1 /*
 2  * Copyright (c) 2016, 2026, 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.IntStream;
35 import java.util.stream.Stream;
36 
37 public class TestGCBasher {
38     private static void parseClassFiles() throws IOException {
39         HashMap<String, ClassInfo> deps = new HashMap<>();
40 
41         FileSystem fs = FileSystems.getFileSystem(URI.create("jrt:/"));
42         try (Stream<Path> s = Files.walk(fs.getPath("/"))) {
43             for (Path p : (Iterable<Path>) s::iterator) {
44                 if (p.toString().endsWith(".class") &&
45                         !p.getFileName().toString().equals("module-info.class")) {
46                     byte[] rData = Files.readAllBytes(p);
47                     Byte[] data = IntStream.range(0, rData.length)
48                             .mapToObj(i -> rData[i])
49                             .toArray(Byte[]::new);
50                     Decompiler d = new Decompiler(data);
51                     ClassInfo ci = d.getClassInfo();
52                     deps.put(ci.getName(), ci);
53                 }
54             }
55         }
56     }
57 
58     public static void main(String[] args) throws IOException {
59         if (args.length != 1) {
60             System.err.println("Usage: TestGCBasher <duration-ms>");
61             return;
62         }
63 
64         long durationNanos = Long.valueOf(args[0]) * 1_000_000L;
65         long startNanos = System.nanoTime();
66         while (System.nanoTime() - startNanos < durationNanos) {
67             parseClassFiles();
68         }
69     }
70 }