7129185: Add Collections.{checked|empty|unmodifiable}Navigable{Map|Set}
authormduigou
Fri, 12 Jul 2013 11:11:30 -0700
changeset 18818 a9ceff754226
parent 18815 5da35ed47cfa
child 18819 c4335fc31aeb
7129185: Add Collections.{checked|empty|unmodifiable}Navigable{Map|Set} Reviewed-by: dmocek, martin, smarks
jdk/src/share/classes/java/util/AbstractMap.java
jdk/src/share/classes/java/util/Collections.java
jdk/src/share/classes/java/util/NavigableSet.java
jdk/test/java/util/Collection/MOAT.java
jdk/test/java/util/Collections/CheckedIdentityMap.java
jdk/test/java/util/Collections/CheckedMapBash.java
jdk/test/java/util/Collections/CheckedSetBash.java
jdk/test/java/util/Collections/EmptyCollectionSerialization.java
jdk/test/java/util/Collections/EmptyNavigableMap.java
jdk/test/java/util/Collections/EmptyNavigableSet.java
jdk/test/java/util/Collections/EmptySortedSet.java
jdk/test/java/util/Map/LockStep.java
jdk/test/java/util/NavigableMap/LockStep.java
--- a/jdk/src/share/classes/java/util/AbstractMap.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/src/share/classes/java/util/AbstractMap.java	Fri Jul 12 11:11:30 2013 -0700
@@ -543,6 +543,8 @@
     /**
      * Utility method for SimpleEntry and SimpleImmutableEntry.
      * Test for equality, checking for nulls.
+     *
+     * NB: Do not replace with Object.equals until JDK-8015417 is resolved.
      */
     private static boolean eq(Object o1, Object o2) {
         return o1 == null ? o2 == null : o1.equals(o2);
--- a/jdk/src/share/classes/java/util/Collections.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/src/share/classes/java/util/Collections.java	Fri Jul 12 11:11:30 2013 -0700
@@ -27,6 +27,7 @@
 import java.io.Serializable;
 import java.io.ObjectOutputStream;
 import java.io.IOException;
+import java.io.InvalidObjectException;
 import java.lang.reflect.Array;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
@@ -138,7 +139,7 @@
      *
      * <p>The implementation was adapted from Tim Peters's list sort for Python
      * (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
-     * TimSort</a>).  It uses techiques from Peter McIlroy's "Optimistic
+     * TimSort</a>).  It uses techniques from Peter McIlroy's "Optimistic
      * Sorting and Information Theoretic Complexity", in Proceedings of the
      * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
      * January 1993.
@@ -199,7 +200,7 @@
      *
      * <p>The implementation was adapted from Tim Peters's list sort for Python
      * (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
-     * TimSort</a>).  It uses techiques from Peter McIlroy's "Optimistic
+     * TimSort</a>).  It uses techniques from Peter McIlroy's "Optimistic
      * Sorting and Information Theoretic Complexity", in Proceedings of the
      * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
      * January 1993.
@@ -1214,6 +1215,94 @@
     }
 
     /**
+     * Returns an unmodifiable view of the specified navigable set.  This method
+     * allows modules to provide users with "read-only" access to internal
+     * navigable sets.  Query operations on the returned navigable set "read
+     * through" to the specified navigable set.  Attempts to modify the returned
+     * navigable set, whether direct, via its iterator, or via its
+     * {@code subSet}, {@code headSet}, or {@code tailSet} views, result in
+     * an {@code UnsupportedOperationException}.<p>
+     *
+     * The returned navigable set will be serializable if the specified
+     * navigable set is serializable.
+     *
+     * @param s the navigable set for which an unmodifiable view is to be
+     *        returned
+     * @return an unmodifiable view of the specified navigable set
+     * @since 1.8
+     */
+    public static <T> NavigableSet<T> unmodifiableNavigableSet(NavigableSet<T> s) {
+        return new UnmodifiableNavigableSet<>(s);
+    }
+
+    /**
+     * Wraps a navigable set and disables all of the mutative operations.
+     *
+     * @param <E> type of elements
+     * @serial include
+     */
+    static class UnmodifiableNavigableSet<E>
+                             extends UnmodifiableSortedSet<E>
+                             implements NavigableSet<E>, Serializable {
+
+        private static final long serialVersionUID = -6027448201786391929L;
+
+        /**
+         * A singleton empty unmodifiable navigable set used for
+         * {@link #emptyNavigableSet()}.
+         *
+         * @param <E> type of elements, if there were any, and bounds
+         */
+        private static class EmptyNavigableSet<E> extends UnmodifiableNavigableSet<E>
+            implements Serializable {
+            private static final long serialVersionUID = -6291252904449939134L;
+
+            public EmptyNavigableSet() {
+                super(new TreeSet<E>());
+            }
+
+            private Object readResolve()        { return EMPTY_NAVIGABLE_SET; }
+        }
+
+        @SuppressWarnings("rawtypes")
+        private static final NavigableSet<?> EMPTY_NAVIGABLE_SET =
+                new EmptyNavigableSet<>();
+
+        /**
+         * The instance we are protecting.
+         */
+        private final NavigableSet<E> ns;
+
+        UnmodifiableNavigableSet(NavigableSet<E> s)         {super(s); ns = s;}
+
+        public E lower(E e)                             { return ns.lower(e); }
+        public E floor(E e)                             { return ns.floor(e); }
+        public E ceiling(E e)                         { return ns.ceiling(e); }
+        public E higher(E e)                           { return ns.higher(e); }
+        public E pollFirst()     { throw new UnsupportedOperationException(); }
+        public E pollLast()      { throw new UnsupportedOperationException(); }
+        public NavigableSet<E> descendingSet()
+                 { return new UnmodifiableNavigableSet<>(ns.descendingSet()); }
+        public Iterator<E> descendingIterator()
+                                         { return descendingSet().iterator(); }
+
+        public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+            return new UnmodifiableNavigableSet<>(
+                ns.subSet(fromElement, fromInclusive, toElement, toInclusive));
+        }
+
+        public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+            return new UnmodifiableNavigableSet<>(
+                ns.headSet(toElement, inclusive));
+        }
+
+        public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+            return new UnmodifiableNavigableSet<>(
+                ns.tailSet(fromElement, inclusive));
+        }
+    }
+
+    /**
      * Returns an unmodifiable view of the specified list.  This method allows
      * modules to provide users with "read-only" access to internal
      * lists.  Query operations on the returned list "read through" to the
@@ -1240,6 +1329,7 @@
     static class UnmodifiableList<E> extends UnmodifiableCollection<E>
                                   implements List<E> {
         private static final long serialVersionUID = -283967356065247728L;
+
         final List<? extends E> list;
 
         UnmodifiableList(List<? extends E> list) {
@@ -1682,7 +1772,8 @@
             private static class UnmodifiableEntry<K,V> implements Map.Entry<K,V> {
                 private Map.Entry<? extends K, ? extends V> e;
 
-                UnmodifiableEntry(Map.Entry<? extends K, ? extends V> e) {this.e = e;}
+                UnmodifiableEntry(Map.Entry<? extends K, ? extends V> e)
+                        {this.e = Objects.requireNonNull(e);}
 
                 public K getKey()        {return e.getKey();}
                 public V getValue()      {return e.getValue();}
@@ -1734,24 +1825,151 @@
 
         private final SortedMap<K, ? extends V> sm;
 
-        UnmodifiableSortedMap(SortedMap<K, ? extends V> m) {super(m); sm = m;}
-
-        public Comparator<? super K> comparator() {return sm.comparator();}
-
-        public SortedMap<K,V> subMap(K fromKey, K toKey) {
-            return new UnmodifiableSortedMap<>(sm.subMap(fromKey, toKey));
-        }
-        public SortedMap<K,V> headMap(K toKey) {
-            return new UnmodifiableSortedMap<>(sm.headMap(toKey));
-        }
-        public SortedMap<K,V> tailMap(K fromKey) {
-            return new UnmodifiableSortedMap<>(sm.tailMap(fromKey));
-        }
-
-        public K firstKey()           {return sm.firstKey();}
-        public K lastKey()            {return sm.lastKey();}
+        UnmodifiableSortedMap(SortedMap<K, ? extends V> m) {super(m); sm = m; }
+        public Comparator<? super K> comparator()   { return sm.comparator(); }
+        public SortedMap<K,V> subMap(K fromKey, K toKey)
+             { return new UnmodifiableSortedMap<>(sm.subMap(fromKey, toKey)); }
+        public SortedMap<K,V> headMap(K toKey)
+                     { return new UnmodifiableSortedMap<>(sm.headMap(toKey)); }
+        public SortedMap<K,V> tailMap(K fromKey)
+                   { return new UnmodifiableSortedMap<>(sm.tailMap(fromKey)); }
+        public K firstKey()                           { return sm.firstKey(); }
+        public K lastKey()                             { return sm.lastKey(); }
+    }
+
+    /**
+     * Returns an unmodifiable view of the specified navigable map.  This method
+     * allows modules to provide users with "read-only" access to internal
+     * navigable maps.  Query operations on the returned navigable map "read
+     * through" to the specified navigable map.  Attempts to modify the returned
+     * navigable map, whether direct, via its collection views, or via its
+     * {@code subMap}, {@code headMap}, or {@code tailMap} views, result in
+     * an {@code UnsupportedOperationException}.<p>
+     *
+     * The returned navigable map will be serializable if the specified
+     * navigable map is serializable.
+     *
+     * @param m the navigable map for which an unmodifiable view is to be
+     *        returned
+     * @return an unmodifiable view of the specified navigable map
+     * @since 1.8
+     */
+    public static <K,V> NavigableMap<K,V> unmodifiableNavigableMap(NavigableMap<K, ? extends V> m) {
+        return new UnmodifiableNavigableMap<>(m);
     }
 
+    /**
+     * @serial include
+     */
+    static class UnmodifiableNavigableMap<K,V>
+          extends UnmodifiableSortedMap<K,V>
+          implements NavigableMap<K,V>, Serializable {
+        private static final long serialVersionUID = -4858195264774772197L;
+
+        /**
+         * A class for the {@link EMPTY_NAVIGABLE_MAP} which needs readResolve
+         * to preserve singleton property.
+         *
+         * @param <K> type of keys, if there were any, and of bounds
+         * @param <V> type of values, if there were any
+         */
+        private static class EmptyNavigableMap<K,V> extends UnmodifiableNavigableMap<K,V>
+            implements Serializable {
+
+            private static final long serialVersionUID = -2239321462712562324L;
+
+            EmptyNavigableMap()                       { super(new TreeMap()); }
+
+            @Override
+            public NavigableSet<K> navigableKeySet()
+                                                { return emptyNavigableSet(); }
+
+            private Object readResolve()        { return EMPTY_NAVIGABLE_MAP; }
+        }
+
+        /**
+         * Singleton for {@link emptyNavigableMap()} which is also immutable.
+         */
+        private static final EmptyNavigableMap<?,?> EMPTY_NAVIGABLE_MAP =
+            new EmptyNavigableMap<>();
+
+        /**
+         * The instance we wrap and protect.
+         */
+        private final NavigableMap<K, ? extends V> nm;
+
+        UnmodifiableNavigableMap(NavigableMap<K, ? extends V> m)
+                                                            {super(m); nm = m;}
+
+        public K lowerKey(K key)                   { return nm.lowerKey(key); }
+        public K floorKey(K key)                   { return nm.floorKey(key); }
+        public K ceilingKey(K key)               { return nm.ceilingKey(key); }
+        public K higherKey(K key)                 { return nm.higherKey(key); }
+
+        public Entry<K, V> lowerEntry(K key) {
+            Entry<K,V> lower = (Entry<K, V>) nm.lowerEntry(key);
+            return (null != lower)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(lower)
+                : null;
+        }
+
+        public Entry<K, V> floorEntry(K key) {
+            Entry<K,V> floor = (Entry<K, V>) nm.floorEntry(key);
+            return (null != floor)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(floor)
+                : null;
+        }
+
+        public Entry<K, V> ceilingEntry(K key) {
+            Entry<K,V> ceiling = (Entry<K, V>) nm.ceilingEntry(key);
+            return (null != ceiling)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(ceiling)
+                : null;
+        }
+
+
+        public Entry<K, V> higherEntry(K key) {
+            Entry<K,V> higher = (Entry<K, V>) nm.higherEntry(key);
+            return (null != higher)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(higher)
+                : null;
+        }
+
+        public Entry<K, V> firstEntry() {
+            Entry<K,V> first = (Entry<K, V>) nm.firstEntry();
+            return (null != first)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(first)
+                : null;
+        }
+
+        public Entry<K, V> lastEntry() {
+            Entry<K,V> last = (Entry<K, V>) nm.lastEntry();
+            return (null != last)
+                ? new UnmodifiableEntrySet.UnmodifiableEntry(last)
+                : null;
+        }
+
+        public Entry<K, V> pollFirstEntry()
+                                 { throw new UnsupportedOperationException(); }
+        public Entry<K, V> pollLastEntry()
+                                 { throw new UnsupportedOperationException(); }
+        public NavigableMap<K, V> descendingMap()
+                       { return unmodifiableNavigableMap(nm.descendingMap()); }
+        public NavigableSet<K> navigableKeySet()
+                     { return unmodifiableNavigableSet(nm.navigableKeySet()); }
+        public NavigableSet<K> descendingKeySet()
+                    { return unmodifiableNavigableSet(nm.descendingKeySet()); }
+
+        public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+            return unmodifiableNavigableMap(
+                nm.subMap(fromKey, fromInclusive, toKey, toInclusive));
+        }
+
+        public NavigableMap<K, V> headMap(K toKey, boolean inclusive)
+             { return unmodifiableNavigableMap(nm.headMap(toKey, inclusive)); }
+        public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive)
+           { return unmodifiableNavigableMap(nm.tailMap(fromKey, inclusive)); }
+    }
 
     // Synch Wrappers
 
@@ -1805,14 +2023,13 @@
         final Object mutex;     // Object on which to synchronize
 
         SynchronizedCollection(Collection<E> c) {
-            if (c==null)
-                throw new NullPointerException();
-            this.c = c;
+            this.c = Objects.requireNonNull(c);
             mutex = this;
         }
+
         SynchronizedCollection(Collection<E> c, Object mutex) {
-            this.c = c;
-            this.mutex = mutex;
+            this.c = Objects.requireNonNull(c);
+            this.mutex = Objects.requireNonNull(mutex);
         }
 
         public int size() {
@@ -2027,6 +2244,120 @@
     }
 
     /**
+     * Returns a synchronized (thread-safe) navigable set backed by the
+     * specified navigable set.  In order to guarantee serial access, it is
+     * critical that <strong>all</strong> access to the backing navigable set is
+     * accomplished through the returned navigable set (or its views).<p>
+     *
+     * It is imperative that the user manually synchronize on the returned
+     * navigable set when iterating over it or any of its {@code subSet},
+     * {@code headSet}, or {@code tailSet} views.
+     * <pre>
+     *  NavigableSet s = Collections.synchronizedNavigableSet(new TreeSet());
+     *      ...
+     *  synchronized (s) {
+     *      Iterator i = s.iterator(); // Must be in the synchronized block
+     *      while (i.hasNext())
+     *          foo(i.next());
+     *  }
+     * </pre>
+     * or:
+     * <pre>
+     *  NavigableSet s = Collections.synchronizedNavigableSet(new TreeSet());
+     *  NavigableSet s2 = s.headSet(foo, true);
+     *      ...
+     *  synchronized (s) {  // Note: s, not s2!!!
+     *      Iterator i = s2.iterator(); // Must be in the synchronized block
+     *      while (i.hasNext())
+     *          foo(i.next());
+     *  }
+     * </pre>
+     * Failure to follow this advice may result in non-deterministic behavior.
+     *
+     * <p>The returned navigable set will be serializable if the specified
+     * navigable set is serializable.
+     *
+     * @param  s the navigable set to be "wrapped" in a synchronized navigable
+     * set
+     * @return a synchronized view of the specified navigable set
+     * @since 1.8
+     */
+    public static <T> NavigableSet<T> synchronizedNavigableSet(NavigableSet<T> s) {
+        return new SynchronizedNavigableSet<>(s);
+    }
+
+    /**
+     * @serial include
+     */
+    static class SynchronizedNavigableSet<E>
+        extends SynchronizedSortedSet<E>
+        implements NavigableSet<E>
+    {
+        private static final long serialVersionUID = -5505529816273629798L;
+
+        private final NavigableSet<E> ns;
+
+        SynchronizedNavigableSet(NavigableSet<E> s) {
+            super(s);
+            ns = s;
+        }
+
+        SynchronizedNavigableSet(NavigableSet<E> s, Object mutex) {
+            super(s, mutex);
+            ns = s;
+        }
+        public E lower(E e)      { synchronized (mutex) {return ns.lower(e);} }
+        public E floor(E e)      { synchronized (mutex) {return ns.floor(e);} }
+        public E ceiling(E e)  { synchronized (mutex) {return ns.ceiling(e);} }
+        public E higher(E e)    { synchronized (mutex) {return ns.higher(e);} }
+        public E pollFirst()  { synchronized (mutex) {return ns.pollFirst();} }
+        public E pollLast()    { synchronized (mutex) {return ns.pollLast();} }
+
+        public NavigableSet<E> descendingSet() {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.descendingSet(), mutex);
+            }
+        }
+
+        public Iterator<E> descendingIterator()
+                 { synchronized (mutex) { return descendingSet().iterator(); } }
+
+        public NavigableSet<E> subSet(E fromElement, E toElement) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.subSet(fromElement, true, toElement, false), mutex);
+            }
+        }
+        public NavigableSet<E> headSet(E toElement) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.headSet(toElement, false), mutex);
+            }
+        }
+        public NavigableSet<E> tailSet(E fromElement) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet(ns.tailSet(fromElement, true), mutex);
+            }
+        }
+
+        public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.subSet(fromElement, fromInclusive, toElement, toInclusive), mutex);
+            }
+        }
+
+        public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.headSet(toElement, inclusive), mutex);
+            }
+        }
+
+        public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet<>(ns.tailSet(fromElement, inclusive));
+            }
+        }
+    }
+
+    /**
      * Returns a synchronized (thread-safe) list backed by the specified
      * list.  In order to guarantee serial access, it is critical that
      * <strong>all</strong> access to the backing list is accomplished
@@ -2235,9 +2566,7 @@
         final Object      mutex;        // Object on which to synchronize
 
         SynchronizedMap(Map<K,V> m) {
-            if (m==null)
-                throw new NullPointerException();
-            this.m = m;
+            this.m = Objects.requireNonNull(m);
             mutex = this;
         }
 
@@ -2416,7 +2745,6 @@
         return new SynchronizedSortedMap<>(m);
     }
 
-
     /**
      * @serial include
      */
@@ -2466,6 +2794,164 @@
         }
     }
 
+    /**
+     * Returns a synchronized (thread-safe) navigable map backed by the
+     * specified navigable map.  In order to guarantee serial access, it is
+     * critical that <strong>all</strong> access to the backing navigable map is
+     * accomplished through the returned navigable map (or its views).<p>
+     *
+     * It is imperative that the user manually synchronize on the returned
+     * navigable map when iterating over any of its collection views, or the
+     * collections views of any of its {@code subMap}, {@code headMap} or
+     * {@code tailMap} views.
+     * <pre>
+     *  NavigableMap m = Collections.synchronizedNavigableMap(new TreeMap());
+     *      ...
+     *  Set s = m.keySet();  // Needn't be in synchronized block
+     *      ...
+     *  synchronized (m) {  // Synchronizing on m, not s!
+     *      Iterator i = s.iterator(); // Must be in synchronized block
+     *      while (i.hasNext())
+     *          foo(i.next());
+     *  }
+     * </pre>
+     * or:
+     * <pre>
+     *  NavigableMap m = Collections.synchronizedNavigableMap(new TreeMap());
+     *  NavigableMap m2 = m.subMap(foo, true, bar, false);
+     *      ...
+     *  Set s2 = m2.keySet();  // Needn't be in synchronized block
+     *      ...
+     *  synchronized (m) {  // Synchronizing on m, not m2 or s2!
+     *      Iterator i = s.iterator(); // Must be in synchronized block
+     *      while (i.hasNext())
+     *          foo(i.next());
+     *  }
+     * </pre>
+     * Failure to follow this advice may result in non-deterministic behavior.
+     *
+     * <p>The returned navigable map will be serializable if the specified
+     * navigable map is serializable.
+     *
+     * @param  m the navigable map to be "wrapped" in a synchronized navigable
+     *              map
+     * @return a synchronized view of the specified navigable map.
+     * @since 1.8
+     */
+    public static <K,V> NavigableMap<K,V> synchronizedNavigableMap(NavigableMap<K,V> m) {
+        return new SynchronizedNavigableMap<>(m);
+    }
+
+    /**
+     * A synchronized NavigableMap.
+     *
+     * @serial include
+     */
+    static class SynchronizedNavigableMap<K,V>
+        extends SynchronizedSortedMap<K,V>
+        implements NavigableMap<K,V>
+    {
+        private static final long serialVersionUID = 699392247599746807L;
+
+        private final NavigableMap<K,V> nm;
+
+        SynchronizedNavigableMap(NavigableMap<K,V> m) {
+            super(m);
+            nm = m;
+        }
+        SynchronizedNavigableMap(NavigableMap<K,V> m, Object mutex) {
+            super(m, mutex);
+            nm = m;
+        }
+
+        public Entry<K, V> lowerEntry(K key)
+                        { synchronized (mutex) { return nm.lowerEntry(key); } }
+        public K lowerKey(K key)
+                          { synchronized (mutex) { return nm.lowerKey(key); } }
+        public Entry<K, V> floorEntry(K key)
+                        { synchronized (mutex) { return nm.floorEntry(key); } }
+        public K floorKey(K key)
+                          { synchronized (mutex) { return nm.floorKey(key); } }
+        public Entry<K, V> ceilingEntry(K key)
+                      { synchronized (mutex) { return nm.ceilingEntry(key); } }
+        public K ceilingKey(K key)
+                        { synchronized (mutex) { return nm.ceilingKey(key); } }
+        public Entry<K, V> higherEntry(K key)
+                       { synchronized (mutex) { return nm.higherEntry(key); } }
+        public K higherKey(K key)
+                         { synchronized (mutex) { return nm.higherKey(key); } }
+        public Entry<K, V> firstEntry()
+                           { synchronized (mutex) { return nm.firstEntry(); } }
+        public Entry<K, V> lastEntry()
+                            { synchronized (mutex) { return nm.lastEntry(); } }
+        public Entry<K, V> pollFirstEntry()
+                       { synchronized (mutex) { return nm.pollFirstEntry(); } }
+        public Entry<K, V> pollLastEntry()
+                        { synchronized (mutex) { return nm.pollLastEntry(); } }
+
+        public NavigableMap<K, V> descendingMap() {
+            synchronized (mutex) {
+                return
+                    new SynchronizedNavigableMap(nm.descendingMap(), mutex);
+            }
+        }
+
+        public NavigableSet<K> keySet() {
+            return navigableKeySet();
+        }
+
+        public NavigableSet<K> navigableKeySet() {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet(nm.navigableKeySet(), mutex);
+            }
+        }
+
+        public NavigableSet<K> descendingKeySet() {
+            synchronized (mutex) {
+                return new SynchronizedNavigableSet(nm.descendingKeySet(), mutex);
+            }
+        }
+
+
+        public SortedMap<K,V> subMap(K fromKey, K toKey) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableMap<>(
+                    nm.subMap(fromKey, true, toKey, false), mutex);
+            }
+        }
+        public SortedMap<K,V> headMap(K toKey) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableMap<>(nm.headMap(toKey, false), mutex);
+            }
+        }
+        public SortedMap<K,V> tailMap(K fromKey) {
+            synchronized (mutex) {
+               return new SynchronizedNavigableMap<>(nm.tailMap(fromKey, true),mutex);
+            }
+        }
+
+        public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableMap(
+                    nm.subMap(fromKey, fromInclusive, toKey, toInclusive), mutex);
+            }
+        }
+
+        public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableMap(
+                        nm.headMap(toKey, inclusive), mutex);
+            }
+        }
+
+        public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+            synchronized (mutex) {
+                return new SynchronizedNavigableMap(
+                    nm.tailMap(fromKey, inclusive), mutex);
+            }
+        }
+    }
+
     // Dynamically typesafe collection wrappers
 
     /**
@@ -2497,12 +2983,12 @@
      * program to wrap the collection with a dynamically typesafe view.
      * For example, this declaration:
      *  <pre> {@code
-     *     Collection<String> c = new HashSet<String>();
+     *     Collection<String> c = new HashSet<>();
      * }</pre>
      * may be replaced temporarily by this one:
      *  <pre> {@code
      *     Collection<String> c = Collections.checkedCollection(
-     *         new HashSet<String>(), String.class);
+     *         new HashSet<>(), String.class);
      * }</pre>
      * Running the program again will cause it to fail at the point where
      * an incorrectly typed element is inserted into the collection, clearly
@@ -2788,6 +3274,7 @@
         implements SortedSet<E>, Serializable
     {
         private static final long serialVersionUID = 1599911165492914959L;
+
         private final SortedSet<E> ss;
 
         CheckedSortedSet(SortedSet<E> s, Class<E> type) {
@@ -2810,6 +3297,87 @@
         }
     }
 
+/**
+     * Returns a dynamically typesafe view of the specified navigable set.
+     * Any attempt to insert an element of the wrong type will result in an
+     * immediate {@link ClassCastException}.  Assuming a navigable set
+     * contains no incorrectly typed elements prior to the time a
+     * dynamically typesafe view is generated, and that all subsequent
+     * access to the navigable set takes place through the view, it is
+     * <em>guaranteed</em> that the navigable set cannot contain an incorrectly
+     * typed element.
+     *
+     * <p>A discussion of the use of dynamically typesafe views may be
+     * found in the documentation for the {@link #checkedCollection
+     * checkedCollection} method.
+     *
+     * <p>The returned navigable set will be serializable if the specified
+     * navigable set is serializable.
+     *
+     * <p>Since {@code null} is considered to be a value of any reference
+     * type, the returned navigable set permits insertion of null elements
+     * whenever the backing sorted set does.
+     *
+     * @param s the navigable set for which a dynamically typesafe view is to be
+     *          returned
+     * @param type the type of element that {@code s} is permitted to hold
+     * @return a dynamically typesafe view of the specified navigable set
+     * @since 1.8
+     */
+    public static <E> NavigableSet<E> checkedNavigableSet(NavigableSet<E> s,
+                                                    Class<E> type) {
+        return new CheckedNavigableSet<>(s, type);
+    }
+
+    /**
+     * @serial include
+     */
+    static class CheckedNavigableSet<E> extends CheckedSortedSet<E>
+        implements NavigableSet<E>, Serializable
+    {
+        private static final long serialVersionUID = -5429120189805438922L;
+
+        private final NavigableSet<E> ns;
+
+        CheckedNavigableSet(NavigableSet<E> s, Class<E> type) {
+            super(s, type);
+            ns = s;
+        }
+
+        public E lower(E e)                             { return ns.lower(e); }
+        public E floor(E e)                             { return ns.floor(e); }
+        public E ceiling(E e)                         { return ns.ceiling(e); }
+        public E higher(E e)                           { return ns.higher(e); }
+        public E pollFirst()                         { return ns.pollFirst(); }
+        public E pollLast()                            {return ns.pollLast(); }
+        public NavigableSet<E> descendingSet()
+                      { return checkedNavigableSet(ns.descendingSet(), type); }
+        public Iterator<E> descendingIterator()
+            {return checkedNavigableSet(ns.descendingSet(), type).iterator(); }
+
+        public NavigableSet<E> subSet(E fromElement, E toElement) {
+            return checkedNavigableSet(ns.subSet(fromElement, true, toElement, false), type);
+        }
+        public NavigableSet<E> headSet(E toElement) {
+            return checkedNavigableSet(ns.headSet(toElement, false), type);
+        }
+        public NavigableSet<E> tailSet(E fromElement) {
+            return checkedNavigableSet(ns.tailSet(fromElement, true), type);
+        }
+
+        public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+            return checkedNavigableSet(ns.subSet(fromElement, fromInclusive, toElement, toInclusive), type);
+        }
+
+        public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+            return checkedNavigableSet(ns.headSet(toElement, inclusive), type);
+        }
+
+        public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+            return checkedNavigableSet(ns.tailSet(fromElement, inclusive), type);
+        }
+    }
+
     /**
      * Returns a dynamically typesafe view of the specified list.
      * Any attempt to insert an element of the wrong type will result in
@@ -3022,11 +3590,9 @@
         }
 
         CheckedMap(Map<K, V> m, Class<K> keyType, Class<V> valueType) {
-            if (m == null || keyType == null || valueType == null)
-                throw new NullPointerException();
-            this.m = m;
-            this.keyType = keyType;
-            this.valueType = valueType;
+            this.m = Objects.requireNonNull(m);
+            this.keyType = Objects.requireNonNull(keyType);
+            this.valueType = Objects.requireNonNull(valueType);
         }
 
         public int size()                      { return m.size(); }
@@ -3303,8 +3869,8 @@
                 private final Class<T> valueType;
 
                 CheckedEntry(Map.Entry<K, V> e, Class<T> valueType) {
-                    this.e = e;
-                    this.valueType = valueType;
+                    this.e = Objects.requireNonNull(e);
+                    this.valueType = Objects.requireNonNull(valueType);
                 }
 
                 public K getKey()        { return e.getKey(); }
@@ -3407,6 +3973,177 @@
         }
     }
 
+    /**
+     * Returns a dynamically typesafe view of the specified navigable map.
+     * Any attempt to insert a mapping whose key or value have the wrong
+     * type will result in an immediate {@link ClassCastException}.
+     * Similarly, any attempt to modify the value currently associated with
+     * a key will result in an immediate {@link ClassCastException},
+     * whether the modification is attempted directly through the map
+     * itself, or through a {@link Map.Entry} instance obtained from the
+     * map's {@link Map#entrySet() entry set} view.
+     *
+     * <p>Assuming a map contains no incorrectly typed keys or values
+     * prior to the time a dynamically typesafe view is generated, and
+     * that all subsequent access to the map takes place through the view
+     * (or one of its collection views), it is <em>guaranteed</em> that the
+     * map cannot contain an incorrectly typed key or value.
+     *
+     * <p>A discussion of the use of dynamically typesafe views may be
+     * found in the documentation for the {@link #checkedCollection
+     * checkedCollection} method.
+     *
+     * <p>The returned map will be serializable if the specified map is
+     * serializable.
+     *
+     * <p>Since {@code null} is considered to be a value of any reference
+     * type, the returned map permits insertion of null keys or values
+     * whenever the backing map does.
+     *
+     * @param <K> type of map keys
+     * @param <V> type of map values
+     * @param m the map for which a dynamically typesafe view is to be
+     *          returned
+     * @param keyType the type of key that {@code m} is permitted to hold
+     * @param valueType the type of value that {@code m} is permitted to hold
+     * @return a dynamically typesafe view of the specified map
+     * @since 1.8
+     */
+    public static <K,V> NavigableMap<K,V> checkedNavigableMap(NavigableMap<K, V> m,
+                                                        Class<K> keyType,
+                                                        Class<V> valueType) {
+        return new CheckedNavigableMap<>(m, keyType, valueType);
+    }
+
+    /**
+     * @serial include
+     */
+    static class CheckedNavigableMap<K,V> extends CheckedSortedMap<K,V>
+        implements NavigableMap<K,V>, Serializable
+    {
+        private static final long serialVersionUID = -4852462692372534096L;
+
+        private final NavigableMap<K, V> nm;
+
+        CheckedNavigableMap(NavigableMap<K, V> m,
+                         Class<K> keyType, Class<V> valueType) {
+            super(m, keyType, valueType);
+            nm = m;
+        }
+
+        public Comparator<? super K> comparator()   { return nm.comparator(); }
+        public K firstKey()                           { return nm.firstKey(); }
+        public K lastKey()                             { return nm.lastKey(); }
+
+        public Entry<K, V> lowerEntry(K key) {
+            Entry<K,V> lower = nm.lowerEntry(key);
+            return (null != lower)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(lower, valueType)
+                : null;
+        }
+
+        public K lowerKey(K key)                   { return nm.lowerKey(key); }
+
+        public Entry<K, V> floorEntry(K key) {
+            Entry<K,V> floor = nm.floorEntry(key);
+            return (null != floor)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(floor, valueType)
+                : null;
+        }
+
+        public K floorKey(K key)                   { return nm.floorKey(key); }
+
+        public Entry<K, V> ceilingEntry(K key) {
+            Entry<K,V> ceiling = nm.ceilingEntry(key);
+            return (null != ceiling)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(ceiling, valueType)
+                : null;
+        }
+
+        public K ceilingKey(K key)               { return nm.ceilingKey(key); }
+
+        public Entry<K, V> higherEntry(K key) {
+            Entry<K,V> higher = nm.higherEntry(key);
+            return (null != higher)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(higher, valueType)
+                : null;
+        }
+
+        public K higherKey(K key)                 { return nm.higherKey(key); }
+
+        public Entry<K, V> firstEntry() {
+            Entry<K,V> first = nm.firstEntry();
+            return (null != first)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(first, valueType)
+                : null;
+        }
+
+        public Entry<K, V> lastEntry() {
+            Entry<K,V> last = nm.lastEntry();
+            return (null != last)
+                ? new CheckedMap.CheckedEntrySet.CheckedEntry(last, valueType)
+                : null;
+        }
+
+        public Entry<K, V> pollFirstEntry() {
+            Entry<K,V> entry = nm.pollFirstEntry();
+            return (null == entry)
+                ? null
+                : new CheckedMap.CheckedEntrySet.CheckedEntry(entry, valueType);
+        }
+
+        public Entry<K, V> pollLastEntry() {
+            Entry<K,V> entry = nm.pollLastEntry();
+            return (null == entry)
+                ? null
+                : new CheckedMap.CheckedEntrySet.CheckedEntry(entry, valueType);
+        }
+
+        public NavigableMap<K, V> descendingMap() {
+            return checkedNavigableMap(nm.descendingMap(), keyType, valueType);
+        }
+
+        public NavigableSet<K> keySet() {
+            return navigableKeySet();
+        }
+
+        public NavigableSet<K> navigableKeySet() {
+            return checkedNavigableSet(nm.navigableKeySet(), keyType);
+        }
+
+        public NavigableSet<K> descendingKeySet() {
+            return checkedNavigableSet(nm.descendingKeySet(), keyType);
+        }
+
+        @Override
+        public NavigableMap<K,V> subMap(K fromKey, K toKey) {
+            return checkedNavigableMap(nm.subMap(fromKey, true, toKey, false),
+                                    keyType, valueType);
+        }
+
+        @Override
+        public NavigableMap<K,V> headMap(K toKey) {
+            return checkedNavigableMap(nm.headMap(toKey, false), keyType, valueType);
+        }
+
+        @Override
+        public NavigableMap<K,V> tailMap(K fromKey) {
+            return checkedNavigableMap(nm.tailMap(fromKey, true), keyType, valueType);
+        }
+
+        public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+            return checkedNavigableMap(nm.subMap(fromKey, fromInclusive, toKey, toInclusive), keyType, valueType);
+        }
+
+        public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+            return checkedNavigableMap(nm.headMap(toKey, inclusive), keyType, valueType);
+        }
+
+        public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+            return checkedNavigableMap(nm.tailMap(fromKey, inclusive), keyType, valueType);
+        }
+    }
+
     // Empty collections
 
     /**
@@ -3428,6 +4165,7 @@
      * <p>Implementations of this method are permitted, but not
      * required, to return the same object from multiple invocations.
      *
+     * @param <T> type of elements, if there were any, in the iterator
      * @return an empty iterator
      * @since 1.7
      */
@@ -3478,6 +4216,7 @@
      * <p>Implementations of this method are permitted, but not
      * required, to return the same object from multiple invocations.
      *
+     * @param <T> type of elements, if there were any, in the iterator
      * @return an empty list iterator
      * @since 1.7
      */
@@ -3542,17 +4281,19 @@
     public static final Set EMPTY_SET = new EmptySet<>();
 
     /**
-     * Returns the empty set (immutable).  This set is serializable.
+     * Returns an empty set (immutable).  This set is serializable.
      * Unlike the like-named field, this method is parameterized.
      *
      * <p>This example illustrates the type-safe way to obtain an empty set:
      * <pre>
      *     Set&lt;String&gt; s = Collections.emptySet();
      * </pre>
-     * Implementation note:  Implementations of this method need not
-     * create a separate <tt>Set</tt> object for each call.   Using this
-     * method is likely to have comparable cost to using the like-named
-     * field.  (Unlike this method, the field does not provide type safety.)
+     * @implNote Implementations of this method need not create a separate
+     * {@code Set} object for each call.  Using this method is likely to have
+     * comparable cost to using the like-named field.  (Unlike this method, the
+     * field does not provide type safety.)
+     *
+     * @return the empty set
      *
      * @see #EMPTY_SET
      * @since 1.5
@@ -3607,121 +4348,45 @@
     }
 
     /**
-     * Returns the empty sorted set (immutable).  This set is serializable.
-     *
-     * <p>This example illustrates the type-safe way to obtain an empty sorted
-     * set:
-     * <pre>
-     *     SortedSet&lt;String&gt; s = Collections.emptySortedSet();
-     * </pre>
-     * Implementation note:  Implementations of this method need not
-     * create a separate <tt>SortedSet</tt> object for each call.
-     *
+     * Returns an empty sorted set (immutable).  This set is serializable.
+     *
+     * <p>This example illustrates the type-safe way to obtain an empty
+     * sorted set:
+     * <pre> {@code
+     *     SortedSet<String> s = Collections.emptySortedSet();
+     * }</pre>
+     *
+     * @implNote Implementations of this method need not create a separate
+     * {@code SortedSet} object for each call.
+     *
+     * @param <E> type of elements, if there were any, in the set
+     * @return the empty sorted set
      * @since 1.8
      */
     @SuppressWarnings("unchecked")
-    public static final <E> SortedSet<E> emptySortedSet() {
-        return (SortedSet<E>) new EmptySortedSet<>();
+    public static <E> SortedSet<E> emptySortedSet() {
+        return (SortedSet<E>) UnmodifiableNavigableSet.EMPTY_NAVIGABLE_SET;
     }
 
     /**
-     * @serial include
+     * Returns an empty navigable set (immutable).  This set is serializable.
+     *
+     * <p>This example illustrates the type-safe way to obtain an empty
+     * navigable set:
+     * <pre> {@code
+     *     NavigableSet<String> s = Collections.emptyNavigableSet();
+     * }</pre>
+     *
+     * @implNote Implementations of this method need not
+     * create a separate {@code NavigableSet} object for each call.
+     *
+     * @param <E> type of elements, if there were any, in the set
+     * @return the empty navigable set
+     * @since 1.8
      */
-    private static class EmptySortedSet<E>
-        extends AbstractSet<E>
-        implements SortedSet<E>, Serializable
-    {
-        private static final long serialVersionUID = 6316515401502265487L;
-        public Iterator<E> iterator() { return emptyIterator(); }
-        public int size() {return 0;}
-        public boolean isEmpty() {return true;}
-        public boolean contains(Object obj) {return false;}
-        public boolean containsAll(Collection<?> c) { return c.isEmpty(); }
-        public Object[] toArray() { return new Object[0]; }
-
-        public <E> E[] toArray(E[] a) {
-            if (a.length > 0)
-                a[0] = null;
-            return a;
-        }
-
-        // Preserves singleton property
-        private Object readResolve() {
-            return new EmptySortedSet<>();
-        }
-
-        @Override
-        public Comparator<? super E> comparator() {
-            return null;
-        }
-
-        @Override
-        @SuppressWarnings("unchecked")
-        public SortedSet<E> subSet(Object fromElement, Object toElement) {
-            Objects.requireNonNull(fromElement);
-            Objects.requireNonNull(toElement);
-
-            if (!(fromElement instanceof Comparable) ||
-                    !(toElement instanceof Comparable))
-            {
-                throw new ClassCastException();
-            }
-
-            if ((((Comparable)fromElement).compareTo(toElement) >= 0) ||
-                    (((Comparable)toElement).compareTo(fromElement) < 0))
-            {
-                throw new IllegalArgumentException();
-            }
-
-            return emptySortedSet();
-        }
-
-        @Override
-        public SortedSet<E> headSet(Object toElement) {
-            Objects.requireNonNull(toElement);
-
-            if (!(toElement instanceof Comparable)) {
-                throw new ClassCastException();
-            }
-
-            return emptySortedSet();
-        }
-
-        @Override
-        public SortedSet<E> tailSet(Object fromElement) {
-            Objects.requireNonNull(fromElement);
-
-            if (!(fromElement instanceof Comparable)) {
-                throw new ClassCastException();
-            }
-
-            return emptySortedSet();
-        }
-
-        @Override
-        public E first() {
-            throw new NoSuchElementException();
-        }
-
-        @Override
-        public E last() {
-            throw new NoSuchElementException();
-        }
-
-        // Override default methods in Collection
-        @Override
-        public void forEach(Consumer<? super E> action) {
-            Objects.requireNonNull(action);
-        }
-
-        @Override
-        public boolean removeIf(Predicate<? super E> filter) {
-            Objects.requireNonNull(filter);
-            return false;
-        }
-
-        @Override
-        public Spliterator<E> spliterator() { return Spliterators.emptySpliterator(); }
+    @SuppressWarnings("unchecked")
+    public static <E> NavigableSet<E> emptyNavigableSet() {
+        return (NavigableSet<E>) UnmodifiableNavigableSet.EMPTY_NAVIGABLE_SET;
     }
 
     /**
@@ -3733,7 +4398,7 @@
     public static final List EMPTY_LIST = new EmptyList<>();
 
     /**
-     * Returns the empty list (immutable).  This list is serializable.
+     * Returns an empty list (immutable).  This list is serializable.
      *
      * <p>This example illustrates the type-safe way to obtain an empty list:
      * <pre>
@@ -3744,6 +4409,9 @@
      * method is likely to have comparable cost to using the like-named
      * field.  (Unlike this method, the field does not provide type safety.)
      *
+     * @param <T> type of elements, if there were any, in the list
+     * @return an empty immutable list
+     *
      * @see #EMPTY_LIST
      * @since 1.5
      */
@@ -3830,17 +4498,18 @@
     public static final Map EMPTY_MAP = new EmptyMap<>();
 
     /**
-     * Returns the empty map (immutable).  This map is serializable.
-     *
-     * <p>This example illustrates the type-safe way to obtain an empty set:
+     * Returns an empty map (immutable).  This map is serializable.
+     *
+     * <p>This example illustrates the type-safe way to obtain an empty map:
      * <pre>
      *     Map&lt;String, Date&gt; s = Collections.emptyMap();
      * </pre>
-     * Implementation note:  Implementations of this method need not
-     * create a separate <tt>Map</tt> object for each call.   Using this
-     * method is likely to have comparable cost to using the like-named
-     * field.  (Unlike this method, the field does not provide type safety.)
-     *
+     * @implNote Implementations of this method need not create a separate
+     * {@code Map} object for each call.  Using this method is likely to have
+     * comparable cost to using the like-named field.  (Unlike this method, the
+     * field does not provide type safety.)
+     *
+     * @return an empty map
      * @see #EMPTY_MAP
      * @since 1.5
      */
@@ -3850,6 +4519,44 @@
     }
 
     /**
+     * Returns an empty sorted map (immutable).  This map is serializable.
+     *
+     * <p>This example illustrates the type-safe way to obtain an empty map:
+     * <pre> {@code
+     *     SortedMap<String, Date> s = Collections.emptySortedMap();
+     * }</pre>
+     *
+     * @implNote Implementations of this method need not create a separate
+     * {@code SortedMap} object for each call.
+     *
+     * @return an empty sorted map
+     * @since 1.8
+     */
+    @SuppressWarnings("unchecked")
+    public static final <K,V> SortedMap<K,V> emptySortedMap() {
+        return (SortedMap<K,V>) UnmodifiableNavigableMap.EMPTY_NAVIGABLE_MAP;
+    }
+
+    /**
+     * Returns an empty navigable map (immutable).  This map is serializable.
+     *
+     * <p>This example illustrates the type-safe way to obtain an empty map:
+     * <pre> {@code
+     *     NavigableMap<String, Date> s = Collections.emptyNavigableMap();
+     * }</pre>
+     *
+     * @implNote Implementations of this method need not create a separate
+     * {@code NavigableMap} object for each call.
+     *
+     * @return an empty navigable map
+     * @since 1.8
+     */
+    @SuppressWarnings("unchecked")
+    public static final <K,V> NavigableMap<K,V> emptyNavigableMap() {
+        return (NavigableMap<K,V>) UnmodifiableNavigableMap.EMPTY_NAVIGABLE_MAP;
+    }
+
+    /**
      * @serial include
      */
     private static class EmptyMap<K,V>
@@ -4153,15 +4860,11 @@
             v = value;
         }
 
-        public int size()                          {return 1;}
-
-        public boolean isEmpty()                   {return false;}
-
-        public boolean containsKey(Object key)     {return eq(key, k);}
-
-        public boolean containsValue(Object value) {return eq(value, v);}
-
-        public V get(Object key)                   {return (eq(key, k) ? v : null);}
+        public int size()                                           {return 1;}
+        public boolean isEmpty()                                {return false;}
+        public boolean containsKey(Object key)             {return eq(key, k);}
+        public boolean containsValue(Object value)       {return eq(value, v);}
+        public V get(Object key)              {return (eq(key, k) ? v : null);}
 
         private transient Set<K> keySet = null;
         private transient Set<Map.Entry<K,V>> entrySet = null;
@@ -4508,6 +5211,8 @@
 
     /**
      * Returns true if the specified arguments are equal, or both null.
+     *
+     * NB: Do not replace with Object.equals until JDK-8015417 is resolved.
      */
     static boolean eq(Object o1, Object o2) {
         return o1==null ? o2==null : o1.equals(o2);
--- a/jdk/src/share/classes/java/util/NavigableSet.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/src/share/classes/java/util/NavigableSet.java	Fri Jul 12 11:11:30 2013 -0700
@@ -303,7 +303,7 @@
      * @throws ClassCastException       {@inheritDoc}
      * @throws NullPointerException     {@inheritDoc}
      * @throws IllegalArgumentException {@inheritDoc}
-na     */
+     */
     SortedSet<E> headSet(E toElement);
 
     /**
--- a/jdk/test/java/util/Collection/MOAT.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Collection/MOAT.java	Fri Jul 12 11:11:30 2013 -0700
@@ -71,6 +71,14 @@
         testCollection(new LinkedList<Integer>());
         testCollection(new LinkedList<Integer>().subList(0,0));
         testCollection(new TreeSet<Integer>());
+        testCollection(Collections.checkedList(new ArrayList<Integer>(), Integer.class));
+        testCollection(Collections.synchronizedList(new ArrayList<Integer>()));
+        testCollection(Collections.checkedSet(new HashSet<Integer>(), Integer.class));
+        testCollection(Collections.checkedSortedSet(new TreeSet<Integer>(), Integer.class));
+        testCollection(Collections.checkedNavigableSet(new TreeSet<Integer>(), Integer.class));
+        testCollection(Collections.synchronizedSet(new HashSet<Integer>()));
+        testCollection(Collections.synchronizedSortedSet(new TreeSet<Integer>()));
+        testCollection(Collections.synchronizedNavigableSet(new TreeSet<Integer>()));
 
         testCollection(new CopyOnWriteArrayList<Integer>());
         testCollection(new CopyOnWriteArrayList<Integer>().subList(0,0));
@@ -98,6 +106,12 @@
         testMap(new Hashtable<Integer,Integer>());
         testMap(new ConcurrentHashMap<Integer,Integer>(10, 0.5f));
         testMap(new ConcurrentSkipListMap<Integer,Integer>());
+        testMap(Collections.checkedMap(new HashMap<Integer,Integer>(), Integer.class, Integer.class));
+        testMap(Collections.checkedSortedMap(new TreeMap<Integer,Integer>(), Integer.class, Integer.class));
+        testMap(Collections.checkedNavigableMap(new TreeMap<Integer,Integer>(), Integer.class, Integer.class));
+        testMap(Collections.synchronizedMap(new HashMap<Integer,Integer>()));
+        testMap(Collections.synchronizedSortedMap(new TreeMap<Integer,Integer>()));
+        testMap(Collections.synchronizedNavigableMap(new TreeMap<Integer,Integer>()));
 
         // Empty collections
         final List<Integer> emptyArray = Arrays.asList(new Integer[]{});
@@ -117,19 +131,29 @@
         testCollection(emptySet);
         testEmptySet(emptySet);
         testEmptySet(EMPTY_SET);
+        testEmptySet(Collections.emptySet());
+        testEmptySet(Collections.emptySortedSet());
+        testEmptySet(Collections.emptyNavigableSet());
         testImmutableSet(emptySet);
 
         List<Integer> emptyList = emptyList();
         testCollection(emptyList);
         testEmptyList(emptyList);
         testEmptyList(EMPTY_LIST);
+        testEmptyList(Collections.emptyList());
         testImmutableList(emptyList);
 
         Map<Integer,Integer> emptyMap = emptyMap();
         testMap(emptyMap);
         testEmptyMap(emptyMap);
         testEmptyMap(EMPTY_MAP);
+        testEmptyMap(Collections.emptyMap());
+        testEmptyMap(Collections.emptySortedMap());
+        testEmptyMap(Collections.emptyNavigableMap());
         testImmutableMap(emptyMap);
+        testImmutableMap(Collections.emptyMap());
+        testImmutableMap(Collections.emptySortedMap());
+        testImmutableMap(Collections.emptyNavigableMap());
 
         // Singleton collections
         Set<Integer> singletonSet = singleton(1);
--- a/jdk/test/java/util/Collections/CheckedIdentityMap.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Collections/CheckedIdentityMap.java	Fri Jul 12 11:11:30 2013 -0700
@@ -24,59 +24,42 @@
 /*
  * @test
  * @bug 6585904
+ * @run testng CheckedIdentityMap
  * @summary Checked collections with underlying maps with identity comparisons
  */
 
 import java.util.*;
 import static java.util.Collections.*;
 
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNotEquals;
+
+import org.testng.annotations.Test;
+
 public class CheckedIdentityMap {
-    void test(String[] args) throws Throwable {
+
+    @Test
+    public void testHashCode() {
         Map<Integer, Integer> m1 = checkedMap(
             new IdentityHashMap<Integer, Integer>(),
             Integer.class, Integer.class);
         Map<Integer, Integer> m2 = checkedMap(
             new IdentityHashMap<Integer, Integer>(),
             Integer.class, Integer.class);
+        // NB: these are unique instances. Compare vs. Integer.valueOf(1)
         m1.put(new Integer(1), new Integer(1));
         m2.put(new Integer(1), new Integer(1));
 
         Map.Entry<Integer, Integer> e1 = m1.entrySet().iterator().next();
         Map.Entry<Integer, Integer> e2 = m2.entrySet().iterator().next();
-        check(! e1.equals(e2));
-        check(e1.hashCode() == hashCode(e1));
-        check(e2.hashCode() == hashCode(e2));
+
+        assertNotEquals(e1, e2);
+        assertEquals(e1.hashCode(), hashCode(e1));
+        assertEquals(e2.hashCode(), hashCode(e2));
     }
 
-    int hashCode(Map.Entry<?,?> e) {
+    static int hashCode(Map.Entry<?,?> e) {
         return (System.identityHashCode(e.getKey()) ^
                 System.identityHashCode(e.getValue()));
     }
-
-    //--------------------- Infrastructure ---------------------------
-    volatile int passed = 0, failed = 0;
-    void pass() {passed++;}
-    void fail() {failed++; Thread.dumpStack();}
-    void fail(String msg) {System.err.println(msg); fail();}
-    void unexpected(Throwable t) {failed++; t.printStackTrace();}
-    void check(boolean cond) {if (cond) pass(); else fail();}
-    void equal(Object x, Object y) {
-        if (x == null ? y == null : x.equals(y)) pass();
-        else fail(x + " not equal to " + y);}
-    public static void main(String[] args) throws Throwable {
-        new CheckedIdentityMap().instanceMain(args);}
-    void instanceMain(String[] args) throws Throwable {
-        try {test(args);} catch (Throwable t) {unexpected(t);}
-        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
-        if (failed > 0) throw new AssertionError("Some tests failed");}
-    abstract class F {abstract void f() throws Throwable;}
-    void THROWS(Class<? extends Throwable> k, F... fs) {
-        for (F f : fs)
-            try {f.f(); fail("Expected " + k.getName() + " not thrown");}
-            catch (Throwable t) {
-                if (k.isAssignableFrom(t.getClass())) pass();
-                else unexpected(t);}}
-    Thread checkedThread(final Runnable r) {
-        return new Thread() {public void run() {
-            try {r.run();} catch (Throwable t) {unexpected(t);}}};}
 }
--- a/jdk/test/java/util/Collections/CheckedMapBash.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Collections/CheckedMapBash.java	Fri Jul 12 11:11:30 2013 -0700
@@ -23,76 +23,83 @@
 
 /*
  * @test
- * @bug     4904067 5023830
+ * @bug     4904067 5023830 7129185
  * @summary Unit test for Collections.checkedMap
  * @author  Josh Bloch
+ * @run testng CheckedMapBash
  */
 
 import java.util.*;
+import java.util.function.Supplier;
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertTrue;
 
 public class CheckedMapBash {
-    static Random rnd = new Random();
-    static Object nil = new Integer(0);
-
-    public static void main(String[] args) {
-        int numItr = 100;
-        int mapSize = 100;
-
-        // Linked List test
-        for (int i=0; i<numItr; i++) {
-            Map m = newMap();
-            Object head = nil;
+    static final Random rnd = new Random();
+    static final Object nil = new Integer(0);
+    static final int numItr = 100;
+    static final int mapSize = 100;
 
-            for (int j=0; j<mapSize; j++) {
-                Object newHead;
-                do {
-                    newHead = new Integer(rnd.nextInt());
-                } while (m.containsKey(newHead));
-                m.put(newHead, head);
-                head = newHead;
-            }
-            if (m.size() != mapSize)
-                fail("Size not as expected.");
-
-            {
-                HashMap hm = new HashMap(m);
-                if (! (hm.hashCode() == m.hashCode() &&
-                       hm.entrySet().hashCode() == m.entrySet().hashCode() &&
-                       hm.keySet().hashCode() == m.keySet().hashCode()))
-                    fail("Incorrect hashCode computation.");
+    @Test(dataProvider = "Bash.Supplier<Map<Integer,Integer>>")
+    public static void testCheckedMap(String description, Supplier<Map<Integer,Integer>> supplier) {
+        Map m = supplier.get();
+        Object head = nil;
 
-                if (! (hm.equals(m) &&
-                       hm.entrySet().equals(m.entrySet()) &&
-                       hm.keySet().equals(m.keySet()) &&
-                       m.equals(hm) &&
-                       m.entrySet().equals(hm.entrySet()) &&
-                       m.keySet().equals(hm.keySet())))
-                    fail("Incorrect equals computation.");
-            }
-
-            Map m2 = newMap(); m2.putAll(m);
-            m2.values().removeAll(m.keySet());
-            if (m2.size()!= 1 || !m2.containsValue(nil))
-                fail("Collection views test failed.");
+        for (int j=0; j<mapSize; j++) {
+            Object newHead;
+            do {
+                newHead = new Integer(rnd.nextInt());
+            } while (m.containsKey(newHead));
+            m.put(newHead, head);
+            head = newHead;
+        }
+        if (m.size() != mapSize)
+            fail("Size not as expected.");
 
-            int j=0;
-            while (head != nil) {
-                if (!m.containsKey(head))
-                    fail("Linked list doesn't contain a link.");
-                Object newHead = m.get(head);
-                if (newHead == null)
-                    fail("Could not retrieve a link.");
-                m.remove(head);
-                head = newHead;
-                j++;
-            }
-            if (!m.isEmpty())
-                fail("Map nonempty after removing all links.");
-            if (j != mapSize)
-                fail("Linked list size not as expected.");
+        {
+            HashMap hm = new HashMap(m);
+            if (! (hm.hashCode() == m.hashCode() &&
+                   hm.entrySet().hashCode() == m.entrySet().hashCode() &&
+                   hm.keySet().hashCode() == m.keySet().hashCode()))
+                fail("Incorrect hashCode computation.");
+
+            if (! (hm.equals(m) &&
+                   hm.entrySet().equals(m.entrySet()) &&
+                   hm.keySet().equals(m.keySet()) &&
+                   m.equals(hm) &&
+                   m.entrySet().equals(hm.entrySet()) &&
+                   m.keySet().equals(hm.keySet())))
+                fail("Incorrect equals computation.");
         }
 
-        Map m = newMap();
+        Map m2 = supplier.get(); m2.putAll(m);
+        m2.values().removeAll(m.keySet());
+        if (m2.size()!= 1 || !m2.containsValue(nil))
+            fail("Collection views test failed.");
+
+        int j=0;
+        while (head != nil) {
+            if (!m.containsKey(head))
+                fail("Linked list doesn't contain a link.");
+            Object newHead = m.get(head);
+            if (newHead == null)
+                fail("Could not retrieve a link.");
+            m.remove(head);
+            head = newHead;
+            j++;
+        }
+        if (!m.isEmpty())
+            fail("Map nonempty after removing all links.");
+        if (j != mapSize)
+            fail("Linked list size not as expected.");
+    }
+
+    @Test(dataProvider = "Supplier<Map<Integer,Integer>>")
+    public static void testCheckeMap2(String description, Supplier<Map<Integer,Integer>> supplier) {
+        Map m = supplier.get();
         for (int i=0; i<mapSize; i++)
             if (m.put(new Integer(i), new Integer(2*i)) != null)
                 fail("put returns a non-null value erroenously.");
@@ -101,7 +108,7 @@
                 fail("contains value "+i);
         if (m.put(nil, nil) == null)
             fail("put returns a null value erroenously.");
-        Map m2 = newMap(); m2.putAll(m);
+        Map m2 = supplier.get(); m2.putAll(m);
         if (!m.equals(m2))
             fail("Clone not equal to original. (1)");
         if (!m2.equals(m))
@@ -134,16 +141,36 @@
             fail("Iterator.remove() failed");
     }
 
-    static Map newMap() {
-        Map m = Collections.checkedMap(new HashMap(),
-                                       Integer.class, Integer.class);
 
-        if (!m.isEmpty())
-            fail("New instance non empty.");
-        return m;
+    @DataProvider(name = "Bash.Supplier<Map<Integer,Integer>>", parallel = true)
+    public static Iterator<Object[]> bashNavigableMapProvider() {
+        ArrayList<Object[]> iters = new ArrayList<>(makeCheckedMaps());
+        iters.ensureCapacity(numItr * iters.size());
+        for(int each=1; each < numItr; each++) {
+            iters.addAll( makeCheckedMaps());
+        }
+        return iters.iterator();
+    }
+
+    @DataProvider(name = "Supplier<Map<Integer,Integer>>", parallel = true)
+    public static Iterator<Object[]> navigableMapProvider() {
+        return makeCheckedMaps().iterator();
     }
 
-    static void fail(String s) {
-        throw new RuntimeException(s);
+    public static Collection<Object[]> makeCheckedMaps() {
+        return Arrays.asList(
+            new Object[]{"Collections.checkedMap(HashMap)",
+                (Supplier) () -> {return Collections.checkedMap(new HashMap(), Integer.class, Integer.class);}},
+            new Object[]{"Collections.checkedMap(TreeSet(reverseOrder)",
+                (Supplier) () -> {return Collections.checkedMap(new TreeMap(Collections.reverseOrder()), Integer.class, Integer.class);}},
+            new Object[]{"Collections.checkedMap(TreeSet).descendingSet()",
+                (Supplier) () -> {return Collections.checkedMap(new TreeMap().descendingMap(), Integer.class, Integer.class);}},
+            new Object[]{"Collections.checkedNavigableMap(TreeSet)",
+                (Supplier) () -> {return Collections.checkedNavigableMap(new TreeMap(), Integer.class, Integer.class);}},
+            new Object[]{"Collections.checkedNavigableMap(TreeSet(reverseOrder)",
+                (Supplier) () -> {return Collections.checkedNavigableMap(new TreeMap(Collections.reverseOrder()), Integer.class, Integer.class);}},
+            new Object[]{"Collections.checkedNavigableMap().descendingSet()",
+                (Supplier) () -> {return Collections.checkedNavigableMap(new TreeMap().descendingMap(), Integer.class, Integer.class);}}
+            );
     }
 }
--- a/jdk/test/java/util/Collections/CheckedSetBash.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Collections/CheckedSetBash.java	Fri Jul 12 11:11:30 2013 -0700
@@ -23,82 +23,93 @@
 
 /*
  * @test
- * @bug     4904067
+ * @bug     4904067 7129185
  * @summary Unit test for Collections.checkedSet
  * @author  Josh Bloch
+ * @run testng CheckedSetBash
  */
 
 import java.util.*;
+import java.util.function.Supplier;
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertTrue;
 
 public class CheckedSetBash {
-    static Random rnd = new Random();
+    static final int numItr = 100;
+    static final int setSize = 100;
+    static final Random rnd = new Random();
 
-    public static void main(String[] args) {
-        int numItr = 100;
-        int setSize = 100;
+    @Test(dataProvider = "Supplier<Set<Integer>>")
+    public static void testCheckedSet(String description, Supplier<Set<Integer>> supplier) {
+
+        Set<Integer> s1 = supplier.get();
+        assertTrue(s1.isEmpty());
+
+        AddRandoms(s1, setSize);
 
-        for (int i=0; i<numItr; i++) {
-            Set s1 = newSet();
-            AddRandoms(s1, setSize);
+        Set<Integer> s2 = supplier.get();
+
+        assertTrue(s2.isEmpty());
+
+        AddRandoms(s2, setSize);
 
-            Set s2 = newSet();
-            AddRandoms(s2, setSize);
-
-            Set intersection = clone(s1);
-            intersection.retainAll(s2);
-            Set diff1 = clone(s1); diff1.removeAll(s2);
-            Set diff2 = clone(s2); diff2.removeAll(s1);
-            Set union = clone(s1); union.addAll(s2);
+        Set<Integer> intersection = clone(s1, supplier);
+        intersection.retainAll(s2);
+        Set<Integer> diff1 = clone(s1, supplier); diff1.removeAll(s2);
+        Set<Integer> diff2 = clone(s2, supplier); diff2.removeAll(s1);
+        Set<Integer> union = clone(s1, supplier); union.addAll(s2);
 
-            if (diff1.removeAll(diff2))
-                fail("Set algebra identity 2 failed");
-            if (diff1.removeAll(intersection))
-                fail("Set algebra identity 3 failed");
-            if (diff2.removeAll(diff1))
-                fail("Set algebra identity 4 failed");
-            if (diff2.removeAll(intersection))
-                fail("Set algebra identity 5 failed");
-            if (intersection.removeAll(diff1))
-                fail("Set algebra identity 6 failed");
-            if (intersection.removeAll(diff1))
-                fail("Set algebra identity 7 failed");
+        if (diff1.removeAll(diff2))
+            fail("Set algebra identity 2 failed");
+        if (diff1.removeAll(intersection))
+            fail("Set algebra identity 3 failed");
+        if (diff2.removeAll(diff1))
+            fail("Set algebra identity 4 failed");
+        if (diff2.removeAll(intersection))
+            fail("Set algebra identity 5 failed");
+        if (intersection.removeAll(diff1))
+            fail("Set algebra identity 6 failed");
+        if (intersection.removeAll(diff1))
+            fail("Set algebra identity 7 failed");
 
-            intersection.addAll(diff1); intersection.addAll(diff2);
-            if (!intersection.equals(union))
-                fail("Set algebra identity 1 failed");
+        intersection.addAll(diff1); intersection.addAll(diff2);
+        if (!intersection.equals(union))
+            fail("Set algebra identity 1 failed");
 
-            if (new HashSet(union).hashCode() != union.hashCode())
-                fail("Incorrect hashCode computation.");
+        if (new HashSet(union).hashCode() != union.hashCode())
+            fail("Incorrect hashCode computation.");
 
-            Iterator e = union.iterator();
-            while (e.hasNext())
-                if (!intersection.remove(e.next()))
-                    fail("Couldn't remove element from copy.");
-            if (!intersection.isEmpty())
-                fail("Copy nonempty after deleting all elements.");
+        Iterator e = union.iterator();
+        while (e.hasNext())
+            if (!intersection.remove(e.next()))
+                fail("Couldn't remove element from copy.");
+        if (!intersection.isEmpty())
+            fail("Copy nonempty after deleting all elements.");
 
-            e = union.iterator();
-            while (e.hasNext()) {
-                Object o = e.next();
-                if (!union.contains(o))
-                    fail("Set doesn't contain one of its elements.");
-                e.remove();
-                if (union.contains(o))
-                    fail("Set contains element after deletion.");
-            }
-            if (!union.isEmpty())
-                fail("Set nonempty after deleting all elements.");
+        e = union.iterator();
+        while (e.hasNext()) {
+            Object o = e.next();
+            if (!union.contains(o))
+                fail("Set doesn't contain one of its elements.");
+            e.remove();
+            if (union.contains(o))
+                fail("Set contains element after deletion.");
+        }
+        if (!union.isEmpty())
+            fail("Set nonempty after deleting all elements.");
 
-            s1.clear();
-            if (!s1.isEmpty())
-                fail("Set nonempty after clear.");
-        }
+        s1.clear();
+        if (!s1.isEmpty())
+            fail("Set nonempty after clear.");
     }
 
     // Done inefficiently so as to exercise toArray
-    static Set clone(Set s) {
-        Set clone = newSet();
-        List arrayList = Arrays.asList(s.toArray());
+    static <T> Set<T> clone(Set<T> s, Supplier<Set<T>> supplier) {
+        Set<T> clone = supplier.get();
+        List<T> arrayList = Arrays.asList((T[]) s.toArray());
         clone.addAll(arrayList);
         if (!s.equals(clone))
             fail("Set not equal to copy.");
@@ -109,13 +120,6 @@
         return clone;
     }
 
-    static Set newSet() {
-        Set s = Collections.checkedSet(new HashSet(), Integer.class);
-        if (!s.isEmpty())
-            fail("New instance non empty.");
-        return s;
-    }
-
     static void AddRandoms(Set s, int n) {
         for (int i=0; i<n; i++) {
             int r = rnd.nextInt() % n;
@@ -136,8 +140,30 @@
         }
     }
 
-    static void fail(String s) {
-        throw new RuntimeException(s);
+    @DataProvider(name = "Supplier<Set<Integer>>", parallel = true)
+    public static Iterator<Object[]> navigableSetsProvider() {
+        ArrayList<Object[]> iters = new ArrayList<>(makeCheckedSets());
+        iters.ensureCapacity(numItr * iters.size());
+        for(int each=1; each < numItr; each++) {
+            iters.addAll( makeCheckedSets());
+        }
+        return iters.iterator();
+    }
 
+    public static Collection<Object[]> makeCheckedSets() {
+        return Arrays.asList(
+            new Object[]{"Collections.checkedSet(HashSet)",
+                (Supplier) () -> {return Collections.checkedSet(new HashSet(), Integer.class);}},
+            new Object[]{"Collections.checkedSet(TreeSet(reverseOrder)",
+                (Supplier) () -> {return Collections.checkedSet(new TreeSet(Collections.reverseOrder()), Integer.class);}},
+            new Object[]{"Collections.checkedSet(TreeSet).descendingSet()",
+                (Supplier) () -> {return Collections.checkedSet(new TreeSet().descendingSet(), Integer.class);}},
+            new Object[]{"Collections.checkedNavigableSet(TreeSet)",
+                (Supplier) () -> {return Collections.checkedNavigableSet(new TreeSet(), Integer.class);}},
+            new Object[]{"Collections.checkedNavigableSet(TreeSet(reverseOrder)",
+                (Supplier) () -> {return Collections.checkedNavigableSet(new TreeSet(Collections.reverseOrder()), Integer.class);}},
+            new Object[]{"Collections.checkedNavigableSet().descendingSet()",
+                (Supplier) () -> {return Collections.checkedNavigableSet(new TreeSet().descendingSet(), Integer.class);}}
+            );
     }
 }
--- a/jdk/test/java/util/Collections/EmptyCollectionSerialization.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Collections/EmptyCollectionSerialization.java	Fri Jul 12 11:11:30 2013 -0700
@@ -23,13 +23,20 @@
 
 /*
  * @test
- * @bug     4684279
+ * @bug     4684279 7129185
  * @summary Empty utility collections should be singletons
  * @author  Josh Bloch
+ * @run testng EmptyCollectionSerialization
  */
 
 import java.util.*;
+import java.util.function.Supplier;
 import java.io.*;
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertSame;
 
 public class EmptyCollectionSerialization {
     private static Object patheticDeepCopy(Object o) throws Exception {
@@ -45,16 +52,48 @@
         return ois.readObject();
     }
 
-    private static boolean isSingleton(Object o) throws Exception {
-        return patheticDeepCopy(o) == o;
+    @Test(dataProvider="SerializableSingletons")
+    public static void serializableSingletons(String description, Supplier<Object> o) {
+        try {
+            Object singleton = o.get();
+            assertSame(o.get(), singleton, description + ": broken Supplier not returning singleton");
+            Object copy = patheticDeepCopy(singleton);
+            assertSame( copy, singleton, description + ": " +
+                copy.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(copy)) +
+                " is not the singleton " +
+                singleton.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(singleton)));
+        } catch(Exception all) {
+            fail(description + ": Unexpected Exception", all);
+        }
+    }
+
+    @DataProvider(name = "SerializableSingletons", parallel = true)
+    public static Iterator<Object[]> navigableMapProvider() {
+        return makeSingletons().iterator();
     }
 
-    public static void main(String[] args) throws Exception {
-        if (!isSingleton(Collections.EMPTY_SET))
-            throw new Exception("EMPTY_SET");
-        if (!isSingleton(Collections.EMPTY_LIST))
-            throw new Exception("EMPTY_LIST");
-        if (!isSingleton(Collections.EMPTY_MAP))
-            throw new Exception("EMPTY_MAP");
+    public static Collection<Object[]> makeSingletons() {
+        return Arrays.asList(
+            new Object[]{"Collections.EMPTY_LIST",
+                (Supplier) () -> {return Collections.EMPTY_LIST;}},
+            new Object[]{"Collections.EMPTY_MAP",
+                (Supplier) () -> {return Collections.EMPTY_MAP;}},
+            new Object[]{"Collections.EMPTY_SET",
+                (Supplier) () -> {return Collections.EMPTY_SET;}},
+            new Object[]{"Collections.singletonMap()",
+                (Supplier) () -> {return Collections.emptyList();}},
+            new Object[]{"Collections.emptyMap()",
+                (Supplier) () -> {return Collections.emptyMap();}},
+            new Object[]{"Collections.emptySet()",
+                (Supplier) () -> {return Collections.emptySet();}},
+            new Object[]{"Collections.emptySortedSet()",
+                (Supplier) () -> {return Collections.emptySortedSet();}},
+            new Object[]{"Collections.emptySortedMap()",
+                (Supplier) () -> {return Collections.emptySortedMap();}},
+            new Object[]{"Collections.emptyNavigableSet()",
+                (Supplier) () -> {return Collections.emptyNavigableSet();}},
+            new Object[]{"Collections.emptyNavigableMap()",
+                (Supplier) () -> {return Collections.emptyNavigableMap();}}
+            );
     }
 }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Collections/EmptyNavigableMap.java	Fri Jul 12 11:11:30 2013 -0700
@@ -0,0 +1,373 @@
+/*
+ * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
+ * 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 4533691 7129185
+ * @summary Unit test for Collections.emptyNavigableMap
+ * @run testng EmptyNavigableMap
+ */
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.NavigableMap;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertSame;
+
+public class EmptyNavigableMap {
+
+    public static <T> void assertInstance(T actual, Class<? extends T> expected) {
+        assertInstance(expected.isInstance(actual), null);
+    }
+
+    public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
+        assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
+            + " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
+    }
+
+    public static <T extends Throwable> void assertEmptyNavigableMap(Object obj) {
+        assertInstance(obj, NavigableMap.class);
+        assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0));
+    }
+
+    public static <T extends Throwable> void assertEmptyNavigableMap(Object obj, String message) {
+        assertInstance(obj, NavigableMap.class, message);
+        assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0),
+            ((null != message) ? message : "") + " Not empty. ");
+    }
+
+    public interface Thrower<T extends Throwable> {
+
+        public void run() throws T;
+    }
+
+    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable) {
+        assertThrows(thrower, throwable, null);
+    }
+
+    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable, String message) {
+        Throwable result;
+        try {
+            thrower.run();
+            fail(((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
+            return;
+        } catch (Throwable caught) {
+            result = caught;
+        }
+
+        assertInstance(result, throwable, ((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
+    }
+
+    public static final boolean isDescending(SortedMap<?,?> set) {
+        if (null == set.comparator()) {
+            // natural order
+            return false;
+        }
+
+        if (Collections.reverseOrder() == set.comparator()) {
+            // reverse natural order.
+            return true;
+        }
+
+        if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
+            // it's a Collections.reverseOrder(Comparator).
+            return true;
+        }
+
+        throw new IllegalStateException("can't determine ordering for " + set);
+    }
+
+    /**
+     * Tests that the comparator is {@code null}.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testComparatorIsNull(String description, NavigableMap<?,?> navigableMap) {
+        Comparator comparator = navigableMap.comparator();
+
+        assertTrue(comparator == null || comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
+    }
+
+    /**
+     * Tests that contains requires Comparable
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testContainsRequiresComparable(String description, NavigableMap<?,?> navigableMap) {
+        assertThrows(() -> {
+            navigableMap.containsKey(new Object());
+        },
+            ClassCastException.class,
+            description + ": Compareable should be required");
+    }
+
+    /**
+     * Tests that the contains method returns {@code false}.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testContains(String description, NavigableMap<?,?> navigableMap) {
+        assertFalse(navigableMap.containsKey(new Integer(1)),
+            description + ": Should not contain any elements.");
+        assertFalse(navigableMap.containsValue(new Integer(1)),
+            description + ": Should not contain any elements.");
+    }
+
+    /**
+     * Tests that the containsAll method returns {@code false}.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testContainsAll(String description, NavigableMap<?,?> navigableMap) {
+        TreeMap treeMap = new TreeMap();
+        treeMap.put("1", 1);
+        treeMap.put("2", 2);
+        treeMap.put("3", 3);
+
+        assertFalse(navigableMap.equals(treeMap), "Should not contain any elements.");
+    }
+
+    /**
+     * Tests that the iterator is empty.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testEmptyIterator(String description, NavigableMap<?,?> navigableMap) {
+        assertFalse(navigableMap.keySet().iterator().hasNext(), "The iterator is not empty.");
+        assertFalse(navigableMap.values().iterator().hasNext(), "The iterator is not empty.");
+        assertFalse(navigableMap.entrySet().iterator().hasNext(), "The iterator is not empty.");
+    }
+
+    /**
+     * Tests that the set is empty.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testIsEmpty(String description, NavigableMap<?,?> navigableMap) {
+        assertTrue(navigableMap.isEmpty(), "The set is not empty.");
+    }
+
+    /**
+     * Tests the headMap() method.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testHeadMap(String description, NavigableMap navigableMap) {
+        assertThrows(
+            () -> { NavigableMap ss = navigableMap.headMap(null, false); },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> { NavigableMap ss = navigableMap.headMap(new Object(), true); },
+            ClassCastException.class,
+            description + ": Must throw ClassCastException for non-Comparable element");
+
+        NavigableMap ss = navigableMap.headMap("1", false);
+
+        assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
+    }
+
+    /**
+     * Tests that the size is 0.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testSizeIsZero(String description, NavigableMap<?,?> navigableMap) {
+        assertTrue(0 == navigableMap.size(), "The size of the set is not 0.");
+    }
+
+    /**
+     * Tests the subMap() method.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testSubMap(String description, NavigableMap navigableMap) {
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(null, BigInteger.TEN);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(BigInteger.ZERO, null);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(null, null);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        Object obj1 = new Object();
+        Object obj2 = new Object();
+
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(obj1, BigInteger.TEN);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(BigInteger.ZERO, obj2);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        assertThrows(
+            () -> {
+                SortedMap ss = navigableMap.subMap(obj1, obj2);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        // minimal range
+        navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, false);
+        navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, true);
+        navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, false);
+        navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, true);
+
+        Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
+        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
+
+            assertThrows(
+                () -> {
+                    navigableMap.subMap(last, true, first, false);
+                },
+                IllegalArgumentException.class, description
+                + ": Must throw IllegalArgumentException when fromElement is not less then then toElement.");
+
+        navigableMap.subMap(first, true, last, false);
+    }
+
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testSubMapRanges(String description, NavigableMap navigableMap) {
+        Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
+        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
+
+        NavigableMap subMap = navigableMap.subMap(first, true, last, true);
+
+        // same subset
+        subMap.subMap(first, true, last, true);
+
+        // slightly smaller
+        NavigableMap ns = subMap.subMap(first, false, last, false);
+        // slight exapansion
+        assertThrows(() -> {
+            ns.subMap(first, true, last, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subMap.subMap(first, false, BigInteger.ONE, false);
+    }
+
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testheadMapRanges(String description, NavigableMap navigableMap) {
+        NavigableMap subMap = navigableMap.headMap(BigInteger.ONE, true);
+
+        // same subset
+        subMap.headMap(BigInteger.ONE, true);
+
+        // slightly smaller
+        NavigableMap ns = subMap.headMap(BigInteger.ONE, false);
+
+        // slight exapansion
+        assertThrows(() -> {
+            ns.headMap(BigInteger.ONE, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subMap.headMap(isDescending(subMap) ? BigInteger.TEN : BigInteger.ZERO, true);
+    }
+
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testTailMapRanges(String description, NavigableMap navigableMap) {
+        NavigableMap subMap = navigableMap.tailMap(BigInteger.ONE, true);
+
+        // same subset
+        subMap.tailMap(BigInteger.ONE, true);
+
+        // slightly smaller
+        NavigableMap ns = subMap.tailMap(BigInteger.ONE, false);
+
+        // slight exapansion
+        assertThrows(() -> {
+            ns.tailMap(BigInteger.ONE, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subMap.tailMap(isDescending(subMap) ? BigInteger.ZERO : BigInteger.TEN, false);
+    }
+
+    /**
+     * Tests the tailMap() method.
+     */
+    @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
+    public void testTailMap(String description, NavigableMap navigableMap) {
+        assertThrows(() -> {
+            navigableMap.tailMap(null);
+        },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(() -> {
+            navigableMap.tailMap(new Object());
+        }, ClassCastException.class);
+
+        NavigableMap ss = navigableMap.tailMap("1", true);
+
+        assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
+    }
+
+    @DataProvider(name = "NavigableMap<?,?>", parallel = true)
+    public static Iterator<Object[]> navigableMapsProvider() {
+        return makeNavigableMaps().iterator();
+    }
+
+    public static Collection<Object[]> makeNavigableMaps() {
+        return Arrays.asList(
+            new Object[]{"UnmodifiableNavigableMap(TreeMap)", Collections.unmodifiableNavigableMap(new TreeMap())},
+            new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap())},
+            new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap().descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap().descendingMap())},
+            new Object[]{"emptyNavigableMap()", Collections.emptyNavigableMap()},
+            new Object[]{"emptyNavigableMap().descendingMap()", Collections.emptyNavigableMap().descendingMap()},
+            new Object[]{"emptyNavigableMap().descendingMap().descendingMap()", Collections.emptyNavigableMap().descendingMap().descendingMap()}
+        );
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Collections/EmptyNavigableSet.java	Fri Jul 12 11:11:30 2013 -0700
@@ -0,0 +1,410 @@
+/*
+ * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
+ * 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 4533691 7129185
+ * @summary Unit test for Collections.emptyNavigableSet
+ * @run testng EmptyNavigableSet
+ */
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.NavigableSet;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertSame;
+
+public class EmptyNavigableSet {
+
+    public static <T> void assertInstance(T actual, Class<? extends T> expected) {
+        assertInstance(expected.isInstance(actual), null);
+    }
+
+    public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
+        assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
+            + " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
+    }
+
+    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj) {
+        assertInstance(obj, NavigableSet.class);
+        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0));
+    }
+
+    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj, String message) {
+        assertInstance(obj, NavigableSet.class, message);
+        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0),
+            ((null != message) ? message : "") + " Not empty. ");
+    }
+
+    public interface Thrower<T extends Throwable> {
+
+        public void run() throws T;
+    }
+
+    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable) {
+        assertThrows(thrower, throwable, null);
+    }
+
+    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable, String message) {
+        Throwable result;
+        try {
+            thrower.run();
+            fail(((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
+            return;
+        } catch (Throwable caught) {
+            result = caught;
+        }
+
+        assertInstance(result, throwable, ((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
+    }
+
+    public static final boolean isDescending(SortedSet<?> set) {
+        if (null == set.comparator()) {
+            // natural order
+            return false;
+        }
+
+        if (Collections.reverseOrder() == set.comparator()) {
+            // reverse natural order.
+            return true;
+        }
+
+        if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
+            // it's a Collections.reverseOrder(Comparator).
+            return true;
+        }
+
+        throw new IllegalStateException("can't determine ordering for " + set);
+    }
+
+    /**
+     * Tests that the comparator is {@code null}.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testComparatorIsNull(String description, NavigableSet<?> navigableSet) {
+        Comparator comparator = navigableSet.comparator();
+
+        assertTrue(comparator == null || comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
+    }
+
+    /**
+     * Tests that contains requires Comparable
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testContainsRequiresComparable(String description, NavigableSet<?> navigableSet) {
+        assertThrows(() -> {
+            navigableSet.contains(new Object());
+        },
+            ClassCastException.class,
+            description + ": Compareable should be required");
+    }
+
+    /**
+     * Tests that the contains method returns {@code false}.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testContains(String description, NavigableSet<?> navigableSet) {
+        assertFalse(navigableSet.contains(new Integer(1)),
+            description + ": Should not contain any elements.");
+    }
+
+    /**
+     * Tests that the containsAll method returns {@code false}.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testContainsAll(String description, NavigableSet<?> navigableSet) {
+        TreeSet treeSet = new TreeSet();
+        treeSet.add("1");
+        treeSet.add("2");
+        treeSet.add("3");
+
+        assertFalse(navigableSet.containsAll(treeSet), "Should not contain any elements.");
+    }
+
+    /**
+     * Tests that the iterator is empty.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
+        Iterator emptyIterator = navigableSet.iterator();
+
+        assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
+            "The iterator is not empty.");
+    }
+
+    /**
+     * Tests that the set is empty.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testIsEmpty(String description, NavigableSet<?> navigableSet) {
+        assertTrue(navigableSet.isEmpty(), "The set is not empty.");
+    }
+
+    /**
+     * Tests that the first() method throws NoSuchElementException
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testFirst(String description, NavigableSet<?> navigableSet) {
+        assertThrows(() -> {
+            navigableSet.first();
+        }, NoSuchElementException.class, description);
+    }
+
+    /**
+     * Tests the headSet() method.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testHeadSet(String description, NavigableSet navigableSet) {
+        assertThrows(
+            () -> { NavigableSet ns = navigableSet.headSet(null, false); },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },
+            ClassCastException.class,
+            description + ": Must throw ClassCastException for non-Comparable element");
+
+        NavigableSet ns = navigableSet.headSet("1", false);
+
+        assertEmptyNavigableSet(ns, description + ": Returned value is not empty navigable set.");
+    }
+
+    /**
+     * Tests that the last() method throws NoSuchElementException
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testLast(String description, NavigableSet<?> navigableSet) {
+        assertThrows(() -> {
+            navigableSet.last();
+        }, NoSuchElementException.class, description);
+    }
+
+    /**
+     * Tests that the size is 0.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testSizeIsZero(String description, NavigableSet<?> navigableSet) {
+        assertTrue(0 == navigableSet.size(), "The size of the set is not 0.");
+    }
+
+    /**
+     * Tests the subSet() method.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testSubSet(String description, NavigableSet navigableSet) {
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, null);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(null, null);
+            },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        Object obj1 = new Object();
+        Object obj2 = new Object();
+
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(obj1, BigInteger.TEN);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, obj2);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        assertThrows(
+            () -> {
+                SortedSet ss = navigableSet.subSet(obj1, obj2);
+            },
+            ClassCastException.class, description
+            + ": Must throw ClassCastException for parameter which is not Comparable.");
+
+        // minimal range
+        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, false);
+        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, true);
+        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, false);
+        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, true);
+
+        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
+        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
+
+            assertThrows(
+                () -> {
+                    navigableSet.subSet(last, true, first, false);
+                },
+                IllegalArgumentException.class, description
+                + ": Must throw IllegalArgumentException when fromElement is not less then then toElement.");
+
+        navigableSet.subSet(first, true, last, false);
+    }
+
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testSubSetRanges(String description, NavigableSet navigableSet) {
+        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
+        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
+
+        NavigableSet subSet = navigableSet.subSet(first, true, last, true);
+
+        // same subset
+        subSet.subSet(first, true, last, true);
+
+        // slightly smaller
+        NavigableSet ns = subSet.subSet(first, false, last, false);
+        // slight exapansion
+        assertThrows(() -> {
+            ns.subSet(first, true, last, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subSet.subSet(first, false, BigInteger.ONE, false);
+    }
+
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testheadSetRanges(String description, NavigableSet navigableSet) {
+        NavigableSet subSet = navigableSet.headSet(BigInteger.ONE, true);
+
+        // same subset
+        subSet.headSet(BigInteger.ONE, true);
+
+        // slightly smaller
+        NavigableSet ns = subSet.headSet(BigInteger.ONE, false);
+
+        // slight exapansion
+        assertThrows(() -> {
+            ns.headSet(BigInteger.ONE, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subSet.headSet(isDescending(subSet) ? BigInteger.TEN : BigInteger.ZERO, true);
+    }
+
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testTailSetRanges(String description, NavigableSet navigableSet) {
+        NavigableSet subSet = navigableSet.tailSet(BigInteger.ONE, true);
+
+        // same subset
+        subSet.tailSet(BigInteger.ONE, true);
+
+        // slightly smaller
+        NavigableSet ns = subSet.tailSet(BigInteger.ONE, false);
+
+        // slight exapansion
+        assertThrows(() -> {
+            ns.tailSet(BigInteger.ONE, true);
+        },
+            IllegalArgumentException.class,
+            description + ": Expansion should not be allowed");
+
+        // much smaller
+        subSet.tailSet(isDescending(subSet) ? BigInteger.ZERO : BigInteger.TEN, false);
+    }
+
+    /**
+     * Tests the tailSet() method.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testTailSet(String description, NavigableSet navigableSet) {
+        assertThrows(() -> {
+            navigableSet.tailSet(null);
+        },
+            NullPointerException.class,
+            description + ": Must throw NullPointerException for null element");
+
+        assertThrows(() -> {
+            navigableSet.tailSet(new Object());
+        }, ClassCastException.class);
+
+        NavigableSet ss = navigableSet.tailSet("1", true);
+
+        assertEmptyNavigableSet(ss, description + ": Returned value is not empty navigable set.");
+    }
+
+    /**
+     * Tests that the array has a size of 0.
+     */
+    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
+    public void testToArray(String description, NavigableSet<?> navigableSet) {
+        Object[] emptyNavigableSetArray = navigableSet.toArray();
+
+        assertTrue(emptyNavigableSetArray.length == 0, "Returned non-empty Array.");
+
+        emptyNavigableSetArray = new Object[20];
+
+        Object[] result = navigableSet.toArray(emptyNavigableSetArray);
+
+        assertSame(emptyNavigableSetArray, result);
+
+        assertTrue(result[0] == null);
+    }
+
+    @DataProvider(name = "NavigableSet<?>", parallel = true)
+    public static Iterator<Object[]> navigableSetsProvider() {
+        return makeNavigableSets().iterator();
+    }
+
+    public static Collection<Object[]> makeNavigableSets() {
+        return Arrays.asList(
+            new Object[]{"UnmodifiableNavigableSet(TreeSet)", Collections.unmodifiableNavigableSet(new TreeSet())},
+            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet())},
+            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet().descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet().descendingSet())},
+            new Object[]{"emptyNavigableSet()", Collections.emptyNavigableSet()},
+            new Object[]{"emptyNavigableSet().descendingSet()", Collections.emptyNavigableSet().descendingSet()},
+            new Object[]{"emptyNavigableSet().descendingSet().descendingSet()", Collections.emptyNavigableSet().descendingSet().descendingSet()}
+        );
+    }
+}
--- a/jdk/test/java/util/Collections/EmptySortedSet.java	Mon Jul 08 14:05:59 2013 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,351 +0,0 @@
-/*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
- * 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.
- *
- * 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.
- */
-
-/*
- * @test
- * @bug 4533691
- * @summary Unit test for Collections.emptySortedSet
- */
-
-import java.lang.reflect.Method;
-import java.math.BigInteger;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.Iterator;
-import java.util.NoSuchElementException;
-import java.util.SortedSet;
-import java.util.TreeSet;
-
-public class EmptySortedSet {
-    static int status = 0;
-    private static final String FAILED = " failed. ";
-    private static final String PERIOD = ".";
-    private final String thisClassName = this.getClass().getName();
-
-    public static void main(String[] args) throws Exception {
-        new EmptySortedSet();
-    }
-
-    public EmptySortedSet() throws Exception {
-        run();
-    }
-
-    /**
-     * Returns {@code true} if the {@link Object} passed in is an empty
-     * {@link SortedSet}.
-     *
-     * @param obj the object to test
-     * @return {@code true} if the {@link Object} is an empty {@link SortedSet}
-     *         otherwise {@code false}.
-     */
-    private boolean isEmptySortedSet(Object obj) {
-        boolean isEmptySortedSet = false;
-
-        // We determine if the object is an empty sorted set by testing if it's
-        // an instance of SortedSet, and if so, if it's empty.  Currently the
-        // testing doesn't include checks of the other methods.
-        if (obj instanceof SortedSet) {
-            SortedSet ss = (SortedSet) obj;
-
-            if ((ss.isEmpty()) && (ss.size() == 0)) {
-                isEmptySortedSet = true;
-            }
-        }
-
-        return isEmptySortedSet;
-    }
-
-    private void run() throws Exception {
-        Method[] methods = this.getClass().getDeclaredMethods();
-
-        for (int i = 0; i < methods.length; i++) {
-            Method method = methods[i];
-            String methodName = method.getName();
-
-            if (methodName.startsWith("test")) {
-                try {
-                    Object obj = method.invoke(this, new Object[0]);
-                } catch(Exception e) {
-                    throw new Exception(this.getClass().getName() + "." +
-                            methodName + " test failed, test exception "
-                            + "follows\n" + e.getCause());
-                }
-            }
-        }
-    }
-
-    private void throwException(String methodName, String reason)
-            throws Exception
-    {
-        StringBuilder sb = new StringBuilder(thisClassName);
-        sb.append(PERIOD);
-        sb.append(methodName);
-        sb.append(FAILED);
-        sb.append(reason);
-        throw new Exception(sb.toString());
-    }
-
-    /**
-     *
-     */
-    private void test00() throws Exception {
-        //throwException("test00", "This test has not been implemented yet.");
-    }
-
-    /**
-     * Tests that the comparator is {@code null}.
-     */
-    private void testComparatorIsNull() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        Comparator comparator = sortedSet.comparator();
-
-        if (comparator != null) {
-            throwException("testComparatorIsNull", "Comparator is not null.");
-        }
-    }
-
-    /**
-     * Tests that the contains method returns {@code false}.
-     */
-    private void testContains() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-
-        if (sortedSet.contains(new Object())) {
-            throwException("testContains", "Should not contain any elements.");
-        }
-    }
-
-    /**
-     * Tests that the containsAll method returns {@code false}.
-     */
-    private void testContainsAll() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        TreeSet treeSet = new TreeSet();
-        treeSet.add("1");
-        treeSet.add("2");
-        treeSet.add("3");
-
-        if (sortedSet.containsAll(treeSet)) {
-            throwException("testContainsAll",
-                    "Should not contain any elements.");
-        }
-    }
-
-    /**
-     * Tests that the iterator is empty.
-     */
-    private void testEmptyIterator() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        Iterator emptyIterator = sortedSet.iterator();
-
-        if ((emptyIterator != null) && (emptyIterator.hasNext())) {
-            throwException("testEmptyIterator", "The iterator is not empty.");
-        }
-    }
-
-    /**
-     * Tests that the set is empty.
-     */
-    private void testIsEmpty() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-
-        if ((sortedSet != null) && (!sortedSet.isEmpty())) {
-            throwException("testSizeIsZero", "The set is not empty.");
-        }
-    }
-
-    /**
-     * Tests that the first() method throws NoSuchElementException
-     */
-    private void testFirst() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-
-        try {
-            sortedSet.first();
-            throwException("testFirst",
-                    "NoSuchElemenException was not thrown.");
-        } catch(NoSuchElementException nsee) {
-            // Do nothing
-        }
-    }
-
-    /**
-     * Tests the headSet() method.
-     */
-    private void testHeadSet() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        SortedSet ss;
-
-        try {
-            ss = sortedSet.headSet(null);
-            throwException("testHeadSet",
-                    "Must throw NullPointerException for null element");
-        } catch(NullPointerException npe) {
-            // Do nothing
-        }
-
-        try {
-            ss = sortedSet.headSet(new Object());
-            throwException("testHeadSet",
-                    "Must throw ClassCastException for non-Comparable element");
-        } catch(ClassCastException cce) {
-            // Do nothing.
-        }
-
-        ss = sortedSet.headSet("1");
-
-        if ((ss == null) || !isEmptySortedSet(ss)) {
-            throwException("testHeadSet",
-                    "Returned value is null or not an EmptySortedSet.");
-        }
-    }
-
-    /**
-     * Tests that the last() method throws NoSuchElementException
-     */
-    private void testLast() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-
-        try {
-            sortedSet.last();
-            throwException("testLast",
-                    "NoSuchElemenException was not thrown.");
-        } catch(NoSuchElementException nsee) {
-            // Do nothing
-        }
-    }
-
-    /**
-     * Tests that the size is 0.
-     */
-    private void testSizeIsZero() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        int size = sortedSet.size();
-
-        if (size > 0) {
-            throwException("testSizeIsZero",
-                    "The size of the set is greater then 0.");
-        }
-    }
-
-    /**
-     * Tests the subSet() method.
-     */
-    private void testSubSet() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        SortedSet ss = sortedSet.headSet("1");
-
-        try {
-            ss = sortedSet.subSet(null, BigInteger.TEN);
-            ss = sortedSet.subSet(BigInteger.ZERO, null);
-            ss = sortedSet.subSet(null, null);
-            throwException("testSubSet",
-                    "Must throw NullPointerException for null element");
-        } catch(NullPointerException npe) {
-            // Do nothing
-        }
-
-        try {
-            Object obj1 = new Object();
-            Object obj2 = new Object();
-            ss = sortedSet.subSet(obj1, BigInteger.TEN);
-            ss = sortedSet.subSet(BigInteger.ZERO, obj2);
-            ss = sortedSet.subSet(obj1, obj2);
-            throwException("testSubSet",
-                    "Must throw ClassCastException for parameter which is "
-                    + "not Comparable.");
-        } catch(ClassCastException cce) {
-            // Do nothing.
-        }
-
-        try {
-            ss = sortedSet.subSet(BigInteger.ZERO, BigInteger.ZERO);
-            ss = sortedSet.subSet(BigInteger.TEN, BigInteger.ZERO);
-            throwException("testSubSet",
-                    "Must throw IllegalArgumentException when fromElement is "
-                    + "not less then then toElement.");
-        } catch(IllegalArgumentException iae) {
-            // Do nothing.
-        }
-
-        ss = sortedSet.subSet(BigInteger.ZERO, BigInteger.TEN);
-
-        if (!isEmptySortedSet(ss)) {
-            throw new Exception("Returned value is not empty sorted set.");
-        }
-    }
-
-    /**
-     * Tests the tailSet() method.
-     */
-    private void testTailSet() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        SortedSet ss;
-
-        try {
-            ss = sortedSet.tailSet(null);
-            throwException("testTailSet",
-                    "Must throw NullPointerException for null element");
-        } catch(NullPointerException npe) {
-            // Do nothing
-        }
-
-        try {
-            SortedSet ss2 = sortedSet.tailSet(new Object());
-            throwException("testTailSet",
-                    "Must throw ClassCastException for non-Comparable element");
-        } catch(ClassCastException cce) {
-            // Do nothing.
-        }
-
-        ss = sortedSet.tailSet("1");
-
-        if ((ss == null) || !isEmptySortedSet(ss)) {
-            throwException("testTailSet",
-                    "Returned value is null or not an EmptySortedSet.");
-        }
-    }
-
-    /**
-     * Tests that the array has a size of 0.
-     */
-    private void testToArray() throws Exception {
-        SortedSet sortedSet = Collections.emptySortedSet();
-        Object[] emptySortedSetArray = sortedSet.toArray();
-
-        if ((emptySortedSetArray == null) || (emptySortedSetArray.length > 0)) {
-            throwException("testToArray",
-                    "Returned null array or array with length > 0.");
-        }
-
-        String[] strings = new String[2];
-        strings[0] = "1";
-        strings[1] = "2";
-        emptySortedSetArray = sortedSet.toArray(strings);
-
-        if ((emptySortedSetArray == null) || (emptySortedSetArray[0] != null)) {
-            throwException("testToArray",
-                    "Returned null array or array with length > 0.");
-        }
-    }
-}
--- a/jdk/test/java/util/Map/LockStep.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/Map/LockStep.java	Fri Jul 12 11:11:30 2013 -0700
@@ -100,7 +100,14 @@
                     new Hashtable(16),
                     new TreeMap(),
                     new ConcurrentHashMap(16),
-                    new ConcurrentSkipListMap() });
+                    new ConcurrentSkipListMap(),
+                    Collections.checkedMap(new HashMap(16), Integer.class, Integer.class),
+                    Collections.checkedSortedMap(new TreeMap(), Integer.class, Integer.class),
+                    Collections.checkedNavigableMap(new TreeMap(), Integer.class, Integer.class),
+                    Collections.synchronizedMap(new HashMap(16)),
+                    Collections.synchronizedSortedMap(new TreeMap()),
+                    Collections.synchronizedNavigableMap(new TreeMap())
+                    });
 
             for (int j = 0; j < 10; j++)
                 put(maps, r.nextInt(100), r.nextInt(100));
--- a/jdk/test/java/util/NavigableMap/LockStep.java	Mon Jul 08 14:05:59 2013 +0200
+++ b/jdk/test/java/util/NavigableMap/LockStep.java	Fri Jul 12 11:11:30 2013 -0700
@@ -55,11 +55,19 @@
 
         lockSteps(new TreeMap(),
                   new ConcurrentSkipListMap());
+        lockSteps(new TreeMap(),
+                  Collections.checkedNavigableMap(new TreeMap(), Integer.class, Integer.class));
+        lockSteps(new TreeMap(),
+                  Collections.synchronizedNavigableMap(new TreeMap()));
         lockSteps(new TreeMap(reverseOrder()),
                   new ConcurrentSkipListMap(reverseOrder()));
 
         lockSteps(new TreeSet(),
                   new ConcurrentSkipListSet());
+        lockSteps(new TreeSet(),
+                  Collections.checkedNavigableSet(new TreeSet(), Integer.class));
+        lockSteps(new TreeSet(),
+                  Collections.synchronizedNavigableSet(new TreeSet()));
         lockSteps(new TreeSet(reverseOrder()),
                   new ConcurrentSkipListSet(reverseOrder()));
     }
@@ -181,7 +189,15 @@
         testEmptyCollection(m.values());
     }
 
-    static final Random rnd = new Random();
+    static final Random rnd;
+
+    static {
+        // sufficiently random for this test
+        long seed = System.nanoTime();
+        System.out.println(LockStep.class.getCanonicalName() + ": Trial random seed: " + seed );
+
+        rnd = new Random(seed);
+    }
 
     static void equalNext(final Iterator<?> it, Object expected) {
         if (maybe(2))
@@ -208,8 +224,15 @@
             check(s.descendingSet().descendingSet().comparator() == null);
         equal(s.isEmpty(), s.size() == 0);
         equal2(s, s.descendingSet());
-        if (maybe(4) && s instanceof Serializable)
-            equal2(s, serialClone(s));
+        if (maybe(4) && s instanceof Serializable) {
+            try {
+                equal2(s, serialClone(s));
+            } catch(RuntimeException uhoh) {
+                if(!(uhoh.getCause() instanceof NotSerializableException)) {
+                    throw uhoh;
+                }
+            }
+        }
         Comparator cmp = comparator(s);
         if (s.isEmpty()) {
             THROWS(NoSuchElementException.class,
@@ -276,6 +299,15 @@
         check(! it2.hasNext());
     }
 
+    static void equalSetsLeaf(final Set s1, final Set s2) {
+        equal2(s1,            s2);
+        equal( s1.size(),     s2.size());
+        equal( s1.isEmpty(),  s2.isEmpty());
+        equal( s1.hashCode(), s2.hashCode());
+        equal( s1.toString(), s2.toString());
+        equal( s1.containsAll(s2), s2.containsAll(s1));
+    }
+
     static void equalNavigableSetsLeaf(final NavigableSet s1,
                                        final NavigableSet s2) {
         equal2(s1,            s2);
@@ -448,8 +480,7 @@
     static void equalNavigableMaps(NavigableMap m1,
                                    NavigableMap m2) {
         equalNavigableMapsLeaf(m1, m2);
-        equalNavigableSetsLeaf((NavigableSet) m1.keySet(),
-                               (NavigableSet) m2.keySet());
+        equalSetsLeaf(m1.keySet(), m2.keySet());
         equalNavigableSets(m1.navigableKeySet(),
                            m2.navigableKeySet());
         equalNavigableSets(m1.descendingKeySet(),
@@ -836,5 +867,7 @@
     @SuppressWarnings("unchecked")
     static <T> T serialClone(T obj) {
         try { return (T) readObject(serializedForm(obj)); }
-        catch (Exception e) { throw new RuntimeException(e); }}
+        catch (Error|RuntimeException e) { throw e; }
+        catch (Throwable e) { throw new RuntimeException(e); }
+    }
 }