--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/ProcessBuilder/BigFork.java	Sun Jun 14 14:23:22 2009 -0700
@@ -0,0 +1,103 @@
+/*
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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<byte[]>(100);
+        try {
+            for (;;) {
+                byte[] chunk = new byte[chunkSize];
+                touchPages(chunk);
+                chunks.add(chunk);
+            }
+        } catch (OutOfMemoryError e) {
+            chunks.set(0, null);        // Free up one chunk
+            System.gc();
+            int size = chunks.size();
+            System.out.printf("size=%.2gGB%n", (double)size/10);
+
+            showCommittedMemory();
+
+            // Can we fork/exec in our current bloated state?
+            Process p = new ProcessBuilder("/bin/true").start();
+            p.waitFor();
+        }
+    }
+}