org.lsst.ccs.subsystems.fcs.drivers

Class CommandDispenser

java.lang.Object

org.lsst.ccs.subsystems.fcs.drivers.CommandDispenser

public class CommandDispenser
extends Object

The CommandDispenser provides methods and internal classes to stored the commands we send to the tcpProxy and to wait for the response. It is used by the method call() of the tcpProxy to stored the initial commands and then to retrieve the response. The response is updated by the tcpProxy readingThread when it arrives from the tcp Socket. The CommandToRegister object has to be removed from the map by the client classes.

Author:

virieux

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CommandDispenser.CommandToRegister An internal class for the command to be registered.
static class	CommandDispenser.TokenLostException An Exception to be thrown when a token has been lost.

Constructor Summary

Constructors

Constructor and Description
CommandDispenser()

Method Summary

Modifier and Type	Method and Description
String	getCommandResponse(String token, long timeout) Returns the response to a command.
boolean	isTokenUsed(String token) Tells if the token is used.
String	register(String command) Registers a command and returns a token to be used to retrieve the command in the map.
String	registerResponse(String token, String response) Registers the response for a command.
void	remove(String token) Remove a token.

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandDispenser

public CommandDispenser()

Method Detail

register

public String register(String command)

Registers a command and returns a token to be used to retrieve the command in the map. The token is the key of the map. The command is stored as a CommandToRegister in the value of the map.

Parameters:

command -

Returns:

registerResponse

public String registerResponse(String token,
                               String response)

Registers the response for a command. The command is retrieve by its token given as argument, and the response is given as argument too.

Parameters:

token -

response -

Returns:

getCommandResponse

public String getCommandResponse(String token,
                                 long timeout)

Returns the response to a command. The command is retrieved by the token given as augument. This methods waits for the response coming from the field bus. If the response is not received during a timeout given as argument, a CanOpenCallTimeoutException is thrown.

Parameters:

token -

timeout -

Returns:

Throws:

CanOpenCallTimeoutException

remove

public void remove(String token)

Remove a token.

Parameters:

token -

isTokenUsed

public boolean isTokenUsed(String token)

Tells if the token is used. beware : in a multihreaded environment there may be race condition where this method returns true but where an Exception is fired upon call of callback Method.

Parameters:

token -

Returns: