/*
* Title: CloudSim Toolkit
* Description: CloudSim (Cloud Simulation) Toolkit for Modeling and Simulation of Clouds
* Licence: GPL - http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2009-2012, The University of Melbourne, Australia
*/
package org.cloudbus.cloudsim.core;
import org.cloudbus.cloudsim.Log;
import org.cloudbus.cloudsim.NetworkTopology;
import org.cloudbus.cloudsim.core.predicates.Predicate;
/**
* This class represents a simulation entity. An entity handles events and can send events to other
* entities. When this class is extended, there are a few methods that need to be implemented:
* <ul>
* <li> {@link #startEntity()} is invoked by the {@link Simulation} class when the simulation is
* started. This method should be responsible for starting the entity up.
* <li> {@link #processEvent(SimEvent)} is invoked by the {@link Simulation} class whenever there is
* an event in the deferred queue, which needs to be processed by the entity.
* <li> {@link #shutdownEntity()} is invoked by the {@link Simulation} before the simulation
* finishes. If you want to save data in log files this is the method in which the corresponding
* code would be placed.
* </ul>
*
* @todo the list above is redundant once all mentioned methods are abstract.
* The documentation duplication may lead to have some of them
* out-of-date and future confusion.
*
* @author Marcos Dias de Assuncao
* @since CloudSim Toolkit 1.0
*/
public abstract class SimEntity implements Cloneable {
/** The entity name. */
private String name;
/** The entity id. */
private int id;
/** The buffer for selected incoming events. */
private SimEvent evbuf;
/** The entity's current state. */
private int state;
/**
* Creates a new entity.
*
* @param name the name to be associated with the entity
*/
public SimEntity(String name) {
if (name.indexOf(" ") != -1) {
throw new IllegalArgumentException("Entity names can't contain spaces.");
}
this.name = name;
id = -1;
state = RUNNABLE;
CloudSim.addEntity(this);
}
/**
* Gets the name of this entity.
*
* @return The entity's name
*/
public String getName() {
return name;
}
/**
* Gets the unique id number assigned to this entity.
*
* @return The id number
*/
public int getId() {
return id;
}
// The schedule functions
/**
* Sends an event to another entity by id number, with data. Note that the tag <code>9999</code>
* is reserved.
*
* @param dest The unique id number of the destination entity
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void schedule(int dest, double delay, int tag, Object data) {
if (!CloudSim.running()) {
return;
}
CloudSim.send(id, dest, delay, tag, data);
}
/**
* Sends an event to another entity by id number and with <b>no</b> data. Note that the tag
* <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
*/
public void schedule(int dest, double delay, int tag) {
schedule(dest, delay, tag, null);
}
/**
* Sends an event to another entity through a port with a given name, with data. Note that the
* tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void schedule(String dest, double delay, int tag, Object data) {
schedule(CloudSim.getEntityId(dest), delay, tag, data);
}
/**
* Sends an event to another entity through a port with a given name, with <b>no</b> data. Note
* that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
*/
public void schedule(String dest, double delay, int tag) {
schedule(dest, delay, tag, null);
}
/**
* Sends an event to another entity by id number, with data
* but no delay. Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleNow(int dest, int tag, Object data) {
schedule(dest, 0, tag, data);
}
/**
* Sends an event to another entity by id number and with <b>no</b> data
* and no delay. Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param tag An user-defined number representing the type of event.
*/
public void scheduleNow(int dest, int tag) {
schedule(dest, 0, tag, null);
}
/**
* Sends an event to another entity through a port with a given name, with data
* but no delay. Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleNow(String dest, int tag, Object data) {
schedule(CloudSim.getEntityId(dest), 0, tag, data);
}
/**
* Send an event to another entity through a port with a given name, with <b>no</b> data
* and no delay.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param tag An user-defined number representing the type of event.
*/
public void scheduleNow(String dest, int tag) {
schedule(dest, 0, tag, null);
}
/**
* Sends a high priority event to another entity by id number, with data.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleFirst(int dest, double delay, int tag, Object data) {
if (!CloudSim.running()) {
return;
}
CloudSim.sendFirst(id, dest, delay, tag, data);
}
/**
* Sends a high priority event to another entity by id number and with <b>no</b> data.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
*/
public void scheduleFirst(int dest, double delay, int tag) {
scheduleFirst(dest, delay, tag, null);
}
/**
* Sends a high priority event to another entity through a port with a given name, with data.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleFirst(String dest, double delay, int tag, Object data) {
scheduleFirst(CloudSim.getEntityId(dest), delay, tag, data);
}
/**
* Sends a high priority event to another entity through a port with a given name, with <b>no</b>
* data. Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param delay How long from the current simulation time the event should be sent
* @param tag An user-defined number representing the type of event.
*/
public void scheduleFirst(String dest, double delay, int tag) {
scheduleFirst(dest, delay, tag, null);
}
/**
* Sends a high priority event to another entity by id number, with data
* and no delay.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleFirstNow(int dest, int tag, Object data) {
scheduleFirst(dest, 0, tag, data);
}
/**
* Sends a high priority event to another entity by id number and with <b>no</b> data
* and no delay.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The unique id number of the destination entity
* @param tag An user-defined number representing the type of event.
*/
public void scheduleFirstNow(int dest, int tag) {
scheduleFirst(dest, 0, tag, null);
}
/**
* Sends a high priority event to another entity through a port with a given name, with data
* and no delay.
* Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param tag An user-defined number representing the type of event.
* @param data The data to be sent with the event.
*/
public void scheduleFirstNow(String dest, int tag, Object data) {
scheduleFirst(CloudSim.getEntityId(dest), 0, tag, data);
}
/**
* Sends a high priority event to another entity through a port with a given name, with <b>no</b>
* data and no delay. Note that the tag <code>9999</code> is reserved.
*
* @param dest The name of the port to send the event through
* @param tag An user-defined number representing the type of event.
*/
public void scheduleFirstNow(String dest, int tag) {
scheduleFirst(dest, 0, tag, null);
}
/**
* Sets the entity to be inactive for a time period.
*
* @param delay the time period for which the entity will be inactive
*/
public void pause(double delay) {
if (delay < 0) {
throw new IllegalArgumentException("Negative delay supplied.");
}
if (!CloudSim.running()) {
return;
}
CloudSim.pause(id, delay);
}
/**
* Counts how many events matching a predicate are waiting in the entity's deferred queue.
*
* @param p The event selection predicate
* @return The count of matching events
*/
public int numEventsWaiting(Predicate p) {
return CloudSim.waiting(id, p);
}
/**
* Counts how many events are waiting in the entity's deferred queue.
*
* @return The count of events
*/
public int numEventsWaiting() {
return CloudSim.waiting(id, CloudSim.SIM_ANY);
}
/**
* Extracts the first event matching a predicate waiting in the entity's deferred queue.
*
* @param p The event selection predicate
* @return the simulation event
*/
public SimEvent selectEvent(Predicate p) {
if (!CloudSim.running()) {
return null;
}
return CloudSim.select(id, p);
}
/**
* Cancels the first event matching a predicate waiting in the entity's future queue.
*
* @param p The event selection predicate
* @return The number of events cancelled (0 or 1)
*/
public SimEvent cancelEvent(Predicate p) {
if (!CloudSim.running()) {
return null;
}
return CloudSim.cancel(id, p);
}
/**
* Gets the first event matching a predicate from the deferred queue, or if none match, wait for
* a matching event to arrive.
*
* @param p The predicate to match
* @return the simulation event
*/
public SimEvent getNextEvent(Predicate p) {
if (!CloudSim.running()) {
return null;
}
if (numEventsWaiting(p) > 0) {
return selectEvent(p);
}
return null;
}
/**
* Waits for an event matching a specific predicate. This method does not check the entity's
* deferred queue.
*
* @param p The predicate to match
*/
public void waitForEvent(Predicate p) {
if (!CloudSim.running()) {
return;
}
CloudSim.wait(id, p);
state = WAITING;
}
/**
* Gets the first event waiting in the entity's deferred queue, or if there are none, wait for an
* event to arrive.
*
* @return the simulation event
*/
public SimEvent getNextEvent() {
return getNextEvent(CloudSim.SIM_ANY);
}
/**
* This method is invoked by the {@link CloudSim} class when the simulation is started.
* It should be responsible for starting the entity up.
*/
public abstract void startEntity();
/**
* Processes events or services that are available for the entity.
* This method is invoked by the {@link CloudSim} class whenever there is an event in the
* deferred queue, which needs to be processed by the entity.
*
* @param ev information about the event just happened
*
* @pre ev != null
* @post $none
*/
public abstract void processEvent(SimEvent ev);
/**
* Shuts down the entity.
* This method is invoked by the {@link CloudSim} before the simulation finishes. If you want
* to save data in log files this is the method in which the corresponding code would be placed.
*/
public abstract void shutdownEntity();
/**
* The run loop to process events fired during the simulation.
* The events that will be processed are defined
* in the {@link #processEvent(org.cloudbus.cloudsim.core.SimEvent)} method.
*
* @see #processEvent(org.cloudbus.cloudsim.core.SimEvent)
*/
public void run() {
SimEvent ev = evbuf != null ? evbuf : getNextEvent();
while (ev != null) {
processEvent(ev);
if (state != RUNNABLE) {
break;
}
ev = getNextEvent();
}
evbuf = null;
}
/**
* Gets a clone of the entity. This is used when independent replications have been specified as
* an output analysis method. Clones or backups of the entities are made in the beginning of the
* simulation in order to reset the entities for each subsequent replication. This method should
* not be called by the user.
*
* @return A clone of the entity
* @throws CloneNotSupportedException when the entity doesn't support cloning
*/
@Override
protected final Object clone() throws CloneNotSupportedException {
SimEntity copy = (SimEntity) super.clone();
copy.setName(name);
copy.setEventBuffer(null);
return copy;
}
// Used to set a cloned entity's name
/**
* Sets the name.
*
* @param new_name the new name
*/
private void setName(String new_name) {
name = new_name;
}
// --------------- PACKAGE LEVEL METHODS ------------------
/**
* Gets the entity state.
*
* @return the state
*/
protected int getState() {
return state;
}
/**
* Gets the event buffer.
*
* @return the event buffer
*/
protected SimEvent getEventBuffer() {
return evbuf;
}
// The entity states
//@todo The states should be an enum.
/** The Constant RUNNABLE. */
public static final int RUNNABLE = 0;
/** The Constant WAITING. */
public static final int WAITING = 1;
/** The Constant HOLDING. */
public static final int HOLDING = 2;
/** The Constant FINISHED. */
public static final int FINISHED = 3;
/**
* Sets the entity state.
*
* @param state the new state
*/
protected void setState(int state) {
this.state = state;
}
/**
* Sets the entity id.
*
* @param id the new id
*/
protected void setId(int id) {
this.id = id;
}
/**
* Sets the event buffer.
*
* @param e the new event buffer
*/
protected void setEventBuffer(SimEvent e) {
evbuf = e;
}
// --------------- EVENT / MESSAGE SEND WITH NETWORK DELAY METHODS ------------------
/**
* Sends an event/message to another entity by <tt>delaying</tt> the simulation time from the
* current time, with a tag representing the event type.
*
* @param entityId the id number of the destination entity
* @param delay how long from the current simulation time the event should be sent. If delay is
* a negative number, then it will be changed to 0
* @param cloudSimTag an user-defined number representing the type of an event/message
* @param data A reference to data to be sent with the event
* @pre entityID > 0
* @pre delay >= 0.0
* @pre data != null
* @post $none
*/
protected void send(int entityId, double delay, int cloudSimTag, Object data) {
if (entityId < 0) {
return;
}
// if delay is -ve, then it doesn't make sense. So resets to 0.0
if (delay < 0) {
delay = 0;
}
if (Double.isInfinite(delay)) {
throw new IllegalArgumentException("The specified delay is infinite value");
}
if (entityId < 0) {
Log.printConcatLine(getName(), ".send(): Error - " + "invalid entity id ", entityId);
return;
}
int srcId = getId();
if (entityId != srcId) {// only delay messages between different entities
delay += getNetworkDelay(srcId, entityId);
}
schedule(entityId, delay, cloudSimTag, data);
}
/**
* Sends an event/message to another entity by <tt>delaying</tt> the simulation time from the
* current time, with a tag representing the event type.
*
* @param entityId the id number of the destination entity
* @param delay how long from the current simulation time the event should be sent. If delay is
* a negative number, then it will be changed to 0
* @param cloudSimTag an user-defined number representing the type of an event/message
* @pre entityID > 0
* @pre delay >= 0.0
* @post $none
*/
protected void send(int entityId, double delay, int cloudSimTag) {
send(entityId, delay, cloudSimTag, null);
}
/**
* Sends an event/message to another entity by <tt>delaying</tt> the simulation time from the
* current time, with a tag representing the event type.
*
* @param entityName the name of the destination entity
* @param delay how long from the current simulation time the event should be sent. If delay is
* a negative number, then it will be changed to 0
* @param cloudSimTag an user-defined number representing the type of an event/message
* @param data A reference to data to be sent with the event
* @pre entityName != null
* @pre delay >= 0.0
* @pre data != null
* @post $none
*/
protected void send(String entityName, double delay, int cloudSimTag, Object data) {
send(CloudSim.getEntityId(entityName), delay, cloudSimTag, data);
}
/**
* Sends an event/message to another entity by <tt>delaying</tt> the simulation time from the
* current time, with a tag representing the event type.
*
* @param entityName the name of the destination entity
* @param delay how long from the current simulation time the event should be sent. If delay is
* a negative number, then it will be changed to 0
* @param cloudSimTag an user-defined number representing the type of an event/message
* @pre entityName != null
* @pre delay >= 0.0
* @post $none
*/
protected void send(String entityName, double delay, int cloudSimTag) {
send(entityName, delay, cloudSimTag, null);
}
/**
* Sends an event/message to another entity, with a tag representing the event type.
*
* @param entityId the id number of the destination entity
* @param cloudSimTag an user-defined number representing the type of an event/message
* @param data A reference to data to be sent with the event
* @pre entityID > 0
* @pre delay >= 0.0
* @pre data != null
* @post $none
*/
protected void sendNow(int entityId, int cloudSimTag, Object data) {
send(entityId, 0, cloudSimTag, data);
}
/**
* Sends an event/message to another entity, with a tag representing the event type.
*
* @param entityId the id number of the destination entity
* @param cloudSimTag an user-defined number representing the type of an event/message
* @pre entityID > 0
* @pre delay >= 0.0
* @post $none
*/
protected void sendNow(int entityId, int cloudSimTag) {
send(entityId, 0, cloudSimTag, null);
}
/**
* Sends an event/message to another entity, with a tag representing the event type.
*
* @param entityName the name of the destination entity
* @param cloudSimTag an user-defined number representing the type of an event/message
* @param data A reference to data to be sent with the event
* @pre entityName != null
* @pre delay >= 0.0
* @pre data != null
* @post $none
*/
protected void sendNow(String entityName, int cloudSimTag, Object data) {
send(CloudSim.getEntityId(entityName), 0, cloudSimTag, data);
}
/**
* Sends an event/message to another entity, with a tag representing the event type.
*
* @param entityName the name of the destination entity
* @param cloudSimTag an user-defined number representing the type of an event/message
* @pre entityName != null
* @pre delay >= 0.0
* @post $none
*/
protected void sendNow(String entityName, int cloudSimTag) {
send(entityName, 0, cloudSimTag, null);
}
/**
* Gets the network delay associated to the sent of a message from a given source to a given
* destination.
*
* @param src source of the message
* @param dst destination of the message
* @return delay to send a message from src to dst
* @pre src >= 0
* @pre dst >= 0
*/
private double getNetworkDelay(int src, int dst) {
if (NetworkTopology.isNetworkEnabled()) {
return NetworkTopology.getDelay(src, dst);
}
return 0.0;
}
}