--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/serviceability/jdwp/DebuggeeLauncher.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2016, 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 java.io.IOException;
+import java.net.ServerSocket;
+import java.util.StringTokenizer;
+import jdk.test.lib.JDKToolFinder;
+import jdk.test.lib.Utils;
+import static jdk.test.lib.Asserts.assertFalse;
+
+/**
+ * Launches the debuggee with the necessary JDWP options and handles the output
+ */
+public class DebuggeeLauncher implements StreamHandler.Listener {
+
+    public interface Listener {
+
+        /**
+         * Callback to use when a module name is received from the debuggee
+         *
+         * @param modName module name reported by the debuggee
+         */
+        void onDebuggeeModuleInfo(String modName);
+
+        /**
+         * Callback to use when the debuggee completes sending out the info
+         */
+        void onDebuggeeSendingCompleted();
+
+        /**
+         * Callback to handle any debuggee error
+         *
+         * @param line line from the debuggee's stderr
+         */
+        void onDebuggeeError(String line);
+    }
+
+    private static int jdwpPort = -1;
+    private static final String CLS_DIR = System.getProperty("test.classes", "").trim();
+    private static final String DEBUGGEE = "AllModulesCommandTestDebuggee";
+    private Process p;
+    private final Listener listener;
+    private StreamHandler inputHandler;
+    private StreamHandler errorHandler;
+
+    /**
+     * @param listener the listener we report the debuggee events to
+     */
+    public DebuggeeLauncher(Listener listener) {
+        this.listener = listener;
+    }
+
+    /**
+     * Starts the debuggee with the necessary JDWP options and handles the
+     * debuggee's stdout and stderr outputs
+     *
+     * @throws Throwable
+     */
+    public void launchDebuggee() throws Throwable {
+
+        ProcessBuilder pb = new ProcessBuilder(getCommand());
+        p = pb.start();
+        inputHandler = new StreamHandler(p.getInputStream(), this);
+        errorHandler = new StreamHandler(p.getErrorStream(), this);
+        inputHandler.start();
+        errorHandler.start();
+    }
+
+    /**
+     * Command to start the debuggee with the JDWP options and using the JDK
+     * under test
+     *
+     * @return the command
+     */
+    private String[] getCommand() {
+        return new String[]{
+            JDKToolFinder.getTestJDKTool("java"),
+            getJdwpOptions(),
+            "-cp",
+            CLS_DIR,
+            DEBUGGEE
+        };
+    }
+
+    /**
+     * Terminates the debuggee
+     */
+    public void terminateDebuggee() {
+        if (p.isAlive()) {
+            p.destroyForcibly();
+        }
+    }
+
+    /**
+     * Debuggee JDWP options
+     *
+     * @return the JDWP options to start the debuggee with
+     */
+    private static String getJdwpOptions() {
+        return "-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=" + getJdwpPort();
+    }
+
+    /**
+     * Find an available port for the JDWP session
+     *
+     * @return JDWP port
+     */
+    public static int getJdwpPort() {
+        if (jdwpPort == -1) {
+            jdwpPort = findFreePort();
+            assertFalse(jdwpPort == -1, "Can not find vailbale port for JDWP");
+        }
+        return jdwpPort;
+    }
+
+    private static int findFreePort() {
+        try (ServerSocket socket = new ServerSocket(0)) {
+            return socket.getLocalPort();
+        } catch (IOException e) {
+        }
+        return -1;
+    }
+
+    @Override
+    public void onStringRead(StreamHandler handler, String line) {
+        if (handler.equals(errorHandler)) {
+            terminateDebuggee();
+            listener.onDebuggeeError(line);
+        } else {
+            processDebuggeeOutput(line);
+        }
+    }
+
+    private void processDebuggeeOutput(String line) {
+        StringTokenizer st = new StringTokenizer(line);
+        String token = st.nextToken();
+        switch (token) {
+            case "module":
+                listener.onDebuggeeModuleInfo(st.nextToken());
+                break;
+            case "ready":
+                listener.onDebuggeeSendingCompleted();
+                break;
+        }
+    }
+}