Moved main loop into FixedRate scheduler. Added sync lock on runnable.

2006Redone Server/src/com/rebotted/GameEngine.java

@@ -3,6 +3,11 @@ package com.rebotted;
 import java.io.File;
 import java.io.IOException;
 import java.net.InetSocketAddress;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.mina.common.IoAcceptor;
 import org.apache.mina.transport.socket.nio.SocketAcceptor;
@@ -73,6 +78,8 @@ public class GameEngine {
 	public static FightCaves fightCaves = new FightCaves();
 	private static PestControl pestControl = new PestControl();
 	public static Trawler trawler = new Trawler();	
+	private final static ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
+	private final static Lock lock = new ReentrantLock();
 
 	/**
 	 * Port and Cycle rate.
@@ -147,51 +154,76 @@ public class GameEngine {
 
 		/**
 		 * Main Server Tick
+		 * 
+		 * This scheduler will tick once every 600ms. If the previous tick takes
+		 * 300ms to execute, this scheduler will wait 300ms only before the next
+		 * tick.
+		 * 
+		 * Each tick, it will attempt to get a lock on the main server thread.
+		 * Without locking this runnable, multiple ticks could occur at once.
 		 */
-		try {
-			while (!GameEngine.shutdownServer) {
-					Thread.sleep(600);
-				itemHandler.process();
-				playerHandler.process();
-				npcHandler.process();
-				shopHandler.process();
-				objectManager.process();
-				CastleWars.process();
-				FightPits.process();
-				pestControl.process();
-				CycleEventHandler.getSingleton().process();
-				PlayersOnlineWebsite.addUpdatePlayersOnlineTask();
-				RegisteredAccsWebsite.addUpdateRegisteredUsersTask();
-				DiscordActivity.updateActivity();
-				if (System.currentTimeMillis() - lastMassSave > 300000) {
-					for (Player p : PlayerHandler.players) {
-						if (p == null) {
-							continue;
+		scheduler.scheduleAtFixedRate(new Runnable() {
+			public void run() {
+				if (lock.tryLock()) {
+					synchronized (lock) {
+						/**
+						 * Main Server Tick
+						 */
+						try {
+							if (GameEngine.shutdownServer) {
+								scheduler.shutdown();
+							}
+							itemHandler.process();
+							playerHandler.process();
+							npcHandler.process();
+							shopHandler.process();
+							objectManager.process();
+							CastleWars.process();
+							FightPits.process();
+							pestControl.process();
+							CycleEventHandler.getSingleton().process();
+							PlayersOnlineWebsite.addUpdatePlayersOnlineTask();
+							RegisteredAccsWebsite
+									.addUpdateRegisteredUsersTask();
+							DiscordActivity.updateActivity();
+							if (System.currentTimeMillis()
+									- lastMassSave > 300000) {
+								for (Player p : PlayerHandler.players) {
+									if (p == null) {
+										continue;
+									}
+									PlayerSave.saveGame((Client) p);
+									System.out.println("Saved game for " + p.playerName + ".");
+									lastMassSave = System.currentTimeMillis();
+								}
+							}
+						} catch (Exception ex) {
+							ex.printStackTrace();
+							System.out.println("A fatal exception has been thrown!");
+							for (Player p : PlayerHandler.players) {
+								if (p == null) {
+									continue;
+								}
+								if (p.inTrade) {
+									((Client) p).getTrading().declineTrade();
+								}
+								if (p.duelStatus == 6) {
+									((Client) p).getDueling().claimStakedItems();
+								}
+								PlayerSave.saveGame((Client) p);
+								System.out.println("Saved game for " + p.playerName + ".");
+								scheduler.shutdown(); // Kills the tickloop thread if Exception is thrown.
+							}
 						}
-						PlayerSave.saveGame((Client) p);
-						System.out.println("Saved game for " + p.playerName
-								+ ".");
-						lastMassSave = System.currentTimeMillis();
-					   }
-                }
-            }
-		} catch (Exception ex) {
-			ex.printStackTrace();
-			System.out.println("A fatal exception has been thrown!");
-			for (Player p : PlayerHandler.players) {
-				if (p == null) {
-					continue;
+					}
+				} else {
+					System.out.println("Can't Keep up! Did the system time change or is the server overloaded?");
 				}
-				if (p.inTrade) {
-					((Client)p).getTrading().declineTrade();
-	            }
-				if(p.duelStatus == 6) {
-					((Client)p).getDueling().claimStakedItems();
-				}
-				PlayerSave.saveGame((Client) p);
-				System.out.println("Saved game for " + p.playerName + ".");
 			}
-		}
+		}, 0, GameConstants.CYCLE_TIME, TimeUnit.MILLISECONDS);
+		
+		
+		
 		acceptor = null;
 		connectionHandler = null;
 		sac = null;