ptolemy.domains.giotto.kernel
Class GiottoReceiver

java.lang.Object
  ptolemy.actor.AbstractReceiver
      ptolemy.domains.giotto.kernel.GiottoReceiver

All Implemented Interfaces:

Receiver, StateReceiver

public class GiottoReceiver
extends AbstractReceiver
implements StateReceiver

A receiver for the Giotto domain. It uses double-buffering. An actor may write to a receiver using put at any time. However, a new token will only be available to get if update has been called before. The update method makes the token from the last put invocation available to get. The GiottoDirector delays calls to update according to the Giotto semantics.

Since:

Ptolemy II 1.0

Version:

$Id: GiottoReceiver.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Christoph Meyer Kirsch and Edward A. Lee

See Also:

GiottoDirector

Accepted Rating:

Yellow (liuj)

Proposed Rating:

Yellow (cm)

Field Summary

private Token	_nextToken
private Token	_token

Constructor Summary

GiottoReceiver()
Construct an empty GiottoReceiver with no container.

GiottoReceiver(IOPort container)
Construct an empty GiottoReceiver with the specified container.

Method Summary

void	clear() Clear this receiver of any contained tokens.
java.util.List<Token>	elementList() Return a list with the token currently in the receiver, or an empty list if there is no such token.
Token	get() Get the contained and available token, i.e., get the last token that has been put into the receiver before the last update.
boolean	hasRoom() Return true, since writing to this receiver is always allowed.
boolean	hasRoom(int numberOfTokens) Return true, since writing to this receiver is always allowed.
boolean	hasToken() Return true if there is a token available.
boolean	hasToken(int numberOfTokens) Return true if the receiver has at least one token available.
void	put(Token token) Put a token into this receiver.
Token	remove() Get the contained and available token, i.e., get the last token that has been put into the receiver before the last update and reset the _token only.
void	reset() Reset the receiver by removing all tokens from the receiver.
void	update() Update the receiver by making the last token that has been passed to put() available to get().

Methods inherited from class ptolemy.actor.AbstractReceiver

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

Field Detail

_nextToken

private Token _nextToken

_token

private Token _token

Constructor Detail

GiottoReceiver

public GiottoReceiver()

Construct an empty GiottoReceiver with no container.

GiottoReceiver

public GiottoReceiver(IOPort container)
               throws IllegalActionException

Construct an empty GiottoReceiver 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. FIXME. Should rename and replace all the reset() with clear().

Specified by:

clear in interface Receiver

Overrides:

clear in class AbstractReceiver

elementList

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

Return a list with the token currently in the receiver, or an empty list if there is no such token.

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 contained and available token, i.e., get the last token that has been put into the receiver before the last update.

Specified by:

get in interface Receiver

Specified by:

get in class AbstractReceiver

Returns:

A token.

Throws:

NoTokenException - If no token is available.

hasRoom

public boolean hasRoom()

Return true, since writing to this receiver is always allowed.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Returns:

True.

hasRoom

public final boolean hasRoom(int numberOfTokens)

Return true, since writing to this receiver is always allowed.

Specified by:

hasRoom in interface Receiver

Specified by:

hasRoom in class AbstractReceiver

Parameters:

numberOfTokens - The size of tokens to be written to the receiver.

Returns:

True.

hasToken

public boolean hasToken()

Return true if there is a token available. A token is available whenever put() has been called at least once followed by a call to the update() method.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Returns:

True if there is a token available.

hasToken

public final boolean hasToken(int numberOfTokens)

Return true if the receiver has at least one token available. Any number of calls to get() is allowed and will return the same available token.

Specified by:

hasToken in interface Receiver

Specified by:

hasToken in class AbstractReceiver

Parameters:

numberOfTokens - The number of tokens available in this receiver.

Returns:

True if there is a token available.

put

public void put(Token token)
         throws NoRoomException

Put a token into this receiver. Any token which has been put into the receiver before without calling update will be lost. The token becomes available to the get() method only after update() is called.

Note that putting a null into this receiver will leave the receiver empty after update. The receiver does not check against this but expects that IOPort will always put non-null tokens into receivers.

Specified by:

put in interface Receiver

Specified by:

put in class AbstractReceiver

Parameters:

token - The token to be put into this receiver.

Throws:

NoRoomException - Not thrown in this base class.

remove

public Token remove()
             throws NoTokenException

Get the contained and available token, i.e., get the last token that has been put into the receiver before the last update and reset the _token only.

Returns:

A token.

Throws:

NoTokenException - If no token is available.

reset

public void reset()

Reset the receiver by removing all tokens from the receiver.

Specified by:

reset in interface Receiver

Overrides:

reset in class AbstractReceiver

update

public void update()

Update the receiver by making the last token that has been passed to put() available to get().