remove crashed servers from the list (#2)

Model/Server.cs

@@ -8,6 +8,7 @@ namespace Model
     public class Server
     {
         public DateTime SpawnedAtUtc { get; set; } = DateTime.UtcNow;
+        public DateTime LastHeartBeatUtc { get; set; }
         public int ProcessId { get; set; }
         public int Port { get; set; }
         public bool IsStarted { get; set; }

Supervisor/NBloodServerListener.cs

@@ -66,6 +66,7 @@ namespace Supervisor
                 new Server()
                 {
                     Port = packetData.Port,
+                    LastHeartBeatUtc = DateTime.UtcNow,
                     IsStarted = packetData.IsStarted,
                     CurrentPlayers = packetData.CurrentPlayers,
                     MaximumPlayers = packetData.MaximumPlayers

Supervisor/Program.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Threading;
 using Model;
 
@@ -17,7 +18,20 @@ namespace Supervisor
             
             while (true)
             {
-                Thread.Sleep(TimeSpan.FromSeconds(1));
+                RemoveCrashedServers();
+                Thread.Sleep(TimeSpan.FromSeconds(3));
+            }
+        }
+
+        private static void RemoveCrashedServers()
+        {
+            var crashedServers = State.Servers.Values
+                .Where(s => s.IsStarted && DateTime.UtcNow - s.LastHeartBeatUtc < TimeSpan.FromMinutes(15))
+                .Select(s => s.Port);
+
+            foreach (var port in crashedServers)
+            {
+                State.Servers.TryRemove(port, out _);
             }
         }
     }