/*

 * Copyright (c) 1999, 2017, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.sun.tools.jdi;

import java.io.IOException;

import java.io.InterruptedIOException;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import java.util.StringTokenizer;

import com.sun.jdi.Bootstrap;

import com.sun.jdi.InternalException;

import com.sun.jdi.VirtualMachine;

import com.sun.jdi.VirtualMachineManager;

import com.sun.jdi.connect.Connector;

import com.sun.jdi.connect.IllegalConnectorArgumentsException;

import com.sun.jdi.connect.LaunchingConnector;

import com.sun.jdi.connect.VMStartException;

import com.sun.jdi.connect.spi.Connection;

import com.sun.jdi.connect.spi.TransportService;

abstract class AbstractLauncher extends ConnectorImpl

                                implements LaunchingConnector

{

    abstract public VirtualMachine

        launch(Map<String, ? extends Connector.Argument> arguments)

        throws IOException, IllegalConnectorArgumentsException,

               VMStartException;

    abstract public String name();

    abstract public String description();

    ThreadGroup grp;

    AbstractLauncher() {

        super();

        grp = Thread.currentThread().getThreadGroup();

        ThreadGroup parent = null;

        while ((parent = grp.getParent()) != null) {

            grp = parent;

        }

    }

    String[] tokenizeCommand(String command, char quote) {

        String quoteStr = String.valueOf(quote); // easier to deal with

        /*

         * Tokenize the command, respecting the given quote character.

         */

        StringTokenizer tokenizer = new StringTokenizer(command,

                                                        quote + " \t\r\n\f",

                                                        true);

        String quoted = null;

        String pending = null;

        List<String> tokenList = new ArrayList<>();

        while (tokenizer.hasMoreTokens()) {

            String token = tokenizer.nextToken();

            if (quoted != null) {

                if (token.equals(quoteStr)) {

                    tokenList.add(quoted);

                    quoted = null;

                } else {

                    quoted += token;

                }

            } else if (pending != null) {

                if (token.equals(quoteStr)) {

                    quoted = pending;

                } else if ((token.length() == 1) &&

                           Character.isWhitespace(token.charAt(0))) {

                    tokenList.add(pending);

                } else {

                    throw new InternalException("Unexpected token: " + token);

                }

                pending = null;

            } else {

                if (token.equals(quoteStr)) {

                    quoted = "";

                } else if ((token.length() == 1) &&

                           Character.isWhitespace(token.charAt(0))) {

                    // continue

                } else {

                    pending = token;

                }

            }

        }

        /*

         * Add final token.

         */

        if (pending != null) {

            tokenList.add(pending);

        }

        /*

         * An unclosed quote at the end of the command. Do an

         * implicit end quote.

         */

        if (quoted != null) {

            tokenList.add(quoted);

        }

        String[] tokenArray = new String[tokenList.size()];

        for (int i = 0; i < tokenList.size(); i++) {

            tokenArray[i] = tokenList.get(i);

        }

        return tokenArray;

    }

    protected VirtualMachine launch(String[] commandArray, String address,

                                    TransportService.ListenKey listenKey,

                                    TransportService ts)

                                    throws IOException, VMStartException {

        Helper helper = new Helper(commandArray, address, listenKey, ts);

        helper.launchAndAccept();

        VirtualMachineManager manager =

            Bootstrap.virtualMachineManager();

        return manager.createVirtualMachine(helper.connection(),

                                            helper.process());

    }

    /**

     * This class simply provides a context for a single launch and

     * accept. It provides instance fields that can be used by

     * all threads involved. This stuff can't be in the Connector proper

     * because the connector is a singleton and is not specific to any

     * one launch.

     */

    private class Helper {

        @SuppressWarnings("unused")

        private final String address;

        private TransportService.ListenKey listenKey;

        private TransportService ts;

        private final String[] commandArray;

        private Process process = null;

        private Connection connection = null;

        private IOException acceptException = null;

        private boolean exited = false;

        Helper(String[] commandArray, String address, TransportService.ListenKey listenKey,

            TransportService ts) {

            this.commandArray = commandArray;

            this.address = address;

            this.listenKey = listenKey;

            this.ts = ts;

        }

        String commandString() {

            String str = "";

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

                if (i > 0) {

                    str += " ";

                }

                str += commandArray[i];

            }

            return str;

        }

        synchronized void launchAndAccept() throws

                                IOException, VMStartException {

            process = Runtime.getRuntime().exec(commandArray);

            Thread acceptingThread = acceptConnection();

            Thread monitoringThread = monitorTarget();

            try {

                while ((connection == null) &&

                       (acceptException == null) &&

                       !exited) {

                    wait();

                }

                if (exited) {

                    throw new VMStartException(

                        "VM initialization failed for: " + commandString(), process);

                }

                if (acceptException != null) {

                    // Rethrow the exception in this thread

                    throw acceptException;

                }

            } catch (InterruptedException e) {

                throw new InterruptedIOException("Interrupted during accept");

            } finally {

                acceptingThread.interrupt();

                monitoringThread.interrupt();

            }

        }

        Process process() {

            return process;

        }

        Connection connection() {

            return connection;

        }

        synchronized void notifyOfExit() {

            exited = true;

            notify();

        }

        synchronized void notifyOfConnection(Connection connection) {

            this.connection = connection;

            notify();

        }

        synchronized void notifyOfAcceptException(IOException acceptException) {

            this.acceptException = acceptException;

            notify();

        }

        Thread monitorTarget() {

            Thread thread = new Thread(grp, "launched target monitor") {

                public void run() {

                    try {

                        process.waitFor();

                        /*

                         * Notify waiting thread of VM error termination

                         */

                        notifyOfExit();

                    } catch (InterruptedException e) {

                        // Connection has been established, stop monitoring

                    }

                }

            };

            thread.setDaemon(true);

            thread.start();

            return thread;

        }

        Thread acceptConnection() {

            Thread thread = new Thread(grp, "connection acceptor") {

                public void run() {

                    try {

                        Connection connection = ts.accept(listenKey, 0, 0);

                        /*

                         * Notify waiting thread of connection

                         */

                        notifyOfConnection(connection);

                    } catch (InterruptedIOException e) {

                        // VM terminated, stop accepting

                    } catch (IOException e) {

                        // Report any other exception to waiting thread

                        notifyOfAcceptException(e);

                    }

                }

            };

            thread.setDaemon(true);

            thread.start();

            return thread;

        }

    }

}