The Demon is the dependencies monitor. It's an Applet that
lets a person view the status of the simulation, not from an
individual developer's perspective, but as an
system-wide overview.
Our system is broken into modules and structured as in the diagram below. The vertical and horizontal bars represent interfaces.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
ServerRMItoDemonIface------DemonRMIIface
[...] . |
. DemonRMI
. | MONITOR
. DemonEngine (single)
. |
. DemonGUI
. |
. DemonApplet
. |
. . . . . . . . . . . . . . . . . . . . . | . . . . . . . . . . . .
|
netscape, appletviewer, etc. --> APPLET VIEWER
|
system monitoring user --> USER
This section describes the different modules in the Demon.
It focuses on their duties and interfaces.
This is the main applet for the Demon. The demon is the simulation interface, which allows the user to set up the initial simulation parameters, and monitor the state of the simulation.
| Method | Throws | Invoker | Purpose |
| void Init () | Nothing | Browser | Starts up the DemonGUI |
| boolean mouseDown (Event e, int x, int y) | Nothing | Browser | Passes mouse events to DemonGUI |
| boolean action (Event event, Object object) | Nothing | Browser | Passes event/ object to DemonGUI |
| void paint (Graphics graphics) | Nothing | applet repaint() | invokes DemonGUI.Draw() |
| void Exit (Exception e) | Nothing | various | Dumps stack trace to system.out, stops applet. |
The DemonGUI is responsible for providing a graphical monitor of the system, and a means of allowing the "boss" of the simulation to select propogations methods, delay factors, levels of automation, etc.
| Method | Throws | Invoker | Purpose |
| DemonGUI (DemonApplet parent_applet) | NullException, Exception | DemonApplet | Constructor |
| void DisplayMap (Map new_map) | NullException, Exception | DemonEngine | Displays the Matrix View of the map to the screen |
| void DisplayStats (Stats new_stats) | NullException, Exception | DemonEngine | Displays the Stats |
| void DisplayClientConnectStatus (ClientConnectStatus new_ccs) | NullException, Exception | DemonEngine | Displays the ccs |
| void Draw (Graphics graphics) | Exception | DemonApplet | Displays the drawable objects |
| void HandleClick (Event event, int x, int y) | Nothing | DemonApplet | Determine the source of the event, and update the engine |
| void HandleAction (Event event, Object object) | Exception | DemonApplet | Determine the source of the event, and update the engine |
| void Notify (String string) | Nothing | DemonEngine | Displays the String to the status area |
| void Freeze () | Nothing | DemonEngine | Disables user input |
| void Unfreeze () | Nothing | DemonEngine | Enables user input |
| void Error (Exception e) | Nothing | DemonEngine | Displays exception stack trace |
This module handles the high-level logic involved in the operation of the Demon. It decides what happens when the user interacts with the DemonGUI, what happens when the Demon receives a message from the Server, etc.
| Method | Throws | Invoker | Purpose |
| DemonEngine (DemonGUI gui, String address, String port) | Exception | DemonGUI | By passing a reference to itself when calling the DemonEngine construtor, DemonGUI gives DemonEngine a way to invoke the DemonGUI methods, enabling two-way communication between the GUI and the engine. This constructor then creates a DemonRMI, establishing a similar two-way interface. It then performs any other needed initialization. |
| void Error (Exception e) | ClientRMI | Called when the DemonRMI wants to pass an exception to the DemonGUI for display. | |
| void ReceiveStats (Stats my_stats) | Exception | DemonRMI | When the DemonRMI receives new statistics from the ServerRMI, it passes the stats to the DemonEngine via this method. The DemonEngine then passes the stats to the DemonGUI, whose job it is to display it. |
| void ReceiveState (int state) | Exception | DemonRMI | Passes Demon's state to GUI from RMI so GUI knows which buttons to turn on and off. |
| void ReceiveMap (Map my_map) | Exception | DemonRMI | When the DemonRMI receives a new map from the ServerRMI, it passes the map to the DemonEngine via this method. The DemonEngine then passes the map to the DemonGUI, and subsequently tells the DemonGUI to display it. |
| void ReceiveClientConnectStatus (ClientConnectStatus status) | Exception | DemonRMI | This method passes a ClientConnectStatus object to the DemonEngine, where it is passed on to the DemonGUI. This object tells the demon the number of users, and the connection status of each user. |
| void QuitClicked () | Exception | DemonGUI | Called when the user clicks on the quit button on the user interface. Subsequently calls the ShutDown() method in the DemonRMI module. Returns when shutdown is complete. |
| boolean SetParameters (int propagation, long delay) | Exception | DemonGUI | Called to pass propagation mechanism and length of cycle delay in millisseconds. Subsequently calls SetParameters() method of DemonRMI. Returns true if propagation and delay are set successfully. |
| void PrintMessage (String s) | DemonRMI | When the DemonRMI wants to print a string to the GUI, it calls this method. This method subsequently calls the Notify() method belonging to the DemonGUI. | |
| boolean SubmitMode (int mode, int runs) | Exception | DemonGUI | Called when the DemonGUI wants to submit the mode to DemonRMI. This method subsequently calls the SubmitMode method belonging to the DemonRMI. Returns true if mode set successfully, otherwise false. |
| void AbortClicked () | Exception | DemonGUI | When the user wants to abort the current simulation run, he clicks Abort and the DemonGUI calls this method. Subsequently, the Abort method belonging to the DemonRMI is called. |
| void Quit () | Exception | DemonGUI | When the applet is destroyed, the DemonGUI calls this method, which subsequently calls Quit() in the DemonRMI to inform the system that an applet is going away. |
This module handles all the communications for the Demon, both incoming (from the server-side), and outgoing (calls onto the DemonRMI made by DemonEngine).
| Method | Throws | Invoker | Purpose |
| DemonRMI (DemonEngine engine) | Nothing | DemonEngine | This constructor receives a reference to the DemonEngine to be able to later make calls to it as RMI calls are received. In the constructor, DemonRMI exports itself. |
| Map Connect (String ip, String port) | RemoteException, Exception | DemonEngine | Makes sure the server exists at given ip/port, and requests an initial map from the server. |
| boolean RegisterWithServer () | RemoteException, Exception | DemonEngine | When called, this method invokes the server demon registration method, which makes sure that the server gets the demon's interface, and thus the server knows how to talk back to the demon. |
| void Quit () | Exception | DemonEngine | Called when the applet is shut down. Last warning to the server. |
| void ReceiveMap (Map my_map) | RemoteException, Exception | ServerRMI (RMI call) | ServerRMI passes the map to DemonRMI, which then passes it to DemonEngine. Makes a call to DemonEngine's ReceiveMap. |
| void ReceiveStats (Stats my_stats) | RemoteException, Exception | ServerRMI (RMI call) | Another pass-through method. ServerRMI calls it, and ReceiveStats passes a Stats object to the engine. Calls the DemonEngine's ReceiveStats. |
| void ReceiveClientConnectStatus (ClientConnectStatus status) | RemoteException, Exception | ServerRMI (RMI call) | Similar to the other two receive methods, except that a ClientConnectStatus is received and passed on. Calls the DemonEngine's ReceiveClientConnectStatus. |
| boolean SubmitMode (int mode, int runs) | RemoteException, Exception | DemonEngine | Send the mode and a number of runs to the server. |
| boolean StartRun (int propagation, long delay) | RemoteException, Exception | DemonEngine | Makes an RMI call to the ServerRMI's SetParameters() method. This will start the simulation, regardless of who has submitted their maps. |
| boolean Abort () | RemoteException, Exception | DemonEngine | Called when we want to stop a simulation. |
| boolean ShutDown () | RemoteException, Exception | DemonEngine | Calls the ServerRMI's Shutdown() method. The ServerRMI then tells each client to shutdown, and returns the cumulative result of those calls as a boolean value. |
This is merely an interface which the DemonRMI presents to ServerRMI. All communication from server to the demon is based on this interface. For descriptions of each method, please see the notes on their implementation in ServerRMI.
| Method | Throws | Invoker | Purpose |
| void ReceiveClientConnectStatus (ClientConnectStatus status) | RemoteException, Exception | ServerRMI (RMI call) | (see same method in DemonRMI) |
| void ReceiveStats (Stats my_stats) | RemoteException, Exception | ServerRMI (RMI call) | (see same method in DemonRMI) |
| void ReceiveMap (Map my_map) | RemoteException, Exception | ServerRMI (RMI call) | (see same method in DemonRMI) |
Version 3.1 - 14-DEC-1998 txe
Updated dates, version numbers, format, return values, diagram
Version 3.0 - 14-DEC-1998 rgb
Updated DemonEngine constructor to take port and address
Added ReceiveState() to DemonEngine
Version 2.6 - 03-DEC-1998 rgb
Added Quit() to DemonEngine
Version 2.5 - 02-DEC-1998 rgb
Added SubmitMode() and AbortClicked() to DemonEngine
Version 2.4 - 20-NOV-1998 jpg
Updated DemonGUI (added Exceptions)
Version 2.3 - 18-NOV-1998 Orim
Added DemonRMI, DemonRMIIface information
Version 2.2 - 18-NOV-1998 rgb
Fixed exceptions thrown in DemonEngine
Added Error() to DemonEngine
Version 2.1 - 16-NOV-1998 jpg
Added DemonGUI, DemonApplet
Version 2.0 - 16-NOV-1998 txe
Initial creation (split from spec.html)