/*

 * 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

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package com.sun.tools.jdi;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

import java.util.ResourceBundle;

import java.util.ServiceLoader;

import com.sun.jdi.JDIPermission;

import com.sun.jdi.VMDisconnectedException;

import com.sun.jdi.VirtualMachine;

import com.sun.jdi.VirtualMachineManager;

import com.sun.jdi.connect.AttachingConnector;

import com.sun.jdi.connect.Connector;

import com.sun.jdi.connect.LaunchingConnector;

import com.sun.jdi.connect.ListeningConnector;

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

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

/* Public for use by com.sun.jdi.Bootstrap */

public class VirtualMachineManagerImpl implements VirtualMachineManagerService {

    private List<Connector> connectors = new ArrayList<>();

    private LaunchingConnector defaultConnector = null;

    private List<VirtualMachine> targets = new ArrayList<>();

    private final ThreadGroup mainGroupForJDI;

    private ResourceBundle messages = null;

    private int vmSequenceNumber = 0;

    private static final int minorVersion = 0;

    private static final Object lock = new Object();

    private static VirtualMachineManagerImpl vmm;

    public static VirtualMachineManager virtualMachineManager() {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            JDIPermission vmmPermission =

                new JDIPermission("virtualMachineManager");

            sm.checkPermission(vmmPermission);

        }

        synchronized (lock) {

            if (vmm == null) {

                vmm = new VirtualMachineManagerImpl();

            }

        }

        return vmm;

    }

    protected VirtualMachineManagerImpl() {

        /*

         * Create a top-level thread group

         */

        ThreadGroup top = Thread.currentThread().getThreadGroup();

        ThreadGroup parent = null;

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

            top = parent;

        }

        mainGroupForJDI = new ThreadGroup(top, "JDI main");

        /*

         * Load the connectors

         */

        ServiceLoader<Connector> connectorLoader =

            ServiceLoader.load(Connector.class, Connector.class.getClassLoader());

        Iterator<Connector> connectors = connectorLoader.iterator();

        while (connectors.hasNext()) {

            Connector connector;

            try {

                connector = connectors.next();

            } catch (ThreadDeath x) {

                throw x;

            } catch (Exception x) {

                System.err.println(x);

                continue;

            } catch (Error x) {

                System.err.println(x);

                continue;

            }

            addConnector(connector);

        }

        /*

         * Load any transport services and encapsulate them with

         * an attaching and listening connector.

         */

        ServiceLoader<TransportService> transportLoader =

            ServiceLoader.load(TransportService.class,

                               TransportService.class.getClassLoader());

        Iterator<TransportService> transportServices =

            transportLoader.iterator();

        while (transportServices.hasNext()) {

            TransportService transportService;

            try {

                transportService = transportServices.next();

            } catch (ThreadDeath x) {

                throw x;

            } catch (Exception x) {

                System.err.println(x);

                continue;

            } catch (Error x) {

                System.err.println(x);

                continue;

            }

            addConnector(GenericAttachingConnector.create(transportService));

            addConnector(GenericListeningConnector.create(transportService));

        }

        // no connectors found

        if (allConnectors().size() == 0) {

            throw new Error("no Connectors loaded");

        }

        // Set the default launcher. In order to be compatible

        // 1.2/1.3/1.4 we try to make the default launcher

        // "com.sun.jdi.CommandLineLaunch". If this connector

        // isn't found then we arbitarly pick the first connector.

        //

        boolean found = false;

        List<LaunchingConnector> launchers = launchingConnectors();

        for (LaunchingConnector lc: launchers) {

            if (lc.name().equals("com.sun.jdi.CommandLineLaunch")) {

                setDefaultConnector(lc);

                found = true;

                break;

            }

        }

        if (!found && launchers.size() > 0) {

            setDefaultConnector(launchers.get(0));

        }

    }

    public LaunchingConnector defaultConnector() {

        if (defaultConnector == null) {

            throw new Error("no default LaunchingConnector");

        }

        return defaultConnector;

    }

    public void setDefaultConnector(LaunchingConnector connector) {

        defaultConnector = connector;

    }

    public List<LaunchingConnector> launchingConnectors() {

        List<LaunchingConnector> launchingConnectors = new ArrayList<>(connectors.size());

        for (Connector connector: connectors) {

            if (connector instanceof LaunchingConnector) {

                launchingConnectors.add((LaunchingConnector)connector);

            }

        }

        return Collections.unmodifiableList(launchingConnectors);

    }

    public List<AttachingConnector> attachingConnectors() {

        List<AttachingConnector> attachingConnectors = new ArrayList<>(connectors.size());

        for (Connector connector: connectors) {

            if (connector instanceof AttachingConnector) {

                attachingConnectors.add((AttachingConnector)connector);

            }

        }

        return Collections.unmodifiableList(attachingConnectors);

    }

    public List<ListeningConnector> listeningConnectors() {

        List<ListeningConnector> listeningConnectors = new ArrayList<>(connectors.size());

        for (Connector connector: connectors) {

            if (connector instanceof ListeningConnector) {

                listeningConnectors.add((ListeningConnector)connector);

            }

        }

        return Collections.unmodifiableList(listeningConnectors);

    }

    public List<Connector> allConnectors() {

        return Collections.unmodifiableList(connectors);

    }

    public List<VirtualMachine> connectedVirtualMachines() {

        return Collections.unmodifiableList(targets);

    }

    public void addConnector(Connector connector) {

        connectors.add(connector);

    }

    public void removeConnector(Connector connector) {

        connectors.remove(connector);

    }

    public synchronized VirtualMachine createVirtualMachine(

                                        Connection connection,

                                        Process process) throws IOException {

        if (!connection.isOpen()) {

            throw new IllegalStateException("connection is not open");

        }

        VirtualMachine vm;

        try {

            vm = new VirtualMachineImpl(this, connection, process,

                                                   ++vmSequenceNumber);

        } catch (VMDisconnectedException e) {

            throw new IOException(e.getMessage());

        }

        targets.add(vm);

        return vm;

    }

    public VirtualMachine createVirtualMachine(Connection connection) throws IOException {

        return createVirtualMachine(connection, null);

    }

    public void addVirtualMachine(VirtualMachine vm) {

        targets.add(vm);

    }

    void disposeVirtualMachine(VirtualMachine vm) {

        targets.remove(vm);

    }

    public int majorInterfaceVersion() {

        return majorVersion;

    }

    public int minorInterfaceVersion() {

        return minorVersion;

    }

    ThreadGroup mainGroupForJDI() {

        return mainGroupForJDI;

    }

    String getString(String key) {

        if (messages == null) {

            messages = ResourceBundle.getBundle("com.sun.tools.jdi.resources.jdi");

        }

        return messages.getString(key);

    }

}