Package ptolemy.domains.algebraic.kernel

Class AlgebraicLoopReceiver

java.lang.Object

ptolemy.actor.AbstractReceiver

ptolemy.domains.algebraic.kernel.AlgebraicLoopReceiver

All Implemented Interfaces:

Receiver

public class AlgebraicLoopReceiver
extends AbstractReceiver

The receiver for use with AlgebraicLoopDirector or any of its subclasses. This receiver can be either present or absent. If it is present, then it has a token, which provides a value. This receiver has capacity 1, honors the defaultValue parameter, and its value can be overwritten or cleared at any time (made absent).

At first, an instance of this class has status absent, unless it has a defaultValue parameter. The clear() method makes the status absent. The put() method makes the status present, and provides a value. The reset() method reverts the status to absent or to the default value if there is one.

The isKnown() method and hasRoom() methods always return true.

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Edward A. Lee

Pt.AcceptedRating:

Red (eal)

Pt.ProposedRating:

Yellow (eal)

Constructor Summary

Constructors

Constructor	Description
AlgebraicLoopReceiver()	Construct an AlgebraicLoopReceiver with unknown status.
AlgebraicLoopReceiver(AlgebraicLoopDirector director)	Construct an AlgebraicLoopReceiver with unknown status.

Method Summary

Modifier and Type	Method	Description
protected Token	_getUpdatedValue()	If this receiver is a break variable, then return the stored updated value.
protected void	_setInitialValue(Token initialValue)	Indicate to this receiver that it is a break variable and set its initial value.
void	clear()	Set the status of this receiver to be absent.
Token	get()	Return the contained Token.
boolean	hasRoom()	Return true.
boolean	hasRoom(int numberOfTokens)	Return true.
boolean	hasToken()	Return true if the status is present.
boolean	hasToken(int numberOfTokens)	Return true if the argument is 1 and this mailbox is not empty, and otherwise return false.
void	put(Token token)	If the specified token is non-null, then set the status of this receiver to present, and to contain the specified token.
void	reset()	Clear stored tokens.

Methods inherited from class ptolemy.actor.AbstractReceiver

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

Methods inherited from class java.lang.Object

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

Constructor Detail

AlgebraicLoopReceiver

public AlgebraicLoopReceiver()

Construct an AlgebraicLoopReceiver with unknown status. This constructor does not need a director.

AlgebraicLoopReceiver

public AlgebraicLoopReceiver(AlgebraicLoopDirector director)

Construct an AlgebraicLoopReceiver with unknown status.

Parameters:

director - The director of this receiver.

Method Detail

clear

public void clear()
           throws IllegalActionException

Set the status of this receiver to be absent.

Specified by:

clear in interface Receiver

Overrides:

clear in class AbstractReceiver

Throws:

IllegalActionException - Always thrown.

get

public Token get()
          throws NoTokenException

Return the contained Token. If there is none, throw an exception.

Specified by:

get in interface Receiver

Specified by:

get in class AbstractReceiver

Returns:

The token contained by this receiver.

Throws:

NoTokenException - If this receiver is absent.

hasRoom

public boolean hasRoom()

Return true.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Returns:

true.

hasRoom

public boolean hasRoom(int numberOfTokens)

Return true.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Parameters:

numberOfTokens - Ignored in this base class.

Returns:

true.

hasToken

public boolean hasToken()

Return true if the status is present.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Returns:

True if the receiver has a token.

hasToken

public boolean hasToken(int numberOfTokens)
                 throws java.lang.IllegalArgumentException

Return true if the argument is 1 and this mailbox is not empty, and otherwise return false.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Parameters:

numberOfTokens - The number of tokens to get from the receiver.

Returns:

True if the argument is 1 and this mailbox is not empty.

Throws:

java.lang.IllegalArgumentException - If the argument is not positive. This is a runtime exception, so it does not need to be declared explicitly.

put

public void put(Token token)
         throws IllegalActionException

If the specified token is non-null, then set the status of this receiver to present, and to contain the specified token. If the specified token is null, then set the status to absent.

Specified by:

put in interface Receiver

Specified by:

put in class AbstractReceiver

Parameters:

token - The token to be put into this receiver.

Throws:

java.lang.IllegalArgumentException - If the argument is null.

IllegalActionException - If a token is present and cannot be compared to the specified token.

reset

public void reset()

Clear stored tokens.

Specified by:

reset in interface Receiver

Overrides:

reset in class AbstractReceiver

_getUpdatedValue

protected Token _getUpdatedValue()

If this receiver is a break variable, then return the stored updated value. Otherwise, return the current value.

Returns:

The token stored by

_setInitialValue

protected void _setInitialValue(Token initialValue)

Indicate to this receiver that it is a break variable and set its initial value. If this receiver is a break variable, then put() does not update the value of the receiver. Instead, the value provided to put() is stored to be retrieved by _getUpdatedValue().

Parameters:

initialValue - The initial value.