--- jsr166/src/main/java/util/PriorityQueue.java	2003/08/06 18:42:49	1.25
+++ jsr166/src/main/java/util/PriorityQueue.java	2003/08/25 19:27:54	1.31
@@ -28,6 +28,18 @@
  * elements are added to a priority queue, its capacity grows
  * automatically.  The details of the growth policy are not specified.
  *
+ * <p>The Iterator provided in method {@link #iterator()} is <em>not</em>
+ * guaranteed to traverse the elements of the PriorityQueue in any
+ * particular order. If you need ordered traversal, consider using
+ * <tt>Arrays.sort(pq.toArray())</tt>.
+ *
+ * <p> <strong>Note that this implementation is not synchronized.</strong>
+ * Multiple threads should not access a <tt>PriorityQueue</tt>
+ * instance concurrently if any of the threads modifies the list
+ * structurally. Instead, use the thread-safe {@link
+ * java.util.concurrent.BlockingPriorityQueue} class.
+ *
+ * 
  * <p>Implementation note: this implementation provides O(log(n)) time
  * for the insertion methods (<tt>offer</tt>, <tt>poll</tt>,
  * <tt>remove()</tt> and <tt>add</tt>) methods; linear time for the
@@ -44,6 +56,8 @@
 public class PriorityQueue<E> extends AbstractQueue<E>
     implements Queue<E>, java.io.Serializable {
 
+    private static final long serialVersionUID = -7720805057305804111L;
+
     private static final int DEFAULT_INITIAL_CAPACITY = 11;
 
     /**
@@ -176,17 +190,16 @@ public class PriorityQueue<E> extends Ab
      */
     public PriorityQueue(Collection<? extends E> c) {
         initializeArray(c);
-        if (c instanceof SortedSet<? extends E>) {
-            SortedSet<? extends E> s = (SortedSet<? extends E>) c;
+        if (c instanceof SortedSet) {
+            // @fixme double-cast workaround for compiler
+            SortedSet<? extends E> s = (SortedSet<? extends E>) (SortedSet)c;
             comparator = (Comparator<? super E>)s.comparator();
             fillFromSorted(s);
-        }
-        else if (c instanceof PriorityQueue<? extends E>) {
+        } else if (c instanceof PriorityQueue) {
             PriorityQueue<? extends E> s = (PriorityQueue<? extends E>) c;
             comparator = (Comparator<? super E>)s.comparator();
             fillFromSorted(s);
-        }
-        else {
+        } else {
             comparator = null;
             fillFromUnsorted(c);
         }