1/*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24import java.io.*;
25import java.lang.reflect.Field;
26
27import org.testng.annotations.BeforeClass;
28import org.testng.annotations.DataProvider;
29import org.testng.annotations.Test;
30
31import static org.testng.Assert.*;
32
33/*
34 * @test
35 * @bug 8077559
36 * @summary Tests Compact String. This one is testing
37 *          if Compact String enable/disable VM Options is indeed working in String class,
38 *          it's verified by testing if the VM option affect coder and
39 *          COMPACT_STRINGS field in String class.
40 * @modules java.base/java.lang:open
41 * @run testng/othervm -XX:+CompactStrings -DCompactStringEnabled=true VMOptionsTest
42 * @run testng/othervm -XX:-CompactStrings -DCompactStringEnabled=false VMOptionsTest
43 */
44
45public class VMOptionsTest {
46    boolean compactStringEnabled;
47    // corresponding "COMPACT_STRINGS" field in String class.
48    Field COMPACT_STRINGS;
49    // corresponding "coder" field in String class.
50    Field coder;
51
52    // corresponding coder type in String class.
53    final byte LATIN1 = 0;
54    final byte UTF16  = 1;
55
56    @BeforeClass
57    public void setUp() throws Exception {
58        compactStringEnabled = Boolean.valueOf(System.getProperty("CompactStringEnabled", null));
59        COMPACT_STRINGS = String.class.getDeclaredField("COMPACT_STRINGS");
60        COMPACT_STRINGS.setAccessible(true);
61        coder = String.class.getDeclaredField("coder");
62        coder.setAccessible(true);
63    }
64
65    @DataProvider
66    public Object[][] provider() {
67        return new Object[][] {
68                new Object[] {"", LATIN1},
69                new Object[] {"abc", LATIN1},
70                new Object[] {"A\uff21", UTF16},
71                new Object[] {"\uff21\uff22", UTF16}
72        };
73    }
74
75    /*
76     * verify the coder field in String objects.
77     */
78    @Test(dataProvider = "provider")
79    public void testCoder(String str, byte expected) throws Exception {
80        byte c = (byte) coder.get(str);
81        expected = compactStringEnabled ? expected : UTF16;
82        assertEquals(c, expected);
83    }
84
85    /*
86     * verify the COMPACT_STRINGS flag in String objects.
87     */
88    @Test(dataProvider = "provider")
89    public void testCompactStringFlag(String str, byte ignore) throws Exception {
90        assertTrue(COMPACT_STRINGS.get(str).equals(compactStringEnabled));
91    }
92}
93