Java example source code file (TestMetaspaceSizeFlags.java)

This example Java source code file (TestMetaspaceSizeFlags.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

exception, max_alignment, metaspaceflags, outputanalyzer, processbuilder, string, testmetaspacesizeflags, too, vm\\n, xx\:\+printflagsfinal, xx\:\-uselargepages, xx\:maxmetaspacesize, xx\:metaspacesize

The TestMetaspaceSizeFlags.java Java example source code

/*
 * 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.
 */

import com.oracle.java.testlibrary.Asserts;
import com.oracle.java.testlibrary.OutputAnalyzer;
import com.oracle.java.testlibrary.ProcessTools;

/*
 * @test TestMetaspaceSizeFlags
 * @key gc
 * @bug 8024650
 * @summary Test that metaspace size flags can be set correctly
 * @library /testlibrary
 */
public class TestMetaspaceSizeFlags {
  public static final long K = 1024L;
  public static final long M = 1024L * K;

  // HotSpot uses a number of different values to align memory size flags.
  // This is currently the largest alignment (unless huge large pages are used).
  public static final long MAX_ALIGNMENT = 32 * M;

  public static void main(String [] args) throws Exception {
    testMaxMetaspaceSizeEQMetaspaceSize(MAX_ALIGNMENT, MAX_ALIGNMENT);
    // 8024650: MaxMetaspaceSize was adjusted instead of MetaspaceSize.
    testMaxMetaspaceSizeLTMetaspaceSize(MAX_ALIGNMENT, MAX_ALIGNMENT * 2);
    testMaxMetaspaceSizeGTMetaspaceSize(MAX_ALIGNMENT * 2, MAX_ALIGNMENT);
    testTooSmallInitialMetaspace(0, 0);
    testTooSmallInitialMetaspace(0, MAX_ALIGNMENT);
    testTooSmallInitialMetaspace(MAX_ALIGNMENT, 0);
  }

  private static void testMaxMetaspaceSizeEQMetaspaceSize(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    MetaspaceFlags mf = runAndGetValue(maxMetaspaceSize, metaspaceSize);
    Asserts.assertEQ(maxMetaspaceSize, metaspaceSize);
    Asserts.assertEQ(mf.maxMetaspaceSize, maxMetaspaceSize);
    Asserts.assertEQ(mf.metaspaceSize, metaspaceSize);
  }

  private static void testMaxMetaspaceSizeLTMetaspaceSize(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    MetaspaceFlags mf = runAndGetValue(maxMetaspaceSize, metaspaceSize);
    Asserts.assertEQ(mf.maxMetaspaceSize, maxMetaspaceSize);
    Asserts.assertEQ(mf.metaspaceSize, maxMetaspaceSize);
  }

  private static void testMaxMetaspaceSizeGTMetaspaceSize(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    MetaspaceFlags mf = runAndGetValue(maxMetaspaceSize, metaspaceSize);
    Asserts.assertGT(maxMetaspaceSize, metaspaceSize);
    Asserts.assertGT(mf.maxMetaspaceSize, mf.metaspaceSize);
    Asserts.assertEQ(mf.maxMetaspaceSize, maxMetaspaceSize);
    Asserts.assertEQ(mf.metaspaceSize, metaspaceSize);
  }

  private static void testTooSmallInitialMetaspace(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    OutputAnalyzer output = run(maxMetaspaceSize, metaspaceSize);
    output.shouldContain("Too small initial Metaspace size");
  }

  private static MetaspaceFlags runAndGetValue(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    OutputAnalyzer output = run(maxMetaspaceSize, metaspaceSize);
    output.shouldNotMatch("Error occurred during initialization of VM\n.*");

    String stringMaxMetaspaceSize = output.firstMatch(".* MaxMetaspaceSize .* := (\\d+).*", 1);
    String stringMetaspaceSize = output.firstMatch(".* MetaspaceSize .* := (\\d+).*", 1);

    return new MetaspaceFlags(Long.parseLong(stringMaxMetaspaceSize),
                              Long.parseLong(stringMetaspaceSize));
  }

  private static OutputAnalyzer run(long maxMetaspaceSize, long metaspaceSize) throws Exception {
    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
        "-XX:MaxMetaspaceSize=" + maxMetaspaceSize,
        "-XX:MetaspaceSize=" + metaspaceSize,
        "-XX:-UseLargePages", // Prevent us from using 2GB large pages on solaris + sparc.
        "-XX:+PrintFlagsFinal",
        "-version");
    return new OutputAnalyzer(pb.start());
  }

  private static class MetaspaceFlags {
    public long maxMetaspaceSize;
    public long metaspaceSize;
    public MetaspaceFlags(long maxMetaspaceSize, long metaspaceSize) {
      this.maxMetaspaceSize = maxMetaspaceSize;
      this.metaspaceSize = metaspaceSize;
    }
  }
}