1/*
2 * Copyright (c) 2013, 2017, 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
24// ClassFileInstaller is needed to place test.Empty into well-known place
25/**
26 * @test
27 * @library /test/lib classes
28 * @build test.Empty
29 * @run driver ClassFileInstaller test.Empty
30 * @run main/othervm/timeout=200 FragmentMetaspaceSimple
31 */
32
33import java.io.DataInputStream;
34import java.io.File;
35import java.io.FileInputStream;
36import java.io.IOException;
37import java.util.ArrayList;
38
39/**
40 * Test that tries to fragment the native memory used by class loaders.
41 * Keeps every other class loader alive in order to fragment the memory space
42 * used to store classes and meta data. Since the memory is probably allocated in
43 * chunks per class loader this will cause a lot of fragmentation if not handled
44 * properly since every other chunk will be unused.
45 */
46public class FragmentMetaspaceSimple {
47    public static void main(String... args) {
48        runSimple(Long.valueOf(System.getProperty("time", "80000")));
49        System.gc();
50    }
51
52    private static void runSimple(long time) {
53        long startTime = System.currentTimeMillis();
54        ArrayList<ClassLoader> cls = new ArrayList<>();
55        char sep = File.separatorChar;
56        String fileName = "test" + sep + "Empty.class";
57        File file = new File(fileName);
58        byte buff[] = read(file);
59
60        int i = 0;
61        for (i = 0; System.currentTimeMillis() < startTime + time; ++i) {
62            ClassLoader ldr = new MyClassLoader(buff);
63            if (i % 1000 == 0) {
64                cls.clear();
65            }
66            // only keep every other class loader alive
67            if (i % 2 == 1) {
68                cls.add(ldr);
69            }
70            Class<?> c = null;
71            try {
72                c = ldr.loadClass("test.Empty");
73                c.getClass().getClassLoader(); // make sure we have a valid class.
74            } catch (ClassNotFoundException ex) {
75                System.out.println("i=" + i + ", len" + buff.length);
76                throw new RuntimeException(ex);
77            }
78            c = null;
79        }
80        cls = null;
81        System.out.println("Finished " + i + " iterations in " +
82                           (System.currentTimeMillis() - startTime) + " ms");
83    }
84
85    private static byte[] read(File file) {
86        byte buff[] = new byte[(int)(file.length())];
87        try {
88            DataInputStream din = new DataInputStream(new FileInputStream(file));
89            din.readFully(buff);
90            din.close();
91        } catch (IOException ex) {
92            throw new RuntimeException(ex);
93        }
94        return buff;
95    }
96
97    static class MyClassLoader extends ClassLoader {
98        byte buff[];
99        MyClassLoader(byte buff[]) {
100            this.buff = buff;
101        }
102
103        public Class<?> loadClass() throws ClassNotFoundException {
104            String name = "test.Empty";
105            try {
106                return defineClass(name, buff, 0, buff.length);
107            } catch (Throwable e) {
108                throw new ClassNotFoundException(name, e);
109            }
110        }
111    }
112}
113