--- a/hotspot/test/gc/metaspace/ClassMetaspaceSizeInJmapHeap.java	Fri Mar 29 13:49:37 2013 -0700
+++ b/hotspot/test/gc/metaspace/ClassMetaspaceSizeInJmapHeap.java	Sat Mar 23 09:16:37 2013 +0100
@@ -39,8 +39,10 @@
     public static void main(String[] args) throws Exception {
         String pid = Integer.toString(ProcessTools.getProcessId());
 
-        ProcessBuilder pb = new ProcessBuilder();
-        pb.command(JDKToolFinder.getJDKTool("jmap"), "-heap",  pid);
+        JDKToolLauncher jmap = JDKToolLauncher.create("jmap")
+                                              .addToolArg("-heap")
+                                              .addToolArg(pid);
+        ProcessBuilder pb = new ProcessBuilder(jmap.getCommand());
 
         File out = new File("ClassMetaspaceSizeInJmapHeap.stdout.txt");
         pb.redirectOutput(out);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/com/oracle/java/testlibrary/JDKToolLauncher.java	Sat Mar 23 09:16:37 2013 +0100
@@ -0,0 +1,114 @@
+/*
+ * 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.
+ */
+
+package com.oracle.java.testlibrary;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import com.oracle.java.testlibrary.JDKToolFinder;
+import com.oracle.java.testlibrary.ProcessTools;
+
+/**
+ * A utility for constructing command lines for starting JDK tool processes.
+ *
+ * The JDKToolLauncher can in particular be combined with a
+ * java.lang.ProcessBuilder to easily run a JDK tool. For example, the
+ * following code run {@code jmap -heap} against a process with GC logging
+ * turned on for the {@code jmap} process:
+ *
+ * <pre>
+ * {@code
+ * JDKToolLauncher jmap = JDKToolLauncher.create("jmap")
+ *                                       .addVMArg("-XX:+PrintGC");
+ *                                       .addVMArg("-XX:+PrintGCDetails")
+ *                                       .addToolArg("-heap")
+ *                                       .addToolArg(pid);
+ * ProcessBuilder pb = new ProcessBuilder(jmap.getCommand());
+ * Process p = pb.start();
+ * }
+ * </pre>
+ */
+public class JDKToolLauncher {
+    private final String executable;
+    private final List<String> vmArgs = new ArrayList<String>();
+    private final List<String> toolArgs = new ArrayList<String>();
+
+    private JDKToolLauncher(String tool) {
+        executable = JDKToolFinder.getJDKTool(tool);
+        vmArgs.addAll(Arrays.asList(ProcessTools.getPlatformSpecificVMArgs()));
+    }
+
+    /**
+     * Creates a new JDKToolLauncher for the specified tool.
+     *
+     * @param tool The name of the tool
+     * @return A new JDKToolLauncher
+     */
+    public static JDKToolLauncher create(String tool) {
+        return new JDKToolLauncher(tool);
+    }
+
+    /**
+     * Adds an argument to the JVM running the tool.
+     *
+     * The JVM arguments are passed to the underlying JVM running the tool.
+     * Arguments will automatically be prepended with "-J".
+     *
+     * Any platform specific arguments required for running the tool are
+     * automatically added.
+     *
+     *
+     * @param arg The argument to VM running the tool
+     * @return The JDKToolLauncher instance
+     */
+    public JDKToolLauncher addVMArg(String arg) {
+        vmArgs.add("-J" + arg);
+        return this;
+    }
+
+    /**
+     * Adds an argument to the tool.
+     *
+     * @param arg The argument to the tool
+     * @return The JDKToolLauncher instance
+     */
+    public JDKToolLauncher addToolArg(String arg) {
+        toolArgs.add(arg);
+        return this;
+    }
+
+    /**
+     * Returns the command that can be used for running the tool.
+     *
+     * @return An array whose elements are the arguments of the command.
+     */
+    public String[] getCommand() {
+        List<String> command = new ArrayList<String>();
+        command.add(executable);
+        command.addAll(vmArgs);
+        command.addAll(toolArgs);
+        return command.toArray(new String[command.size()]);
+    }
+}