stella.rmi
Interface ListenerControlling

All Superinterfaces:

Remote

All Known Subinterfaces:

AdapterControlling, AdcControlling, AutoClearControlling, AutoFocusControlling, BuildingControlling, CalibrationControlling, CcdControlling, DitherControlling, DomeControlling, FocusControlling, GuiderControlling, PointingModelControlling, ReadoutModeControlling, SesControlling, ShelterControlling, TelescopeControlling, WifsipControlling

All Known Implementing Classes:

AdapterMaster, AuxiliaryMaster, CalibrationMaster, DomeMaster, EnvironmentMaster, GenericMaster, GenericMaster.Standalone, SesMaster, ShelterMaster, TelescopeMaster, TestReceiver, WifsipMaster

public interface ListenerControlling
extends Remote

This interface defines the remote capabilities of registering and deregister from a caster. It is intended to allow in-situ shifting from one caster to another without restarting the program. This is useful for e.g. shifting the building control from the automatic (SCS) mode to a manual (JLAunchBox) mode. The methods provided are:

• #registerAt: Registers at the command-caster with the given name. The caster must be a remote reference to a RmiCommandCaster as well as a RmiAcknowledgeListener and a RmiDoneListener. Additionally, we grab the caster and register it as an acknowledge and done listener to our casting capabilities.
• #deregisterAt: Deregisters at the caster with the given name. The caster must be a remote reference to a RmiCommandCaster as well as a RmiAcknowledgeListener and a RmiDoneListener. Additionally, we remove it from our acknowledge and done listener list.
• external(java.rmi.Remote) If issued with true, we switch to external mode. Only in this mode, a single external caster is allowed to register at this object. If issued with false, we deregister from any external caster.
• automatic(): Only if automatic mode is enabled, we accept commands from a default command caster. No further rmi-methods, like BuildingControl#openRoof are allowed, except the {link #manual} command. If we switch to automatic mode, we register at the default command caster, if specified. If an external caster was specified, it is deregistered.
• manual(): Only in manual mode, further rmi-methods are accepted. If we switch to manual mode, we deregister from any default or external caster.

So, how can we change the, e.g., EnvironmentMaster to accept commands from an alternate caster? First, we issue a external(java.rmi.Remote) to the master. Any default caster is deregistered, if we are in automatic mode. Then, we call #registerAt with the new external caster. A reference to this caster is kept locally. When we want to stop interference from the external caster we call external with false, which changes the state of the master to the state it was prior to the first call to external(java.rmi.Remote). If we have an externla caster active and then call either automatic() or manual(), the external caster is deregistered and the master attains the desired state.

Method Summary

boolean	automatic() Goes to automatic mode.
boolean	external(Remote caster) Allows or prohibits excess from an external caster.
String	getStatus() Returns a status decription of the master.
boolean	initialize() (Re)initializes a master listener.
boolean	manual() Goes to manual mode.
boolean	park() Parks the master listener by simply calling GenericMaster.parkMaster().
void	quit() Parks the master listener by simply calling GenericMaster.quitMaster().
boolean	reset() Resets the master listener.
boolean	setPassive(boolean passive) Sets the listener in passive mode.

Method Detail

automatic

boolean automatic()
                  throws RemoteException

Goes to automatic mode. In automatic mode, we register at a default caster and accept commands sent from this caster. Other access, like RMI from the outside is forbidden, except the manual() method.

Returns:

True if automatic mode was attained.

Throws:

RemoteException

manual

boolean manual()
               throws RemoteException

Goes to manual mode. In manual, we deregister from a default caster and allow access to RMI-bound clients (e.g. {link BuldingControlling#openRoof}).

Returns:

True if manual mode was attained.

Throws:

RemoteException

setPassive

boolean setPassive(boolean passive)
                   throws RemoteException

Sets the listener in passive mode. This is a workaround if any crucial parts of the server fails that cannot be fixed easiliy. In passiv mode, any remote command received is answered immedeately with a complete.

Throws:

RemoteException

external

boolean external(Remote caster)
                 throws RemoteException

Allows or prohibits excess from an external caster. If a default caster was specified at a call to this method with true, this caster is deregistered. If called with false, the old master state is reestablished.

Returns:

True if everything went o.k.

Throws:

RemoteException

getStatus

String getStatus()
                 throws RemoteException

Returns a status decription of the master. This rmi-method should be enabled also in automatic mode.

Throws:

RemoteException

initialize

boolean initialize()
                   throws RemoteException

(Re)initializes a master listener. In a normal implementation, this metohd simply calls GenericMaster.initializeMaster().

Throws:

RemoteException

reset

boolean reset()
              throws RemoteException

Resets the master listener. In a normal implementation, this metohd simply calls GenericMaster.resetMaster().

Throws:

RemoteException

park

boolean park()
             throws RemoteException

Parks the master listener by simply calling GenericMaster.parkMaster().

Throws:

RemoteException

quit

void quit()
          throws RemoteException

Parks the master listener by simply calling GenericMaster.quitMaster().

Throws:

RemoteException