/*

 * Copyright (c) 1998, 2006, 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.*;

import java.util.Arrays;

import java.util.Properties;

import java.util.StringTokenizer;

/**

 * RMI regression test utility class that uses Runtime.exec to spawn a

 * java process that will run a named java class.

 */

public class JavaVM {

    protected Process vm = null;

    private String classname = "";

    private String args = "";

    private String options = "";

    private OutputStream outputStream = System.out;

    private OutputStream errorStream = System.err;

    private String policyFileName = null;

    // This is used to shorten waiting time at startup.

    private volatile boolean started = false;

    private boolean forcesOutput = true; // default behavior

    private static void mesg(Object mesg) {

        System.err.println("JAVAVM: " + mesg.toString());

    }

    /** string name of the program execd by JavaVM */

    private static String javaProgram = "java";

    static {

        try {

            javaProgram = TestLibrary.getProperty("java.home", "") +

                File.separator + "bin" + File.separator + javaProgram;

        } catch (SecurityException se) {

        }

    }

    public JavaVM(String classname) {

        this.classname = classname;

    }

    public JavaVM(String classname,

                  String options, String args) {

        this.classname = classname;

        this.options = options;

        this.args = args;

    }

    public JavaVM(String classname,

                  String options, String args,

                  OutputStream out, OutputStream err) {

        this(classname, options, args);

        this.outputStream = out;

        this.errorStream = err;

    }

    /* This constructor will instantiate a JavaVM object for which caller

     * can ask for forcing initial version output on child vm process

     * (if forcesVersionOutput is true), or letting the started vm behave freely

     * (when forcesVersionOutput is false).

     */

    public JavaVM(String classname,

                  String options, String args,

                  OutputStream out, OutputStream err,

                  boolean forcesVersionOutput) {

        this(classname, options, args, out, err);

        this.forcesOutput = forcesVersionOutput;

    }

    public void setStarted() {

        started = true;

    }

    // Prepends passed opts array to current options

    public void addOptions(String[] opts) {

        String newOpts = "";

        for (int i = 0 ; i < opts.length ; i ++) {

            newOpts += " " + opts[i];

        }

        newOpts += " ";

        options = newOpts + options;

    }

    // Prepends passed arguments array to current args

    public void addArguments(String[] arguments) {

        String newArgs = "";

        for (int i = 0 ; i < arguments.length ; i ++) {

            newArgs += " " + arguments[i];

        }

        newArgs += " ";

        args = newArgs + args;

    }

    public void setPolicyFile(String policyFileName) {

        this.policyFileName = policyFileName;

    }

    /**

     * This method is used for setting VM options on spawned VMs.

     * It returns the extra command line options required

     * to turn on jcov code coverage analysis.

     */

    protected static String getCodeCoverageOptions() {

        return TestLibrary.getExtraProperty("jcov.options","");

    }

    /**

     * Exec the VM as specified in this object's constructor.

     */

    public void start() throws IOException {

        if (vm != null) return;

        /*

         * If specified, add option for policy file

         */

        if (policyFileName != null) {

            String option = "-Djava.security.policy=" + policyFileName;

            addOptions(new String[] { option });

        }

        addOptions(new String[] { getCodeCoverageOptions() });

        /*

         * If forcesOutput is true :

         *  We force the new starting vm to output something so that we can know

         *  when it is effectively started by redirecting standard output through

         *  the next StreamPipe call (the vm is considered started when a first

         *  output has been streamed out).

         *  We do this by prepnding a "-showversion" option in the command line.

         */

        if (forcesOutput) {

            addOptions(new String[] {"-showversion"});

        }

        StringTokenizer optionsTokenizer = new StringTokenizer(options);

        StringTokenizer argsTokenizer = new StringTokenizer(args);

        int optionsCount = optionsTokenizer.countTokens();

        int argsCount = argsTokenizer.countTokens();

        String javaCommand[] = new String[optionsCount + argsCount + 2];

        int count = 0;

        javaCommand[count++] = JavaVM.javaProgram;

        while (optionsTokenizer.hasMoreTokens()) {

            javaCommand[count++] = optionsTokenizer.nextToken();

        }

        javaCommand[count++] = classname;

        while (argsTokenizer.hasMoreTokens()) {

            javaCommand[count++] = argsTokenizer.nextToken();

        }

        mesg("command = " + Arrays.asList(javaCommand).toString());

        System.err.println("");

        vm = Runtime.getRuntime().exec(javaCommand);

        /* output from the execed process may optionally be captured. */

        StreamPipe.plugTogether(this, vm.getInputStream(), this.outputStream);

        StreamPipe.plugTogether(this, vm.getErrorStream(), this.errorStream);

        try {

            if (forcesOutput) {

                // Wait distant vm to start, by using waiting time slices of 100 ms.

                // Wait at most for 2secs, after it considers the vm to be started.

                final long vmStartSleepTime = 100;

                final int maxTrials = 20;

                int numTrials = 0;

                while (!started && numTrials < maxTrials) {

                    numTrials++;

                    Thread.sleep(vmStartSleepTime);

                }

                // Outputs running status of distant vm

                String message =

                    "after " + (numTrials * vmStartSleepTime) + " milliseconds";

                if (started) {

                    mesg("distant vm process running, " + message);

                }

                else {

                    mesg("unknown running status of distant vm process, " + message);

                }

            }

            else {

                // Since we have no way to know if the distant vm is started,

                // we just consider the vm to be started after a 2secs waiting time.

                Thread.sleep(2000);

                mesg("distant vm considered to be started after a waiting time of 2 secs");

            }

        } catch (InterruptedException e) {

            Thread.currentThread().interrupt();

            mesg("Thread interrupted while checking if distant vm is started. Giving up check.");

            mesg("Distant vm state unknown");

            return;

        }

    }

    public void destroy() {

        if (vm != null) {

            vm.destroy();

        }

        vm = null;

    }

    protected Process getVM() {

        return vm;

    }

}