70 lines
2.9 KiB
Java
70 lines
2.9 KiB
Java
|
/*
|
||
|
* Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
|
||
|
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||
|
*
|
||
|
* This code is free software; you can redistribute it and/or modify it
|
||
|
* under the terms of the GNU General Public License version 2 only, as
|
||
|
* published by the Free Software Foundation.
|
||
|
*
|
||
|
* This code is distributed in the hope that it will be useful, but WITHOUT
|
||
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||
|
* version 2 for more details (a copy is included in the LICENSE file that
|
||
|
* accompanied this code).
|
||
|
*
|
||
|
* You should have received a copy of the GNU General Public License version
|
||
|
* 2 along with this work; if not, write to the Free Software Foundation,
|
||
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||
|
*
|
||
|
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
||
|
* or visit www.oracle.com if you need additional information or have any
|
||
|
* questions.
|
||
|
*/
|
||
|
package compiler.gcbarriers;
|
||
|
|
||
|
import java.util.Arrays;
|
||
|
|
||
|
/**
|
||
|
* @test
|
||
|
* @bug 8312749
|
||
|
* @summary Test that, when using a larger object alignment, ZGC arraycopy
|
||
|
* barriers are only applied to actual OOPs, and not to object
|
||
|
* alignment padding words.
|
||
|
* @requires vm.gc.ZGenerational
|
||
|
* @run main/othervm -Xbatch -XX:-TieredCompilation
|
||
|
* -XX:CompileOnly=compiler.gcbarriers.TestArrayCopyWithLargeObjectAlignment::*
|
||
|
* -XX:ObjectAlignmentInBytes=16
|
||
|
* -XX:+UseZGC -XX:+ZGenerational
|
||
|
* compiler.gcbarriers.TestArrayCopyWithLargeObjectAlignment
|
||
|
*/
|
||
|
|
||
|
public class TestArrayCopyWithLargeObjectAlignment {
|
||
|
|
||
|
static Object[] doCopyOf(Object[] array) {
|
||
|
return Arrays.copyOf(array, array.length);
|
||
|
}
|
||
|
|
||
|
static Object[] doClone(Object[] array) {
|
||
|
return array.clone();
|
||
|
}
|
||
|
|
||
|
public static void main(String[] args) {
|
||
|
for (int i = 0; i < 10_000; i++) {
|
||
|
// This test allocates an array 'a', copies it into a new array 'b'
|
||
|
// using Arrays.copyOf, and clones 'b' into yet another array. For
|
||
|
// ObjectAlignmentInBytes=16, the intrinsic implementation of
|
||
|
// Arrays.copyOf leaves the object alignment padding word "b[1]"
|
||
|
// untouched, preserving the badHeapWordVal value '0xbaadbabe'. The
|
||
|
// test checks that this padding word is not processed as a valid
|
||
|
// OOP by the ZGC arraycopy stub underlying the intrinsic
|
||
|
// implementation of Object.clone. Allocating b using the intrinsic
|
||
|
// implementation of Arrays.copyOf is key to reproducing the issue
|
||
|
// because, unlike regular (fast or slow) array allocation,
|
||
|
// Arrays.copyOf does not zero-clear the padding word.
|
||
|
Object[] a = {new Object()};
|
||
|
Object[] b = doCopyOf(a);
|
||
|
doClone(b);
|
||
|
}
|
||
|
}
|
||
|
}
|