1 /*
 2  * Copyright (c) 2016, 2023, 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 
25 package gc.stress.gcbasher;
26 
27 import java.io.IOException;
28 import java.net.URI;
29 import java.nio.file.FileSystems;
30 import java.nio.file.FileSystem;
31 import java.nio.file.Files;
32 import java.nio.file.Path;
33 import java.util.HashMap;
34 import java.util.stream.Stream;
35 
36 public class TestGCBasher {
37     private static void parseClassFiles() throws IOException {
38         HashMap<String, ClassInfo> deps = new HashMap<>();
39 
40         FileSystem fs = FileSystems.getFileSystem(URI.create("jrt:/"));
41         try (Stream<Path> s = Files.walk(fs.getPath("/"))) {
42             for (Path p : (Iterable<Path>)s::iterator) {
43                 if (p.toString().endsWith(".class") &&
44                     !p.getFileName().toString().equals("module-info.class")) {
45                     byte[] data = Files.readAllBytes(p);
46                     Decompiler d = new Decompiler(data);
47                     ClassInfo ci = d.getClassInfo();
48                     deps.put(ci.getName(), ci);
49                 }
50             }
51         }
52     }
53 
54     public static void main(String[] args) throws IOException {
55         if (args.length != 1) {
56             System.err.println("Usage: TestGCBasher <duration-ms>");
57             return;
58         }
59 
60         long durationNanos = Long.valueOf(args[0]) * 1_000_000L;
61         long startNanos = System.nanoTime();
62         while (System.nanoTime() - startNanos < durationNanos) {
63             parseClassFiles();
64         }
65     }
66 }