view test/runtime/Metaspace/FragmentMetaspace.java @ 12986:1b422ef5288a

8025728: Missing volatile specifier for field G1AllocRegion::_alloc_region Summary: The field G1AllocRegion::_alloc_region needs to be declared volatile as it is used with that intention. Otherwise the compiler may generate the code that reloads the value which might have changed in the meantime, leading to spurious crashes. Reviewed-by: iveresov, simonis, tschatzl Contributed-by: Axel Siebenborn <axel.siebenborn@sap.com>
author tschatzl
date Wed, 23 Oct 2013 10:23:06 +0200
parents 699d9df07e59
children
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/*
 * Copyright (c) 2013, 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.
 */

/**
 * @test
 * @library /runtime/testlibrary
 * @build GeneratedClassLoader
 * @run main/othervm/timeout=200 FragmentMetaspace
 */

import java.io.IOException;

/**
 * Test that tries to fragment the native memory used by class loaders.
 * This test creates class loaders that load classes of increasing size for every
 * iteration. By increasing the size of the class meta data needed for every iteration
 * we stress the subsystem for allocating native memory for meta data.
 */
public class FragmentMetaspace {

    public static void main(String... args) {
        runGrowing(Long.valueOf(System.getProperty("time", "80000")));
        // try to clean up and unload classes to decrease
        // class verification time in debug vm
        System.gc();
    }

    private static void runGrowing(long time) {
        long startTime = System.currentTimeMillis();
        for (int i = 0; System.currentTimeMillis() < startTime + time; ++i) {
            try {
                GeneratedClassLoader gcl = new GeneratedClassLoader();

                Class<?> c = gcl.getGeneratedClasses(i, 100)[0];
                c.newInstance();
                c = null;

                gcl = null;
            } catch (IOException|InstantiationException|IllegalAccessException ex) {
                throw new RuntimeException(ex);
            }
        }
    }
}