1 /*
  2  * Copyright (c) 2024, 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 ValueCopyingTest
 26  * @summary Verify that interpreter doesn't tear up primitive fields when copying a value
 27  * @library /test/lib
 28  * @modules java.base/jdk.internal.vm.annotation
 29  * @enablePreview
 30  * @compile ValueCopyingTest.java
 31  * @run main/othervm -Xint -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlineLayout runtime.valhalla.inlinetypes.ValueCopyingTest
 32  */
 33 
 34 package runtime.valhalla.inlinetypes;
 35 
 36 import jdk.internal.vm.annotation.LooselyConsistentValue;
 37 import jdk.internal.vm.annotation.NullRestricted;
 38 import jdk.internal.vm.annotation.Strict;
 39 import jdk.test.lib.Asserts;
 40 
 41 public class ValueCopyingTest {
 42 
 43   static final int NUM_WORKERS = 16;
 44 
 45   static ValueCopyingTest target = new ValueCopyingTest();
 46 
 47   @LooselyConsistentValue
 48   static value class TestValue {
 49     int i;
 50     byte b;
 51     TestValue(int i0) {
 52       i = i0;
 53       b = 0;
 54     }
 55   }
 56 
 57   @Strict
 58   @NullRestricted
 59   TestValue tv = new TestValue(0);
 60 
 61   static class Worker implements Runnable {
 62     int i;
 63     TestValue v;
 64     Worker(byte b) {
 65       i = b | (b << 8) | (b << 16) | (b << 24);
 66       v = new TestValue(i);
 67     }
 68 
 69     static void checkValue(int i) {
 70       byte b = (byte)(i & 0xFF);
 71       Asserts.assertTrue(((i >> 8) & 0xFF) == b, "Tearing detected");
 72       Asserts.assertTrue(((i >> 16) & 0xFF) == b, "Tearing detected");
 73       Asserts.assertTrue(((i >> 24) & 0xFF) == b, "Tearing detected");
 74     }
 75 
 76     public void run() {
 77       for (int n = 0; n < 10000000; n++) {
 78         ValueCopyingTest.target.tv = v;
 79         int ri = ValueCopyingTest.target.tv.i;
 80         checkValue(ri);
 81       }
 82     }
 83   }
 84 
 85   static public void main(String[] args) throws InterruptedException {
 86     Thread[] workers = new Thread[NUM_WORKERS];
 87     for (int i = 0; i < NUM_WORKERS; i++) {
 88       workers[i] = new Thread(new Worker((byte)i));
 89     }
 90     for (int i = 0; i < NUM_WORKERS; i++) {
 91       workers[i].start();
 92     }
 93     try {
 94       for (int i = 0; i < NUM_WORKERS; i++) {
 95         workers[i].join();
 96       }
 97     } catch(InterruptedException e) {
 98       e.printStackTrace();
 99       throw e;
100     }
101   }
102 }