--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/utilities/quickSort.cpp Tue Jun 28 14:23:27 2011 +0200
@@ -0,0 +1,218 @@
+/*
+ * 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "utilities/quickSort.hpp"
+
+#ifndef PRODUCT
+
+// Unit tests
+
+#include "runtime/os.hpp"
+#include <stdlib.h>
+
+static int test_comparator(int a, int b) {
+ if (a == b) {
+ return 0;
+ }
+ if (a < b) {
+ return -1;
+ }
+ return 1;
+}
+
+static int test_even_odd_comparator(int a, int b) {
+ bool a_is_odd = (a % 2) == 1;
+ bool b_is_odd = (b % 2) == 1;
+ if (a_is_odd == b_is_odd) {
+ return 0;
+ }
+ if (a_is_odd) {
+ return -1;
+ }
+ return 1;
+}
+
+static int test_stdlib_comparator(const void* a, const void* b) {
+ int ai = *(int*)a;
+ int bi = *(int*)b;
+ if (ai == bi) {
+ return 0;
+ }
+ if (ai < bi) {
+ return -1;
+ }
+ return 1;
+}
+
+void QuickSort::print_array(const char* prefix, int* array, int length) {
+ tty->print("%s:", prefix);
+ for (int i = 0; i < length; i++) {
+ tty->print(" %d", array[i]);
+ }
+ tty->print_cr("");
+}
+
+bool QuickSort::compare_arrays(int* actual, int* expected, int length) {
+ for (int i = 0; i < length; i++) {
+ if (actual[i] != expected[i]) {
+ print_array("Sorted array ", actual, length);
+ print_array("Expected array", expected, length);
+ return false;
+ }
+ }
+ return true;
+}
+
+template <class C>
+bool QuickSort::sort_and_compare(int* arrayToSort, int* expectedResult, int length, C comparator, bool idempotent) {
+ sort<int, C>(arrayToSort, length, comparator, idempotent);
+ return compare_arrays(arrayToSort, expectedResult, length);
+}
+
+bool QuickSort::test_quick_sort() {
+ tty->print_cr("test_quick_sort\n");
+ {
+ int* test_array = NULL;
+ int* expected_array = NULL;
+ assert(sort_and_compare(test_array, expected_array, 0, test_comparator), "Empty array not handled");
+ }
+ {
+ int test_array[] = {3};
+ int expected_array[] = {3};
+ assert(sort_and_compare(test_array, expected_array, 1, test_comparator), "Single value array not handled");
+ }
+ {
+ int test_array[] = {3,2};
+ int expected_array[] = {2,3};
+ assert(sort_and_compare(test_array, expected_array, 2, test_comparator), "Array with 2 values not correctly sorted");
+ }
+ {
+ int test_array[] = {3,2,1};
+ int expected_array[] = {1,2,3};
+ assert(sort_and_compare(test_array, expected_array, 3, test_comparator), "Array with 3 values not correctly sorted");
+ }
+ {
+ int test_array[] = {4,3,2,1};
+ int expected_array[] = {1,2,3,4};
+ assert(sort_and_compare(test_array, expected_array, 4, test_comparator), "Array with 4 values not correctly sorted");
+ }
+ {
+ int test_array[] = {7,1,5,3,6,9,8,2,4,0};
+ int expected_array[] = {0,1,2,3,4,5,6,7,8,9};
+ assert(sort_and_compare(test_array, expected_array, 10, test_comparator), "Array with 10 values not correctly sorted");
+ }
+ {
+ int test_array[] = {4,4,1,4};
+ int expected_array[] = {1,4,4,4};
+ assert(sort_and_compare(test_array, expected_array, 4, test_comparator), "3 duplicates not sorted correctly");
+ }
+ {
+ int test_array[] = {0,1,2,3,4,5,6,7,8,9};
+ int expected_array[] = {0,1,2,3,4,5,6,7,8,9};
+ assert(sort_and_compare(test_array, expected_array, 10, test_comparator), "Already sorted array not correctly sorted");
+ }
+ {
+ // one of the random arrays that found an issue in the partion method.
+ int test_array[] = {76,46,81,8,64,56,75,11,51,55,11,71,59,27,9,64,69,75,21,25,39,40,44,32,7,8,40,41,24,78,24,74,9,65,28,6,40,31,22,13,27,82};
+ int expected_array[] = {6,7,8,8,9,9,11,11,13,21,22,24,24,25,27,27,28,31,32,39,40,40,40,41,44,46,51,55,56,59,64,64,65,69,71,74,75,75,76,78,81,82};
+ assert(sort_and_compare(test_array, expected_array, 42, test_comparator), "Not correctly sorted");
+ }
+ {
+ int test_array[] = {2,8,1,4};
+ int expected_array[] = {1,4,2,8};
+ assert(sort_and_compare(test_array, expected_array, 4, test_even_odd_comparator), "Even/odd not sorted correctly");
+ }
+ { // Some idempotent tests
+ {
+ // An array of lenght 3 is only sorted by find_pivot. Make sure that it is idempotent.
+ int test_array[] = {1,4,8};
+ int expected_array[] = {1,4,8};
+ assert(sort_and_compare(test_array, expected_array, 3, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {1,7,9,4,8,2};
+ int expected_array[] = {1,7,9,4,8,2};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {1,9,7,4,2,8};
+ int expected_array[] = {1,9,7,4,2,8};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {7,9,1,2,8,4};
+ int expected_array[] = {7,9,1,2,8,4};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {7,1,9,2,4,8};
+ int expected_array[] = {7,1,9,2,4,8};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {9,1,7,4,8,2};
+ int expected_array[] = {9,1,7,4,8,2};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ {
+ int test_array[] = {9,7,1,4,2,8};
+ int expected_array[] = {9,7,1,4,2,8};
+ assert(sort_and_compare(test_array, expected_array, 6, test_even_odd_comparator, true), "Even/odd not idempotent");
+ }
+ }
+
+ // test sorting random arrays
+ for (int i = 0; i < 1000; i++) {
+ int length = os::random() % 100;
+ int* test_array = new int[length];
+ int* expected_array = new int[length];
+ for (int j = 0; j < length; j++) {
+ // Choose random values, but get a chance of getting duplicates
+ test_array[j] = os::random() % (length * 2);
+ expected_array[j] = test_array[j];
+ }
+
+ // Compare sorting to stdlib::qsort()
+ qsort(expected_array, length, sizeof(int), test_stdlib_comparator);
+ assert(sort_and_compare(test_array, expected_array, length, test_comparator), "Random array not correctly sorted");
+
+ // Make sure sorting is idempotent.
+ // Both test_array and expected_array are sorted by the test_comparator.
+ // Now sort them once with the test_even_odd_comparator. Then sort the
+ // test_array one more time with test_even_odd_comparator and verify that
+ // it is idempotent.
+ sort(expected_array, length, test_even_odd_comparator, true);
+ sort(test_array, length, test_even_odd_comparator, true);
+ assert(compare_arrays(test_array, expected_array, length), "Sorting identical arrays rendered different results");
+ sort(test_array, length, test_even_odd_comparator, true);
+ assert(compare_arrays(test_array, expected_array, length), "Sorting already sorted array changed order of elements - not idempotent");
+
+ delete[] test_array;
+ delete[] expected_array;
+ }
+ return true;
+}
+
+#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/utilities/quickSort.hpp Tue Jun 28 14:23:27 2011 +0200
@@ -0,0 +1,138 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_QUICKSORT_HPP
+#define SHARE_VM_UTILITIES_QUICKSORT_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/globals.hpp"
+#include "utilities/debug.hpp"
+
+class QuickSort : AllStatic {
+
+ private:
+ template<class T>
+ static void swap(T* array, int x, int y) {
+ T tmp = array[x];
+ array[x] = array[y];
+ array[y] = tmp;
+ }
+
+ // As pivot we use the median of the first, last and middle elements.
+ // We swap in these three values at the right place in the array. This
+ // means that this method not only returns the index of the pivot
+ // element. It also alters the array so that:
+ // array[first] <= array[middle] <= array[last]
+ // A side effect of this is that arrays of length <= 3 are sorted.
+ template<class T, class C>
+ static int find_pivot(T* array, int length, C comparator) {
+ assert(length > 1, "length of array must be > 0");
+
+ int middle_index = length / 2;
+ int last_index = length - 1;
+
+ if (comparator(array[0], array[middle_index]) == 1) {
+ swap(array, 0, middle_index);
+ }
+ if (comparator(array[0], array[last_index]) == 1) {
+ swap(array, 0, last_index);
+ }
+ if (comparator(array[middle_index], array[last_index]) == 1) {
+ swap(array, middle_index, last_index);
+ }
+ // Now the value in the middle of the array is the median
+ // of the fist, last and middle values. Use this as pivot.
+ return middle_index;
+ }
+
+ template<class T, class C, bool idempotent>
+ static int partition(T* array, int pivot, int length, C comparator) {
+ int left_index = -1;
+ int right_index = length;
+ T pivot_val = array[pivot];
+
+ while (true) {
+ do {
+ left_index++;
+ } while (comparator(array[left_index], pivot_val) == -1);
+ do {
+ right_index--;
+ } while (comparator(array[right_index], pivot_val) == 1);
+
+ if (left_index < right_index) {
+ if (!idempotent || comparator(array[left_index], array[right_index]) != 0) {
+ swap(array, left_index, right_index);
+ }
+ } else {
+ return right_index;
+ }
+ }
+
+ ShouldNotReachHere();
+ return 0;
+ }
+
+ template<class T, class C, bool idempotent>
+ static void inner_sort(T* array, int length, C comparator) {
+ if (length < 2) {
+ return;
+ }
+ int pivot = find_pivot(array, length, comparator);
+ if (length < 4) {
+ // arrays up to length 3 will be sorted after finding the pivot
+ return;
+ }
+ int split = partition<T, C, idempotent>(array, pivot, length, comparator);
+ int first_part_length = split + 1;
+ inner_sort<T, C, idempotent>(array, first_part_length, comparator);
+ inner_sort<T, C, idempotent>(&array[first_part_length], length - first_part_length, comparator);
+ }
+
+ public:
+ // The idempotent parameter prevents the sort from
+ // reordering a previous valid sort by not swapping
+ // fields that compare as equal. This requires extra
+ // calls to the comparator, so the performance
+ // impact depends on the comparator.
+ template<class T, class C>
+ static void sort(T* array, int length, C comparator, bool idempotent) {
+ // Switch "idempotent" from function paramter to template parameter
+ if (idempotent) {
+ inner_sort<T, C, true>(array, length, comparator);
+ } else {
+ inner_sort<T, C, false>(array, length, comparator);
+ }
+ }
+
+ // for unit testing
+#ifndef PRODUCT
+ static void print_array(const char* prefix, int* array, int length);
+ static bool compare_arrays(int* actual, int* expected, int length);
+ template <class C> static bool sort_and_compare(int* arrayToSort, int* expectedResult, int length, C comparator, bool idempotent = false);
+ static bool test_quick_sort();
+#endif
+};
+
+
+#endif //SHARE_VM_UTILITIES_QUICKSORT_HPP