ptolemy.domains.de.kernel

Class DEReceiver

java.lang.Object

ptolemy.actor.AbstractReceiver

ptolemy.domains.de.kernel.DEReceiver

All Implemented Interfaces:

Receiver

Direct Known Subclasses:

ATCReceiver, MetroIIPtidesReceiver, PtidesReceiver, TCSReceiver, WirelessReceiver

public class DEReceiver
extends AbstractReceiver

An implementation of the ptolemy.actor.Receiver interface for the DE domain.

The put() method stores the given token in this receiver and posts a trigger event to the director. The director is responsible to dequeue that trigger event and invoke the actor that contains this receiver. The get() method returns the first available token from the receiver.

Before firing an actor, the director is expected to put at least one token into at least one of the receivers contained by the actor.

Since:

Ptolemy II 0.2

Version:

$Id$

Author:

Lukito Muliadi, Edward A. Lee, Jie Liu, Haiyang Zheng

Pt.AcceptedRating:

Yellow (hyzheng)

Pt.ProposedRating:

Green (hyzheng)

Field Summary

Fields

Modifier and Type	Field and Description
protected long	_directorVersion The version of the workspace of container, used for caching by _getDirector().
protected java.util.LinkedList	_tokens List for storing tokens.

Constructor Summary

Constructors

Constructor and Description
DEReceiver() Construct an empty DEReceiver with no container.
DEReceiver(IOPort container) Construct an empty DEReceiver with the specified container.

Method Summary

Modifier and Type	Method and Description
void	clear() Clear this receiver of any contained tokens.
java.util.List<Token>	elementList() Return a list with tokens that are currently in the receiver available for get() or getArray(), beginning with the oldest one.
Token	get() Get the first token from the receiver.
boolean	hasRoom() Return true, indicating that there is always room.
boolean	hasRoom(int tokens) Return true if the receiver has room for putting the given number of tokens into it (via the put() method).
boolean	hasToken() Return true if there is at least one token available to the get() method.
boolean	hasToken(int numberOfTokens) Return true if there are numberOfTokens tokens tokens available to the get() method.
void	put(Token token) Put a token into this receiver and post a trigger event to the director.

Methods inherited from class ptolemy.actor.AbstractReceiver

getArray, getContainer, getCurrentTime, getModelTime, isKnown, putArray, putArrayToAll, putToAll, reset, setContainer, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_directorVersion

protected long _directorVersion

The version of the workspace of container, used for caching by _getDirector(). Derived classes that modify the cache may need to update this variable.

_tokens

protected java.util.LinkedList _tokens

List for storing tokens. Access with clear(), add(), and take().

Constructor Detail

DEReceiver

public DEReceiver()

Construct an empty DEReceiver with no container.

DEReceiver

public DEReceiver(IOPort container)
           throws IllegalActionException

Construct an empty DEReceiver with the specified container.

Parameters:

container - The container.

Throws:

IllegalActionException - If the container does not accept this receiver.

Method Detail

clear

public void clear()

Clear this receiver of any contained tokens.

Specified by:

clear in interface Receiver

Overrides:

clear in class AbstractReceiver

elementList

public java.util.List<Token> elementList()

Return a list with tokens that are currently in the receiver available for get() or getArray(), beginning with the oldest one.

Specified by:

elementList in interface Receiver

Overrides:

elementList in class AbstractReceiver

Returns:

A list of instances of Token.

get

public Token get()
          throws NoTokenException

Get the first token from the receiver. The token returned is one that was put in the receiver with a timestamp equal to or earlier than the current time. If there is no token, throw an exception. If this receiver contains more than one event, the oldest event is removed first. In other words, this receiver has a FIFO behavior.

Specified by:

get in interface Receiver

Specified by:

get in class AbstractReceiver

Returns:

A token.

Throws:

NoTokenException - If there are no more tokens. This is a runtime exception, so it need not to be declared explicitly.

hasRoom

public final boolean hasRoom()

Return true, indicating that there is always room.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Returns:

True.

hasRoom

public boolean hasRoom(int tokens)

Return true if the receiver has room for putting the given number of tokens into it (via the put() method). Returning true in this method should also guarantee that calling the put() method will not result in an exception.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Parameters:

tokens - An int indicating the number of spaces available.

Returns:

True.

hasToken

public boolean hasToken()

Return true if there is at least one token available to the get() method.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Returns:

True if there are more tokens.

hasToken

public boolean hasToken(int numberOfTokens)

Return true if there are numberOfTokens tokens tokens available to the get() method.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Parameters:

numberOfTokens - An int indicating how many tokens are needed.

Returns:

True if there are numberOfTokens tokens available.

put

public void put(Token token)
         throws IllegalActionException,
                NoRoomException

Put a token into this receiver and post a trigger event to the director. The director will be responsible to dequeue the trigger event at the correct timestamp and microstep and invoke the corresponding actor whose input port contains this receiver. This receiver may contain more than one events.

Specified by:

put in interface Receiver

Specified by:

put in class AbstractReceiver

Parameters:

token - The token to be put, or null to put no token.

Throws:

IllegalActionException - If cannot get the director or if the current microstep is zero.

NoRoomException - Not thrown in this class.