1 /*
 2  * Copyright (c) 2022, 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 import jdk.test.lib.RandomFactory;
25 
26 import java.lang.foreign.Arena;
27 import java.lang.foreign.MemorySegment;
28 
29 import java.io.IOException;
30 import java.nio.ByteBuffer;
31 import java.nio.channels.FileChannel;
32 import java.nio.file.Path;
33 import java.util.Random;
34 import java.util.concurrent.TimeUnit;
35 
36 import static java.nio.file.StandardOpenOption.*;
37 
38 /*
39  * @test
40  * @bug 8286637
41  * @summary Ensure that memory mapping beyond 32-bit range does not cause an
42  *          EXCEPTION_ACCESS_VIOLATION.
43  * @requires vm.bits == 64
44  * @library /test/lib
45  * @build jdk.test.lib.RandomFactory FileChannelUtils
46  * @run main/othervm LargeMapTest
47  * @key randomness
48  */
49 public class LargeMapTest {
50     private static final long LENGTH = (1L << 32) + 512;
51     private static final int  EXTRA  = 1024;
52     private static final long BASE   = LENGTH - EXTRA;
53     private static final Random GEN  = RandomFactory.getRandom();
54 
55     public static void main(String[] args) throws IOException {
56         System.out.println(System.getProperty("sun.arch.data.model"));
57         System.out.println(System.getProperty("os.arch"));
58         System.out.println(System.getProperty("java.version"));
59 
60         System.out.println("  Writing large file...");
61         long t0 = System.nanoTime();
62         Path p = FileChannelUtils.createSparseTempFile("test", ".dat");
63         p.toFile().deleteOnExit();
64         ByteBuffer bb;
65         try (FileChannel fc = FileChannel.open(p, WRITE)) {
66             fc.position(BASE);
67             byte[] b = new byte[EXTRA];
68             GEN.nextBytes(b);
69             bb = ByteBuffer.wrap(b);
70             fc.write(bb);
71             long t1 = System.nanoTime();
72             System.out.printf("  Wrote large file in %d ns (%d ms) %n",
73                     t1 - t0, TimeUnit.NANOSECONDS.toMillis(t1 - t0));
74         }
75         bb.rewind();
76 
77         try (FileChannel fc = FileChannel.open(p, READ, WRITE)) {
78             MemorySegment mappedMemorySegment =
79                 fc.map(FileChannel.MapMode.READ_WRITE, 0, p.toFile().length(),
80                        Arena.ofAuto());
81             MemorySegment target = mappedMemorySegment.asSlice(BASE, EXTRA);
82             if (!target.asByteBuffer().equals(bb)) {
83                 throw new RuntimeException("Expected buffers to be equal");
84             }
85         }
86     }
87 }