--- /dev/null 2018-11-30 10:10:44.238550338 +0100 +++ new/test/hotspot/jtreg/gc/shenandoah/TestArrayCopyStress.java 2018-11-30 10:21:47.506053941 +0100 @@ -0,0 +1,78 @@ +/* + * Copyright (c) 2018, Red Hat, Inc. All rights reserved. + * + * 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. + * + */ + +import java.util.concurrent.*; + +/* + * @test TestArrayCopyStress + * @key gc + * @requires vm.gc.Shenandoah + * + * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:TieredStopAtLevel=0 -Xmx16m TestArrayCopyStress + */ +public class TestArrayCopyStress { + + private static final int ARRAY_SIZE = 1000; + private static final int ITERATIONS = 10000; + + static class Foo { + int num; + + Foo(int num) { + this.num = num; + } + } + + static class Bar {} + + public static void main(String[] args) throws Exception { + for (int i = 0; i < ITERATIONS; i++) { + testConjoint(); + } + } + + private static void testConjoint() { + Foo[] array = new Foo[ARRAY_SIZE]; + for (int i = 0; i < ARRAY_SIZE; i++) { + array[i] = new Foo(i); + } + + int src_idx = ThreadLocalRandom.current().nextInt(0, ARRAY_SIZE); + int dst_idx = ThreadLocalRandom.current().nextInt(0, ARRAY_SIZE); + int len = ThreadLocalRandom.current().nextInt(0, Math.min(ARRAY_SIZE - src_idx, ARRAY_SIZE - dst_idx)); + System.arraycopy(array, src_idx, array, dst_idx, len); + + for (int i = 0; i < ARRAY_SIZE; i++) { + if (i >= dst_idx && i < dst_idx + len) { + assertEquals(array[i].num, i - (dst_idx - src_idx)); + } else { + assertEquals(array[i].num, i); + } + } + } + + private static void assertEquals(int a, int b) { + if (a != b) throw new RuntimeException("assert failed"); + } + +}