for purposes of atomic access, it can
+ * guarantee atomicity only with respect to other invocations of
+ * {@code compareAndSet} and {@code set} on the same updater.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <T> The type of the object holding the updatable field
+ */
+public abstract class AtomicIntegerFieldUpdater<T> {
+    /**
+     * Creates and returns an updater for objects with the given field.
+     * The Class argument is needed to check that reflective types and
+     * generic types match.
+     *
+     * @param tclass the class of the objects holding the field
+     * @param fieldName the name of the field to be updated
+     * @param <U> the type of instances of tclass
+     * @return the updater
+     * @throws IllegalArgumentException if the field is not a
+     * volatile integer type
+     * @throws RuntimeException with a nested reflection-based
+     * exception if the class does not hold field or is the wrong type,
+     * or the field is inaccessible to the caller according to Java language
+     * access control
+     */
+    @CallerSensitive
+    public static <U> AtomicIntegerFieldUpdater<U> newUpdater(Class<U> tclass,
+                                                              String fieldName) {
+        return new AtomicIntegerFieldUpdaterImpl<U>
+            (tclass, fieldName, Reflection.getCallerClass());
+    }
+
+    /**
+     * Protected do-nothing constructor for use by subclasses.
+     */
+    protected AtomicIntegerFieldUpdater() {
+    }
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * @param obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     * @throws ClassCastException if {@code obj} is not an instance
+     * of the class possessing the field established in the constructor
+     */
+    public abstract boolean compareAndSet(T obj, int expect, int update);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * <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 obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     * @throws ClassCastException if {@code obj} is not an instance
+     * of the class possessing the field established in the constructor
+     */
+    public abstract boolean weakCompareAndSet(T obj, int expect, int update);
+
+    /**
+     * Sets the field of the given object managed by this updater to the
+     * given updated value. This operation is guaranteed to act as a volatile
+     * store with respect to subsequent invocations of {@code compareAndSet}.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     */
+    public abstract void set(T obj, int newValue);
+
+    /**
+     * Eventually sets the field of the given object managed by this
+     * updater to the given updated value.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public abstract void lazySet(T obj, int newValue);
+
+    /**
+     * Gets the current value held in the field of the given object managed
+     * by this updater.
+     *
+     * @param obj An object whose field to get
+     * @return the current value
+     */
+    public abstract int get(T obj);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given value and returns the old value.
+     *
+     * @param obj An object whose field to get and set
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public int getAndSet(T obj, int newValue) {
+        int prev;
+        do {
+            prev = get(obj);
+        } while (!compareAndSet(obj, prev, newValue));
+        return prev;
+    }
+
+    /**
+     * Atomically increments by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the previous value
+     */
+    public int getAndIncrement(T obj) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev + 1;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically decrements by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the previous value
+     */
+    public int getAndDecrement(T obj) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev - 1;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically adds the given value to the current value of the field of
+     * the given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public int getAndAdd(T obj, int delta) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev + delta;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically increments by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the updated value
+     */
+    public int incrementAndGet(T obj) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev + 1;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically decrements by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the updated value
+     */
+    public int decrementAndGet(T obj) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev - 1;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically adds the given value to the current value of the field of
+     * the given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public int addAndGet(T obj, int delta) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = prev + delta;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final int getAndUpdate(T obj, IntUnaryOperator updateFunction) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final int updateAndGet(T obj, IntUnaryOperator updateFunction) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.applyAsInt(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final int getAndAccumulate(T obj, int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final int accumulateAndGet(T obj, int x,
+                                      IntBinaryOperator accumulatorFunction) {
+        int prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.applyAsInt(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Standard hotspot implementation using intrinsics.
+     */
+    private static final class AtomicIntegerFieldUpdaterImpl<T>
+        extends AtomicIntegerFieldUpdater<T> {
+        private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
+        private final long offset;
+        /**
+         * if field is protected, the subclass constructing updater, else
+         * the same as tclass
+         */
+        private final Class<?> cclass;
+        /** class holding the field */
+        private final Class<T> tclass;
+
+        AtomicIntegerFieldUpdaterImpl(final Class<T> tclass,
+                                      final String fieldName,
+                                      final Class<?> caller) {
+            final Field field;
+            final int modifiers;
+            try {
+                field = AccessController.doPrivileged(
+                    new PrivilegedExceptionAction<Field>() {
+                        public Field run() throws NoSuchFieldException {
+                            return tclass.getDeclaredField(fieldName);
+                        }
+                    });
+                modifiers = field.getModifiers();
+                sun.reflect.misc.ReflectUtil.ensureMemberAccess(
+                    caller, tclass, null, modifiers);
+                ClassLoader cl = tclass.getClassLoader();
+                ClassLoader ccl = caller.getClassLoader();
+                if ((ccl != null) && (ccl != cl) &&
+                    ((cl == null) || !isAncestor(cl, ccl))) {
+                    sun.reflect.misc.ReflectUtil.checkPackageAccess(tclass);
+                }
+            } catch (PrivilegedActionException pae) {
+                throw new RuntimeException(pae.getException());
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+
+            if (field.getType() != int.class)
+                throw new IllegalArgumentException("Must be integer type");
+
+            if (!Modifier.isVolatile(modifiers))
+                throw new IllegalArgumentException("Must be volatile type");
+
+            // Access to protected field members is restricted to receivers only
+            // of the accessing class, or one of its subclasses, and the
+            // accessing class must in turn be a subclass (or package sibling)
+            // of the protected member's defining class.
+            // If the updater refers to a protected field of a declaring class
+            // outside the current package, the receiver argument will be
+            // narrowed to the type of the accessing class.
+            this.cclass = (Modifier.isProtected(modifiers) &&
+                           tclass.isAssignableFrom(caller) &&
+                           !isSamePackage(tclass, caller))
+                          ? caller : tclass;
+            this.tclass = tclass;
+            this.offset = U.objectFieldOffset(field);
+        }
+
+        /**
+         * Returns true if the second classloader can be found in the first
+         * classloader's delegation chain.
+         * Equivalent to the inaccessible: first.isAncestor(second).
+         */
+        private static boolean isAncestor(ClassLoader first, ClassLoader second) {
+            ClassLoader acl = first;
+            do {
+                acl = acl.getParent();
+                if (second == acl) {
+                    return true;
+                }
+            } while (acl != null);
+            return false;
+        }
+
+        /**
+         * Returns true if the two classes have the same class loader and
+         * package qualifier
+         */
+        private static boolean isSamePackage(Class<?> class1, Class<?> class2) {
+            return class1.getClassLoader() == class2.getClassLoader()
+                   && Objects.equals(getPackageName(class1), getPackageName(class2));
+        }
+
+        private static String getPackageName(Class<?> cls) {
+            String cn = cls.getName();
+            int dot = cn.lastIndexOf('.');
+            return (dot != -1) ? cn.substring(0, dot) : "";
+        }
+
+        /**
+         * Checks that target argument is instance of cclass.  On
+         * failure, throws cause.
+         */
+        private final void accessCheck(T obj) {
+            if (!cclass.isInstance(obj))
+                throwAccessCheckException(obj);
+        }
+
+        /**
+         * Throws access exception if accessCheck failed due to
+         * protected access, else ClassCastException.
+         */
+        private final void throwAccessCheckException(T obj) {
+            if (cclass == tclass)
+                throw new ClassCastException();
+            else
+                throw new RuntimeException(
+                    new IllegalAccessException(
+                        "Class " +
+                        cclass.getName() +
+                        " can not access a protected member of class " +
+                        tclass.getName() +
+                        " using an instance of " +
+                        obj.getClass().getName()));
+        }
+
+        public final boolean compareAndSet(T obj, int expect, int update) {
+            accessCheck(obj);
+            return U.compareAndSwapInt(obj, offset, expect, update);
+        }
+
+        public final boolean weakCompareAndSet(T obj, int expect, int update) {
+            accessCheck(obj);
+            return U.compareAndSwapInt(obj, offset, expect, update);
+        }
+
+        public final void set(T obj, int newValue) {
+            accessCheck(obj);
+            U.putIntVolatile(obj, offset, newValue);
+        }
+
+        public final void lazySet(T obj, int newValue) {
+            accessCheck(obj);
+            U.putOrderedInt(obj, offset, newValue);
+        }
+
+        public final int get(T obj) {
+            accessCheck(obj);
+            return U.getIntVolatile(obj, offset);
+        }
+
+        public final int getAndSet(T obj, int newValue) {
+            accessCheck(obj);
+            return U.getAndSetInt(obj, offset, newValue);
+        }
+
+        public final int getAndAdd(T obj, int delta) {
+            accessCheck(obj);
+            return U.getAndAddInt(obj, offset, delta);
+        }
+
+        public final int getAndIncrement(T obj) {
+            return getAndAdd(obj, 1);
+        }
+
+        public final int getAndDecrement(T obj) {
+            return getAndAdd(obj, -1);
+        }
+
+        public final int incrementAndGet(T obj) {
+            return getAndAdd(obj, 1) + 1;
+        }
+
+        public final int decrementAndGet(T obj) {
+            return getAndAdd(obj, -1) - 1;
+        }
+
+        public final int addAndGet(T obj, int delta) {
+            return getAndAdd(obj, delta) + delta;
+        }
+
+    }
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicLong.java

@@ -0,0 +1,350 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.LongUnaryOperator;
+import java.util.function.LongBinaryOperator;
+import sun.misc.Unsafe;
+
+/**
+ * A {@code long} value that may be updated atomically.  See the
+ * {@link java.util.concurrent.atomic} package specification for
+ * description of the properties of atomic variables. An
+ * {@code AtomicLong} is used in applications such as atomically
+ * incremented sequence numbers, and cannot be used as a replacement
+ * for a {@link java.lang.Long}. However, this class does extend
+ * {@code Number} to allow uniform access by tools and utilities that
+ * deal with numerically-based classes.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ */
+public class AtomicLong extends Number implements java.io.Serializable {
+    private static final long serialVersionUID = 1927816293512124184L;
+
+    // setup to use Unsafe.compareAndSwapLong for updates
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final long valueOffset;
+
+    /**
+     * Records whether the underlying JVM supports lockless
+     * compareAndSwap for longs. While the Unsafe.compareAndSwapLong
+     * method works in either case, some constructions should be
+     * handled at Java level to avoid locking user-visible locks.
+     */
+    static final boolean VM_SUPPORTS_LONG_CAS = VMSupportsCS8();
+
+    /**
+     * Returns whether underlying JVM supports lockless CompareAndSet
+     * for longs. Called only once and cached in VM_SUPPORTS_LONG_CAS.
+     */
+    private static native boolean VMSupportsCS8();
+
+    static {
+        try {
+            valueOffset = unsafe.objectFieldOffset
+                (AtomicLong.class.getDeclaredField("value"));
+        } catch (Exception ex) { throw new Error(ex); }
+    }
+
+    private volatile long value;
+
+    /**
+     * Creates a new AtomicLong with the given initial value.
+     *
+     * @param initialValue the initial value
+     */
+    public AtomicLong(long initialValue) {
+        value = initialValue;
+    }
+
+    /**
+     * Creates a new AtomicLong with initial value {@code 0}.
+     */
+    public AtomicLong() {
+    }
+
+    /**
+     * Gets the current value.
+     *
+     * @return the current value
+     */
+    public final long get() {
+        return value;
+    }
+
+    /**
+     * Sets to the given value.
+     *
+     * @param newValue the new value
+     */
+    public final void set(long newValue) {
+        value = newValue;
+    }
+
+    /**
+     * Eventually sets to the given value.
+     *
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(long newValue) {
+        unsafe.putOrderedLong(this, valueOffset, newValue);
+    }
+
+    /**
+     * Atomically sets to the given value and returns the old value.
+     *
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public final long getAndSet(long newValue) {
+        return unsafe.getAndSetLong(this, valueOffset, newValue);
+    }
+
+    /**
+     * 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(long expect, long update) {
+        return unsafe.compareAndSwapLong(this, valueOffset, expect, update);
+    }
+
+    /**
+     * 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(long expect, long update) {
+        return unsafe.compareAndSwapLong(this, valueOffset, expect, update);
+    }
+
+    /**
+     * Atomically increments by one the current value.
+     *
+     * @return the previous value
+     */
+    public final long getAndIncrement() {
+        return unsafe.getAndAddLong(this, valueOffset, 1L);
+    }
+
+    /**
+     * Atomically decrements by one the current value.
+     *
+     * @return the previous value
+     */
+    public final long getAndDecrement() {
+        return unsafe.getAndAddLong(this, valueOffset, -1L);
+    }
+
+    /**
+     * Atomically adds the given value to the current value.
+     *
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public final long getAndAdd(long delta) {
+        return unsafe.getAndAddLong(this, valueOffset, delta);
+    }
+
+    /**
+     * Atomically increments by one the current value.
+     *
+     * @return the updated value
+     */
+    public final long incrementAndGet() {
+        return unsafe.getAndAddLong(this, valueOffset, 1L) + 1L;
+    }
+
+    /**
+     * Atomically decrements by one the current value.
+     *
+     * @return the updated value
+     */
+    public final long decrementAndGet() {
+        return unsafe.getAndAddLong(this, valueOffset, -1L) - 1L;
+    }
+
+    /**
+     * Atomically adds the given value to the current value.
+     *
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public final long addAndGet(long delta) {
+        return unsafe.getAndAddLong(this, valueOffset, delta) + delta;
+    }
+
+    /**
+     * 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 long getAndUpdate(LongUnaryOperator updateFunction) {
+        long prev, next;
+        do {
+            prev = get();
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 long updateAndGet(LongUnaryOperator updateFunction) {
+        long prev, next;
+        do {
+            prev = get();
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * 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 long getAndAccumulate(long x,
+                                       LongBinaryOperator accumulatorFunction) {
+        long prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 long accumulateAndGet(long x,
+                                       LongBinaryOperator accumulatorFunction) {
+        long prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return Long.toString(get());
+    }
+
+    /**
+     * 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 long}.
+     */
+    public long longValue() {
+        return 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 (double)get();
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicLongArray.java

@@ -0,0 +1,362 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.LongUnaryOperator;
+import java.util.function.LongBinaryOperator;
+import sun.misc.Unsafe;
+
+/**
+ * A {@code long} array in which elements may be updated atomically.
+ * See the {@link java.util.concurrent.atomic} package specification
+ * for description of the properties of atomic variables.
+ * @since 1.5
+ * @author Doug Lea
+ */
+public class AtomicLongArray implements java.io.Serializable {
+    private static final long serialVersionUID = -2308431214976778248L;
+
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final int base = unsafe.arrayBaseOffset(long[].class);
+    private static final int shift;
+    private final long[] array;
+
+    static {
+        int scale = unsafe.arrayIndexScale(long[].class);
+        if ((scale & (scale - 1)) != 0)
+            throw new Error("data type scale not a power of two");
+        shift = 31 - Integer.numberOfLeadingZeros(scale);
+    }
+
+    private long checkedByteOffset(int i) {
+        if (i < 0 || i >= array.length)
+            throw new IndexOutOfBoundsException("index " + i);
+
+        return byteOffset(i);
+    }
+
+    private static long byteOffset(int i) {
+        return ((long) i << shift) + base;
+    }
+
+    /**
+     * Creates a new AtomicLongArray of the given length, with all
+     * elements initially zero.
+     *
+     * @param length the length of the array
+     */
+    public AtomicLongArray(int length) {
+        array = new long[length];
+    }
+
+    /**
+     * Creates a new AtomicLongArray with the same length as, and
+     * all elements copied from, the given array.
+     *
+     * @param array the array to copy elements from
+     * @throws NullPointerException if array is null
+     */
+    public AtomicLongArray(long[] array) {
+        // Visibility guaranteed by final field guarantees
+        this.array = array.clone();
+    }
+
+    /**
+     * Returns the length of the array.
+     *
+     * @return the length of the array
+     */
+    public final int length() {
+        return array.length;
+    }
+
+    /**
+     * Gets the current value at position {@code i}.
+     *
+     * @param i the index
+     * @return the current value
+     */
+    public final long get(int i) {
+        return getRaw(checkedByteOffset(i));
+    }
+
+    private long getRaw(long offset) {
+        return unsafe.getLongVolatile(array, offset);
+    }
+
+    /**
+     * Sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     */
+    public final void set(int i, long newValue) {
+        unsafe.putLongVolatile(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Eventually sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(int i, long newValue) {
+        unsafe.putOrderedLong(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given value
+     * and returns the old value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public final long getAndSet(int i, long newValue) {
+        return unsafe.getAndSetLong(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given
+     * updated value if the current value {@code ==} the expected value.
+     *
+     * @param i the index
+     * @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(int i, long expect, long update) {
+        return compareAndSetRaw(checkedByteOffset(i), expect, update);
+    }
+
+    private boolean compareAndSetRaw(long offset, long expect, long update) {
+        return unsafe.compareAndSwapLong(array, offset, expect, update);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} 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 i the index
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     */
+    public final boolean weakCompareAndSet(int i, long expect, long update) {
+        return compareAndSet(i, expect, update);
+    }
+
+    /**
+     * Atomically increments by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the previous value
+     */
+    public final long getAndIncrement(int i) {
+        return getAndAdd(i, 1);
+    }
+
+    /**
+     * Atomically decrements by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the previous value
+     */
+    public final long getAndDecrement(int i) {
+        return getAndAdd(i, -1);
+    }
+
+    /**
+     * Atomically adds the given value to the element at index {@code i}.
+     *
+     * @param i the index
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public final long getAndAdd(int i, long delta) {
+        return unsafe.getAndAddLong(array, checkedByteOffset(i), delta);
+    }
+
+    /**
+     * Atomically increments by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the updated value
+     */
+    public final long incrementAndGet(int i) {
+        return getAndAdd(i, 1) + 1;
+    }
+
+    /**
+     * Atomically decrements by one the element at index {@code i}.
+     *
+     * @param i the index
+     * @return the updated value
+     */
+    public final long decrementAndGet(int i) {
+        return getAndAdd(i, -1) - 1;
+    }
+
+    /**
+     * Atomically adds the given value to the element at index {@code i}.
+     *
+     * @param i the index
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public long addAndGet(int i, long delta) {
+        return getAndAdd(i, delta) + delta;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final long getAndUpdate(int i, LongUnaryOperator updateFunction) {
+        long offset = checkedByteOffset(i);
+        long prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final long updateAndGet(int i, LongUnaryOperator updateFunction) {
+        long offset = checkedByteOffset(i);
+        long prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final long getAndAccumulate(int i, long x,
+                                      LongBinaryOperator accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        long prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final long accumulateAndGet(int i, long x,
+                                      LongBinaryOperator accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        long prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current values of array.
+     * @return the String representation of the current values of array
+     */
+    public String toString() {
+        int iMax = array.length - 1;
+        if (iMax == -1)
+            return "[]";
+
+        StringBuilder b = new StringBuilder();
+        b.append('[');
+        for (int i = 0; ; i++) {
+            b.append(getRaw(byteOffset(i)));
+            if (i == iMax)
+                return b.append(']').toString();
+            b.append(',').append(' ');
+        }
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicLongFieldUpdater.java

@@ -0,0 +1,659 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Objects;
+import java.util.function.LongBinaryOperator;
+import java.util.function.LongUnaryOperator;
+import sun.reflect.CallerSensitive;
+import sun.reflect.Reflection;
+
+/**
+ * A reflection-based utility that enables atomic updates to
+ * designated {@code volatile long} fields of designated classes.
+ * This class is designed for use in atomic data structures in which
+ * several fields of the same node are independently subject to atomic
+ * updates.
+ *
+ * <p>Note that the guarantees of the {@code compareAndSet}
+ * method in this class are weaker than in other atomic classes.
+ * Because this class cannot ensure that all uses of the field
+ * are appropriate for purposes of atomic access, it can
+ * guarantee atomicity only with respect to other invocations of
+ * {@code compareAndSet} and {@code set} on the same updater.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <T> The type of the object holding the updatable field
+ */
+public abstract class AtomicLongFieldUpdater<T> {
+    /**
+     * Creates and returns an updater for objects with the given field.
+     * The Class argument is needed to check that reflective types and
+     * generic types match.
+     *
+     * @param tclass the class of the objects holding the field
+     * @param fieldName the name of the field to be updated
+     * @param <U> the type of instances of tclass
+     * @return the updater
+     * @throws IllegalArgumentException if the field is not a
+     * volatile long type
+     * @throws RuntimeException with a nested reflection-based
+     * exception if the class does not hold field or is the wrong type,
+     * or the field is inaccessible to the caller according to Java language
+     * access control
+     */
+    @CallerSensitive
+    public static <U> AtomicLongFieldUpdater<U> newUpdater(Class<U> tclass,
+                                                           String fieldName) {
+        Class<?> caller = Reflection.getCallerClass();
+        if (AtomicLong.VM_SUPPORTS_LONG_CAS)
+            return new CASUpdater<U>(tclass, fieldName, caller);
+        else
+            return new LockedUpdater<U>(tclass, fieldName, caller);
+    }
+
+    /**
+     * Protected do-nothing constructor for use by subclasses.
+     */
+    protected AtomicLongFieldUpdater() {
+    }
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * @param obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     * @throws ClassCastException if {@code obj} is not an instance
+     * of the class possessing the field established in the constructor
+     */
+    public abstract boolean compareAndSet(T obj, long expect, long update);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * <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 obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     * @throws ClassCastException if {@code obj} is not an instance
+     * of the class possessing the field established in the constructor
+     */
+    public abstract boolean weakCompareAndSet(T obj, long expect, long update);
+
+    /**
+     * Sets the field of the given object managed by this updater to the
+     * given updated value. This operation is guaranteed to act as a volatile
+     * store with respect to subsequent invocations of {@code compareAndSet}.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     */
+    public abstract void set(T obj, long newValue);
+
+    /**
+     * Eventually sets the field of the given object managed by this
+     * updater to the given updated value.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public abstract void lazySet(T obj, long newValue);
+
+    /**
+     * Gets the current value held in the field of the given object managed
+     * by this updater.
+     *
+     * @param obj An object whose field to get
+     * @return the current value
+     */
+    public abstract long get(T obj);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given value and returns the old value.
+     *
+     * @param obj An object whose field to get and set
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public long getAndSet(T obj, long newValue) {
+        long prev;
+        do {
+            prev = get(obj);
+        } while (!compareAndSet(obj, prev, newValue));
+        return prev;
+    }
+
+    /**
+     * Atomically increments by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the previous value
+     */
+    public long getAndIncrement(T obj) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev + 1;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically decrements by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the previous value
+     */
+    public long getAndDecrement(T obj) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev - 1;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically adds the given value to the current value of the field of
+     * the given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @param delta the value to add
+     * @return the previous value
+     */
+    public long getAndAdd(T obj, long delta) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev + delta;
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically increments by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the updated value
+     */
+    public long incrementAndGet(T obj) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev + 1;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically decrements by one the current value of the field of the
+     * given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @return the updated value
+     */
+    public long decrementAndGet(T obj) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev - 1;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically adds the given value to the current value of the field of
+     * the given object managed by this updater.
+     *
+     * @param obj An object whose field to get and set
+     * @param delta the value to add
+     * @return the updated value
+     */
+    public long addAndGet(T obj, long delta) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = prev + delta;
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final long getAndUpdate(T obj, LongUnaryOperator updateFunction) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final long updateAndGet(T obj, LongUnaryOperator updateFunction) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.applyAsLong(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final long getAndAccumulate(T obj, long x,
+                                       LongBinaryOperator accumulatorFunction) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final long accumulateAndGet(T obj, long x,
+                                       LongBinaryOperator accumulatorFunction) {
+        long prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.applyAsLong(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    private static final class CASUpdater<T> extends AtomicLongFieldUpdater<T> {
+        private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
+        private final long offset;
+        /**
+         * if field is protected, the subclass constructing updater, else
+         * the same as tclass
+         */
+        private final Class<?> cclass;
+        /** class holding the field */
+        private final Class<T> tclass;
+
+        CASUpdater(final Class<T> tclass, final String fieldName,
+                   final Class<?> caller) {
+            final Field field;
+            final int modifiers;
+            try {
+                field = AccessController.doPrivileged(
+                    new PrivilegedExceptionAction<Field>() {
+                        public Field run() throws NoSuchFieldException {
+                            return tclass.getDeclaredField(fieldName);
+                        }
+                    });
+                modifiers = field.getModifiers();
+                sun.reflect.misc.ReflectUtil.ensureMemberAccess(
+                    caller, tclass, null, modifiers);
+                ClassLoader cl = tclass.getClassLoader();
+                ClassLoader ccl = caller.getClassLoader();
+                if ((ccl != null) && (ccl != cl) &&
+                    ((cl == null) || !isAncestor(cl, ccl))) {
+                    sun.reflect.misc.ReflectUtil.checkPackageAccess(tclass);
+                }
+            } catch (PrivilegedActionException pae) {
+                throw new RuntimeException(pae.getException());
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+
+            if (field.getType() != long.class)
+                throw new IllegalArgumentException("Must be long type");
+
+            if (!Modifier.isVolatile(modifiers))
+                throw new IllegalArgumentException("Must be volatile type");
+
+            // Access to protected field members is restricted to receivers only
+            // of the accessing class, or one of its subclasses, and the
+            // accessing class must in turn be a subclass (or package sibling)
+            // of the protected member's defining class.
+            // If the updater refers to a protected field of a declaring class
+            // outside the current package, the receiver argument will be
+            // narrowed to the type of the accessing class.
+            this.cclass = (Modifier.isProtected(modifiers) &&
+                           tclass.isAssignableFrom(caller) &&
+                           !isSamePackage(tclass, caller))
+                          ? caller : tclass;
+            this.tclass = tclass;
+            this.offset = U.objectFieldOffset(field);
+        }
+
+        /**
+         * Checks that target argument is instance of cclass.  On
+         * failure, throws cause.
+         */
+        private final void accessCheck(T obj) {
+            if (!cclass.isInstance(obj))
+                throwAccessCheckException(obj);
+        }
+
+        /**
+         * Throws access exception if accessCheck failed due to
+         * protected access, else ClassCastException.
+         */
+        private final void throwAccessCheckException(T obj) {
+            if (cclass == tclass)
+                throw new ClassCastException();
+            else
+                throw new RuntimeException(
+                    new IllegalAccessException(
+                        "Class " +
+                        cclass.getName() +
+                        " can not access a protected member of class " +
+                        tclass.getName() +
+                        " using an instance of " +
+                        obj.getClass().getName()));
+        }
+
+        public final boolean compareAndSet(T obj, long expect, long update) {
+            accessCheck(obj);
+            return U.compareAndSwapLong(obj, offset, expect, update);
+        }
+
+        public final boolean weakCompareAndSet(T obj, long expect, long update) {
+            accessCheck(obj);
+            return U.compareAndSwapLong(obj, offset, expect, update);
+        }
+
+        public final void set(T obj, long newValue) {
+            accessCheck(obj);
+            U.putLongVolatile(obj, offset, newValue);
+        }
+
+        public final void lazySet(T obj, long newValue) {
+            accessCheck(obj);
+            U.putOrderedLong(obj, offset, newValue);
+        }
+
+        public final long get(T obj) {
+            accessCheck(obj);
+            return U.getLongVolatile(obj, offset);
+        }
+
+        public final long getAndSet(T obj, long newValue) {
+            accessCheck(obj);
+            return U.getAndSetLong(obj, offset, newValue);
+        }
+
+        public final long getAndAdd(T obj, long delta) {
+            accessCheck(obj);
+            return U.getAndAddLong(obj, offset, delta);
+        }
+
+        public final long getAndIncrement(T obj) {
+            return getAndAdd(obj, 1);
+        }
+
+        public final long getAndDecrement(T obj) {
+            return getAndAdd(obj, -1);
+        }
+
+        public final long incrementAndGet(T obj) {
+            return getAndAdd(obj, 1) + 1;
+        }
+
+        public final long decrementAndGet(T obj) {
+            return getAndAdd(obj, -1) - 1;
+        }
+
+        public final long addAndGet(T obj, long delta) {
+            return getAndAdd(obj, delta) + delta;
+        }
+    }
+
+    private static final class LockedUpdater<T> extends AtomicLongFieldUpdater<T> {
+        private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
+        private final long offset;
+        /**
+         * if field is protected, the subclass constructing updater, else
+         * the same as tclass
+         */
+        private final Class<?> cclass;
+        /** class holding the field */
+        private final Class<T> tclass;
+
+        LockedUpdater(final Class<T> tclass, final String fieldName,
+                      final Class<?> caller) {
+            Field field = null;
+            int modifiers = 0;
+            try {
+                field = AccessController.doPrivileged(
+                    new PrivilegedExceptionAction<Field>() {
+                        public Field run() throws NoSuchFieldException {
+                            return tclass.getDeclaredField(fieldName);
+                        }
+                    });
+                modifiers = field.getModifiers();
+                sun.reflect.misc.ReflectUtil.ensureMemberAccess(
+                    caller, tclass, null, modifiers);
+                ClassLoader cl = tclass.getClassLoader();
+                ClassLoader ccl = caller.getClassLoader();
+                if ((ccl != null) && (ccl != cl) &&
+                    ((cl == null) || !isAncestor(cl, ccl))) {
+                    sun.reflect.misc.ReflectUtil.checkPackageAccess(tclass);
+                }
+            } catch (PrivilegedActionException pae) {
+                throw new RuntimeException(pae.getException());
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+
+            if (field.getType() != long.class)
+                throw new IllegalArgumentException("Must be long type");
+
+            if (!Modifier.isVolatile(modifiers))
+                throw new IllegalArgumentException("Must be volatile type");
+
+            // Access to protected field members is restricted to receivers only
+            // of the accessing class, or one of its subclasses, and the
+            // accessing class must in turn be a subclass (or package sibling)
+            // of the protected member's defining class.
+            // If the updater refers to a protected field of a declaring class
+            // outside the current package, the receiver argument will be
+            // narrowed to the type of the accessing class.
+            this.cclass = (Modifier.isProtected(modifiers) &&
+                           tclass.isAssignableFrom(caller) &&
+                           !isSamePackage(tclass, caller))
+                          ? caller : tclass;
+            this.tclass = tclass;
+            this.offset = U.objectFieldOffset(field);
+        }
+
+        /**
+         * Checks that target argument is instance of cclass.  On
+         * failure, throws cause.
+         */
+        private final void accessCheck(T obj) {
+            if (!cclass.isInstance(obj))
+                throw accessCheckException(obj);
+        }
+
+        /**
+         * Returns access exception if accessCheck failed due to
+         * protected access, else ClassCastException.
+         */
+        private final RuntimeException accessCheckException(T obj) {
+            if (cclass == tclass)
+                return new ClassCastException();
+            else
+                return new RuntimeException(
+                    new IllegalAccessException(
+                        "Class " +
+                        cclass.getName() +
+                        " can not access a protected member of class " +
+                        tclass.getName() +
+                        " using an instance of " +
+                        obj.getClass().getName()));
+        }
+
+        public final boolean compareAndSet(T obj, long expect, long update) {
+            accessCheck(obj);
+            synchronized (this) {
+                long v = U.getLong(obj, offset);
+                if (v != expect)
+                    return false;
+                U.putLong(obj, offset, update);
+                return true;
+            }
+        }
+
+        public final boolean weakCompareAndSet(T obj, long expect, long update) {
+            return compareAndSet(obj, expect, update);
+        }
+
+        public final void set(T obj, long newValue) {
+            accessCheck(obj);
+            synchronized (this) {
+                U.putLong(obj, offset, newValue);
+            }
+        }
+
+        public final void lazySet(T obj, long newValue) {
+            set(obj, newValue);
+        }
+
+        public final long get(T obj) {
+            accessCheck(obj);
+            synchronized (this) {
+                return U.getLong(obj, offset);
+            }
+        }
+    }
+
+    /**
+     * Returns true if the second classloader can be found in the first
+     * classloader's delegation chain.
+     * Equivalent to the inaccessible: first.isAncestor(second).
+     */
+    static boolean isAncestor(ClassLoader first, ClassLoader second) {
+        ClassLoader acl = first;
+        do {
+            acl = acl.getParent();
+            if (second == acl) {
+                return true;
+            }
+        } while (acl != null);
+        return false;
+    }
+
+    /**
+     * Returns true if the two classes have the same class loader and
+     * package qualifier
+     */
+    private static boolean isSamePackage(Class<?> class1, Class<?> class2) {
+        return class1.getClassLoader() == class2.getClassLoader()
+               && Objects.equals(getPackageName(class1), getPackageName(class2));
+}
+
+    private static String getPackageName(Class<?> cls) {
+        String cn = cls.getName();
+        int dot = cn.lastIndexOf('.');
+        return (dot != -1) ? cn.substring(0, dot) : "";
+    }
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicMarkableReference.java

@@ -0,0 +1,212 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+
+/**
+ * An {@code AtomicMarkableReference} maintains an object reference
+ * along with a mark bit, that can be updated atomically.
+ *
+ * <p>Implementation note: This implementation maintains markable
+ * references by creating internal objects representing "boxed"
+ * [reference, boolean] pairs.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <V> The type of object referred to by this reference
+ */
+public class AtomicMarkableReference<V> {
+
+    private static class Pair<T> {
+        final T reference;
+        final boolean mark;
+        private Pair(T reference, boolean mark) {
+            this.reference = reference;
+            this.mark = mark;
+        }
+        static <T> Pair<T> of(T reference, boolean mark) {
+            return new Pair<T>(reference, mark);
+        }
+    }
+
+    private volatile Pair<V> pair;
+
+    /**
+     * Creates a new {@code AtomicMarkableReference} with the given
+     * initial values.
+     *
+     * @param initialRef the initial reference
+     * @param initialMark the initial mark
+     */
+    public AtomicMarkableReference(V initialRef, boolean initialMark) {
+        pair = Pair.of(initialRef, initialMark);
+    }
+
+    /**
+     * Returns the current value of the reference.
+     *
+     * @return the current value of the reference
+     */
+    public V getReference() {
+        return pair.reference;
+    }
+
+    /**
+     * Returns the current value of the mark.
+     *
+     * @return the current value of the mark
+     */
+    public boolean isMarked() {
+        return pair.mark;
+    }
+
+    /**
+     * Returns the current values of both the reference and the mark.
+     * Typical usage is {@code boolean[1] holder; ref = v.get(holder); }.
+     *
+     * @param markHolder an array of size of at least one. On return,
+     * {@code markholder[0]} will hold the value of the mark.
+     * @return the current value of the reference
+     */
+    public V get(boolean[] markHolder) {
+        Pair<V> pair = this.pair;
+        markHolder[0] = pair.mark;
+        return pair.reference;
+    }
+
+    /**
+     * Atomically sets the value of both the reference and mark
+     * to the given update values if the
+     * current reference is {@code ==} to the expected reference
+     * and the current mark is equal to the expected mark.
+     *
+     * <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 expectedReference the expected value of the reference
+     * @param newReference the new value for the reference
+     * @param expectedMark the expected value of the mark
+     * @param newMark the new value for the mark
+     * @return {@code true} if successful
+     */
+    public boolean weakCompareAndSet(V       expectedReference,
+                                     V       newReference,
+                                     boolean expectedMark,
+                                     boolean newMark) {
+        return compareAndSet(expectedReference, newReference,
+                             expectedMark, newMark);
+    }
+
+    /**
+     * Atomically sets the value of both the reference and mark
+     * to the given update values if the
+     * current reference is {@code ==} to the expected reference
+     * and the current mark is equal to the expected mark.
+     *
+     * @param expectedReference the expected value of the reference
+     * @param newReference the new value for the reference
+     * @param expectedMark the expected value of the mark
+     * @param newMark the new value for the mark
+     * @return {@code true} if successful
+     */
+    public boolean compareAndSet(V       expectedReference,
+                                 V       newReference,
+                                 boolean expectedMark,
+                                 boolean newMark) {
+        Pair<V> current = pair;
+        return
+            expectedReference == current.reference &&
+            expectedMark == current.mark &&
+            ((newReference == current.reference &&
+              newMark == current.mark) ||
+             casPair(current, Pair.of(newReference, newMark)));
+    }
+
+    /**
+     * Unconditionally sets the value of both the reference and mark.
+     *
+     * @param newReference the new value for the reference
+     * @param newMark the new value for the mark
+     */
+    public void set(V newReference, boolean newMark) {
+        Pair<V> current = pair;
+        if (newReference != current.reference || newMark != current.mark)
+            this.pair = Pair.of(newReference, newMark);
+    }
+
+    /**
+     * Atomically sets the value of the mark to the given update value
+     * if the current reference is {@code ==} to the expected
+     * reference.  Any given invocation of this operation may fail
+     * (return {@code false}) spuriously, but repeated invocation
+     * when the current value holds the expected value and no other
+     * thread is also attempting to set the value will eventually
+     * succeed.
+     *
+     * @param expectedReference the expected value of the reference
+     * @param newMark the new value for the mark
+     * @return {@code true} if successful
+     */
+    public boolean attemptMark(V expectedReference, boolean newMark) {
+        Pair<V> current = pair;
+        return
+            expectedReference == current.reference &&
+            (newMark == current.mark ||
+             casPair(current, Pair.of(expectedReference, newMark)));
+    }
+
+    // Unsafe mechanics
+
+    private static final sun.misc.Unsafe UNSAFE = sun.misc.Unsafe.getUnsafe();
+    private static final long pairOffset =
+        objectFieldOffset(UNSAFE, "pair", AtomicMarkableReference.class);
+
+    private boolean casPair(Pair<V> cmp, Pair<V> val) {
+        return UNSAFE.compareAndSwapObject(this, pairOffset, cmp, val);
+    }
+
+    static long objectFieldOffset(sun.misc.Unsafe UNSAFE,
+                                  String field, Class<?> klazz) {
+        try {
+            return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field));
+        } catch (NoSuchFieldException e) {
+            // Convert Exception to corresponding Error
+            NoSuchFieldError error = new NoSuchFieldError(field);
+            error.initCause(e);
+            throw error;
+        }
+    }
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicReference.java

@@ -0,0 +1,240 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.UnaryOperator;
+import java.util.function.BinaryOperator;
+import sun.misc.Unsafe;
+
+/**
+ * An object reference that may be updated atomically. See the {@link
+ * java.util.concurrent.atomic} package specification for description
+ * of the properties of atomic variables.
+ * @since 1.5
+ * @author Doug Lea
+ * @param <V> The type of object referred to by this reference
+ */
+public class AtomicReference<V> implements java.io.Serializable {
+    private static final long serialVersionUID = -1848883965231344442L;
+
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final long valueOffset;
+
+    static {
+        try {
+            valueOffset = unsafe.objectFieldOffset
+                (AtomicReference.class.getDeclaredField("value"));
+        } catch (Exception ex) { throw new Error(ex); }
+    }
+
+    private volatile V value;
+
+    /**
+     * Creates a new AtomicReference with the given initial value.
+     *
+     * @param initialValue the initial value
+     */
+    public AtomicReference(V initialValue) {
+        value = initialValue;
+    }
+
+    /**
+     * Creates a new AtomicReference with null initial value.
+     */
+    public AtomicReference() {
+    }
+
+    /**
+     * Gets the current value.
+     *
+     * @return the current value
+     */
+    public final V get() {
+        return value;
+    }
+
+    /**
+     * Sets to the given value.
+     *
+     * @param newValue the new value
+     */
+    public final void set(V newValue) {
+        value = newValue;
+    }
+
+    /**
+     * Eventually sets to the given value.
+     *
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(V newValue) {
+        unsafe.putOrderedObject(this, valueOffset, newValue);
+    }
+
+    /**
+     * 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(V expect, V update) {
+        return unsafe.compareAndSwapObject(this, valueOffset, expect, update);
+    }
+
+    /**
+     * 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(V expect, V update) {
+        return unsafe.compareAndSwapObject(this, valueOffset, expect, update);
+    }
+
+    /**
+     * Atomically sets to the given value and returns the old value.
+     *
+     * @param newValue the new value
+     * @return the previous value
+     */
+    @SuppressWarnings("unchecked")
+    public final V getAndSet(V newValue) {
+        return (V)unsafe.getAndSetObject(this, valueOffset, newValue);
+    }
+
+    /**
+     * 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 V getAndUpdate(UnaryOperator<V> updateFunction) {
+        V prev, next;
+        do {
+            prev = get();
+            next = updateFunction.apply(prev);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 V updateAndGet(UnaryOperator<V> updateFunction) {
+        V prev, next;
+        do {
+            prev = get();
+            next = updateFunction.apply(prev);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * 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 V getAndAccumulate(V x,
+                                    BinaryOperator<V> accumulatorFunction) {
+        V prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSet(prev, next));
+        return prev;
+    }
+
+    /**
+     * 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 V accumulateAndGet(V x,
+                                    BinaryOperator<V> accumulatorFunction) {
+        V prev, next;
+        do {
+            prev = get();
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSet(prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return String.valueOf(get());
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicReferenceArray.java

@@ -0,0 +1,330 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.UnaryOperator;
+import java.util.function.BinaryOperator;
+import java.util.Arrays;
+import java.lang.reflect.Array;
+import sun.misc.Unsafe;
+
+/**
+ * An array of object references in which elements may be updated
+ * atomically.  See the {@link java.util.concurrent.atomic} package
+ * specification for description of the properties of atomic
+ * variables.
+ * @since 1.5
+ * @author Doug Lea
+ * @param <E> The base class of elements held in this array
+ */
+public class AtomicReferenceArray<E> implements java.io.Serializable {
+    private static final long serialVersionUID = -6209656149925076980L;
+
+    private static final Unsafe unsafe;
+    private static final int base;
+    private static final int shift;
+    private static final long arrayFieldOffset;
+    private final Object[] array; // must have exact type Object[]
+
+    static {
+        try {
+            unsafe = Unsafe.getUnsafe();
+            arrayFieldOffset = unsafe.objectFieldOffset
+                (AtomicReferenceArray.class.getDeclaredField("array"));
+            base = unsafe.arrayBaseOffset(Object[].class);
+            int scale = unsafe.arrayIndexScale(Object[].class);
+            if ((scale & (scale - 1)) != 0)
+                throw new Error("data type scale not a power of two");
+            shift = 31 - Integer.numberOfLeadingZeros(scale);
+        } catch (Exception e) {
+            throw new Error(e);
+        }
+    }
+
+    private long checkedByteOffset(int i) {
+        if (i < 0 || i >= array.length)
+            throw new IndexOutOfBoundsException("index " + i);
+
+        return byteOffset(i);
+    }
+
+    private static long byteOffset(int i) {
+        return ((long) i << shift) + base;
+    }
+
+    /**
+     * Creates a new AtomicReferenceArray of the given length, with all
+     * elements initially null.
+     *
+     * @param length the length of the array
+     */
+    public AtomicReferenceArray(int length) {
+        array = new Object[length];
+    }
+
+    /**
+     * Creates a new AtomicReferenceArray with the same length as, and
+     * all elements copied from, the given array.
+     *
+     * @param array the array to copy elements from
+     * @throws NullPointerException if array is null
+     */
+    public AtomicReferenceArray(E[] array) {
+        // Visibility guaranteed by final field guarantees
+        this.array = Arrays.copyOf(array, array.length, Object[].class);
+    }
+
+    /**
+     * Returns the length of the array.
+     *
+     * @return the length of the array
+     */
+    public final int length() {
+        return array.length;
+    }
+
+    /**
+     * Gets the current value at position {@code i}.
+     *
+     * @param i the index
+     * @return the current value
+     */
+    public final E get(int i) {
+        return getRaw(checkedByteOffset(i));
+    }
+
+    @SuppressWarnings("unchecked")
+    private E getRaw(long offset) {
+        return (E) unsafe.getObjectVolatile(array, offset);
+    }
+
+    /**
+     * Sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     */
+    public final void set(int i, E newValue) {
+        unsafe.putObjectVolatile(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Eventually sets the element at position {@code i} to the given value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public final void lazySet(int i, E newValue) {
+        unsafe.putOrderedObject(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given
+     * value and returns the old value.
+     *
+     * @param i the index
+     * @param newValue the new value
+     * @return the previous value
+     */
+    @SuppressWarnings("unchecked")
+    public final E getAndSet(int i, E newValue) {
+        return (E)unsafe.getAndSetObject(array, checkedByteOffset(i), newValue);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} to the given
+     * updated value if the current value {@code ==} the expected value.
+     *
+     * @param i the index
+     * @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(int i, E expect, E update) {
+        return compareAndSetRaw(checkedByteOffset(i), expect, update);
+    }
+
+    private boolean compareAndSetRaw(long offset, E expect, E update) {
+        return unsafe.compareAndSwapObject(array, offset, expect, update);
+    }
+
+    /**
+     * Atomically sets the element at position {@code i} 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 i the index
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     */
+    public final boolean weakCompareAndSet(int i, E expect, E update) {
+        return compareAndSet(i, expect, update);
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final E getAndUpdate(int i, UnaryOperator<E> updateFunction) {
+        long offset = checkedByteOffset(i);
+        E prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.apply(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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.
+     *
+     * @param i the index
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final E updateAndGet(int i, UnaryOperator<E> updateFunction) {
+        long offset = checkedByteOffset(i);
+        E prev, next;
+        do {
+            prev = getRaw(offset);
+            next = updateFunction.apply(prev);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final E getAndAccumulate(int i, E x,
+                                    BinaryOperator<E> accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        E prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the element at index {@code 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 at index {@code i} as its first
+     * argument, and the given update as the second argument.
+     *
+     * @param i the index
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final E accumulateAndGet(int i, E x,
+                                    BinaryOperator<E> accumulatorFunction) {
+        long offset = checkedByteOffset(i);
+        E prev, next;
+        do {
+            prev = getRaw(offset);
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSetRaw(offset, prev, next));
+        return next;
+    }
+
+    /**
+     * Returns the String representation of the current values of array.
+     * @return the String representation of the current values of array
+     */
+    public String toString() {
+        int iMax = array.length - 1;
+        if (iMax == -1)
+            return "[]";
+
+        StringBuilder b = new StringBuilder();
+        b.append('[');
+        for (int i = 0; ; i++) {
+            b.append(getRaw(byteOffset(i)));
+            if (i == iMax)
+                return b.append(']').toString();
+            b.append(',').append(' ');
+        }
+    }
+
+    /**
+     * Reconstitutes the instance from a stream (that is, deserializes it).
+     */
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.IOException, ClassNotFoundException,
+        java.io.InvalidObjectException {
+        // Note: This must be changed if any additional fields are defined
+        Object a = s.readFields().get("array", null);
+        if (a == null || !a.getClass().isArray())
+            throw new java.io.InvalidObjectException("Not array type");
+        if (a.getClass() != Object[].class)
+            a = Arrays.copyOf((Object[])a, Array.getLength(a), Object[].class);
+        unsafe.putObjectVolatile(this, arrayFieldOffset, a);
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicReferenceFieldUpdater.java

@@ -0,0 +1,471 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Objects;
+import java.util.function.BinaryOperator;
+import java.util.function.UnaryOperator;
+import sun.reflect.CallerSensitive;
+import sun.reflect.Reflection;
+
+/**
+ * A reflection-based utility that enables atomic updates to
+ * designated {@code volatile} reference fields of designated
+ * classes.  This class is designed for use in atomic data structures
+ * in which several reference fields of the same node are
+ * independently subject to atomic updates. For example, a tree node
+ * might be declared as
+ *
+ * <pre> {@code
+ * class Node {
+ *   private volatile Node left, right;
+ *
+ *   private static final AtomicReferenceFieldUpdater<Node, Node> leftUpdater =
+ *     AtomicReferenceFieldUpdater.newUpdater(Node.class, Node.class, "left");
+ *   private static AtomicReferenceFieldUpdater<Node, Node> rightUpdater =
+ *     AtomicReferenceFieldUpdater.newUpdater(Node.class, Node.class, "right");
+ *
+ *   Node getLeft() { return left; }
+ *   boolean compareAndSetLeft(Node expect, Node update) {
+ *     return leftUpdater.compareAndSet(this, expect, update);
+ *   }
+ *   // ... and so on
+ * }}</pre>
+ *
+ * <p>Note that the guarantees of the {@code compareAndSet}
+ * method in this class are weaker than in other atomic classes.
+ * Because this class cannot ensure that all uses of the field
+ * are appropriate for purposes of atomic access, it can
+ * guarantee atomicity only with respect to other invocations of
+ * {@code compareAndSet} and {@code set} on the same updater.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <T> The type of the object holding the updatable field
+ * @param <V> The type of the field
+ */
+public abstract class AtomicReferenceFieldUpdater<T,V> {
+
+    /**
+     * Creates and returns an updater for objects with the given field.
+     * The Class arguments are needed to check that reflective types and
+     * generic types match.
+     *
+     * @param tclass the class of the objects holding the field
+     * @param vclass the class of the field
+     * @param fieldName the name of the field to be updated
+     * @param <U> the type of instances of tclass
+     * @param <W> the type of instances of vclass
+     * @return the updater
+     * @throws ClassCastException if the field is of the wrong type
+     * @throws IllegalArgumentException if the field is not volatile
+     * @throws RuntimeException with a nested reflection-based
+     * exception if the class does not hold field or is the wrong type,
+     * or the field is inaccessible to the caller according to Java language
+     * access control
+     */
+    @CallerSensitive
+    public static <U,W> AtomicReferenceFieldUpdater<U,W> newUpdater(Class<U> tclass,
+                                                                    Class<W> vclass,
+                                                                    String fieldName) {
+        return new AtomicReferenceFieldUpdaterImpl<U,W>
+            (tclass, vclass, fieldName, Reflection.getCallerClass());
+    }
+
+    /**
+     * Protected do-nothing constructor for use by subclasses.
+     */
+    protected AtomicReferenceFieldUpdater() {
+    }
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * @param obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     */
+    public abstract boolean compareAndSet(T obj, V expect, V update);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given updated value if the current value {@code ==} the
+     * expected value. This method is guaranteed to be atomic with respect to
+     * other calls to {@code compareAndSet} and {@code set}, but not
+     * necessarily with respect to other changes in the field.
+     *
+     * <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 obj An object whose field to conditionally set
+     * @param expect the expected value
+     * @param update the new value
+     * @return {@code true} if successful
+     */
+    public abstract boolean weakCompareAndSet(T obj, V expect, V update);
+
+    /**
+     * Sets the field of the given object managed by this updater to the
+     * given updated value. This operation is guaranteed to act as a volatile
+     * store with respect to subsequent invocations of {@code compareAndSet}.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     */
+    public abstract void set(T obj, V newValue);
+
+    /**
+     * Eventually sets the field of the given object managed by this
+     * updater to the given updated value.
+     *
+     * @param obj An object whose field to set
+     * @param newValue the new value
+     * @since 1.6
+     */
+    public abstract void lazySet(T obj, V newValue);
+
+    /**
+     * Gets the current value held in the field of the given object managed
+     * by this updater.
+     *
+     * @param obj An object whose field to get
+     * @return the current value
+     */
+    public abstract V get(T obj);
+
+    /**
+     * Atomically sets the field of the given object managed by this updater
+     * to the given value and returns the old value.
+     *
+     * @param obj An object whose field to get and set
+     * @param newValue the new value
+     * @return the previous value
+     */
+    public V getAndSet(T obj, V newValue) {
+        V prev;
+        do {
+            prev = get(obj);
+        } while (!compareAndSet(obj, prev, newValue));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the previous value
+     * @since 1.8
+     */
+    public final V getAndUpdate(T obj, UnaryOperator<V> updateFunction) {
+        V prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.apply(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this updater
+     * 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 obj An object whose field to get and set
+     * @param updateFunction a side-effect-free function
+     * @return the updated value
+     * @since 1.8
+     */
+    public final V updateAndGet(T obj, UnaryOperator<V> updateFunction) {
+        V prev, next;
+        do {
+            prev = get(obj);
+            next = updateFunction.apply(prev);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the previous value
+     * @since 1.8
+     */
+    public final V getAndAccumulate(T obj, V x,
+                                    BinaryOperator<V> accumulatorFunction) {
+        V prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return prev;
+    }
+
+    /**
+     * Atomically updates the field of the given object managed by this
+     * updater 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 obj An object whose field to get and set
+     * @param x the update value
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @return the updated value
+     * @since 1.8
+     */
+    public final V accumulateAndGet(T obj, V x,
+                                    BinaryOperator<V> accumulatorFunction) {
+        V prev, next;
+        do {
+            prev = get(obj);
+            next = accumulatorFunction.apply(prev, x);
+        } while (!compareAndSet(obj, prev, next));
+        return next;
+    }
+
+    private static final class AtomicReferenceFieldUpdaterImpl<T,V>
+        extends AtomicReferenceFieldUpdater<T,V> {
+        private static final sun.misc.Unsafe U = sun.misc.Unsafe.getUnsafe();
+        private final long offset;
+        /**
+         * if field is protected, the subclass constructing updater, else
+         * the same as tclass
+         */
+        private final Class<?> cclass;
+        /** class holding the field */
+        private final Class<T> tclass;
+        /** field value type */
+        private final Class<V> vclass;
+
+        /*
+         * Internal type checks within all update methods contain
+         * internal inlined optimizations checking for the common
+         * cases where the class is final (in which case a simple
+         * getClass comparison suffices) or is of type Object (in
+         * which case no check is needed because all objects are
+         * instances of Object). The Object case is handled simply by
+         * setting vclass to null in constructor.  The targetCheck and
+         * updateCheck methods are invoked when these faster
+         * screenings fail.
+         */
+
+        AtomicReferenceFieldUpdaterImpl(final Class<T> tclass,
+                                        final Class<V> vclass,
+                                        final String fieldName,
+                                        final Class<?> caller) {
+            final Field field;
+            final Class<?> fieldClass;
+            final int modifiers;
+            try {
+                field = AccessController.doPrivileged(
+                    new PrivilegedExceptionAction<Field>() {
+                        public Field run() throws NoSuchFieldException {
+                            return tclass.getDeclaredField(fieldName);
+                        }
+                    });
+                modifiers = field.getModifiers();
+                sun.reflect.misc.ReflectUtil.ensureMemberAccess(
+                    caller, tclass, null, modifiers);
+                ClassLoader cl = tclass.getClassLoader();
+                ClassLoader ccl = caller.getClassLoader();
+                if ((ccl != null) && (ccl != cl) &&
+                    ((cl == null) || !isAncestor(cl, ccl))) {
+                    sun.reflect.misc.ReflectUtil.checkPackageAccess(tclass);
+                }
+                fieldClass = field.getType();
+            } catch (PrivilegedActionException pae) {
+                throw new RuntimeException(pae.getException());
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+
+            if (vclass != fieldClass)
+                throw new ClassCastException();
+            if (vclass.isPrimitive())
+                throw new IllegalArgumentException("Must be reference type");
+
+            if (!Modifier.isVolatile(modifiers))
+                throw new IllegalArgumentException("Must be volatile type");
+
+            // Access to protected field members is restricted to receivers only
+            // of the accessing class, or one of its subclasses, and the
+            // accessing class must in turn be a subclass (or package sibling)
+            // of the protected member's defining class.
+            // If the updater refers to a protected field of a declaring class
+            // outside the current package, the receiver argument will be
+            // narrowed to the type of the accessing class.
+            this.cclass = (Modifier.isProtected(modifiers) &&
+                           tclass.isAssignableFrom(caller) &&
+                           !isSamePackage(tclass, caller))
+                          ? caller : tclass;
+            this.tclass = tclass;
+            this.vclass = vclass;
+            this.offset = U.objectFieldOffset(field);
+        }
+
+        /**
+         * Returns true if the second classloader can be found in the first
+         * classloader's delegation chain.
+         * Equivalent to the inaccessible: first.isAncestor(second).
+         */
+        private static boolean isAncestor(ClassLoader first, ClassLoader second) {
+            ClassLoader acl = first;
+            do {
+                acl = acl.getParent();
+                if (second == acl) {
+                    return true;
+                }
+            } while (acl != null);
+            return false;
+        }
+
+        /**
+         * Returns true if the two classes have the same class loader and
+         * package qualifier
+         */
+        private static boolean isSamePackage(Class<?> class1, Class<?> class2) {
+            return class1.getClassLoader() == class2.getClassLoader()
+                   && Objects.equals(getPackageName(class1), getPackageName(class2));
+        }
+
+        private static String getPackageName(Class<?> cls) {
+            String cn = cls.getName();
+            int dot = cn.lastIndexOf('.');
+            return (dot != -1) ? cn.substring(0, dot) : "";
+        }
+
+        /**
+         * Checks that target argument is instance of cclass.  On
+         * failure, throws cause.
+         */
+        private final void accessCheck(T obj) {
+            if (!cclass.isInstance(obj))
+                throwAccessCheckException(obj);
+        }
+
+        /**
+         * Throws access exception if accessCheck failed due to
+         * protected access, else ClassCastException.
+         */
+        private final void throwAccessCheckException(T obj) {
+            if (cclass == tclass)
+                throw new ClassCastException();
+            else
+                throw new RuntimeException(
+                    new IllegalAccessException(
+                        "Class " +
+                        cclass.getName() +
+                        " can not access a protected member of class " +
+                        tclass.getName() +
+                        " using an instance of " +
+                        obj.getClass().getName()));
+        }
+
+        private final void valueCheck(V v) {
+            if (v != null && !(vclass.isInstance(v)))
+                throwCCE();
+        }
+
+        static void throwCCE() {
+            throw new ClassCastException();
+        }
+
+        public final boolean compareAndSet(T obj, V expect, V update) {
+            accessCheck(obj);
+            valueCheck(update);
+            return U.compareAndSwapObject(obj, offset, expect, update);
+        }
+
+        public final boolean weakCompareAndSet(T obj, V expect, V update) {
+            // same implementation as strong form for now
+            accessCheck(obj);
+            valueCheck(update);
+            return U.compareAndSwapObject(obj, offset, expect, update);
+        }
+
+        public final void set(T obj, V newValue) {
+            accessCheck(obj);
+            valueCheck(newValue);
+            U.putObjectVolatile(obj, offset, newValue);
+        }
+
+        public final void lazySet(T obj, V newValue) {
+            accessCheck(obj);
+            valueCheck(newValue);
+            U.putOrderedObject(obj, offset, newValue);
+        }
+
+        @SuppressWarnings("unchecked")
+        public final V get(T obj) {
+            accessCheck(obj);
+            return (V)U.getObjectVolatile(obj, offset);
+        }
+
+        @SuppressWarnings("unchecked")
+        public final V getAndSet(T obj, V newValue) {
+            accessCheck(obj);
+            valueCheck(newValue);
+            return (V)U.getAndSetObject(obj, offset, newValue);
+        }
+    }
+}

jdkSrc/jdk8/java/util/concurrent/atomic/AtomicStampedReference.java

@@ -0,0 +1,212 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+
+/**
+ * An {@code AtomicStampedReference} maintains an object reference
+ * along with an integer "stamp", that can be updated atomically.
+ *
+ * <p>Implementation note: This implementation maintains stamped
+ * references by creating internal objects representing "boxed"
+ * [reference, integer] pairs.
+ *
+ * @since 1.5
+ * @author Doug Lea
+ * @param <V> The type of object referred to by this reference
+ */
+public class AtomicStampedReference<V> {
+
+    private static class Pair<T> {
+        final T reference;
+        final int stamp;
+        private Pair(T reference, int stamp) {
+            this.reference = reference;
+            this.stamp = stamp;
+        }
+        static <T> Pair<T> of(T reference, int stamp) {
+            return new Pair<T>(reference, stamp);
+        }
+    }
+
+    private volatile Pair<V> pair;
+
+    /**
+     * Creates a new {@code AtomicStampedReference} with the given
+     * initial values.
+     *
+     * @param initialRef the initial reference
+     * @param initialStamp the initial stamp
+     */
+    public AtomicStampedReference(V initialRef, int initialStamp) {
+        pair = Pair.of(initialRef, initialStamp);
+    }
+
+    /**
+     * Returns the current value of the reference.
+     *
+     * @return the current value of the reference
+     */
+    public V getReference() {
+        return pair.reference;
+    }
+
+    /**
+     * Returns the current value of the stamp.
+     *
+     * @return the current value of the stamp
+     */
+    public int getStamp() {
+        return pair.stamp;
+    }
+
+    /**
+     * Returns the current values of both the reference and the stamp.
+     * Typical usage is {@code int[1] holder; ref = v.get(holder); }.
+     *
+     * @param stampHolder an array of size of at least one.  On return,
+     * {@code stampholder[0]} will hold the value of the stamp.
+     * @return the current value of the reference
+     */
+    public V get(int[] stampHolder) {
+        Pair<V> pair = this.pair;
+        stampHolder[0] = pair.stamp;
+        return pair.reference;
+    }
+
+    /**
+     * Atomically sets the value of both the reference and stamp
+     * to the given update values if the
+     * current reference is {@code ==} to the expected reference
+     * and the current stamp is equal to the expected stamp.
+     *
+     * <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 expectedReference the expected value of the reference
+     * @param newReference the new value for the reference
+     * @param expectedStamp the expected value of the stamp
+     * @param newStamp the new value for the stamp
+     * @return {@code true} if successful
+     */
+    public boolean weakCompareAndSet(V   expectedReference,
+                                     V   newReference,
+                                     int expectedStamp,
+                                     int newStamp) {
+        return compareAndSet(expectedReference, newReference,
+                             expectedStamp, newStamp);
+    }
+
+    /**
+     * Atomically sets the value of both the reference and stamp
+     * to the given update values if the
+     * current reference is {@code ==} to the expected reference
+     * and the current stamp is equal to the expected stamp.
+     *
+     * @param expectedReference the expected value of the reference
+     * @param newReference the new value for the reference
+     * @param expectedStamp the expected value of the stamp
+     * @param newStamp the new value for the stamp
+     * @return {@code true} if successful
+     */
+    public boolean compareAndSet(V   expectedReference,
+                                 V   newReference,
+                                 int expectedStamp,
+                                 int newStamp) {
+        Pair<V> current = pair;
+        return
+            expectedReference == current.reference &&
+            expectedStamp == current.stamp &&
+            ((newReference == current.reference &&
+              newStamp == current.stamp) ||
+             casPair(current, Pair.of(newReference, newStamp)));
+    }
+
+    /**
+     * Unconditionally sets the value of both the reference and stamp.
+     *
+     * @param newReference the new value for the reference
+     * @param newStamp the new value for the stamp
+     */
+    public void set(V newReference, int newStamp) {
+        Pair<V> current = pair;
+        if (newReference != current.reference || newStamp != current.stamp)
+            this.pair = Pair.of(newReference, newStamp);
+    }
+
+    /**
+     * Atomically sets the value of the stamp to the given update value
+     * if the current reference is {@code ==} to the expected
+     * reference.  Any given invocation of this operation may fail
+     * (return {@code false}) spuriously, but repeated invocation
+     * when the current value holds the expected value and no other
+     * thread is also attempting to set the value will eventually
+     * succeed.
+     *
+     * @param expectedReference the expected value of the reference
+     * @param newStamp the new value for the stamp
+     * @return {@code true} if successful
+     */
+    public boolean attemptStamp(V expectedReference, int newStamp) {
+        Pair<V> current = pair;
+        return
+            expectedReference == current.reference &&
+            (newStamp == current.stamp ||
+             casPair(current, Pair.of(expectedReference, newStamp)));
+    }
+
+    // Unsafe mechanics
+
+    private static final sun.misc.Unsafe UNSAFE = sun.misc.Unsafe.getUnsafe();
+    private static final long pairOffset =
+        objectFieldOffset(UNSAFE, "pair", AtomicStampedReference.class);
+
+    private boolean casPair(Pair<V> cmp, Pair<V> val) {
+        return UNSAFE.compareAndSwapObject(this, pairOffset, cmp, val);
+    }
+
+    static long objectFieldOffset(sun.misc.Unsafe UNSAFE,
+                                  String field, Class<?> klazz) {
+        try {
+            return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field));
+        } catch (NoSuchFieldException e) {
+            // Convert Exception to corresponding Error
+            NoSuchFieldError error = new NoSuchFieldError(field);
+            error.initCause(e);
+            throw error;
+        }
+    }
+}

jdkSrc/jdk8/java/util/concurrent/atomic/DoubleAccumulator.java

@@ -0,0 +1,294 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.io.Serializable;
+import java.util.function.DoubleBinaryOperator;
+
+/**
+ * One or more variables that together maintain a running {@code double}
+ * value updated using a supplied function.  When updates (method
+ * {@link #accumulate}) are contended across threads, the set of variables
+ * may grow dynamically to reduce contention.  Method {@link #get}
+ * (or, equivalently, {@link #doubleValue}) returns the current value
+ * across the variables maintaining updates.
+ *
+ * <p>This class is usually preferable to alternatives when multiple
+ * threads update a common value that is used for purposes such as
+ * summary statistics that are frequently updated but less frequently
+ * read.
+ *
+ * <p>The supplied accumulator 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.  For example, to maintain a running maximum value, you
+ * could supply {@code Double::max} along with {@code
+ * Double.NEGATIVE_INFINITY} as the identity. The order of
+ * accumulation within or across threads is not guaranteed. Thus, this
+ * class may not be applicable if numerical stability is required,
+ * especially when combining values of substantially different orders
+ * of magnitude.
+ *
+ * <p>Class {@link DoubleAdder} provides analogs of the functionality
+ * of this class for the common special case of maintaining sums.  The
+ * call {@code new DoubleAdder()} is equivalent to {@code new
+ * DoubleAccumulator((x, y) -> x + y, 0.0)}.
+ *
+ * <p>This class extends {@link Number}, but does <em>not</em> define
+ * methods such as {@code equals}, {@code hashCode} and {@code
+ * compareTo} because instances are expected to be mutated, and so are
+ * not useful as collection keys.
+ *
+ * @since 1.8
+ * @author Doug Lea
+ */
+public class DoubleAccumulator extends Striped64 implements Serializable {
+    private static final long serialVersionUID = 7249069246863182397L;
+
+    private final DoubleBinaryOperator function;
+    private final long identity; // use long representation
+
+    /**
+     * Creates a new instance using the given accumulator function
+     * and identity element.
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @param identity identity (initial value) for the accumulator function
+     */
+    public DoubleAccumulator(DoubleBinaryOperator accumulatorFunction,
+                             double identity) {
+        this.function = accumulatorFunction;
+        base = this.identity = Double.doubleToRawLongBits(identity);
+    }
+
+    /**
+     * Updates with the given value.
+     *
+     * @param x the value
+     */
+    public void accumulate(double x) {
+        Cell[] as; long b, v, r; int m; Cell a;
+        if ((as = cells) != null ||
+            (r = Double.doubleToRawLongBits
+             (function.applyAsDouble
+              (Double.longBitsToDouble(b = base), x))) != b  && !casBase(b, r)) {
+            boolean uncontended = true;
+            if (as == null || (m = as.length - 1) < 0 ||
+                (a = as[getProbe() & m]) == null ||
+                !(uncontended =
+                  (r = Double.doubleToRawLongBits
+                   (function.applyAsDouble
+                    (Double.longBitsToDouble(v = a.value), x))) == v ||
+                  a.cas(v, r)))
+                doubleAccumulate(x, function, uncontended);
+        }
+    }
+
+    /**
+     * Returns the current value.  The returned value is <em>NOT</em>
+     * an atomic snapshot; invocation in the absence of concurrent
+     * updates returns an accurate result, but concurrent updates that
+     * occur while the value is being calculated might not be
+     * incorporated.
+     *
+     * @return the current value
+     */
+    public double get() {
+        Cell[] as = cells; Cell a;
+        double result = Double.longBitsToDouble(base);
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    result = function.applyAsDouble
+                        (result, Double.longBitsToDouble(a.value));
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Resets variables maintaining updates to the identity value.
+     * This method may be a useful alternative to creating a new
+     * updater, but is only effective if there are no concurrent
+     * updates.  Because this method is intrinsically racy, it should
+     * only be used when it is known that no threads are concurrently
+     * updating.
+     */
+    public void reset() {
+        Cell[] as = cells; Cell a;
+        base = identity;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    a.value = identity;
+            }
+        }
+    }
+
+    /**
+     * Equivalent in effect to {@link #get} followed by {@link
+     * #reset}. This method may apply for example during quiescent
+     * points between multithreaded computations.  If there are
+     * updates concurrent with this method, the returned value is
+     * <em>not</em> guaranteed to be the final value occurring before
+     * the reset.
+     *
+     * @return the value before reset
+     */
+    public double getThenReset() {
+        Cell[] as = cells; Cell a;
+        double result = Double.longBitsToDouble(base);
+        base = identity;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null) {
+                    double v = Double.longBitsToDouble(a.value);
+                    a.value = identity;
+                    result = function.applyAsDouble(result, v);
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return Double.toString(get());
+    }
+
+    /**
+     * Equivalent to {@link #get}.
+     *
+     * @return the current value
+     */
+    public double doubleValue() {
+        return get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as a {@code long}
+     * after a narrowing primitive conversion.
+     */
+    public long longValue() {
+        return (long)get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as an {@code int}
+     * after a narrowing primitive conversion.
+     */
+    public int intValue() {
+        return (int)get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as a {@code float}
+     * after a narrowing primitive conversion.
+     */
+    public float floatValue() {
+        return (float)get();
+    }
+
+    /**
+     * Serialization proxy, used to avoid reference to the non-public
+     * Striped64 superclass in serialized forms.
+     * @serial include
+     */
+    private static class SerializationProxy implements Serializable {
+        private static final long serialVersionUID = 7249069246863182397L;
+
+        /**
+         * The current value returned by get().
+         * @serial
+         */
+        private final double value;
+        /**
+         * The function used for updates.
+         * @serial
+         */
+        private final DoubleBinaryOperator function;
+        /**
+         * The identity value
+         * @serial
+         */
+        private final long identity;
+
+        SerializationProxy(DoubleAccumulator a) {
+            function = a.function;
+            identity = a.identity;
+            value = a.get();
+        }
+
+        /**
+         * Returns a {@code DoubleAccumulator} object with initial state
+         * held by this proxy.
+         *
+         * @return a {@code DoubleAccumulator} object with initial state
+         * held by this proxy.
+         */
+        private Object readResolve() {
+            double d = Double.longBitsToDouble(identity);
+            DoubleAccumulator a = new DoubleAccumulator(function, d);
+            a.base = Double.doubleToRawLongBits(value);
+            return a;
+        }
+    }
+
+    /**
+     * Returns a
+     * <a href="../../../../serialized-form.html#java.util.concurrent.atomic.DoubleAccumulator.SerializationProxy">
+     * SerializationProxy</a>
+     * representing the state of this instance.
+     *
+     * @return a {@link SerializationProxy}
+     * representing the state of this instance
+     */
+    private Object writeReplace() {
+        return new SerializationProxy(this);
+    }
+
+    /**
+     * @param s the stream
+     * @throws java.io.InvalidObjectException always
+     */
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.InvalidObjectException {
+        throw new java.io.InvalidObjectException("Proxy required");
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/DoubleAdder.java

@@ -0,0 +1,267 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.io.Serializable;
+
+/**
+ * One or more variables that together maintain an initially zero
+ * {@code double} sum.  When updates (method {@link #add}) are
+ * contended across threads, the set of variables may grow dynamically
+ * to reduce contention.  Method {@link #sum} (or, equivalently {@link
+ * #doubleValue}) returns the current total combined across the
+ * variables maintaining the sum. The order of accumulation within or
+ * across threads is not guaranteed. Thus, this class may not be
+ * applicable if numerical stability is required, especially when
+ * combining values of substantially different orders of magnitude.
+ *
+ * <p>This class is usually preferable to alternatives when multiple
+ * threads update a common value that is used for purposes such as
+ * summary statistics that are frequently updated but less frequently
+ * read.
+ *
+ * <p>This class extends {@link Number}, but does <em>not</em> define
+ * methods such as {@code equals}, {@code hashCode} and {@code
+ * compareTo} because instances are expected to be mutated, and so are
+ * not useful as collection keys.
+ *
+ * @since 1.8
+ * @author Doug Lea
+ */
+public class DoubleAdder extends Striped64 implements Serializable {
+    private static final long serialVersionUID = 7249069246863182397L;
+
+    /*
+     * Note that we must use "long" for underlying representations,
+     * because there is no compareAndSet for double, due to the fact
+     * that the bitwise equals used in any CAS implementation is not
+     * the same as double-precision equals.  However, we use CAS only
+     * to detect and alleviate contention, for which bitwise equals
+     * works best anyway. In principle, the long/double conversions
+     * used here should be essentially free on most platforms since
+     * they just re-interpret bits.
+     */
+
+    /**
+     * Creates a new adder with initial sum of zero.
+     */
+    public DoubleAdder() {
+    }
+
+    /**
+     * Adds the given value.
+     *
+     * @param x the value to add
+     */
+    public void add(double x) {
+        Cell[] as; long b, v; int m; Cell a;
+        if ((as = cells) != null ||
+            !casBase(b = base,
+                     Double.doubleToRawLongBits
+                     (Double.longBitsToDouble(b) + x))) {
+            boolean uncontended = true;
+            if (as == null || (m = as.length - 1) < 0 ||
+                (a = as[getProbe() & m]) == null ||
+                !(uncontended = a.cas(v = a.value,
+                                      Double.doubleToRawLongBits
+                                      (Double.longBitsToDouble(v) + x))))
+                doubleAccumulate(x, null, uncontended);
+        }
+    }
+
+    /**
+     * Returns the current sum.  The returned value is <em>NOT</em> an
+     * atomic snapshot; invocation in the absence of concurrent
+     * updates returns an accurate result, but concurrent updates that
+     * occur while the sum is being calculated might not be
+     * incorporated.  Also, because floating-point arithmetic is not
+     * strictly associative, the returned result need not be identical
+     * to the value that would be obtained in a sequential series of
+     * updates to a single variable.
+     *
+     * @return the sum
+     */
+    public double sum() {
+        Cell[] as = cells; Cell a;
+        double sum = Double.longBitsToDouble(base);
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    sum += Double.longBitsToDouble(a.value);
+            }
+        }
+        return sum;
+    }
+
+    /**
+     * Resets variables maintaining the sum to zero.  This method may
+     * be a useful alternative to creating a new adder, but is only
+     * effective if there are no concurrent updates.  Because this
+     * method is intrinsically racy, it should only be used when it is
+     * known that no threads are concurrently updating.
+     */
+    public void reset() {
+        Cell[] as = cells; Cell a;
+        base = 0L; // relies on fact that double 0 must have same rep as long
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    a.value = 0L;
+            }
+        }
+    }
+
+    /**
+     * Equivalent in effect to {@link #sum} followed by {@link
+     * #reset}. This method may apply for example during quiescent
+     * points between multithreaded computations.  If there are
+     * updates concurrent with this method, the returned value is
+     * <em>not</em> guaranteed to be the final value occurring before
+     * the reset.
+     *
+     * @return the sum
+     */
+    public double sumThenReset() {
+        Cell[] as = cells; Cell a;
+        double sum = Double.longBitsToDouble(base);
+        base = 0L;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null) {
+                    long v = a.value;
+                    a.value = 0L;
+                    sum += Double.longBitsToDouble(v);
+                }
+            }
+        }
+        return sum;
+    }
+
+    /**
+     * Returns the String representation of the {@link #sum}.
+     * @return the String representation of the {@link #sum}
+     */
+    public String toString() {
+        return Double.toString(sum());
+    }
+
+    /**
+     * Equivalent to {@link #sum}.
+     *
+     * @return the sum
+     */
+    public double doubleValue() {
+        return sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as a {@code long} after a
+     * narrowing primitive conversion.
+     */
+    public long longValue() {
+        return (long)sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as an {@code int} after a
+     * narrowing primitive conversion.
+     */
+    public int intValue() {
+        return (int)sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as a {@code float}
+     * after a narrowing primitive conversion.
+     */
+    public float floatValue() {
+        return (float)sum();
+    }
+
+    /**
+     * Serialization proxy, used to avoid reference to the non-public
+     * Striped64 superclass in serialized forms.
+     * @serial include
+     */
+    private static class SerializationProxy implements Serializable {
+        private static final long serialVersionUID = 7249069246863182397L;
+
+        /**
+         * The current value returned by sum().
+         * @serial
+         */
+        private final double value;
+
+        SerializationProxy(DoubleAdder a) {
+            value = a.sum();
+        }
+
+        /**
+         * Returns a {@code DoubleAdder} object with initial state
+         * held by this proxy.
+         *
+         * @return a {@code DoubleAdder} object with initial state
+         * held by this proxy.
+         */
+        private Object readResolve() {
+            DoubleAdder a = new DoubleAdder();
+            a.base = Double.doubleToRawLongBits(value);
+            return a;
+        }
+    }
+
+    /**
+     * Returns a
+     * <a href="../../../../serialized-form.html#java.util.concurrent.atomic.DoubleAdder.SerializationProxy">
+     * SerializationProxy</a>
+     * representing the state of this instance.
+     *
+     * @return a {@link SerializationProxy}
+     * representing the state of this instance
+     */
+    private Object writeReplace() {
+        return new SerializationProxy(this);
+    }
+
+    /**
+     * @param s the stream
+     * @throws java.io.InvalidObjectException always
+     */
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.InvalidObjectException {
+        throw new java.io.InvalidObjectException("Proxy required");
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/LongAccumulator.java

@@ -0,0 +1,290 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.io.Serializable;
+import java.util.function.LongBinaryOperator;
+
+/**
+ * One or more variables that together maintain a running {@code long}
+ * value updated using a supplied function.  When updates (method
+ * {@link #accumulate}) are contended across threads, the set of variables
+ * may grow dynamically to reduce contention.  Method {@link #get}
+ * (or, equivalently, {@link #longValue}) returns the current value
+ * across the variables maintaining updates.
+ *
+ * <p>This class is usually preferable to {@link AtomicLong} when
+ * multiple threads update a common value that is used for purposes such
+ * as collecting statistics, not for fine-grained synchronization
+ * control.  Under low update contention, the two classes have similar
+ * characteristics. But under high contention, expected throughput of
+ * this class is significantly higher, at the expense of higher space
+ * consumption.
+ *
+ * <p>The order of accumulation within or across threads is not
+ * guaranteed and cannot be depended upon, so this class is only
+ * applicable to functions for which the order of accumulation does
+ * not matter. The supplied accumulator 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.  For example, to maintain a running maximum
+ * value, you could supply {@code Long::max} along with {@code
+ * Long.MIN_VALUE} as the identity.
+ *
+ * <p>Class {@link LongAdder} provides analogs of the functionality of
+ * this class for the common special case of maintaining counts and
+ * sums.  The call {@code new LongAdder()} is equivalent to {@code new
+ * LongAccumulator((x, y) -> x + y, 0L}.
+ *
+ * <p>This class extends {@link Number}, but does <em>not</em> define
+ * methods such as {@code equals}, {@code hashCode} and {@code
+ * compareTo} because instances are expected to be mutated, and so are
+ * not useful as collection keys.
+ *
+ * @since 1.8
+ * @author Doug Lea
+ */
+public class LongAccumulator extends Striped64 implements Serializable {
+    private static final long serialVersionUID = 7249069246863182397L;
+
+    private final LongBinaryOperator function;
+    private final long identity;
+
+    /**
+     * Creates a new instance using the given accumulator function
+     * and identity element.
+     * @param accumulatorFunction a side-effect-free function of two arguments
+     * @param identity identity (initial value) for the accumulator function
+     */
+    public LongAccumulator(LongBinaryOperator accumulatorFunction,
+                           long identity) {
+        this.function = accumulatorFunction;
+        base = this.identity = identity;
+    }
+
+    /**
+     * Updates with the given value.
+     *
+     * @param x the value
+     */
+    public void accumulate(long x) {
+        Cell[] as; long b, v, r; int m; Cell a;
+        if ((as = cells) != null ||
+            (r = function.applyAsLong(b = base, x)) != b && !casBase(b, r)) {
+            boolean uncontended = true;
+            if (as == null || (m = as.length - 1) < 0 ||
+                (a = as[getProbe() & m]) == null ||
+                !(uncontended =
+                  (r = function.applyAsLong(v = a.value, x)) == v ||
+                  a.cas(v, r)))
+                longAccumulate(x, function, uncontended);
+        }
+    }
+
+    /**
+     * Returns the current value.  The returned value is <em>NOT</em>
+     * an atomic snapshot; invocation in the absence of concurrent
+     * updates returns an accurate result, but concurrent updates that
+     * occur while the value is being calculated might not be
+     * incorporated.
+     *
+     * @return the current value
+     */
+    public long get() {
+        Cell[] as = cells; Cell a;
+        long result = base;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    result = function.applyAsLong(result, a.value);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Resets variables maintaining updates to the identity value.
+     * This method may be a useful alternative to creating a new
+     * updater, but is only effective if there are no concurrent
+     * updates.  Because this method is intrinsically racy, it should
+     * only be used when it is known that no threads are concurrently
+     * updating.
+     */
+    public void reset() {
+        Cell[] as = cells; Cell a;
+        base = identity;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    a.value = identity;
+            }
+        }
+    }
+
+    /**
+     * Equivalent in effect to {@link #get} followed by {@link
+     * #reset}. This method may apply for example during quiescent
+     * points between multithreaded computations.  If there are
+     * updates concurrent with this method, the returned value is
+     * <em>not</em> guaranteed to be the final value occurring before
+     * the reset.
+     *
+     * @return the value before reset
+     */
+    public long getThenReset() {
+        Cell[] as = cells; Cell a;
+        long result = base;
+        base = identity;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null) {
+                    long v = a.value;
+                    a.value = identity;
+                    result = function.applyAsLong(result, v);
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Returns the String representation of the current value.
+     * @return the String representation of the current value
+     */
+    public String toString() {
+        return Long.toString(get());
+    }
+
+    /**
+     * Equivalent to {@link #get}.
+     *
+     * @return the current value
+     */
+    public long longValue() {
+        return get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as an {@code int}
+     * after a narrowing primitive conversion.
+     */
+    public int intValue() {
+        return (int)get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as a {@code float}
+     * after a widening primitive conversion.
+     */
+    public float floatValue() {
+        return (float)get();
+    }
+
+    /**
+     * Returns the {@linkplain #get current value} as a {@code double}
+     * after a widening primitive conversion.
+     */
+    public double doubleValue() {
+        return (double)get();
+    }
+
+    /**
+     * Serialization proxy, used to avoid reference to the non-public
+     * Striped64 superclass in serialized forms.
+     * @serial include
+     */
+    private static class SerializationProxy implements Serializable {
+        private static final long serialVersionUID = 7249069246863182397L;
+
+        /**
+         * The current value returned by get().
+         * @serial
+         */
+        private final long value;
+        /**
+         * The function used for updates.
+         * @serial
+         */
+        private final LongBinaryOperator function;
+        /**
+         * The identity value
+         * @serial
+         */
+        private final long identity;
+
+        SerializationProxy(LongAccumulator a) {
+            function = a.function;
+            identity = a.identity;
+            value = a.get();
+        }
+
+        /**
+         * Returns a {@code LongAccumulator} object with initial state
+         * held by this proxy.
+         *
+         * @return a {@code LongAccumulator} object with initial state
+         * held by this proxy.
+         */
+        private Object readResolve() {
+            LongAccumulator a = new LongAccumulator(function, identity);
+            a.base = value;
+            return a;
+        }
+    }
+
+    /**
+     * Returns a
+     * <a href="../../../../serialized-form.html#java.util.concurrent.atomic.LongAccumulator.SerializationProxy">
+     * SerializationProxy</a>
+     * representing the state of this instance.
+     *
+     * @return a {@link SerializationProxy}
+     * representing the state of this instance
+     */
+    private Object writeReplace() {
+        return new SerializationProxy(this);
+    }
+
+    /**
+     * @param s the stream
+     * @throws java.io.InvalidObjectException always
+     */
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.InvalidObjectException {
+        throw new java.io.InvalidObjectException("Proxy required");
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/LongAdder.java

@@ -0,0 +1,268 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.io.Serializable;
+
+/**
+ * One or more variables that together maintain an initially zero
+ * {@code long} sum.  When updates (method {@link #add}) are contended
+ * across threads, the set of variables may grow dynamically to reduce
+ * contention. Method {@link #sum} (or, equivalently, {@link
+ * #longValue}) returns the current total combined across the
+ * variables maintaining the sum.
+ *
+ * <p>This class is usually preferable to {@link AtomicLong} when
+ * multiple threads update a common sum that is used for purposes such
+ * as collecting statistics, not for fine-grained synchronization
+ * control.  Under low update contention, the two classes have similar
+ * characteristics. But under high contention, expected throughput of
+ * this class is significantly higher, at the expense of higher space
+ * consumption.
+ *
+ * <p>LongAdders can be used with a {@link
+ * java.util.concurrent.ConcurrentHashMap} to maintain a scalable
+ * frequency map (a form of histogram or multiset). For example, to
+ * add a count to a {@code ConcurrentHashMap<String,LongAdder> freqs},
+ * initializing if not already present, you can use {@code
+ * freqs.computeIfAbsent(k -> new LongAdder()).increment();}
+ *
+ * <p>This class extends {@link Number}, but does <em>not</em> define
+ * methods such as {@code equals}, {@code hashCode} and {@code
+ * compareTo} because instances are expected to be mutated, and so are
+ * not useful as collection keys.
+ *
+ * @since 1.8
+ * @author Doug Lea
+ */
+public class LongAdder extends Striped64 implements Serializable {
+    private static final long serialVersionUID = 7249069246863182397L;
+
+    /**
+     * Creates a new adder with initial sum of zero.
+     */
+    public LongAdder() {
+    }
+
+    /**
+     * Adds the given value.
+     *
+     * @param x the value to add
+     */
+    public void add(long x) {
+        Cell[] as; long b, v; int m; Cell a;
+        if ((as = cells) != null || !casBase(b = base, b + x)) {
+            boolean uncontended = true;
+            if (as == null || (m = as.length - 1) < 0 ||
+                (a = as[getProbe() & m]) == null ||
+                !(uncontended = a.cas(v = a.value, v + x)))
+                longAccumulate(x, null, uncontended);
+        }
+    }
+
+    /**
+     * Equivalent to {@code add(1)}.
+     */
+    public void increment() {
+        add(1L);
+    }
+
+    /**
+     * Equivalent to {@code add(-1)}.
+     */
+    public void decrement() {
+        add(-1L);
+    }
+
+    /**
+     * Returns the current sum.  The returned value is <em>NOT</em> an
+     * atomic snapshot; invocation in the absence of concurrent
+     * updates returns an accurate result, but concurrent updates that
+     * occur while the sum is being calculated might not be
+     * incorporated.
+     *
+     * @return the sum
+     */
+    public long sum() {
+        Cell[] as = cells; Cell a;
+        long sum = base;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    sum += a.value;
+            }
+        }
+        return sum;
+    }
+
+    /**
+     * Resets variables maintaining the sum to zero.  This method may
+     * be a useful alternative to creating a new adder, but is only
+     * effective if there are no concurrent updates.  Because this
+     * method is intrinsically racy, it should only be used when it is
+     * known that no threads are concurrently updating.
+     */
+    public void reset() {
+        Cell[] as = cells; Cell a;
+        base = 0L;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null)
+                    a.value = 0L;
+            }
+        }
+    }
+
+    /**
+     * Equivalent in effect to {@link #sum} followed by {@link
+     * #reset}. This method may apply for example during quiescent
+     * points between multithreaded computations.  If there are
+     * updates concurrent with this method, the returned value is
+     * <em>not</em> guaranteed to be the final value occurring before
+     * the reset.
+     *
+     * @return the sum
+     */
+    public long sumThenReset() {
+        Cell[] as = cells; Cell a;
+        long sum = base;
+        base = 0L;
+        if (as != null) {
+            for (int i = 0; i < as.length; ++i) {
+                if ((a = as[i]) != null) {
+                    sum += a.value;
+                    a.value = 0L;
+                }
+            }
+        }
+        return sum;
+    }
+
+    /**
+     * Returns the String representation of the {@link #sum}.
+     * @return the String representation of the {@link #sum}
+     */
+    public String toString() {
+        return Long.toString(sum());
+    }
+
+    /**
+     * Equivalent to {@link #sum}.
+     *
+     * @return the sum
+     */
+    public long longValue() {
+        return sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as an {@code int} after a narrowing
+     * primitive conversion.
+     */
+    public int intValue() {
+        return (int)sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as a {@code float}
+     * after a widening primitive conversion.
+     */
+    public float floatValue() {
+        return (float)sum();
+    }
+
+    /**
+     * Returns the {@link #sum} as a {@code double} after a widening
+     * primitive conversion.
+     */
+    public double doubleValue() {
+        return (double)sum();
+    }
+
+    /**
+     * Serialization proxy, used to avoid reference to the non-public
+     * Striped64 superclass in serialized forms.
+     * @serial include
+     */
+    private static class SerializationProxy implements Serializable {
+        private static final long serialVersionUID = 7249069246863182397L;
+
+        /**
+         * The current value returned by sum().
+         * @serial
+         */
+        private final long value;
+
+        SerializationProxy(LongAdder a) {
+            value = a.sum();
+        }
+
+        /**
+         * Return a {@code LongAdder} object with initial state
+         * held by this proxy.
+         *
+         * @return a {@code LongAdder} object with initial state
+         * held by this proxy.
+         */
+        private Object readResolve() {
+            LongAdder a = new LongAdder();
+            a.base = value;
+            return a;
+        }
+    }
+
+    /**
+     * Returns a
+     * <a href="../../../../serialized-form.html#java.util.concurrent.atomic.LongAdder.SerializationProxy">
+     * SerializationProxy</a>
+     * representing the state of this instance.
+     *
+     * @return a {@link SerializationProxy}
+     * representing the state of this instance
+     */
+    private Object writeReplace() {
+        return new SerializationProxy(this);
+    }
+
+    /**
+     * @param s the stream
+     * @throws java.io.InvalidObjectException always
+     */
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.InvalidObjectException {
+        throw new java.io.InvalidObjectException("Proxy required");
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/Striped64.java

@@ -0,0 +1,413 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent.atomic;
+import java.util.function.LongBinaryOperator;
+import java.util.function.DoubleBinaryOperator;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * A package-local class holding common representation and mechanics
+ * for classes supporting dynamic striping on 64bit values. The class
+ * extends Number so that concrete subclasses must publicly do so.
+ */
+@SuppressWarnings("serial")
+abstract class Striped64 extends Number {
+    /*
+     * This class maintains a lazily-initialized table of atomically
+     * updated variables, plus an extra "base" field. The table size
+     * is a power of two. Indexing uses masked per-thread hash codes.
+     * Nearly all declarations in this class are package-private,
+     * accessed directly by subclasses.
+     *
+     * Table entries are of class Cell; a variant of AtomicLong padded
+     * (via @sun.misc.Contended) to reduce cache contention. Padding
+     * is overkill for most Atomics because they are usually
+     * irregularly scattered in memory and thus don't interfere much
+     * with each other. But Atomic objects residing in arrays will
+     * tend to be placed adjacent to each other, and so will most
+     * often share cache lines (with a huge negative performance
+     * impact) without this precaution.
+     *
+     * In part because Cells are relatively large, we avoid creating
+     * them until they are needed.  When there is no contention, all
+     * updates are made to the base field.  Upon first contention (a
+     * failed CAS on base update), the table is initialized to size 2.
+     * The table size is doubled upon further contention until
+     * reaching the nearest power of two greater than or equal to the
+     * number of CPUS. Table slots remain empty (null) until they are
+     * needed.
+     *
+     * A single spinlock ("cellsBusy") is used for initializing and
+     * resizing the table, as well as populating slots with new Cells.
+     * There is no need for a blocking lock; when the lock is not
+     * available, threads try other slots (or the base).  During these
+     * retries, there is increased contention and reduced locality,
+     * which is still better than alternatives.
+     *
+     * The Thread probe fields maintained via ThreadLocalRandom serve
+     * as per-thread hash codes. We let them remain uninitialized as
+     * zero (if they come in this way) until they contend at slot
+     * 0. They are then initialized to values that typically do not
+     * often conflict with others.  Contention and/or table collisions
+     * are indicated by failed CASes when performing an update
+     * operation. Upon a collision, if the table size is less than
+     * the capacity, it is doubled in size unless some other thread
+     * holds the lock. If a hashed slot is empty, and lock is
+     * available, a new Cell is created. Otherwise, if the slot
+     * exists, a CAS is tried.  Retries proceed by "double hashing",
+     * using a secondary hash (Marsaglia XorShift) to try to find a
+     * free slot.
+     *
+     * The table size is capped because, when there are more threads
+     * than CPUs, supposing that each thread were bound to a CPU,
+     * there would exist a perfect hash function mapping threads to
+     * slots that eliminates collisions. When we reach capacity, we
+     * search for this mapping by randomly varying the hash codes of
+     * colliding threads.  Because search is random, and collisions
+     * only become known via CAS failures, convergence can be slow,
+     * and because threads are typically not bound to CPUS forever,
+     * may not occur at all. However, despite these limitations,
+     * observed contention rates are typically low in these cases.
+     *
+     * It is possible for a Cell to become unused when threads that
+     * once hashed to it terminate, as well as in the case where
+     * doubling the table causes no thread to hash to it under
+     * expanded mask.  We do not try to detect or remove such cells,
+     * under the assumption that for long-running instances, observed
+     * contention levels will recur, so the cells will eventually be
+     * needed again; and for short-lived ones, it does not matter.
+     */
+
+    /**
+     * Padded variant of AtomicLong supporting only raw accesses plus CAS.
+     *
+     * JVM intrinsics note: It would be possible to use a release-only
+     * form of CAS here, if it were provided.
+     */
+    @sun.misc.Contended static final class Cell {
+        volatile long value;
+        Cell(long x) { value = x; }
+        final boolean cas(long cmp, long val) {
+            return UNSAFE.compareAndSwapLong(this, valueOffset, cmp, val);
+        }
+
+        // Unsafe mechanics
+        private static final sun.misc.Unsafe UNSAFE;
+        private static final long valueOffset;
+        static {
+            try {
+                UNSAFE = sun.misc.Unsafe.getUnsafe();
+                Class<?> ak = Cell.class;
+                valueOffset = UNSAFE.objectFieldOffset
+                    (ak.getDeclaredField("value"));
+            } catch (Exception e) {
+                throw new Error(e);
+            }
+        }
+    }
+
+    /** Number of CPUS, to place bound on table size */
+    static final int NCPU = Runtime.getRuntime().availableProcessors();
+
+    /**
+     * Table of cells. When non-null, size is a power of 2.
+     */
+    transient volatile Cell[] cells;
+
+    /**
+     * Base value, used mainly when there is no contention, but also as
+     * a fallback during table initialization races. Updated via CAS.
+     */
+    transient volatile long base;
+
+    /**
+     * Spinlock (locked via CAS) used when resizing and/or creating Cells.
+     */
+    transient volatile int cellsBusy;
+
+    /**
+     * Package-private default constructor
+     */
+    Striped64() {
+    }
+
+    /**
+     * CASes the base field.
+     */
+    final boolean casBase(long cmp, long val) {
+        return UNSAFE.compareAndSwapLong(this, BASE, cmp, val);
+    }
+
+    /**
+     * CASes the cellsBusy field from 0 to 1 to acquire lock.
+     */
+    final boolean casCellsBusy() {
+        return UNSAFE.compareAndSwapInt(this, CELLSBUSY, 0, 1);
+    }
+
+    /**
+     * Returns the probe value for the current thread.
+     * Duplicated from ThreadLocalRandom because of packaging restrictions.
+     */
+    static final int getProbe() {
+        return UNSAFE.getInt(Thread.currentThread(), PROBE);
+    }
+
+    /**
+     * Pseudo-randomly advances and records the given probe value for the
+     * given thread.
+     * Duplicated from ThreadLocalRandom because of packaging restrictions.
+     */
+    static final int advanceProbe(int probe) {
+        probe ^= probe << 13;   // xorshift
+        probe ^= probe >>> 17;
+        probe ^= probe << 5;
+        UNSAFE.putInt(Thread.currentThread(), PROBE, probe);
+        return probe;
+    }
+
+    /**
+     * Handles cases of updates involving initialization, resizing,
+     * creating new Cells, and/or contention. See above for
+     * explanation. This method suffers the usual non-modularity
+     * problems of optimistic retry code, relying on rechecked sets of
+     * reads.
+     *
+     * @param x the value
+     * @param fn the update function, or null for add (this convention
+     * avoids the need for an extra field or function in LongAdder).
+     * @param wasUncontended false if CAS failed before call
+     */
+    final void longAccumulate(long x, LongBinaryOperator fn,
+                              boolean wasUncontended) {
+        int h;
+        if ((h = getProbe()) == 0) {
+            ThreadLocalRandom.current(); // force initialization
+            h = getProbe();
+            wasUncontended = true;
+        }
+        boolean collide = false;                // True if last slot nonempty
+        for (;;) {
+            Cell[] as; Cell a; int n; long v;
+            if ((as = cells) != null && (n = as.length) > 0) {
+                if ((a = as[(n - 1) & h]) == null) {
+                    if (cellsBusy == 0) {       // Try to attach new Cell
+                        Cell r = new Cell(x);   // Optimistically create
+                        if (cellsBusy == 0 && casCellsBusy()) {
+                            boolean created = false;
+                            try {               // Recheck under lock
+                                Cell[] rs; int m, j;
+                                if ((rs = cells) != null &&
+                                    (m = rs.length) > 0 &&
+                                    rs[j = (m - 1) & h] == null) {
+                                    rs[j] = r;
+                                    created = true;
+                                }
+                            } finally {
+                                cellsBusy = 0;
+                            }
+                            if (created)
+                                break;
+                            continue;           // Slot is now non-empty
+                        }
+                    }
+                    collide = false;
+                }
+                else if (!wasUncontended)       // CAS already known to fail
+                    wasUncontended = true;      // Continue after rehash
+                else if (a.cas(v = a.value, ((fn == null) ? v + x :
+                                             fn.applyAsLong(v, x))))
+                    break;
+                else if (n >= NCPU || cells != as)
+                    collide = false;            // At max size or stale
+                else if (!collide)
+                    collide = true;
+                else if (cellsBusy == 0 && casCellsBusy()) {
+                    try {
+                        if (cells == as) {      // Expand table unless stale
+                            Cell[] rs = new Cell[n << 1];
+                            for (int i = 0; i < n; ++i)
+                                rs[i] = as[i];
+                            cells = rs;
+                        }
+                    } finally {
+                        cellsBusy = 0;
+                    }
+                    collide = false;
+                    continue;                   // Retry with expanded table
+                }
+                h = advanceProbe(h);
+            }
+            else if (cellsBusy == 0 && cells == as && casCellsBusy()) {
+                boolean init = false;
+                try {                           // Initialize table
+                    if (cells == as) {
+                        Cell[] rs = new Cell[2];
+                        rs[h & 1] = new Cell(x);
+                        cells = rs;
+                        init = true;
+                    }
+                } finally {
+                    cellsBusy = 0;
+                }
+                if (init)
+                    break;
+            }
+            else if (casBase(v = base, ((fn == null) ? v + x :
+                                        fn.applyAsLong(v, x))))
+                break;                          // Fall back on using base
+        }
+    }
+
+    /**
+     * Same as longAccumulate, but injecting long/double conversions
+     * in too many places to sensibly merge with long version, given
+     * the low-overhead requirements of this class. So must instead be
+     * maintained by copy/paste/adapt.
+     */
+    final void doubleAccumulate(double x, DoubleBinaryOperator fn,
+                                boolean wasUncontended) {
+        int h;
+        if ((h = getProbe()) == 0) {
+            ThreadLocalRandom.current(); // force initialization
+            h = getProbe();
+            wasUncontended = true;
+        }
+        boolean collide = false;                // True if last slot nonempty
+        for (;;) {
+            Cell[] as; Cell a; int n; long v;
+            if ((as = cells) != null && (n = as.length) > 0) {
+                if ((a = as[(n - 1) & h]) == null) {
+                    if (cellsBusy == 0) {       // Try to attach new Cell
+                        Cell r = new Cell(Double.doubleToRawLongBits(x));
+                        if (cellsBusy == 0 && casCellsBusy()) {
+                            boolean created = false;
+                            try {               // Recheck under lock
+                                Cell[] rs; int m, j;
+                                if ((rs = cells) != null &&
+                                    (m = rs.length) > 0 &&
+                                    rs[j = (m - 1) & h] == null) {
+                                    rs[j] = r;
+                                    created = true;
+                                }
+                            } finally {
+                                cellsBusy = 0;
+                            }
+                            if (created)
+                                break;
+                            continue;           // Slot is now non-empty
+                        }
+                    }
+                    collide = false;
+                }
+                else if (!wasUncontended)       // CAS already known to fail
+                    wasUncontended = true;      // Continue after rehash
+                else if (a.cas(v = a.value,
+                               ((fn == null) ?
+                                Double.doubleToRawLongBits
+                                (Double.longBitsToDouble(v) + x) :
+                                Double.doubleToRawLongBits
+                                (fn.applyAsDouble
+                                 (Double.longBitsToDouble(v), x)))))
+                    break;
+                else if (n >= NCPU || cells != as)
+                    collide = false;            // At max size or stale
+                else if (!collide)
+                    collide = true;
+                else if (cellsBusy == 0 && casCellsBusy()) {
+                    try {
+                        if (cells == as) {      // Expand table unless stale
+                            Cell[] rs = new Cell[n << 1];
+                            for (int i = 0; i < n; ++i)
+                                rs[i] = as[i];
+                            cells = rs;
+                        }
+                    } finally {
+                        cellsBusy = 0;
+                    }
+                    collide = false;
+                    continue;                   // Retry with expanded table
+                }
+                h = advanceProbe(h);
+            }
+            else if (cellsBusy == 0 && cells == as && casCellsBusy()) {
+                boolean init = false;
+                try {                           // Initialize table
+                    if (cells == as) {
+                        Cell[] rs = new Cell[2];
+                        rs[h & 1] = new Cell(Double.doubleToRawLongBits(x));
+                        cells = rs;
+                        init = true;
+                    }
+                } finally {
+                    cellsBusy = 0;
+                }
+                if (init)
+                    break;
+            }
+            else if (casBase(v = base,
+                             ((fn == null) ?
+                              Double.doubleToRawLongBits
+                              (Double.longBitsToDouble(v) + x) :
+                              Double.doubleToRawLongBits
+                              (fn.applyAsDouble
+                               (Double.longBitsToDouble(v), x)))))
+                break;                          // Fall back on using base
+        }
+    }
+
+    // Unsafe mechanics
+    private static final sun.misc.Unsafe UNSAFE;
+    private static final long BASE;
+    private static final long CELLSBUSY;
+    private static final long PROBE;
+    static {
+        try {
+            UNSAFE = sun.misc.Unsafe.getUnsafe();
+            Class<?> sk = Striped64.class;
+            BASE = UNSAFE.objectFieldOffset
+                (sk.getDeclaredField("base"));
+            CELLSBUSY = UNSAFE.objectFieldOffset
+                (sk.getDeclaredField("cellsBusy"));
+            Class<?> tk = Thread.class;
+            PROBE = UNSAFE.objectFieldOffset
+                (tk.getDeclaredField("threadLocalRandomProbe"));
+        } catch (Exception e) {
+            throw new Error(e);
+        }
+    }
+
+}

jdkSrc/jdk8/java/util/concurrent/atomic/package-info.java

@@ -0,0 +1,212 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * A small toolkit of classes that support lock-free thread-safe
+ * programming on single variables.  In essence, the classes in this
+ * package extend the notion of {@code volatile} values, fields, and
+ * array elements to those that also provide an atomic conditional update
+ * operation of the form:
+ *
+ *  <pre> {@code boolean compareAndSet(expectedValue, updateValue);}</pre>
+ *
+ * <p>This method (which varies in argument types across different
+ * classes) atomically sets a variable to the {@code updateValue} if it
+ * currently holds the {@code expectedValue}, reporting {@code true} on
+ * success.  The classes in this package also contain methods to get and
+ * unconditionally set values, as well as a weaker conditional atomic
+ * update operation {@code weakCompareAndSet} described below.
+ *
+ * <p>The specifications of these methods enable implementations to
+ * employ efficient machine-level atomic instructions that are available
+ * on contemporary processors.  However on some platforms, support may
+ * entail some form of internal locking.  Thus the methods are not
+ * strictly guaranteed to be non-blocking --
+ * a thread may block transiently before performing the operation.
+ *
+ * <p>Instances of classes
+ * {@link java.util.concurrent.atomic.AtomicBoolean},
+ * {@link java.util.concurrent.atomic.AtomicInteger},
+ * {@link java.util.concurrent.atomic.AtomicLong}, and
+ * {@link java.util.concurrent.atomic.AtomicReference}
+ * each provide access and updates to a single variable of the
+ * corresponding type.  Each class also provides appropriate utility
+ * methods for that type.  For example, classes {@code AtomicLong} and
+ * {@code AtomicInteger} provide atomic increment methods.  One
+ * application is to generate sequence numbers, as in:
+ *
+ *  <pre> {@code
+ * class Sequencer {
+ *   private final AtomicLong sequenceNumber
+ *     = new AtomicLong(0);
+ *   public long next() {
+ *     return sequenceNumber.getAndIncrement();
+ *   }
+ * }}</pre>
+ *
+ * <p>It is straightforward to define new utility functions that, like
+ * {@code getAndIncrement}, apply a function to a value atomically.
+ * For example, given some transformation
+ * <pre> {@code long transform(long input)}</pre>
+ *
+ * write your utility method as follows:
+ *  <pre> {@code
+ * long getAndTransform(AtomicLong var) {
+ *   long prev, next;
+ *   do {
+ *     prev = var.get();
+ *     next = transform(prev);
+ *   } while (!var.compareAndSet(prev, next));
+ *   return prev; // return next; for transformAndGet
+ * }}</pre>
+ *
+ * <p>The memory effects for accesses and updates of atomics generally
+ * follow the rules for volatiles, as stated in
+ * <a href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4">
+ * The Java Language Specification (17.4 Memory Model)</a>:
+ *
+ * <ul>
+ *
+ *   <li> {@code get} has the memory effects of reading a
+ * {@code volatile} variable.
+ *
+ *   <li> {@code set} has the memory effects of writing (assigning) a
+ * {@code volatile} variable.
+ *
+ *   <li> {@code lazySet} has the memory effects of writing (assigning)
+ *   a {@code volatile} variable except that it permits reorderings with
+ *   subsequent (but not previous) memory actions that do not themselves
+ *   impose reordering constraints with ordinary non-{@code volatile}
+ *   writes.  Among other usage contexts, {@code lazySet} may apply when
+ *   nulling out, for the sake of garbage collection, a reference that is
+ *   never accessed again.
+ *
+ *   <li>{@code weakCompareAndSet} atomically reads and conditionally
+ *   writes a variable but does <em>not</em>
+ *   create any happens-before orderings, so provides no guarantees
+ *   with respect to previous or subsequent reads and writes of any
+ *   variables other than the target of the {@code weakCompareAndSet}.
+ *
+ *   <li> {@code compareAndSet}
+ *   and all other read-and-update operations such as {@code getAndIncrement}
+ *   have the memory effects of both reading and
+ *   writing {@code volatile} variables.
+ * </ul>
+ *
+ * <p>In addition to classes representing single values, this package
+ * contains <em>Updater</em> classes that can be used to obtain
+ * {@code compareAndSet} operations on any selected {@code volatile}
+ * field of any selected class.
+ *
+ * {@link java.util.concurrent.atomic.AtomicReferenceFieldUpdater},
+ * {@link java.util.concurrent.atomic.AtomicIntegerFieldUpdater}, and
+ * {@link java.util.concurrent.atomic.AtomicLongFieldUpdater} are
+ * reflection-based utilities that provide access to the associated
+ * field types.  These are mainly of use in atomic data structures in
+ * which several {@code volatile} fields of the same node (for
+ * example, the links of a tree node) are independently subject to
+ * atomic updates.  These classes enable greater flexibility in how
+ * and when to use atomic updates, at the expense of more awkward
+ * reflection-based setup, less convenient usage, and weaker
+ * guarantees.
+ *
+ * <p>The
+ * {@link java.util.concurrent.atomic.AtomicIntegerArray},
+ * {@link java.util.concurrent.atomic.AtomicLongArray}, and
+ * {@link java.util.concurrent.atomic.AtomicReferenceArray} classes
+ * further extend atomic operation support to arrays of these types.
+ * These classes are also notable in providing {@code volatile} access
+ * semantics for their array elements, which is not supported for
+ * ordinary arrays.
+ *
+ * <p id="weakCompareAndSet">The atomic classes also support method
+ * {@code weakCompareAndSet}, which has limited applicability.  On some
+ * platforms, the weak version may be more efficient than {@code
+ * compareAndSet} in the normal case, but differs in that any given
+ * invocation of the {@code weakCompareAndSet} method may return {@code
+ * false} <em>spuriously</em> (that is, for no apparent reason).  A
+ * {@code false} return means only that the operation may be retried if
+ * desired, relying on the guarantee that repeated invocation when the
+ * variable holds {@code expectedValue} and no other thread is also
+ * attempting to set the variable will eventually succeed.  (Such
+ * spurious failures may for example be due to memory contention effects
+ * that are unrelated to whether the expected and current values are
+ * equal.)  Additionally {@code weakCompareAndSet} does not provide
+ * ordering guarantees that are usually needed for synchronization
+ * control.  However, the method may be useful for updating counters and
+ * statistics when such updates are unrelated to the other
+ * happens-before orderings of a program.  When a thread sees an update
+ * to an atomic variable caused by a {@code weakCompareAndSet}, it does
+ * not necessarily see updates to any <em>other</em> variables that
+ * occurred before the {@code weakCompareAndSet}.  This may be
+ * acceptable when, for example, updating performance statistics, but
+ * rarely otherwise.
+ *
+ * <p>The {@link java.util.concurrent.atomic.AtomicMarkableReference}
+ * class associates a single boolean with a reference.  For example, this
+ * bit might be used inside a data structure to mean that the object
+ * being referenced has logically been deleted.
+ *
+ * The {@link java.util.concurrent.atomic.AtomicStampedReference}
+ * class associates an integer value with a reference.  This may be
+ * used for example, to represent version numbers corresponding to
+ * series of updates.
+ *
+ * <p>Atomic classes are designed primarily as building blocks for
+ * implementing non-blocking data structures and related infrastructure
+ * classes.  The {@code compareAndSet} method is not a general
+ * replacement for locking.  It applies only when critical updates for an
+ * object are confined to a <em>single</em> variable.
+ *
+ * <p>Atomic classes are not general purpose replacements for
+ * {@code java.lang.Integer} and related classes.  They do <em>not</em>
+ * define methods such as {@code equals}, {@code hashCode} and
+ * {@code compareTo}.  (Because atomic variables are expected to be
+ * mutated, they are poor choices for hash table keys.)  Additionally,
+ * classes are provided only for those types that are commonly useful in
+ * intended applications.  For example, there is no atomic class for
+ * representing {@code byte}.  In those infrequent cases where you would
+ * like to do so, you can use an {@code AtomicInteger} to hold
+ * {@code byte} values, and cast appropriately.
+ *
+ * You can also hold floats using
+ * {@link java.lang.Float#floatToRawIntBits} and
+ * {@link java.lang.Float#intBitsToFloat} conversions, and doubles using
+ * {@link java.lang.Double#doubleToRawLongBits} and
+ * {@link java.lang.Double#longBitsToDouble} conversions.
+ *
+ * @since 1.5
+ */
+package java.util.concurrent.atomic;