[Server] Invalidate session after a timeout

ServerLib/CWebservice.cs

@@ -39,6 +39,7 @@ namespace ServerLib
             }
             catch (Exception)
             { }
+            CSessionControl.ResetSessionTimeout(sessionKey);
             return sessionKey;
         }
 
@@ -296,6 +297,7 @@ namespace ServerLib
 
         public bool IsServerOnline()
         {
+            _GetSession();
             return true;
         }
         #endregion

ServerLib/Session.cs

@@ -39,11 +39,19 @@ namespace ServerLib
             get { return _Roles; }
         }
        
+        private DateTime _LastSeen;
+        public DateTime LastSeen
+        {
+            get { return _LastSeen; }
+            internal set { _LastSeen = value; }
+        }
+
         public CSession(Guid id, int profileId, EUserRoles roles)
         {
             _ID = id;
             _ProfileId = profileId;
             _Roles = roles;
+            _LastSeen = DateTime.Now;
         }
     }
 }

ServerLib/SessionControl.cs

@@ -18,12 +18,35 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Timers;
 
 namespace ServerLib
 {
     static class CSessionControl
     {
-        private static readonly Dictionary<Guid, CSession> _ActiveSessions = new Dictionary<Guid, CSession>();
+        private static readonly Dictionary<Guid, CSession> _ActiveSessions;
+        private const int _UserTimeoutCheckIntervall = 120000;
+        private const int _UserTimeout = 120000;
+
+        static CSessionControl()
+        {
+            _ActiveSessions = new Dictionary<Guid, CSession>();
+            Timer timer = new Timer(_UserTimeoutCheckIntervall) {AutoReset = true, Enabled = true};
+            timer.Elapsed += _CheckForUserTimeouts;
+            timer.Start();
+        }
+
+        private static void _CheckForUserTimeouts(object sender, ElapsedEventArgs e)
+        {
+            var sessionIdsToRemove = _ActiveSessions.Where(pair => (DateTime.Now-pair.Value.LastSeen).TotalMilliseconds > _UserTimeout)
+                         .Select(pair => pair.Key)
+                         .ToList();
+
+            foreach (var sessionToRemove in sessionIdsToRemove)
+            {
+                InvalidateSessions(sessionToRemove);
+            }
+        }
 
         public static Guid OpenSession(string userName, string password)
         {
@@ -83,5 +106,14 @@ namespace ServerLib
                 return -1;
             return _ActiveSessions[sessionId].ProfileId;
         }
+
+        internal static void ResetSessionTimeout(Guid sessionId)
+        {
+            CSession value;
+            if (_ActiveSessions.TryGetValue(sessionId, out value))
+            {
+                value.LastSeen = DateTime.Now;
+            }
+        }
     }
 }