The Server is a standalone application. It reads in a
Map file from...
Our system is broken into modules and structured as in the diagram below. The vertical and horizontal bars represent interfaces.
[...]
ClientRMIIface
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. . . . . . . . . | . . . . . . . . . . . . . . . . . . . . . . . .
| .
| .
ServerRMItoClientIface .
| .
ServerRMI----ServerRMItoDemonIface-----DemonRMIIface
SERVER | . [...]
(single) ServerThread .
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ServerEngine .
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Server .
| .
. . . . . . . . . | . . . . . . . . . . . . . . . . . . . . . . . .
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OS SHELL
This section describes the different modules in the Server.
It focuses on their duties and interfaces.
The Server is an application, and initiates program execution on the server side of the system.
| Method | Throws | Invoker | Purpose |
| Server(String file_name, int port) | main | This is called to instantiate an object of type Server and starts the execution of the server side of the system. A private member of type ServerEngine is instantiated here passing "this" as an argument. The file_name and port arguments are also passed to the ServerEngine constructor. | |
| void PrintMessage (String s) | ServerEngine | This call prints the indicated string to the screen. | |
| void Error (Exception e) | ServerEngine | This call prints the stack trace for the passed exception. | |
| void ShutDown () | ServerEngine | Kills the currently running application. |
The ServerEngine handles the logic for:
| Method | Throws | Invoker | Purpose |
| ServerEngine (Server s, String file_name, int port) | MapReadException | Server | By passing a reference to itself when calling the ServerEngine construtor, Server gives ServerEngine a way to invoke the Server methods, enabling two-way communication between the Server and the engine. This constructor then creates a ServerRMI using the port value passed, establishing a similar two-way interface. It also reads in a Map using the given file_name, and tells the ServerRMI to get ready to accept connections from the same number of clients as there are Modules in the Map. It then performs any other needed initialization. |
| void UpdateMap (Module m, int client_id) | ServerRMI | Whenever the server receives a changed module from the client, those changes need to be handled in the ServerEngine via this method. | |
| void BeginSimulation (int p, int long d) | ServerRMI | This method sets the propagation method and delay variables before starting the simulation by creating and starting a new ServerThread. | |
| void PrintMessage (String s) | ServerThread, ServerRMI | This function prints the indicated message via the Server. | |
| void Error (Exception e) | ServerThread, ServerRMI | This function passes the exception on to Server's Error method to print a stack trace. | |
| Map GetMap () | ServerThread, ServerRMI | This function returns the current Map. | |
| int GetNumClients () | ServerThread | This function returns the current number of clients. | |
| long GetDelay () | ServerThread | This function returns the current delay. | |
| int GetPropagationMethod () | ServerThread | This function returns the current propagation method. | |
| int GetMode () | ServerThread | This function returns the current mode as an int corresponding to either automatic or manual mode. | |
| int GetIterations () | ServerThread | This function returns the number of requested iterations for the current run of the simulation. | |
| void ShutDown () | ServerRMI | Kills the currently running application via the Server. | |
| void SubmitMode (int m, int runs) | ServerRMI | This function ets the mode to automatic or manual according to the passed value. It also sets the iterations value to 1 if manual has been selected and equal to "runs" if automatic has been selected. | |
| void Abort () | ServerRMI | This method kills the currently running ServerThread in order to stop the simulation. The map is stabilzed in preparation to be sent back out to the clients and the demon. |
A ServerThread is in charge of stabilizing the modified Map and sending out the modifications to the clients.
| Method | Throws | Invoker | Purpose |
| ServerThread(ServerRMI r, ServerEngine se) | ServerEngine | This constructor gives the ServerThread the hooks it needs to modify the current Map and send copies to clients. | |
| void run() | ServerEngine | This function contains the code for stabilizing and sending out copies of the Map. |
A SendInitialMapThread is created and run to send out the initial
version of the map.
DEPRECATED
| Method | Throws | Invoker | Purpose |
| SendInitialMapThread(ServerRMI r, ServerEngine se) | ServerEngine | This constructor gives the SendInitialMapThread the hooks it needs to send out a copy of the current map to all clients and the demon. | |
| void run() | ServerEngine | This function contains the code for sending out the initial copy of the Map. |
The ServerRMI module handles the server's side of the communication with the clients. It talks to the clients via the ClientRMI module, to the demon using the DemonRMI module, and to the ServerEngine.
| Method | Throws | Invoker | Purpose |
| ServerRMI (ServerEngine engine) | ServerEngine () | By passing a reference to itself when calling the ServerRMI construtor, ServerEngine gives ServerRMI a way to invoke the ServerEngine methods, enabling two-way communication between the engine and the RMI. This constructor then sets the SecurityManager, creates the registry, and binds itself to it under the name of "ServerRMI". | |
| Map ConnectClient () | RemoteException, Exception | ClientRMI (RMI call) | Receives a request from a client for an initial map. A map is returned, based on which the client picks its module number. |
| boolean RegisterClient (int module, ClientRMIIface obj) | RemoteException, Exception | ClientRMI (RMI call) | Receives a request from a client to register for a module. If the module is not taken, the client's interface is stored, and it is given an affirmative answer. |
| boolean RegisterDemon (DemonRMIIface obj) | RemoteException, Exception | DemonRMI (RMI call) | Recieves a request from the Demon to register. Due to the current implementation, this can only be done once, and the demon is given an affirmative answer. |
| void ReceiveModule(Module m, int client_id) | RemoteException, Exception | ClientRMI (RMI call) | The client passes the server its modified module through this call. ServerEngine's UpdateMap() method is invoked. |
| boolean SubmitMode(int mode, int runs) | RemoteException, Exception | DemonRMI (RMI call) | The demon passes the server the way this simulation will be run. ServerEngine's SubmitMode() method is invoked, and a new (editable) map is sent to all the clients. |
| boolean StartRun(int propagation, long delay) | RemoteException, Exception | DemonRMI (RMI call) | The demon passes the two simulation variables, propagation method, and delay. ServerEngine's BeginSimulation() is called. |
| boolean Abort() | RemoteException, Exception | DemonRMI (RMI call) | Receives a request from the demon for the single run to be stopped. The engine is notified, and all maps re-sent. |
| boolean Shutdown() | RemoteException, Exception | DemonRMI (RMI call) | Receives a request from the demon for all the clients to be shut down. Each client is notified of the shutdown, and then we return to the demon. |
| boolean ClientQuit() | RemoteException, Exception | ClientRMI (RMI call) | This is the last call the client makes before it is manually shut down. The serverRMI's internal object (Connections) is updated. Proper authorization (client's iface) is needed. |
| boolean DemonQuit() | RemoteException, Exception | DemonRMI (RMI call) | Same as ClientQuit(). |
| int SendMapAll(Map m) | RemoteException | ServerEngine, internal | This method sends the map to all present clients, as well as the demon. |
| int SendMapClient(Map m, int client_id) | RemoteException | ServerEngine | ServerEngine sends the map to a specific client through its RMIIface. |
| int SendMapDemon(Map m) | RemoteException | ServerEngine | Just like previous call, only to demon. |
| int SendStatsClient(Stats stats, int client_id) | RemoteException | ServerEngine | Stats object is passed to a given client thorugh its RMIIface. |
| int SendStatsDemon(Stats stats) | RemoteException | ServerEngine | Just like previous call, only to demon. |
Interface exposed to the clients. For notes on each method, please see ServerRMI, where these methods are actually implemented.
| Method | Throws | Invoker | Purpose |
| Map ConnectClient () | RemoteException, Exception | ClientRMI (RMI call) | (see same method in ServerRMI) |
| boolean RegisterClient (int module_num, ClientRMIIface obj) | RemoteException, Exception | ClientRMI (RMI call) | (see same method in ServerRMI) |
| void ReceiveModule (Module m, int client_id) | RemoteException, Exception | ClientRMI (RMI call) | (see same method in ServerRMI) |
| void ClientQuit () | RemoteException, Exception | ClientRMI (RMI call) | (see same method in ServerRMI) |
Interface exposed to the demon. For notes on each method, please see ServerRMI, where these methods are actually implemented.
| Method | Throws | Invoker | Purpose |
| boolean RegisterDemon (DemonRMIIface obj) | RemoteException, Exception | DemonRMI (RMI call) | (see same method in ServerRMI) |
| boolean StartRun (int propagation, long delay) | RemoteException, Exception | DemonRMI (RMI call) | (see same method in ServerRMI) |
| boolean Shutdown () | RemoteException, Exception | DemonRMI (RMI call) | (see same method in ServerRMI) |
| void DemonQuit () | RemoteException, Exception | DemonRMI (RMI call) | (see same method in ServerRMI) |
Version 3.1 - 14-DEC-1998 txe
Fixed format, dates, version numbers, table of contents, diagram
Version 3.0 - 14-DEC-1998 smg
Added and modified methods of Server, ServerEngine. Deprecated
SentInitialMapThread.
Version 2.2 - 20-NOV-1998 smg
Added prototype 2 info for Server, ServerEngine, ServerThread. Added
SendInitialMapThread.
Version 2.1 - 18-NOV-1998 Orim
Added ServerRMI, ServerRMI*Iface information
Version 2.0 - 16-NOV-1998 txe
Initial creation (split from spec.html)