gridsimcore.java

一个非常著名的网格模拟器,能够运行网格调度算法!

/*
 * Title:        GridSim Toolkit
 * Description:  GridSim (Grid Simulation) Toolkit for Modeling and Simulation
 *               of Parallel and Distributed Systems such as Clusters and Grids
 * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html
 *
 * $Id: GridSimCore.java,v 1.13 2006/03/09 05:56:31 anthony Exp $
 */

package gridsim;

import eduni.simjava.*;
import gridsim.net.*;
import gridsim.util.*;
import java.util.Collection;


/**
 * Since GridSim version 3.0, this is the overall class of GridSim package,
 * that must be extended by other GridSim
 * entities. It inherits event management and threaded entity features from
 * the {@link eduni.simjava.Sim_entity} class. This class adds networking and
 * event delivery features, which allow synchronous or asynchronous
 * communication for service access or delivery.
 * <p>
 * All classes that extend this class can implement a method called
 * {@link eduni.simjava.Sim_entity#body()}, which is automatically invoked
 * when a simulation runs, since it is expected to be
 * responsible for simulating entity behavior. In addition,
 * {@link eduni.simjava.Sim_entity#body()} method is
 * the place to receive incoming events.
 * <p>
 * The entities that extend this class can be instantiated <i>with</i> or
 * <i>without</i> networked I/O ports. A networked GridSim entity gains
 * communication capability via the objects of GridSim's I/O entity classes,
 * {@link gridsim.net.Input} and {@link gridsim.net.Output} classes. Each I/O
 * entity will have a unique name assuming each GridSim entity that the user
 * creates has a unique name. For example, a resource entity with the name
 * <b>Resource2</b>,
 * will have an input entity whose name is prefixed with <b>Input_</b>,
 * making the input entity's full name <b>Input_Resource2</b>, which is
 * expected to be unique. <b>Input_Resource2</b> entity handles all incoming
 * events. A resource has an output entity whose name is prefixed with
 * <b>Output_</b>, e.g. <b>Output_Resource2</b>. <b>Output_Resource2</b>
 * entity handles all outgoing events.
 * <p>
 * The I/O entities are concurrent entities, but they
 * are visible within the GridSim entity and are able to communicate with
 * other GridSim entities by sending messages.
 * <p>
 * There are two ways to send a message or object to an entity, i.e. with or
 * without I/O port. Below shows the differences:
 * <ul>
 *      <li>using {@link #send(int, double, int, Object)},
 *          {@link #send(int, double, int)}, {@link #send(String,double,int)},
 *          or {@link #send(String, double, int, Object)} method.
 *          <p>
 *          These methods will send an event directly to the destination entity
 *          <b>without</b> using I/O port. Regardless how big the size of the
 *          Object data is, <br>
 *          <i>event arrival time = current simulation time + delay time</i>
 *          <p>
 *          For example: <tt>send(destID, delay, tag, obj)</tt>. <br>
 *          On the destinated entity, by creating a Sim_event object:
 *          <ul>
 *              <li> Sim_event.get_data() is obj of type Object. NOTE:
 *                   Object can be a generic type, such as IO_data, Gridlet,
 *                   String, etc.
 *              <li> Sim_event.get_dest() is destID of type int.
 *              <li> Sim_event.get_src() is sender ID of type int. NOTE:
 *                   sender ID is the entity ID that uses/calls this method.
 *              <li> Sim_event.get_tag() is tag of type int.
 *              <li> Sim_event.get_scheduled_by() is sender ID of type int.
 *          </ul>
 *      <br>
 *
 *      <li>using {@link #send(Sim_port, double, int, Object)} or
 *          {@link #send(Sim_port, double, int)} method.
 *          <p>
 *          These methods will send an event to the destination entity
 *          <b>with</b> I/O port. The size of the Object data sent is taken
 *          into a consideration for determining the event arrival time.
 *          <p>
 *          For example: <tt>send(ouputPort, delay, tag, obj)</tt> where
 *          obj <b>MUST</b> be of type <tt>IO_data</tt>. <br>
 *          On the destinated entity, by creating a Sim_event object:
 *          <ul>
 *              <li> Sim_event.get_data() is (IO_data) obj.getData() of type
 *                   Object. NOTE:
 *                   Object can be a generic type, such as Gridlet, String,
 *                   Integer, etc.
 *              <li> Sim_event.get_dest() is (IO_data) obj.getDestID() of
 *                   type int.
 *              <li> Sim_event.get_src() is an entity ID of type int.
 *                   <b>NOTE:</b> entity ID is not from the sender ID, but from
 *                   <tt>Input_xxx</tt>, where xxx = destinated entity name.
 *                   For example, to send to <tt>Resource2</tt>, the entity ID
 *                   is an ID of <tt>Input_Resource2</tt>.
 *              <li> Sim_event.get_tag() is tag of type int.
 *              <li> Sim_event.get_scheduled_by() is an entity ID of type int.
 *                   Same explanation of Sim_event.get_src().
 *          </ul>
 *          <br>
 *          <b>NOTE:</b> When sending using I/O port, object must be of type
 *             <tt>IO_data</tt>, otherwise <tt>ClassCastException</tt> will be
 *             reported on {@link gridsim.net.Output#body()} method.
 *
 * </ul>
 * <p>
 * Since GridSim 3.1, a network extension has been incorporated into
 * this simulation infrastructure. To make use of this, you need to create a
 * resource entity <b>only</b> using {@link #GridSimCore(String, Link)}
 * constructors.
 * Then you need to attach this entity into the overall network topology, i.e.
 * connecting this entity to a router, etc. See the examples provided
 * in the package for more details.
 * <p>
 * Another important feature of a network extension is the ability to
 * ping to a particular entity by using {@link #ping(int, int)} or
 * {@link #pingBlockingCall(int, int)} overloading methods.
 * <p>
 * However, there are few conditions to be met:
 * <ul>
 * <li> only work for entities which are connected through a network topology
 *      using the network extension entities, such as {@link gridsim.net.Link}
 *      and {@link gridsim.net.Router}.
 * <li> pinging to itself is permitted but the <tt>Round Trip Time</tt> is
 *      always 0 (zero).
 * <li> <b>most importantly</b>, you need to implement the below source code
 *      for the incoming ping request to work. This is required <b>only</b> for
 *      an entity that extends from {@link gridsim.GridSim} or
 *      {@link gridsim.GridSimCore}. <br>
 *      NOTE: {@link gridsim.GridResource} class is not effected as it
 *            already has the below code. <br><br><br>
 *
 * <code>
 * ... // other code <br>
 * <br>
 * public void body() { <br>
 * &nbsp;&nbsp; Sim_event ev = new Sim_event(); <br>
 * &nbsp;&nbsp; while (Sim_system.running()) { <br>
 * &nbsp;&nbsp;&nbsp;&nbsp; super.sim_get_next(ev); <br> <br>
 * &nbsp;&nbsp;&nbsp;&nbsp; // Entity's behaviour for handling ping request <br>
 * &nbsp;&nbsp;&nbsp;&nbsp; if (ev.get_tag() == GridSimTags.INFOPKT_SUBMIT) { <br>
 * &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; processPingRequest(ev); <br>
 * &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; continue; // skip the rest <br>
 * &nbsp;&nbsp;&nbsp;&nbsp; } <br> <br>
 * &nbsp;&nbsp;&nbsp;&nbsp; ... // other code for handling other incoming requests <br>
 * &nbsp;&nbsp; } <br>
 * } <br>
 * <br>
 * private void processPingRequest(Sim_event ev) { <br>
 * &nbsp;&nbsp; InfoPacket pkt = (InfoPacket) ev.get_data(); <br>
 * &nbsp;&nbsp; pkt.setTag(GridSimTags.INFOPKT_RETURN); <br>
 * &nbsp;&nbsp; pkt.setDestID( pkt.getSrcID() ); <br>
 * <br>
 * &nbsp;&nbsp; // sends back to the sender <br>
 * &nbsp;&nbsp; super.send(super.output, GridSimTags.SCHEDULE_NOW,
 * GridSimTags.INFOPKT_RETURN,
 * &nbsp;&nbsp;&nbsp;&nbsp; new IO_data(pkt,pkt.getSize(),pkt.getSrcID()) ); <br>
 * } <br>
 *
 * </code>
 * </ul>
 *
 * @author       Manzur Murshed and Rajkumar Buyya
 * @author       Anthony Sulistio (re-written this class)
 * @since        GridSim Toolkit 3.0
 * @see eduni.simjava.Sim_entity
 * @see gridsim.net.Output
 * @see gridsim.net.Input
 * @invariant $none
 */
public class GridSimCore extends Sim_entity
{
    private boolean networkedFlag_;  // true, if networked entity, other false

    // false means NOT invoked
    private boolean terminateIOEntitiesFlag_ = false;

    // If this GridSim uses Network extensions, then the link that is joined to
    // this entity.
    private Link link_;

    /** Reading data received via input port */
    protected Sim_port input;

    /** Sending data via output port to external entities */
    protected Sim_port output;

    // Output port but only for a network extension.
    private Output out_ = null;


    /**
     * Allocates a new GridSim object
     * <b>without</b> NETWORK communication channels: "input" and
     * "output" Sim_port. In summary, this object has <tt>NO</tt>
     * network communication or bandwidth speed.
     * @param name       the name to be associated with this entity (as
     *                   required by Sim_entity class from simjava package)
     * @throws Exception This happens when creating this entity before
     *                   initializing GridSim package or this entity name is
     *                   <tt>null</tt> or empty
     * @see gridsim.GridSim#init(int, Calendar, boolean, String[], String[],
     *          String)
     * @see eduni.simjava.Sim_entity
     * @pre name != null
     * @post $none
     */
    protected GridSimCore(String name) throws Exception
    {
        super(name);
        networkedFlag_ = false;
        input = null;
        output = null;
        link_ = null;
    }

    /**
     * Allocates a new GridSim object
     * <b>with</b> NETWORK communication channels: "input" and
     * "output" Sim_port. In addition, this method will create <tt>Input</tt>
     * and <tt>Output</tt> object.
     * <p>
     * However, this is the old approach using one-to-all connection where you
     * can not specify a network topology and there is no wired link from
     * this entity to others. Use {@link #GridSimCore(String, Link)} instead.
     *
     * @param name       the name to be associated with this entity (as
     *                   required by Sim_entity class from simjava package)
     * @param baudRate   network communication or bandwidth speed
     * @throws Exception This happens when creating this entity before
     *                   initializing GridSim package or this entity name is
     *                   <tt>null</tt> or empty
     * @see gridsim.GridSim#init(int, Calendar, boolean, String[], String[],
     *          String)
     * @see eduni.simjava.Sim_entity
     * @see gridsim.net.Input
     * @see gridsim.net.Output
     * @pre name != null
     * @pre baudRate > 0.0
     * @post $none
     */
    protected GridSimCore(String name, double baudRate) throws Exception
    {
        super(name);
        networkedFlag_ = true;
        link_ = null;

        input = new Sim_port("input");
        output = new Sim_port("output");

        super.add_port(input);
        super.add_port(output);

        // Every GridSim entity with network has its own input/output channels.
        // Connect this entity "input" port to its input buffer "in_port"
        new Input("Input_" + name, baudRate);
        Sim_system.link_ports(name, "input", "Input_" + name, "input_buffer");

        new Output("Output_" + name, baudRate);
        Sim_system.link_ports(name, "output", "Output_"+name, "output_buffer");
    }

    /**
     * Allocates a new GridSim object
     * <b>with</b> NETWORK communication channels: "input" and
     * "output" Sim_port. In addition, this method will create <tt>Input</tt>
     * and <tt>Output</tt> object.
     * <p>
     * You need to manually create the network topology, i.e. connecting
     * this entity to a router/other entity.
     *
     * @param name       the name to be associated with this entity (as
     *                   required by Sim_entity class from simjava package)
     * @param link       the link that this GridSim entity will use to
                         communicate with other GridSim or Network entities.
     * @throws Exception This happens when creating this entity before
     *                   initializing GridSim package or this entity name is
     *                   <tt>null</tt> or empty
     * @see gridsim.GridSim#init(int, Calendar, boolean, String[], String[],
     *          String)
     * @see eduni.simjava.Sim_entity
     * @see gridsim.net.Input
     * @see gridsim.net.Output
     * @pre name != null
     * @pre link != null
     * @post $none
     */
    protected GridSimCore(String name, Link link) throws Exception
    {
        super(name);
        networkedFlag_ = true;
        link_ = link;

        input = new Sim_port("input");
        output = new Sim_port("output");

        super.add_port(input);
        super.add_port(output);

        // Every GridSim entity with network has its own input/output channels.
        // Connect this entity "input" port to its input buffer "in_port"
        Input in = new Input("Input_" + name, link_.getBaudRate());
        in.addLink(link_);
        Sim_system.link_ports(name, "input", "Input_" + name, "input_buffer");

        out_ = new Output("Output_" + name, link_.getBaudRate());
        out_.addLink(link_);
        Sim_system.link_ports(name, "output", "Output_"+name, "output_buffer");
    }

    /**
     * Returns the Link that connects this entity to other entities if Network
     * Extensions are being used.
     * @return a Link object
     * @pre $none
     * @post $none
     */
    public Link getLink() {
        return link_;
    }

    /**
     * Sets the background traffic generator for this entity.
     * <p>
     * When simulation starts, the Output entity will automatically sends junk
     * packets to resource entities.
     * @param gen   a background traffic generator
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     * @pre gen != null
     * @post $none
     */
    public boolean setBackgroundTraffic(TrafficGenerator gen)
    {
        if (gen == null || out_ == null) {
            return false;
        }

        return out_.setBackgroundTraffic(gen);
    }