src/java.base/share/classes/java/util/PriorityQueue.java

rev 54801 : [mq]: 8223593-Refactor-code-for-reallocating-storage

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2019, 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.  Oracle designates this

@@ -26,10 +26,11 @@
 package java.util;
 
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import jdk.internal.access.SharedSecrets;
+import jdk.internal.util.ArraysSupport;
 
 /**
  * An unbounded priority {@linkplain Queue queue} based on a priority heap.
  * The elements of the priority queue are ordered according to their
  * {@linkplain Comparable natural ordering}, or by a {@link Comparator}

@@ -280,42 +281,23 @@
         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) {
         int oldCapacity = queue.length;
         // Double size if small; else grow by 50%
-        int newCapacity = oldCapacity + ((oldCapacity < 64) ?
-                                         (oldCapacity + 2) :
-                                         (oldCapacity >> 1));
-        // overflow-conscious code
-        if (newCapacity - MAX_ARRAY_SIZE > 0)
-            newCapacity = hugeCapacity(minCapacity);
+        int newCapacity = ArraysSupport.newCapacity(oldCapacity,
+                minCapacity - oldCapacity,
+                oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1);
         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.
      *
      * @return {@code true} (as specified by {@link Collection#add})
      * @throws ClassCastException if the specified element cannot be