diff -r 000000000000 -r 212417b74b72 rt/emul/compact/src/main/java/java/util/concurrent/ConcurrentSkipListSet.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/emul/compact/src/main/java/java/util/concurrent/ConcurrentSkipListSet.java Sat Mar 19 10:46:31 2016 +0100
@@ -0,0 +1,491 @@
+/*
+ * 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;
+import java.util.*;
+import sun.misc.Unsafe;
+
+/**
+ * A scalable concurrent {@link NavigableSet} implementation based on
+ * a {@link ConcurrentSkipListMap}. The elements of the set are kept
+ * sorted according to their {@linkplain Comparable natural ordering},
+ * or by a {@link Comparator} provided at set creation time, depending
+ * on which constructor is used.
+ *
+ *
This implementation provides expected average log(n) time
+ * cost for the contains, add, and remove
+ * operations and their variants. Insertion, removal, and access
+ * operations safely execute concurrently by multiple threads.
+ * Iterators are weakly consistent, returning elements
+ * reflecting the state of the set at some point at or since the
+ * creation of the iterator. They do not throw {@link
+ * ConcurrentModificationException}, and may proceed concurrently with
+ * other operations. Ascending ordered views and their iterators are
+ * faster than descending ones.
+ *
+ *
Beware that, unlike in most collections, the size
+ * method is not a constant-time operation. Because of the
+ * asynchronous nature of these sets, determining the current number
+ * of elements requires a traversal of the elements, and so may report
+ * inaccurate results if this collection is modified during traversal.
+ * Additionally, the bulk operations addAll,
+ * removeAll, retainAll, containsAll,
+ * equals, and toArray are not guaranteed
+ * to be performed atomically. For example, an iterator operating
+ * concurrently with an addAll operation might view only some
+ * of the added elements.
+ *
+ *
This class and its iterators implement all of the
+ * optional methods of the {@link Set} and {@link Iterator}
+ * interfaces. Like most other concurrent collection implementations,
+ * this class does not permit the use of null elements,
+ * because null arguments and return values cannot be reliably
+ * distinguished from the absence of elements.
+ *
+ *
This class is a member of the
+ *
+ * Java Collections Framework.
+ *
+ * @author Doug Lea
+ * @param the type of elements maintained by this set
+ * @since 1.6
+ */
+public class ConcurrentSkipListSet
+ extends AbstractSet
+ implements NavigableSet, Cloneable, java.io.Serializable {
+
+ private static final long serialVersionUID = -2479143111061671589L;
+
+ /**
+ * The underlying map. Uses Boolean.TRUE as value for each
+ * element. This field is declared final for the sake of thread
+ * safety, which entails some ugliness in clone()
+ */
+ private final ConcurrentNavigableMap m;
+
+ /**
+ * Constructs a new, empty set that orders its elements according to
+ * their {@linkplain Comparable natural ordering}.
+ */
+ public ConcurrentSkipListSet() {
+ m = new ConcurrentSkipListMap();
+ }
+
+ /**
+ * Constructs a new, empty set that orders its elements according to
+ * the specified comparator.
+ *
+ * @param comparator the comparator that will be used to order this set.
+ * If null, the {@linkplain Comparable natural
+ * ordering} of the elements will be used.
+ */
+ public ConcurrentSkipListSet(Comparator super E> comparator) {
+ m = new ConcurrentSkipListMap(comparator);
+ }
+
+ /**
+ * Constructs a new set containing the elements in the specified
+ * collection, that orders its elements according to their
+ * {@linkplain Comparable natural ordering}.
+ *
+ * @param c The elements that will comprise the new set
+ * @throws ClassCastException if the elements in c are
+ * not {@link Comparable}, or are not mutually comparable
+ * @throws NullPointerException if the specified collection or any
+ * of its elements are null
+ */
+ public ConcurrentSkipListSet(Collection extends E> c) {
+ m = new ConcurrentSkipListMap();
+ addAll(c);
+ }
+
+ /**
+ * Constructs a new set containing the same elements and using the
+ * same ordering as the specified sorted set.
+ *
+ * @param s sorted set whose elements will comprise the new set
+ * @throws NullPointerException if the specified sorted set or any
+ * of its elements are null
+ */
+ public ConcurrentSkipListSet(SortedSet s) {
+ m = new ConcurrentSkipListMap(s.comparator());
+ addAll(s);
+ }
+
+ /**
+ * For use by submaps
+ */
+ ConcurrentSkipListSet(ConcurrentNavigableMap m) {
+ this.m = m;
+ }
+
+ /**
+ * Returns a shallow copy of this ConcurrentSkipListSet
+ * instance. (The elements themselves are not cloned.)
+ *
+ * @return a shallow copy of this set
+ */
+ public ConcurrentSkipListSet clone() {
+ ConcurrentSkipListSet clone = null;
+ try {
+ clone = (ConcurrentSkipListSet) super.clone();
+ clone.setMap(new ConcurrentSkipListMap(m));
+ } catch (CloneNotSupportedException e) {
+ throw new InternalError();
+ }
+
+ return clone;
+ }
+
+ /* ---------------- Set operations -------------- */
+
+ /**
+ * Returns the number of elements in this set. If this set
+ * contains more than Integer.MAX_VALUE elements, it
+ * returns Integer.MAX_VALUE.
+ *
+ * Beware that, unlike in most collections, this method is
+ * NOT a constant-time operation. Because of the
+ * asynchronous nature of these sets, determining the current
+ * number of elements requires traversing them all to count them.
+ * Additionally, it is possible for the size to change during
+ * execution of this method, in which case the returned result
+ * will be inaccurate. Thus, this method is typically not very
+ * useful in concurrent applications.
+ *
+ * @return the number of elements in this set
+ */
+ public int size() {
+ return m.size();
+ }
+
+ /**
+ * Returns true if this set contains no elements.
+ * @return true if this set contains no elements
+ */
+ public boolean isEmpty() {
+ return m.isEmpty();
+ }
+
+ /**
+ * Returns true if this set contains the specified element.
+ * More formally, returns true if and only if this set
+ * contains an element e such that o.equals(e).
+ *
+ * @param o object to be checked for containment in this set
+ * @return true if this set contains the specified element
+ * @throws ClassCastException if the specified element cannot be
+ * compared with the elements currently in this set
+ * @throws NullPointerException if the specified element is null
+ */
+ public boolean contains(Object o) {
+ return m.containsKey(o);
+ }
+
+ /**
+ * Adds the specified element to this set if it is not already present.
+ * More formally, adds the specified element e to this set if
+ * the set contains no element e2 such that e.equals(e2).
+ * If this set already contains the element, the call leaves the set
+ * unchanged and returns false.
+ *
+ * @param e element to be added to this set
+ * @return true if this set did not already contain the
+ * specified element
+ * @throws ClassCastException if e cannot be compared
+ * with the elements currently in this set
+ * @throws NullPointerException if the specified element is null
+ */
+ public boolean add(E e) {
+ return m.putIfAbsent(e, Boolean.TRUE) == null;
+ }
+
+ /**
+ * Removes the specified element from this set if it is present.
+ * More formally, removes an element e such that
+ * o.equals(e), if this set contains such an element.
+ * Returns true if this set contained the element (or
+ * equivalently, if this set changed as a result of the call).
+ * (This set will not contain the element once the call returns.)
+ *
+ * @param o object to be removed from this set, if present
+ * @return true if this set contained the specified element
+ * @throws ClassCastException if o cannot be compared
+ * with the elements currently in this set
+ * @throws NullPointerException if the specified element is null
+ */
+ public boolean remove(Object o) {
+ return m.remove(o, Boolean.TRUE);
+ }
+
+ /**
+ * Removes all of the elements from this set.
+ */
+ public void clear() {
+ m.clear();
+ }
+
+ /**
+ * Returns an iterator over the elements in this set in ascending order.
+ *
+ * @return an iterator over the elements in this set in ascending order
+ */
+ public Iterator iterator() {
+ return m.navigableKeySet().iterator();
+ }
+
+ /**
+ * Returns an iterator over the elements in this set in descending order.
+ *
+ * @return an iterator over the elements in this set in descending order
+ */
+ public Iterator descendingIterator() {
+ return m.descendingKeySet().iterator();
+ }
+
+
+ /* ---------------- AbstractSet Overrides -------------- */
+
+ /**
+ * Compares the specified object with this set for equality. Returns
+ * true if the specified object is also a set, the two sets
+ * have the same size, and every member of the specified set is
+ * contained in this set (or equivalently, every member of this set is
+ * contained in the specified set). This definition ensures that the
+ * equals method works properly across different implementations of the
+ * set interface.
+ *
+ * @param o the object to be compared for equality with this set
+ * @return true if the specified object is equal to this set
+ */
+ public boolean equals(Object o) {
+ // Override AbstractSet version to avoid calling size()
+ if (o == this)
+ return true;
+ if (!(o instanceof Set))
+ return false;
+ Collection> c = (Collection>) o;
+ try {
+ return containsAll(c) && c.containsAll(this);
+ } catch (ClassCastException unused) {
+ return false;
+ } catch (NullPointerException unused) {
+ return false;
+ }
+ }
+
+ /**
+ * Removes from this set all of its elements that are contained in
+ * the specified collection. If the specified collection is also
+ * a set, this operation effectively modifies this set so that its
+ * value is the asymmetric set difference of the two sets.
+ *
+ * @param c collection containing elements to be removed from this set
+ * @return true if this set changed as a result of the call
+ * @throws ClassCastException if the types of one or more elements in this
+ * set are incompatible with the specified collection
+ * @throws NullPointerException if the specified collection or any
+ * of its elements are null
+ */
+ public boolean removeAll(Collection> c) {
+ // Override AbstractSet version to avoid unnecessary call to size()
+ boolean modified = false;
+ for (Iterator> i = c.iterator(); i.hasNext(); )
+ if (remove(i.next()))
+ modified = true;
+ return modified;
+ }
+
+ /* ---------------- Relational operations -------------- */
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null
+ */
+ public E lower(E e) {
+ return m.lowerKey(e);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null
+ */
+ public E floor(E e) {
+ return m.floorKey(e);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null
+ */
+ public E ceiling(E e) {
+ return m.ceilingKey(e);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null
+ */
+ public E higher(E e) {
+ return m.higherKey(e);
+ }
+
+ public E pollFirst() {
+ Map.Entry e = m.pollFirstEntry();
+ return (e == null) ? null : e.getKey();
+ }
+
+ public E pollLast() {
+ Map.Entry e = m.pollLastEntry();
+ return (e == null) ? null : e.getKey();
+ }
+
+
+ /* ---------------- SortedSet operations -------------- */
+
+
+ public Comparator super E> comparator() {
+ return m.comparator();
+ }
+
+ /**
+ * @throws NoSuchElementException {@inheritDoc}
+ */
+ public E first() {
+ return m.firstKey();
+ }
+
+ /**
+ * @throws NoSuchElementException {@inheritDoc}
+ */
+ public E last() {
+ return m.lastKey();
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code fromElement} or
+ * {@code toElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet subSet(E fromElement,
+ boolean fromInclusive,
+ E toElement,
+ boolean toInclusive) {
+ return new ConcurrentSkipListSet
+ (m.subMap(fromElement, fromInclusive,
+ toElement, toInclusive));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code toElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet headSet(E toElement, boolean inclusive) {
+ return new ConcurrentSkipListSet(m.headMap(toElement, inclusive));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code fromElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet tailSet(E fromElement, boolean inclusive) {
+ return new ConcurrentSkipListSet(m.tailMap(fromElement, inclusive));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code fromElement} or
+ * {@code toElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet subSet(E fromElement, E toElement) {
+ return subSet(fromElement, true, toElement, false);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code toElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet headSet(E toElement) {
+ return headSet(toElement, false);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if {@code fromElement} is null
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet tailSet(E fromElement) {
+ return tailSet(fromElement, true);
+ }
+
+ /**
+ * Returns a reverse order view of the elements contained in this set.
+ * The descending set is backed by this set, so changes to the set are
+ * reflected in the descending set, and vice-versa.
+ *
+ * The returned set has an ordering equivalent to
+ * {@link Collections#reverseOrder(Comparator) Collections.reverseOrder}(comparator()).
+ * The expression {@code s.descendingSet().descendingSet()} returns a
+ * view of {@code s} essentially equivalent to {@code s}.
+ *
+ * @return a reverse order view of this set
+ */
+ public NavigableSet descendingSet() {
+ return new ConcurrentSkipListSet(m.descendingMap());
+ }
+
+ // Support for resetting map in clone
+ private void setMap(ConcurrentNavigableMap map) {
+ UNSAFE.putObjectVolatile(this, mapOffset, map);
+ }
+
+ private static final sun.misc.Unsafe UNSAFE;
+ private static final long mapOffset;
+ static {
+ try {
+ UNSAFE = sun.misc.Unsafe.getUnsafe();
+ Class k = ConcurrentSkipListSet.class;
+ mapOffset = UNSAFE.objectFieldOffset
+ (k.getDeclaredField("m"));
+ } catch (Exception e) {
+ throw new Error(e);
+ }
+ }
+}