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Java example source code file (BigFork.java)
The BigFork.java Java example source code/* * Copyright 2009 Google Inc. 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 java.util.*; import java.io.*; /** * A manual test that demonstrates the ability to start a subprocess * on Linux without getting ENOMEM. Run this test like: * * java -Xmx7000m BigFork * * providing a -Xmx flag suitable for your operating environment. * Here's the bad old behavior: * * ==> java -Xmx7000m -esa -ea BigFork * ------- * CommitLimit: 6214700 kB * Committed_AS: 2484452 kB * ------- * size=4.6GB * ------- * CommitLimit: 6214700 kB * Committed_AS: 7219680 kB * ------- * Exception in thread "main" java.io.IOException: Cannot run program "/bin/true": java.io.IOException: error=12, Cannot allocate memory * at java.lang.ProcessBuilder.start(ProcessBuilder.java:1018) * at BigFork.main(BigFork.java:79) * Caused by: java.io.IOException: java.io.IOException: error=12, Cannot allocate memory * at java.lang.UNIXProcess.<init>(UNIXProcess.java:190) * at java.lang.ProcessImpl.start(ProcessImpl.java:128) * at java.lang.ProcessBuilder.start(ProcessBuilder.java:1010) * ... 1 more */ public class BigFork { static final Random rnd = new Random(); static void touchPages(byte[] chunk) { final int pageSize = 4096; for (int i = 0; i < chunk.length; i+= pageSize) { chunk[i] = (byte) rnd.nextInt(); } } static void showCommittedMemory() throws IOException { BufferedReader r = new BufferedReader( new InputStreamReader( new FileInputStream("/proc/meminfo"))); System.out.println("-------"); String line; while ((line = r.readLine()) != null) { if (line.startsWith("Commit")) { System.out.printf("%s%n", line); } } System.out.println("-------"); } public static void main(String[] args) throws Throwable { showCommittedMemory(); final int chunkSize = 1024 * 1024 * 100; List<byte[]> chunks = new ArrayList Other Java examples (source code examples)Here is a short list of links related to this Java BigFork.java source code file: |
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