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

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@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 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

@@ -72,94 +72,44 @@
  * @author John Rose
  * @since  1.2
  */
 public class Arrays {
 
-    /**
-     * The minimum array length below which a parallel sorting
-     * algorithm will not further partition the sorting task. Using
-     * smaller sizes typically results in memory contention across
-     * tasks that makes parallel speedups unlikely.
-     */
-    private static final int MIN_ARRAY_SORT_GRAN = 1 << 13;
-
     // Suppresses default constructor, ensuring non-instantiability.
     private Arrays() {}
 
-    /**
-     * A comparator that implements the natural ordering of a group of
-     * mutually comparable elements. May be used when a supplied
-     * comparator is null. To simplify code-sharing within underlying
-     * implementations, the compare method only declares type Object
-     * for its second argument.
-     *
-     * Arrays class implementor's note: It is an empirical matter
-     * whether ComparableTimSort offers any performance benefit over
-     * TimSort used with this comparator.  If not, you are better off
-     * deleting or bypassing ComparableTimSort.  There is currently no
-     * empirical case for separating them for parallel sorting, so all
-     * public Object parallelSort methods use the same comparator
-     * based implementation.
-     */
-    static final class NaturalOrder implements Comparator<Object> {
-        @SuppressWarnings("unchecked")
-        public int compare(Object first, Object second) {
-            return ((Comparable<Object>)first).compareTo(second);
-        }
-        static final NaturalOrder INSTANCE = new NaturalOrder();
-    }
-
-    /**
-     * Checks that {@code fromIndex} and {@code toIndex} are in
-     * the range and throws an exception if they aren't.
-     */
-    static void rangeCheck(int arrayLength, int fromIndex, int toIndex) {
-        if (fromIndex > toIndex) {
-            throw new IllegalArgumentException(
-                    "fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
-        }
-        if (fromIndex < 0) {
-            throw new ArrayIndexOutOfBoundsException(fromIndex);
-        }
-        if (toIndex > arrayLength) {
-            throw new ArrayIndexOutOfBoundsException(toIndex);
-        }
-    }
-
     /*
      * Sorting methods. Note that all public "sort" methods take the
-     * same form: Performing argument checks if necessary, and then
+     * same form: performing argument checks if necessary, and then
      * expanding arguments into those required for the internal
      * implementation methods residing in other package-private
      * classes (except for legacyMergeSort, included in this class).
      */
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(int[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to
      * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
      * the range to be sorted is empty.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -168,38 +118,36 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(int[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(long[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to
      * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
      * the range to be sorted is empty.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -208,38 +156,36 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(long[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(short[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
-    }
+        DualPivotQuicksort.sort(a, 0, a.length);
+    }   
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to
      * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
      * the range to be sorted is empty.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -248,38 +194,36 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(short[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-    }
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
+    }    
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(char[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to
      * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
      * the range to be sorted is empty.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -288,38 +232,36 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(char[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
     }
-
+    
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(byte[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1);
+        DualPivotQuicksort.sort(a, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to
      * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
      * the range to be sorted is empty.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -328,11 +270,11 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(byte[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1);
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *

@@ -342,20 +284,19 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
      * {@code 0.0f} and {@code Float.NaN} is considered greater than any
      * other value and all {@code Float.NaN} values are considered equal.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(float[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to

@@ -368,14 +309,13 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
      * {@code 0.0f} and {@code Float.NaN} is considered greater than any
      * other value and all {@code Float.NaN} values are considered equal.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -384,11 +324,11 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(float[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *

@@ -398,20 +338,19 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
      * {@code 0.0d} and {@code Double.NaN} is considered greater than any
      * other value and all {@code Double.NaN} values are considered equal.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      */
     public static void sort(double[] a) {
-        DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending order. The range
      * to be sorted extends from the index {@code fromIndex}, inclusive, to

@@ -424,14 +363,13 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
      * {@code 0.0d} and {@code Double.NaN} is considered greater than any
      * other value and all {@code Double.NaN} values are considered equal.
      *
-     * <p>Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort
      * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
-     * offers O(n log(n)) performance on many data sets that cause other
-     * quicksorts to degrade to quadratic performance, and is typically
+     * offers O(n log(n)) performance on all data sets, and is typically
      * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted

@@ -440,59 +378,39 @@
      * @throws ArrayIndexOutOfBoundsException
      *     if {@code fromIndex < 0} or {@code toIndex > a.length}
      */
     public static void sort(double[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+        DualPivotQuicksort.sort(a, 0, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(byte[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(byte[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(byte[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1);
-        else
-            new ArraysParallelSortHelpers.FJByte.Sorter
-                (null, a, new byte[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},
      * inclusive, to the index {@code toIndex}, exclusive. If
      * {@code fromIndex == toIndex}, the range to be sorted is empty.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(byte[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(byte[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -502,67 +420,39 @@
      *
      * @since 1.8
      */
     public static void parallelSort(byte[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1);
-        else
-            new ArraysParallelSortHelpers.FJByte.Sorter
-                (null, a, new byte[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(char[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(char[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(char[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJChar.Sorter
-                (null, a, new char[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},
      * inclusive, to the index {@code toIndex}, exclusive. If
      * {@code fromIndex == toIndex}, the range to be sorted is empty.
      *
-      @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(char[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(char[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -572,67 +462,39 @@
      *
      * @since 1.8
      */
     public static void parallelSort(char[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJChar.Sorter
-                (null, a, new char[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(short[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(short[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(short[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJShort.Sorter
-                (null, a, new short[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},
      * inclusive, to the index {@code toIndex}, exclusive. If
      * {@code fromIndex == toIndex}, the range to be sorted is empty.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(short[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(short[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -642,67 +504,39 @@
      *
      * @since 1.8
      */
     public static void parallelSort(short[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJShort.Sorter
-                (null, a, new short[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, fromIndex, toIndex);
     }
-
+    
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(int[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(int[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(int[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJInt.Sorter
-                (null, a, new int[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},
      * inclusive, to the index {@code toIndex}, exclusive. If
      * {@code fromIndex == toIndex}, the range to be sorted is empty.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(int[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(int[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -712,67 +546,39 @@
      *
      * @since 1.8
      */
     public static void parallelSort(int[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJInt.Sorter
-                (null, a, new int[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(long[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(long[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(long[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJLong.Sorter
-                (null, a, new long[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},
      * inclusive, to the index {@code toIndex}, exclusive. If
      * {@code fromIndex == toIndex}, the range to be sorted is empty.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(long[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(long[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -782,19 +588,11 @@
      *
      * @since 1.8
      */
     public static void parallelSort(long[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJLong.Sorter
-                (null, a, new long[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *

@@ -804,35 +602,21 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
      * {@code 0.0f} and {@code Float.NaN} is considered greater than any
      * other value and all {@code Float.NaN} values are considered equal.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(float[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(float[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(float[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJFloat.Sorter
-                (null, a, new float[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},

@@ -845,20 +629,14 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
      * {@code 0.0f} and {@code Float.NaN} is considered greater than any
      * other value and all {@code Float.NaN} values are considered equal.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(float[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(float[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -868,19 +646,11 @@
      *
      * @since 1.8
      */
     public static void parallelSort(float[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJFloat.Sorter
-                (null, a, new float[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), fromIndex, toIndex);
     }
 
     /**
      * Sorts the specified array into ascending numerical order.
      *

@@ -890,35 +660,21 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
      * {@code 0.0d} and {@code Double.NaN} is considered greater than any
      * other value and all {@code Double.NaN} values are considered equal.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(double[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(double[]) Arrays.sort} method. The algorithm requires a
-     * working space no greater than the size of the original array. The
-     * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
-     * execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      *
      * @since 1.8
      */
     public static void parallelSort(double[] a) {
-        int n = a.length, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJDouble.Sorter
-                (null, a, new double[n], 0, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), 0, a.length);
     }
 
     /**
      * Sorts the specified range of the array into ascending numerical order.
      * The range to be sorted extends from the index {@code fromIndex},

@@ -931,20 +687,14 @@
      * even itself. This method uses the total order imposed by the method
      * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
      * {@code 0.0d} and {@code Double.NaN} is considered greater than any
      * other value and all {@code Double.NaN} values are considered equal.
      *
-     * @implNote The sorting algorithm is a parallel sort-merge that breaks the
-     * array into sub-arrays that are themselves sorted and then merged. When
-     * the sub-array length reaches a minimum granularity, the sub-array is
-     * sorted using the appropriate {@link Arrays#sort(double[]) Arrays.sort}
-     * method. If the length of the specified array is less than the minimum
-     * granularity, then it is sorted using the appropriate {@link
-     * Arrays#sort(double[]) Arrays.sort} method. The algorithm requires a working
-     * space no greater than the size of the specified range of the original
-     * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
-     * used to execute any parallel tasks.
+     * @implNote The sorting algorithm is a Dual-Pivot Quicksort by
+     * Vladimir Yaroslavskiy, Jon Bentley and Josh Bloch. This algorithm
+     * offers O(n log(n)) performance on all data sets, and is typically
+     * faster than traditional (one-pivot) Quicksort implementations.
      *
      * @param a the array to be sorted
      * @param fromIndex the index of the first element, inclusive, to be sorted
      * @param toIndex the index of the last element, exclusive, to be sorted
      *

@@ -954,22 +704,62 @@
      *
      * @since 1.8
      */
     public static void parallelSort(double[] a, int fromIndex, int toIndex) {
         rangeCheck(a.length, fromIndex, toIndex);
-        int n = toIndex - fromIndex, p, g;
-        if (n <= MIN_ARRAY_SORT_GRAN ||
-            (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
-            DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
-        else
-            new ArraysParallelSortHelpers.FJDouble.Sorter
-                (null, a, new double[n], fromIndex, n, 0,
-                 ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
-                 MIN_ARRAY_SORT_GRAN : g).invoke();
+        DualPivotQuicksort.sort(a, ForkJoinPool.getCommonPoolParallelism(), fromIndex, toIndex);
     }
 
     /**
+     * Checks that {@code fromIndex} and {@code toIndex} are in
+     * the range and throws an exception if they aren't.
+     */
+    static void rangeCheck(int arrayLength, int fromIndex, int toIndex) {
+        if (fromIndex > toIndex) {
+            throw new IllegalArgumentException(
+                "fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
+        }
+        if (fromIndex < 0) {
+            throw new ArrayIndexOutOfBoundsException(fromIndex);
+        }
+        if (toIndex > arrayLength) {
+            throw new ArrayIndexOutOfBoundsException(toIndex);
+        }
+    }    
+    
+    /**
+     * A comparator that implements the natural ordering of a group of
+     * mutually comparable elements. May be used when a supplied
+     * comparator is null. To simplify code-sharing within underlying
+     * implementations, the compare method only declares type Object
+     * for its second argument.
+     *
+     * Arrays class implementor's note: It is an empirical matter
+     * whether ComparableTimSort offers any performance benefit over
+     * TimSort used with this comparator.  If not, you are better off
+     * deleting or bypassing ComparableTimSort.  There is currently no
+     * empirical case for separating them for parallel sorting, so all
+     * public Object parallelSort methods use the same comparator
+     * based implementation.
+     */
+    static final class NaturalOrder implements Comparator<Object> {
+        @SuppressWarnings("unchecked")
+        public int compare(Object first, Object second) {
+            return ((Comparable<Object>)first).compareTo(second);
+        }
+        static final NaturalOrder INSTANCE = new NaturalOrder();
+    }    
+
+    /**
+     * The minimum array length below which a parallel sorting
+     * algorithm will not further partition the sorting task. Using
+     * smaller sizes typically results in memory contention across
+     * tasks that makes parallel speedups unlikely.
+     */
+    private static final int MIN_ARRAY_SORT_GRAN = 1 << 13;
+
+    /**
      * Sorts the specified array of objects into ascending order, according
      * to the {@linkplain Comparable natural ordering} of its elements.
      * All elements in the array must implement the {@link Comparable}
      * interface.  Furthermore, all elements in the array must be
      * <i>mutually comparable</i> (that is, {@code e1.compareTo(e2)} must

@@ -3000,11 +2790,11 @@
      * of elements in the two arrays are equal.  In other words, two arrays
      * are equal if they contain the same elements in the same order.  Also,
      * two array references are considered equal if both are {@code null}.
      *
      * Two doubles {@code d1} and {@code d2} are considered equal if:
-     * <pre>    {@code new Double(d1).equals(new Double(d2))}</pre>
+     * <pre>{@code new Double(d1).equals(new Double(d2))}</pre>
      * (Unlike the {@code ==} operator, this method considers
      * {@code NaN} equals to itself, and 0.0d unequal to -0.0d.)
      *
      * @param a one array to be tested for equality
      * @param a2 the other array to be tested for equality

@@ -3033,11 +2823,11 @@
      * specified ranges in the two arrays are equal.  In other words, two arrays
      * are equal if they contain, over the specified ranges, the same elements
      * in the same order.
      *
      * <p>Two doubles {@code d1} and {@code d2} are considered equal if:
-     * <pre>    {@code new Double(d1).equals(new Double(d2))}</pre>
+     * <pre>{@code new Double(d1).equals(new Double(d2))}</pre>
      * (Unlike the {@code ==} operator, this method considers
      * {@code NaN} equals to itself, and 0.0d unequal to -0.0d.)
      *
      * @param a the first array to be tested for equality
      * @param aFromIndex the index (inclusive) of the first element in the

@@ -3083,11 +2873,11 @@
      * of elements in the two arrays are equal.  In other words, two arrays
      * are equal if they contain the same elements in the same order.  Also,
      * two array references are considered equal if both are {@code null}.
      *
      * Two floats {@code f1} and {@code f2} are considered equal if:
-     * <pre>    {@code new Float(f1).equals(new Float(f2))}</pre>
+     * <pre>{@code new Float(f1).equals(new Float(f2))}</pre>
      * (Unlike the {@code ==} operator, this method considers
      * {@code NaN} equals to itself, and 0.0f unequal to -0.0f.)
      *
      * @param a one array to be tested for equality
      * @param a2 the other array to be tested for equality

@@ -3116,11 +2906,11 @@
      * specified ranges in the two arrays are equal.  In other words, two arrays
      * are equal if they contain, over the specified ranges, the same elements
      * in the same order.
      *
      * <p>Two floats {@code f1} and {@code f2} are considered equal if:
-     * <pre>    {@code new Float(f1).equals(new Float(f2))}</pre>
+     * <pre>{@code new Float(f1).equals(new Float(f2))}</pre>
      * (Unlike the {@code ==} operator, this method considers
      * {@code NaN} equals to itself, and 0.0f unequal to -0.0f.)
      *
      * @param a the first array to be tested for equality
      * @param aFromIndex the index (inclusive) of the first element in the

@@ -8919,9 +8709,8 @@
                 if (v != 0) {
                     return i;
                 }
             }
         }
-
         return aLength != bLength ? length : -1;
     }
 }
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