0N/A/*
2362N/A * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
0N/A * published by the Free Software Foundation.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
2362N/A * or visit www.oracle.com if you need additional information or have any
2362N/A * questions.
0N/A */
0N/A
0N/A/*
0N/A * @test
0N/A * @bug 4687909
0N/A * @summary Check Inet6Address.hashCode returns a reasonable spread of hash
0N/A * codes.
0N/A */
0N/Aimport java.net.InetAddress;
0N/Aimport java.net.UnknownHostException;
0N/Aimport java.util.Random;
0N/A
0N/Apublic class HashSpread {
0N/A
0N/A static Random r = new Random();
0N/A
0N/A /**
0N/A * Generate and return a random IPv6 address.
0N/A */
0N/A static InetAddress randomIPv6Adress() {
0N/A StringBuffer sb = new StringBuffer();
0N/A
0N/A for (int i=0; i<8; i++) {
0N/A
0N/A if (i > 0)
0N/A sb.append(":");
0N/A
0N/A for (int j=0; j<4; j++) {
0N/A int v = r.nextInt(16);
0N/A if (v < 10) {
0N/A sb.append(Integer.toString(v));
0N/A } else {
0N/A char c = (char) ('A' + v - 10);
0N/A sb.append(c);
0N/A }
0N/A }
0N/A }
0N/A
0N/A try {
0N/A return InetAddress.getByName(sb.toString());
0N/A } catch (UnknownHostException x) {
0N/A throw new Error("Internal error in test");
0N/A }
0N/A }
0N/A
0N/A public static void main(String args[]) throws Exception {
0N/A
0N/A int iterations = 10000;
0N/A if (args.length > 0) {
0N/A iterations = Integer.parseInt(args[0]);
0N/A }
0N/A
0N/A int MIN_SHORT = (int)Short.MIN_VALUE;
0N/A int MAX_SHORT = (int)Short.MAX_VALUE;
0N/A
0N/A /*
0N/A * Iterate through 10k hash codes and count the number
0N/A * in the MIN_SHORT-MAX_SHORT range.
0N/A */
0N/A int narrow = 0;
0N/A for (int i=0; i<iterations; i++) {
0N/A int hc = randomIPv6Adress().hashCode();
0N/A if (hc >= MIN_SHORT && hc <= MAX_SHORT) {
0N/A narrow++;
0N/A }
0N/A }
0N/A
0N/A /*
0N/A * If >85% of hash codes in the range then fail.
0N/A */
0N/A double percent = (double)narrow / (double)iterations * 100.0;
0N/A if (percent > 85.0) {
0N/A throw new RuntimeException(percent + " of hash codes were in " +
0N/A MIN_SHORT + " to " + MAX_SHORT + " range.");
0N/A }
0N/A
0N/A }
0N/A
0N/A}