Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: test/compiler/unsafe/TestRawAliasing.java
test/compiler/unsafe/TestRawAliasing.java
- changeset 8879
- 6bc9abf210fd
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| 8878:d3cc20285653 | 8879:6bc9abf210fd |
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| 1 /* | |
| 2 * Copyright (c) 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 /* | |
| 25 * @test | |
| 26 * @bug 8178047 | |
| 27 * @run main/othervm -XX:CompileCommand=exclude,*.main -XX:-TieredCompilation -XX:-BackgroundCompilation compiler.unsafe.TestRawAliasing | |
| 28 */ | |
| 29 | |
| 30 package compiler.unsafe; | |
| 31 | |
| 32 import java.lang.reflect.Field; | |
| 33 | |
| 34 public class TestRawAliasing { | |
| 35 static private final sun.misc.Unsafe UNSAFE; | |
| 36 static { | |
| 37 try { | |
| 38 Field f = sun.misc.Unsafe.class.getDeclaredField("theUnsafe"); | |
| 39 f.setAccessible(true); | |
| 40 UNSAFE = (sun.misc.Unsafe) f.get(null); | |
| 41 } catch (Exception e) { | |
| 42 throw new RuntimeException("Unable to get Unsafe instance.", e); | |
| 43 } | |
| 44 } | |
| 45 | |
| 46 static private final int OFFSET_X = 50; | |
| 47 static private final int OFFSET_Y = 100; | |
| 48 | |
| 49 private static int test(long base_plus_offset_x, long base_plus_offset_y, int magic_value) { | |
| 50 // write 0 to a location | |
| 51 UNSAFE.putByte(base_plus_offset_x - OFFSET_X, (byte)0); | |
| 52 // write unfoldable value to really the same location with another base | |
| 53 UNSAFE.putByte(base_plus_offset_y - OFFSET_Y, (byte)magic_value); | |
| 54 // read the value back, should be equal to "unfoldable_value" | |
| 55 return UNSAFE.getByte(base_plus_offset_x - OFFSET_X); | |
| 56 } | |
| 57 | |
| 58 private static final int OFF_HEAP_AREA_SIZE = 128; | |
| 59 private static final byte MAGIC = 123; | |
| 60 | |
| 61 // main is excluded from compilation since we don't want the test method to inline and make base values fold | |
| 62 public static void main(String... args) { | |
| 63 long base = UNSAFE.allocateMemory(OFF_HEAP_AREA_SIZE); | |
| 64 for (int i = 0; i < 100_000; i++) { | |
| 65 if (test(base + OFFSET_X, base + OFFSET_Y, MAGIC) != MAGIC) { | |
| 66 throw new RuntimeException("Unexpected magic value"); | |
| 67 } | |
| 68 } | |
| 69 } | |
| 70 } |
