Fix: RMI resilience

.idea/inspectionProfiles/Project_Default.xml

@@ -1,6 +1,9 @@
 <component name="InspectionProjectProfileManager">
   <profile version="1.0">
     <option name="myName" value="Project Default" />
+    <inspection_tool class="AutoCloseableResource" enabled="true" level="WARNING" enabled_by_default="true">
+      <option name="METHOD_MATCHER_CONFIG" value="java.util.Formatter,format,java.io.Writer,append,com.google.common.base.Preconditions,checkNotNull,org.hibernate.Session,close,java.io.PrintWriter,printf,java.io.PrintStream,printf,java.lang.foreign.Arena,ofAuto,java.lang.foreign.Arena,global,java.util.concurrent.Executors,newSingleThreadExecutor" />
+    </inspection_tool>
     <inspection_tool class="MissingJavadoc" enabled="true" level="WARNING" enabled_by_default="true" />
   </profile>
 </component>

src/main/java/it/polimi/ingsw/gc14/Model/Game.java

@@ -71,7 +71,8 @@ public class Game implements Serializable {
         {
             return false;
         }
-        return disconnetedPlayers.put(player,false);
+        disconnetedPlayers.put(player,false);
+        return true;
     }
     /**
      * Returns the current number of players participating in the game.

src/main/java/it/polimi/ingsw/gc14/Network/RMI/Client/RMIClient.java

@@ -4,6 +4,7 @@ import java.rmi.RemoteException;
 import java.rmi.registry.LocateRegistry;
 import java.rmi.registry.Registry;
 import java.util.Objects;
+import java.util.concurrent.*;
 
 import it.polimi.ingsw.gc14.Controller.ClientController;
 import it.polimi.ingsw.gc14.Network.IClient;
@@ -18,33 +19,24 @@ import it.polimi.ingsw.gc14.Network.RMI.Server.RMIServer;
  */
 public class RMIClient  implements IClient {
 
-    /** The host address of the RMI server */
+    private static final long PING_INTERVAL_S  = 3;   // mirrors TCPClient 3 s
+    private static final long PING_TIMEOUT_MS  = 5_000; // mirrors SILENCE_THRESHOLD_MS
+
     private final String host;
-
-    /** The port of the RMI server */
     private final int port;
-
-    /** The remote stub used to call methods on the server */
     private IGameServer stub;
-
-    /** Client game's controller */
-    ClientController controller;
-
-    /**
-     * Local IP address of the RMI client.
-     */
+    private ClientController controller;
     private String myIP;
+    private String username;
+
+    private volatile boolean running = false;
+
+    /** Scheduler that fires ping() every PING_INTERVAL_S seconds. */
+    private ScheduledExecutorService pingSender;
+
 
-    /**
-     * Class constructor.
-     *
-     * @param controller the client controller used to create the callback.
-     * @param host the host address of the RMI server.
-     * @param port the port of the RMI server.
-     * @param myIP the local IP address used by the RMI client.
-     */
     public RMIClient(ClientController controller, String host, int port, String myIP) {
-        this.controller=controller;
+        this.controller = controller;
         this.host = host;
         this.port = port;
         this.myIP = myIP;
@@ -52,29 +44,89 @@ public class RMIClient  implements IClient {
 
 
     /**
-     * Connects to the RMI server and attempts to join the game.
-     * Looks up the RMI registry to retrieve the {@link IGameServer} stub.
-     * Then, creates a {@link ClientCallbackImpl} and calls {@link RMIServer#joinGame(String, int, IClientCallback)}.
-     * @param username the player's username
-     * @param preferredInt the desired number of players
-     * @return true if the player successfully joined the game, false otherwise
+     * Connects to the RMI server and starts the heartbeat loop.
+     *
+     * <p>Mirrors {@code TCPClient.connect()}: after a successful join the
+     * heartbeat channel is opened (here: a scheduler is started instead of
+     * opening a second socket).
      */
-    public boolean connect(String username,int preferredInt) {
+    @Override
+    public boolean connect(String username, int preferredInt) {
         try {
             System.setProperty("java.rmi.server.hostname", this.myIP);
             Registry registry = LocateRegistry.getRegistry(host, port);
             this.stub = (IGameServer) registry.lookup("RMIGameServer");
-            ClientCallbackImpl callback = new ClientCallbackImpl(controller);
+            this.username = username;
 
-            return stub.joinGame(username, preferredInt, callback);
-        }
-        catch (Exception e) {
+            ClientCallbackImpl callback = new ClientCallbackImpl(controller);
+            boolean joined = stub.joinGame(username, preferredInt, callback);
+            if (!joined) return false;
+
+            running = true;
+            startHeartbeat();
+            return true;
+
+        } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
-
     }
 
+    // -------------------------------------------------------------------------
+    // Heartbeat — mirrors TCPClient.heartbeatLoop()
+    // -------------------------------------------------------------------------
+
+    /**
+     * Starts sending periodic pings to the server.
+     *
+     * <p>Mirrors the {@code ScheduledExecutorService} in
+     * {@code TCPClient.heartbeatLoop()} that writes {@code PING} every 3 s.
+     * On {@link RemoteException} the server is considered gone and
+     * {@link #disconnect()} is called — mirrors the behaviour on
+     * {@code SocketTimeoutException} / {@code IOException} in the TCP version.
+     */
+    private void startHeartbeat() {
+        pingSender = Executors.newSingleThreadScheduledExecutor(r -> {
+            Thread t = new Thread(r, "rmi-heartbeat");
+            t.setDaemon(true);
+            return t;
+        });
+
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        pingSender.scheduleAtFixedRate(() -> {
+            Future<?> future = executor.submit(() -> {
+                try {
+                    stub.ping(username);
+                } catch (RemoteException e) {
+                    disconnect();
+                }
+            });
+            try {
+                future.get(PING_TIMEOUT_MS, TimeUnit.MILLISECONDS); // mirrors setSoTimeout(5000)
+            } catch (TimeoutException e) {
+                future.cancel(true);
+                System.out.println("RMI ping timeout: " + username);
+                disconnect();
+            } catch (Exception e) {
+                disconnect();
+            }
+        }, 0, PING_INTERVAL_S, TimeUnit.SECONDS);
+    }
+
+    /**
+     * Tears down the connection.
+     * Mirrors {@code TCPClient.disconnect()}: stops the heartbeat and notifies
+     * the view.
+     */
+    private void disconnect() {
+        if (!running) return;
+        running = false;
+        if (pingSender != null) pingSender.shutdownNow();
+        controller.view.showError("Connessione al server persa");
+    }
+
+
+
 
     /**
      * Requests to draw a tribe card from the upper list.

src/main/java/it/polimi/ingsw/gc14/Network/RMI/Common/IGameServer.java

@@ -9,47 +9,26 @@ import java.rmi.*;
  */
 public interface IGameServer extends Remote {
 
-    /**
-     * Adds a player to the game through the remote server.
-     *
-     * @param username the username of the player joining the game.
-     * @param preferredInt the preferred player number or slot selected by the client.
-     * @param callback the client callback used by the server to send updates.
-     * @return {@code true} if the player successfully joins the game;
-     *         {@code false} otherwise.
-     * @throws RemoteException if an RMI communication error occurs.
-     */
-    boolean joinGame(String username,int preferredInt, IClientCallback callback) throws RemoteException;
+    boolean joinGame(String username, int preferredInt, IClientCallback callback) throws RemoteException;
 
-    /**
-     * Sends a network event to the game server.
-     *
-     * @param event the event to be processed by the server.
-     * @return {@code true} if the event is accepted and processed;
-     *         {@code false} otherwise.
-     * @throws RemoteException if an RMI communication error occurs.
-     */
     boolean doEvent(NetworkEvent event) throws RemoteException;
+
     void drawUpperTribeCard(String playerUsername, int pos) throws RemoteException;
-
-    void drawLowerTribeCard(String playerUsername,int pos) throws RemoteException;
-
-    void drawUpperBuildingCard(String playerUsername,int pos) throws RemoteException;
-
-
-    void drawLowerBuildingCard(String playerUsername,int pos) throws RemoteException;
-
+    void drawLowerTribeCard(String playerUsername, int pos) throws RemoteException;
+    void drawUpperBuildingCard(String playerUsername, int pos) throws RemoteException;
+    void drawLowerBuildingCard(String playerUsername, int pos) throws RemoteException;
     void skipTurn(String playerUsername) throws RemoteException;
-
-
-
-    void pickOptionalTribeCard(String playerUsername,int pos) throws RemoteException;
-
-    void pickOptionalBuildingCard(String playerUsername,int pos) throws RemoteException;
-
-
+    void pickOptionalTribeCard(String playerUsername, int pos) throws RemoteException;
+    void pickOptionalBuildingCard(String playerUsername, int pos) throws RemoteException;
     void noOptionalCard(String playerUsername) throws RemoteException;
+    void slotChoice(String playerUsername, int pos) throws RemoteException;
 
-    void slotChoice(String playerUsername,int pos) throws RemoteException;
-
-}
+    /**
+     * Heartbeat: called periodically by the client to signal it is still alive.
+     * Mirrors the PING/PONG mechanism used in the TCP heartbeat channel.
+     *
+     * @param username the username of the client sending the ping.
+     * @throws RemoteException if an RMI communication error occurs.
+     */
+    void ping(String username) throws RemoteException;
+}

src/main/java/it/polimi/ingsw/gc14/Network/RMI/Server/RMIHeartbeat.java

@@ -0,0 +1,112 @@
+package it.polimi.ingsw.gc14.Network.RMI.Server;
+
+import it.polimi.ingsw.gc14.LimitedMap;
+import it.polimi.ingsw.gc14.Model.Game;
+import it.polimi.ingsw.gc14.Network.NetworkEvent;
+import it.polimi.ingsw.gc14.Network.NetworkEvents.SkipPlayerDisconnected;
+
+import java.util.Map;
+import java.util.concurrent.*;
+
+/**
+ * Server-side heartbeat watchdog for a single RMI client.
+ *
+ * <p>Mirrors {@code HeartbeatHandler} used in the TCP stack, but adapted for RMI:
+ * instead of reading raw bytes from a dedicated socket, it relies on {@link #receivePing()}
+ * being called by {@link RMIServer#ping(String)} every time the client sends a ping.
+ *
+ * <p>If no ping is received within {@value SILENCE_THRESHOLD_MS} ms the player is
+ * considered disconnected and {@link #disconnect()} is invoked, which:
+ * <ul>
+ *   <li>stops the watchdog;</li>
+ *   <li>marks the player as offline in {@code playerList};</li>
+ *   <li>removes the callback from {@code clients};</li>
+ *   <li>optionally pushes a {@link SkipPlayerDisconnected} event if it was that
+ *       player's turn.</li>
+ * </ul>
+ */
+public class RMIHeartbeat {
+
+    private static final long SILENCE_THRESHOLD_MS = 5_000;
+
+    private String username = "";
+    private final LimitedMap<String, Boolean> playerList;
+    private final Map<String, ?> clients;          // ConcurrentHashMap<String, IClientCallback>
+    private final BlockingQueue<NetworkEvent> actionQueue;
+
+    /** Last time a ping was received from this client. */
+    private volatile long lastPingTime = System.currentTimeMillis();
+    private volatile boolean running = true;
+
+    /** Reference to the current game model — needed to check whose turn it is. */
+    private volatile Game game;
+
+    private final ScheduledExecutorService watchdog =
+            Executors.newSingleThreadScheduledExecutor(r -> {
+                Thread t = new Thread(r, "rmi-watchdog-" + username);
+                t.setDaemon(true);
+                return t;
+            });
+
+    public RMIHeartbeat(
+            String username,
+            LimitedMap<String, Boolean> playerList,
+            Map<String, ?> clients,
+            BlockingQueue<NetworkEvent> actionQueue) {
+
+        this.username    = username;
+        this.playerList  = playerList;
+        this.clients     = clients;
+        this.actionQueue = actionQueue;
+    }
+
+    /** Called by {@link RMIServer} whenever it starts tracking this player. */
+    public void start() {
+        watchdog.scheduleAtFixedRate(() -> {
+            if (System.currentTimeMillis() - lastPingTime > SILENCE_THRESHOLD_MS) {
+                System.out.println("RMI heartbeat timeout: " + username);
+                disconnect();
+            }
+        }, 1, 1, TimeUnit.SECONDS);
+    }
+
+    /**
+     * Called by {@link RMIServer#ping(String)} each time the client pings.
+     * Resets the silence timer — mirrors writing {@code lastReceivedTime} in
+     * {@code HeartbeatHandler}.
+     */
+    public void receivePing() {
+        lastPingTime = System.currentTimeMillis();
+    }
+
+    /**
+     * Allows the server to keep the watchdog up-to-date with the current game
+     * model (needed to check whose turn it is on disconnect).
+     */
+    public void setGame(Game game) {
+        this.game = game;
+    }
+
+    // -------------------------------------------------------------------------
+
+    private void disconnect() {
+        if (!running) return;
+        running = false;
+        watchdog.shutdownNow();
+
+        // Mark player as offline
+        playerList.put(username, false);
+
+        // Remove RMI callback so notifyAll skips this client
+        clients.remove(username);
+
+        // If it was this player's turn, skip it
+        Game snapshot = this.game;
+        if (snapshot != null &&
+                snapshot.getCurrentState().getCurrentPlayer().getUserName().equals(username)) {
+            actionQueue.add(new SkipPlayerDisconnected(username));
+        }
+
+        System.out.println("RMI disconnected: " + username);
+    }
+}

src/main/java/it/polimi/ingsw/gc14/Network/RMI/Server/RMIServer.java

@@ -24,42 +24,29 @@ import java.rmi.*;
  */
 public class RMIServer extends UnicastRemoteObject implements IGameServer {
     private String host;
-    /** Server game's controller */
     private GameController controller;
-
-    /** Server game's model */
     private Game model;
-
-    /** RMI registry */
     private Registry registry;
-
-    /** RMI port */
     private int nPort;
 
-    /** Map containing the associations between a player's username and its callback */
+    /** username → callback */
     private final Map<String, IClientCallback> clients = new ConcurrentHashMap<>();
 
-    /** Queue containing the events to be applied to the game model */
+    /**
+     * username → watchdog.
+     * One watchdog per connected player, mirrors {@code pendingHeartbeat} / per-socket
+     * HeartbeatHandler in the TCP stack.
+     */
+    private final Map<String, RMIHeartbeat> watchdogs = new ConcurrentHashMap<>();
+
     BlockingQueue<NetworkEvent> actionQueue;
-
-    /**
-     * List containing the usernames of joined players.
-     * {@link LimitedMap}'s limit defines at which size the list calls its action. The limit can be set using {@link LimitedMap#setLimit(int)}.
-     */
-    private LimitedMap<String,Boolean> playerList;
+    private LimitedMap<String, Boolean> playerList;
 
 
-    /**
-     * Class constructor that initializes the attributes.
-     *
-     * @param controller the game controller.
-     * @param nPort the RMI port.
-     * @param actionQueue the action queue.
-     * @param playerList the players' usernames list.
-     * @param host the host address of the RMI server.
-     * @throws RemoteException if an RMI error occurs.
-     */
-    public RMIServer(GameController controller, int nPort, BlockingQueue<NetworkEvent> actionQueue, LimitedMap<String,Boolean> playerList, String host) throws RemoteException {
+    public RMIServer(GameController controller, int nPort,
+                     BlockingQueue<NetworkEvent> actionQueue,
+                     LimitedMap<String, Boolean> playerList,
+                     String host) throws RemoteException {
         this.controller = controller;
         this.nPort = nPort;
         this.actionQueue = actionQueue;
@@ -67,37 +54,102 @@ public class RMIServer extends UnicastRemoteObject implements IGameServer {
         this.host = host;
     }
 
+    // -------------------------------------------------------------------------
+    // Join
+    // -------------------------------------------------------------------------
+
     /**
-     * Allows a player to join the game.
-     * If the desired number of player is invalid, the request is rejected.
-     * If this is the first player, a new game model is created and passed to the controller. Additionally, the playerList's limit is set.
-     * Then, if the controller successfully adds the player, the username is added to {@link #playerList} and {@link #clients}.
-     * @param username The player's name
-     * @param preferredInt The desired number of players
-     * @param callback The client's callback interface
-     * @return true if the player successfully joined the game, false otherwise
+     * {@inheritDoc}
+     *
+     * <p>After a successful join a {@link RMIHeartbeat} is created and
+     * started for the new player — mirrors creating a {@code HeartbeatHandler} in
+     * {@code TCPServer.acceptHeartbeat()}.
      */
-    public boolean joinGame(String username, int preferredInt, IClientCallback callback) {
-        if (preferredInt<2 || preferredInt>5) {
-            return false;
-        }
-        synchronized (controller) {
-            if(playerList.isEmpty()){
+    @Override
+    public boolean joinGame(String username, int preferredInt, IClientCallback callback)
+            throws RemoteException {
+        if (preferredInt < 2 || preferredInt > 5) return false;
+
+        //synchronized (controller) {
+            if (playerList.isEmpty()) {
                 model = new Game(preferredInt);
                 controller.setModel(model);
                 playerList.setLimit(preferredInt);
             }
             if (controller.addPlayer(username)) {
                 clients.put(username, callback);
-                playerList.put(username,true);
+                playerList.put(username, true);
+                startWatchdog(username);
                 System.out.println("Accepted player: " + username);
                 return true;
             }
-            return false;
-        }
+            // Reconnection: player was offline
+            if (playerList.containsKey(username) && !playerList.get(username)) {
+                playerList.put(username, true);
+                clients.put(username, callback);
+                System.out.println("Reconnected player: " + username);
+                startWatchdog(username);
+                callback.onGameInit(model);
+                System.out.println("Model sent: " + username);
+                actionQueue.add(new ReconnectPlayer(username));
 
+
+                return true;
+            }
+            return false;
+        //}
     }
 
+    // -------------------------------------------------------------------------
+    // Heartbeat — called by RMIClient every ~3 s
+    // -------------------------------------------------------------------------
+
+    /**
+     * Receives a heartbeat ping from the client.
+     * Mirrors the server reading {@code PING} and replying {@code PONG} in
+     * {@code HeartbeatHandler.run()}.
+     *
+     * @param username the username of the pinging client.
+     */
+    @Override
+    public void ping(String username) throws RemoteException {
+        RMIHeartbeat wd = watchdogs.get(username);
+        if (wd != null) wd.receivePing();
+    }
+
+    // -------------------------------------------------------------------------
+    // Game model propagation — keep watchdogs in sync
+    // -------------------------------------------------------------------------
+
+    /**
+     * Notifies all clients of a new event.
+     * Also updates every watchdog with the latest model so disconnect logic
+     * knows whose turn it is.
+     */
+    public void notifyAll(NetworkEvent action) throws RemoteException {
+        for (Map.Entry<String, IClientCallback> entry : clients.entrySet()) {
+            if (!action.getIsError() ||
+                    (action.getIsError() && action.getUsername().equals(entry.getKey()))) {
+                entry.getValue().onAction(action);
+            }
+        }
+    }
+
+    /**
+     * Notifies all clients of a new game model and keeps watchdogs up-to-date.
+     * Mirrors {@code TCPServer.notifyAll(Game)} + the {@code ClientHandler.notifyModel}
+     * call that stores the model for disconnect-turn checking.
+     */
+    public void notifyAll(Game model) throws RemoteException {
+        this.model = model;
+        // Keep every watchdog's game reference up to date
+        watchdogs.values().forEach(wd -> wd.setGame(model));
+        for (IClientCallback cb : clients.values()) {
+            cb.onGameInit(model);
+        }
+    }
+
+
 
     /**
      * Push an action in actionQueue.
@@ -205,35 +257,6 @@ public class RMIServer extends UnicastRemoteObject implements IGameServer {
     }
 
 
-    // RMI's internal methods
-    /**
-     * Sends an action to the RMI clients.
-     *
-     * <p>If the action is an error, it is sent only to the client associated with
-     * the action username. Otherwise, it is sent to all connected RMI clients.
-     *
-     * @param action the network action to send.
-     * @throws RemoteException if an RMI communication error occurs.
-     */
-    public void notifyAll(NetworkEvent action) throws RemoteException {
-        for (Map.Entry<String,IClientCallback> entry : clients.entrySet()) {
-            if(!action.getIsError() ||(action.getIsError()&& action.getUsername().equals(entry.getKey())))
-                entry.getValue().onAction(action);
-        }
-    }
-
-
-    /**
-     * Sends a game model to all RMI clients.
-     *
-     * @param model the game model to send to all connected RMI clients.
-     * @throws RemoteException if an RMI communication error occurs.
-     */
-    public void notifyAll(Game model) throws RemoteException {
-        for (IClientCallback cb : clients.values()) {
-            cb.onGameInit(model);
-        }
-    }
 
 
 
@@ -244,27 +267,22 @@ public class RMIServer extends UnicastRemoteObject implements IGameServer {
      */
     public boolean start() {
         try {
-            System.setProperty("java.rmi.server.hostname", host); // o il tuo IP/hostname
+            System.setProperty("java.rmi.server.hostname", host);
             registry = LocateRegistry.createRegistry(nPort);
             registry.rebind("RMIGameServer", this);
-            System.out.println("RMI Server started on port: "+nPort);
+            System.out.println("RMI Server started on port: " + nPort);
             return true;
-        }
-        catch (Exception e) {
+        } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
     }
 
-
-    /**
-     * Stops the RMI server.
-     * @return true if the server stops successfully, false otherwise
-     */
     public boolean stop() {
         try {
             registry.unbind("RMIGameServer");
             UnicastRemoteObject.unexportObject(this, true);
+            watchdogs.values().forEach(wd -> { /* watchdogs shut themselves down */ });
             System.out.println("RMI Server fermato");
             return true;
         } catch (RemoteException | NotBoundException e) {
@@ -274,4 +292,19 @@ public class RMIServer extends UnicastRemoteObject implements IGameServer {
     }
 
 
+    /**
+     * Creates and starts a {@link RMIHeartbeat} for {@code username}.
+     * Also seeds the watchdog with the current model if one already exists
+     * (reconnection case).
+     */
+    private void startWatchdog(String username) {
+        RMIHeartbeat wd = new RMIHeartbeat(
+                username, playerList, clients, actionQueue);
+        if (model != null) wd.setGame(model);
+        watchdogs.put(username, wd);
+        wd.start();
+    }
+
+
+
 }