--- jsr166/src/main/java/util/PriorityQueue.java	2006/05/28 23:36:29	1.65
+++ jsr166/src/main/java/util/PriorityQueue.java	2011/10/25 20:29:12	1.75
@@ -1,8 +1,26 @@
 /*
- * %W% %E%
+ * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
  */
 
 package java.util;
@@ -56,7 +74,6 @@ package java.util;
  * Java Collections Framework</a>.
  *
  * @since 1.5
- * @version %I%, %G%
  * @author Josh Bloch, Doug Lea
  * @param <E> the type of elements held in this collection
  */
@@ -153,17 +170,21 @@ public class PriorityQueue<E> extends Ab
      * @throws NullPointerException if the specified collection or any
      *         of its elements are null
      */
+    @SuppressWarnings("unchecked")
     public PriorityQueue(Collection<? extends E> c) {
-        initFromCollection(c);
-        if (c instanceof SortedSet)
-            comparator = (Comparator<? super E>)
-                ((SortedSet<? extends E>)c).comparator();
-        else if (c instanceof PriorityQueue)
-            comparator = (Comparator<? super E>)
-                ((PriorityQueue<? extends E>)c).comparator();
+        if (c instanceof SortedSet<?>) {
+            SortedSet<? extends E> ss = (SortedSet<? extends E>) c;
+            this.comparator = (Comparator<? super E>) ss.comparator();
+            initElementsFromCollection(ss);
+        }
+        else if (c instanceof PriorityQueue<?>) {
+            PriorityQueue<? extends E> pq = (PriorityQueue<? extends E>) c;
+            this.comparator = (Comparator<? super E>) pq.comparator();
+            initFromPriorityQueue(pq);
+        }
         else {
-            comparator = null;
-            heapify();
+            this.comparator = null;
+            initFromCollection(c);
         }
     }
 
@@ -181,9 +202,10 @@ public class PriorityQueue<E> extends Ab
      * @throws NullPointerException if the specified priority queue or any
      *         of its elements are null
      */
+    @SuppressWarnings("unchecked")
     public PriorityQueue(PriorityQueue<? extends E> c) {
-        comparator = (Comparator<? super E>)c.comparator();
-        initFromCollection(c);
+        this.comparator = (Comparator<? super E>) c.comparator();
+        initFromPriorityQueue(c);
     }
 
     /**
@@ -199,9 +221,33 @@ public class PriorityQueue<E> extends Ab
      * @throws NullPointerException if the specified sorted set or any
      *         of its elements are null
      */
+    @SuppressWarnings("unchecked")
     public PriorityQueue(SortedSet<? extends E> c) {
-        comparator = (Comparator<? super E>)c.comparator();
-        initFromCollection(c);
+        this.comparator = (Comparator<? super E>) c.comparator();
+        initElementsFromCollection(c);
+    }
+
+    private void initFromPriorityQueue(PriorityQueue<? extends E> c) {
+        if (c.getClass() == PriorityQueue.class) {
+            this.queue = c.toArray();
+            this.size = c.size();
+        } else {
+            initFromCollection(c);
+        }
+    }
+
+    private void initElementsFromCollection(Collection<? extends E> c) {
+        Object[] a = c.toArray();
+        // If c.toArray incorrectly doesn't return Object[], copy it.
+        if (a.getClass() != Object[].class)
+            a = Arrays.copyOf(a, a.length, Object[].class);
+        int len = a.length;
+        if (len == 1 || this.comparator != null)
+            for (int i = 0; i < len; i++)
+                if (a[i] == null)
+                    throw new NullPointerException();
+        this.queue = a;
+        this.size = a.length;
     }
 
     /**
@@ -210,34 +256,43 @@ public class PriorityQueue<E> extends Ab
      * @param c the collection
      */
     private void initFromCollection(Collection<? extends E> c) {
-        Object[] a = c.toArray();
-        // If c.toArray incorrectly doesn't return Object[], copy it.
-        if (a.getClass() != Object[].class)
-            a = Arrays.copyOf(a, a.length, Object[].class);
-        queue = a;
-        size = a.length;
+        initElementsFromCollection(c);
+        heapify();
     }
 
     /**
+     * The maximum size of array to allocate.
+     * Some VMs reserve some header words in an array.
+     * Attempts to allocate larger arrays may result in
+     * OutOfMemoryError: Requested array size exceeds VM limit
+     */
+    private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
+
+    /**
      * Increases the capacity of the array.
      *
      * @param minCapacity the desired minimum capacity
      */
     private void grow(int minCapacity) {
-        if (minCapacity < 0) // overflow
-            throw new OutOfMemoryError();
-	int oldCapacity = queue.length;
+        int oldCapacity = queue.length;
         // Double size if small; else grow by 50%
-        int newCapacity = ((oldCapacity < 64)?
-                           ((oldCapacity + 1) * 2):
-                           ((oldCapacity / 2) * 3));
-        if (newCapacity < 0) // overflow
-            newCapacity = Integer.MAX_VALUE;
-        if (newCapacity < minCapacity)
-            newCapacity = minCapacity;
+        int newCapacity = oldCapacity + ((oldCapacity < 64) ?
+                                         (oldCapacity + 2) :
+                                         (oldCapacity >> 1));
+        // overflow-conscious code
+        if (newCapacity - MAX_ARRAY_SIZE > 0)
+            newCapacity = hugeCapacity(minCapacity);
         queue = Arrays.copyOf(queue, newCapacity);
     }
 
+    private static int hugeCapacity(int minCapacity) {
+        if (minCapacity < 0) // overflow
+            throw new OutOfMemoryError();
+        return (minCapacity > MAX_ARRAY_SIZE) ?
+            Integer.MAX_VALUE :
+            MAX_ARRAY_SIZE;
+    }
+
     /**
      * Inserts the specified element into this priority queue.
      *
@@ -276,13 +331,11 @@ public class PriorityQueue<E> extends Ab
     }
 
     public E peek() {
-        if (size == 0)
-            return null;
-        return (E) queue[0];
+        return (size == 0) ? null : (E) queue[0];
     }
 
     private int indexOf(Object o) {
-	if (o != null) {
+        if (o != null) {
             for (int i = 0; i < size; i++)
                 if (o.equals(queue[i]))
                     return i;
@@ -302,13 +355,13 @@ public class PriorityQueue<E> extends Ab
      * @return {@code true} if this queue changed as a result of the call
      */
     public boolean remove(Object o) {
-	int i = indexOf(o);
-	if (i == -1)
-	    return false;
-	else {
-	    removeAt(i);
-	    return true;
-	}
+        int i = indexOf(o);
+        if (i == -1)
+            return false;
+        else {
+            removeAt(i);
+            return true;
+        }
     }
 
     /**
@@ -319,8 +372,8 @@ public class PriorityQueue<E> extends Ab
      * @return {@code true} if removed
      */
     boolean removeEq(Object o) {
-	for (int i = 0; i < size; i++) {
-	    if (o == queue[i]) {
+        for (int i = 0; i < size; i++) {
+            if (o == queue[i]) {
                 removeAt(i);
                 return true;
             }
@@ -337,7 +390,7 @@ public class PriorityQueue<E> extends Ab
      * @return {@code true} if this queue contains the specified element
      */
     public boolean contains(Object o) {
-	return indexOf(o) != -1;
+        return indexOf(o) != -1;
     }
 
     /**
@@ -379,8 +432,7 @@ public class PriorityQueue<E> extends Ab
      * The following code can be used to dump the queue into a newly
      * allocated array of <tt>String</tt>:
      *
-     * <pre>
-     *     String[] y = x.toArray(new String[0]);</pre>
+     *  <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
      *
      * Note that <tt>toArray(new Object[0])</tt> is identical in function to
      * <tt>toArray()</tt>.
@@ -398,7 +450,7 @@ public class PriorityQueue<E> extends Ab
         if (a.length < size)
             // Make a new array of a's runtime type, but my contents:
             return (T[]) Arrays.copyOf(queue, size, a.getClass());
-	System.arraycopy(queue, 0, a, 0, size);
+        System.arraycopy(queue, 0, a, 0, size);
         if (a.length > size)
             a[size] = null;
         return a;
@@ -491,7 +543,7 @@ public class PriorityQueue<E> extends Ab
                 lastRetElt = null;
             } else {
                 throw new IllegalStateException();
-	    }
+            }
             expectedModCount = modCount;
         }
     }
@@ -537,7 +589,7 @@ public class PriorityQueue<E> extends Ab
      * avoid missing traversing elements.
      */
     private E removeAt(int i) {
-        assert i >= 0 && i < size;
+        // assert i >= 0 && i < size;
         modCount++;
         int s = --size;
         if (s == i) // removed last element
@@ -681,7 +733,7 @@ public class PriorityQueue<E> extends Ab
      * @param s the stream
      */
     private void writeObject(java.io.ObjectOutputStream s)
-        throws java.io.IOException{
+        throws java.io.IOException {
         // Write out element count, and any hidden stuff
         s.defaultWriteObject();
 
@@ -707,14 +759,14 @@ public class PriorityQueue<E> extends Ab
         // Read in (and discard) array length
         s.readInt();
 
-	queue = new Object[size];
+        queue = new Object[size];
 
         // Read in all elements.
         for (int i = 0; i < size; i++)
             queue[i] = s.readObject();
 
-	// Elements are guaranteed to be in "proper order", but the
-	// spec has never explained what that might be.
-	heapify();
+        // Elements are guaranteed to be in "proper order", but the
+        // spec has never explained what that might be.
+        heapify();
     }
 }