/*

 * Copyright (c) 1998, 2011, 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

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/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

package com.sun.tools.example.debug.bdi;

import com.sun.jdi.VirtualMachine;

import com.sun.jdi.VMDisconnectedException;

/**

 * Our repository of what we know about the state of one

 * running VM.

 */

class Session {

    final VirtualMachine vm;

    final ExecutionManager runtime;

    final OutputListener diagnostics;

    boolean running = true;  // Set false by JDIEventSource

    boolean interrupted = false;  // Set false by JDIEventSource

    private JDIEventSource eventSourceThread = null;

    private int traceFlags;

    private boolean dead = false;

    public Session(VirtualMachine vm, ExecutionManager runtime,

                   OutputListener diagnostics) {

        this.vm = vm;

        this.runtime = runtime;

        this.diagnostics = diagnostics;

        this.traceFlags = VirtualMachine.TRACE_NONE;

    }

    /**

     * Determine if VM is interrupted, i.e, present and not running.

     */

    public boolean isInterrupted() {

        return interrupted;

    }

    public void setTraceMode(int traceFlags) {

        this.traceFlags = traceFlags;

        if (!dead) {

            vm.setDebugTraceMode(traceFlags);

        }

    }

    public boolean attach() {

        vm.setDebugTraceMode(traceFlags);

        diagnostics.putString("Connected to VM");

        eventSourceThread = new JDIEventSource(this);

        eventSourceThread.start();

        return true;

    }

    public void detach() {

        if (!dead) {

            eventSourceThread.interrupt();

            eventSourceThread = null;

            //### The VM may already be disconnected

            //### if the debuggee did a System.exit().

            //### Exception handler here is a kludge,

            //### Rather, there are many other places

            //### where we need to handle this exception,

            //### and initiate a detach due to an error

            //### condition, e.g., connection failure.

            try {

                vm.dispose();

            } catch (VMDisconnectedException ee) {}

            dead = true;

            diagnostics.putString("Disconnected from VM");

        }

    }

}