AutoReconnect

lib/src/Core/AsyncQueue.dart

@@ -12,7 +12,7 @@ class AsyncQueue<T> extends AsyncReply<T?> {
     _list.add(reply);
 
     //super._resultReady = false;
-    super.setResultReady(false);
+    super.ready = false; // setResultReady(false);
 
     reply.then(processQueue);
   }
@@ -35,7 +35,7 @@ class AsyncQueue<T> extends AsyncReply<T?> {
         break;
 
     //super._resultReady = (_list.length == 0);
-    super.setResultReady(_list.length == 0);
+    super.ready = _list.length == 0; // .setResultReady(_list.length == 0);
   }
 
   AsyncQueue() {}

lib/src/Core/AsyncReply.dart

@@ -23,6 +23,8 @@ SOFTWARE.
 */
 import 'dart:async';
 import 'dart:core';
+import 'package:esiur/esiur.dart';
+
 import 'AsyncException.dart';
 import 'ProgressType.dart';
 
@@ -55,9 +57,9 @@ class AsyncReply<T> implements Future<T> {
     return _result;
   }
 
-  void setResultReady(bool val) {
+  // void setResultReady(bool val) {
-    _resultReady = val;
+  //   _resultReady = val;
-  }
+  // }
 
   AsyncReply<T> next(Function(T) callback) {
     then(callback);
@@ -127,7 +129,11 @@ class AsyncReply<T> implements Future<T> {
 
   AsyncReply<T> timeout(Duration timeLimit, {FutureOr<T?> onTimeout()?}) {
     Future.delayed(timeLimit, () {
-      if (!_resultReady && _exception == null) onTimeout?.call();
+      if (!_resultReady && _exception == null) {
+        triggerError(AsyncException(ErrorType.Management,
+            ExceptionCode.Timeout.index, "Execution timeout expired"));
+        onTimeout?.call();
+      }
     });
 
     return this;
@@ -152,6 +158,7 @@ class AsyncReply<T> implements Future<T> {
 
   AsyncReply<T> trigger(T result) {
     if (_resultReady) return this;
+    if (_exception != null) return this;
 
     _result = result;
     _resultReady = true;

lib/src/Core/ExceptionCode.dart

@@ -34,5 +34,6 @@ enum ExceptionCode {
   AlreadyListened,
   AlreadyUnlistened,
   NotListenable,
-  ParseError
+  ParseError,
+  Timeout
 }

lib/src/Net/IIP/DistributedConnection.dart

@@ -122,8 +122,13 @@ class DistributedConnection extends NetworkConnection with IStore {
 
   bool _ready = false, _readyToEstablish = false;
 
-  KeyList<int, DistributedResource> _resources =
+  KeyList<int, WeakReference<DistributedResource>> _attachedResources =
+      new KeyList<int, WeakReference<DistributedResource>>();
+
+  KeyList<int, DistributedResource> _neededResources =
       new KeyList<int, DistributedResource>();
+  KeyList<int, WeakReference<DistributedResource>> _suspendedResources =
+      new KeyList<int, WeakReference<DistributedResource>>();
 
   KeyList<int, AsyncReply<DistributedResource>> _resourceRequests =
       new KeyList<int, AsyncReply<DistributedResource>>();
@@ -285,6 +290,7 @@ class DistributedConnection extends NetworkConnection with IStore {
       _session?.localAuthentication.domain = domain;
       _session?.localAuthentication.username = username;
       _localPasswordOrToken = passwordOrToken;
+      _invalidCredentials = false;
     }
 
     if (_session == null)
@@ -302,77 +308,151 @@ class DistributedConnection extends NetworkConnection with IStore {
 
     if (_hostname == null) throw Exception("Host not specified.");
 
-    if (socket != null) {
+    _connectSocket(socket);
-      socket.connect(_hostname as String, _port)
-        ..then((x) {
-          assign(socket as ISocket);
-        })
-        ..error((x) {
-          _openReply?.triggerError(x);
-          _openReply = null;
-        });
-    }
 
     return _openReply as AsyncReply<bool>;
   }
 
+  _connectSocket(ISocket socket) {
+    socket.connect(_hostname as String, _port)
+      ..then((x) {
+        assign(socket);
+      })
+      ..error((x) {
+        if (autoReconnect) {
+          print("Reconnecting socket...");
+          Future.delayed(Duration(seconds: 5), () => _connectSocket(socket));
+        } else {
+          _openReply?.triggerError(x);
+          _openReply = null;
+        }
+      });
+  }
+
+  bool autoReconnect = false;
+  bool _invalidCredentials = false;
+
   @override
   void disconnected() {
     // clean up
     _ready = false;
     _readyToEstablish = false;
 
-    _requests.values.forEach((x) { try { 
+    print("Disconnected ..");
-              x.triggerError(AsyncException(ErrorType.Management, 0, "Connection closed"));
+
-            } catch (ex){ }
+    _keepAliveTimer?.cancel();
+    _keepAliveTimer = null;
+
+    _requests.values.forEach((x) {
+      try {
+        x.triggerError(
+            AsyncException(ErrorType.Management, 0, "Connection closed"));
+      } catch (ex) {}
     });
 
-    _resourceRequests.values.forEach((x) { try { 
+    _resourceRequests.values.forEach((x) {
-              x.triggerError(AsyncException(ErrorType.Management, 0, "Connection closed"));
+      try {
-            } catch (ex){ }
+        x.triggerError(
+            AsyncException(ErrorType.Management, 0, "Connection closed"));
+      } catch (ex) {}
     });
 
-    _templateRequests.values.forEach((x) { try { 
+    _templateRequests.values.forEach((x) {
-              x.triggerError(AsyncException(ErrorType.Management, 0, "Connection closed"));
+      try {
-            } catch (ex){ }
+        x.triggerError(
+            AsyncException(ErrorType.Management, 0, "Connection closed"));
+      } catch (ex) {}
     });
 
     _requests.clear();
     _resourceRequests.clear();
     _templateRequests.clear();
 
-    
+    for (var x in _attachedResources.values) {
-
+      var r = x.target;
-    if (server != null){
+      if (r != null) {
-    // @TODO: check if we need this with reconnect
+        r.suspend();
-      _resources.values.forEach((x) => x.suspend());
+        _suspendedResources[r.distributedResourceInstanceId ?? 0] = x;
-      _unsubscribeAll();
+      }
-      Warehouse.remove(this);
     }
 
+    if (server != null) {
+      _suspendedResources.clear();
 
+      _unsubscribeAll();
+      Warehouse.remove(this);
+
+      // @TODO: implement this
+      // if (ready)
+      //   _server.membership?.Logout(session);
+
+    } else if (autoReconnect && !_invalidCredentials) {
+      Future.delayed(Duration(seconds: 5), reconnect);
+    } else {
+      _suspendedResources.clear();
+    }
+
+    _attachedResources.clear();
+    _ready = false;
   }
 
   Future<bool> reconnect() async {
-    if (await connect()) {
+    try {
-      var bag = AsyncBag();
+      if (!await connect()) return false;
 
-      for (var i = 0; i < _resources.keys.length; i++) {
+      try {
-        var index = _resources.keys.elementAt(i);
+        var toBeRestored = <DistributedResource>[];
-        // print("Re $i ${_resources[index].instance.template.className}");
+
-        bag.add(fetch(index, null));
+        _suspendedResources.forEach((key, value) {
+          var r = value.target;
+          if (r != null) toBeRestored.add(r);
+        });
+
+        for (var r in toBeRestored) {
+          var link = DC.stringToBytes(r.distributedResourceLink ?? "");
+
+          print("Restoring " + (r.distributedResourceLink ?? ""));
+
+          try {
+            var ar = await (sendRequest(IIPPacketAction.QueryLink)
+                  ..addUint16(link.length)
+                  ..addDC(link))
+                .done();
+
+            var dataType = ar?[0] as TransmissionType;
+            var data = ar?[1] as DC;
+
+            if (dataType.identifier ==
+                TransmissionTypeIdentifier.ResourceList) {
+              // parse them as int
+              var id = data.getUint32(8);
+              if (id != r.distributedResourceInstanceId)
+                r.distributedResourceInstanceId = id;
+
+              _neededResources[id] = r;
+              _suspendedResources.remove(id);
+
+              await fetch(id, null);
+            }
+          } catch (ex) {
+            if (ex is AsyncException &&
+                ex.code == ExceptionCode.ResourceNotFound) {
+              // skip this resource
+            } else {
+              break;
+            }
+          }
+        }
+      } catch (ex) {
+        print(ex);
+      }
+    } catch (ex) {
+      return false;
     }
-
-      bag.seal();
-
-      await bag;
 
     return true;
   }
 
-    return false;
-  }
-
   /// <summary>
   /// KeyList to store user variables related to this connection.
   /// </summary>
@@ -526,8 +606,6 @@ class DistributedConnection extends NetworkConnection with IStore {
     //     Timer(Duration(seconds: KeepAliveInterval), _keepAliveTimer_Elapsed);
   }
 
-
-
   void _keepAliveTimer_Elapsed() {
     if (!isConnected) return;
 
@@ -541,23 +619,25 @@ class DistributedConnection extends NetworkConnection with IStore {
 
     _lastKeepAliveSent = now;
 
-    sendRequest(IIPPacketAction.KeepAlive)
+    //print("keep alive sent");
+
+    (sendRequest(IIPPacketAction.KeepAlive)
           ..addDateTime(now)
-      ..addUint32(interval)
+          ..addUint32(interval))
-      ..done().then((x) {
+        .done()
+      ..then((x) {
         jitter = x?[1];
 
         _keepAliveTimer = Timer(
             Duration(seconds: KeepAliveInterval), _keepAliveTimer_Elapsed);
 
-        print("Keep Alive Received ${jitter}");
+        //print("Keep Alive Received ${jitter}");
-      }).error((ex) {
+      })
+      ..error((ex) {
         _keepAliveTimer?.cancel();
         close();
-      }).timeout(Duration(microseconds: keepAliveTime), onTimeout: () {
+      })
-        _keepAliveTimer?.cancel();
+      ..timeout(Duration(seconds: keepAliveTime));
-        close();
-      });
   }
 
   int processPacket(
@@ -743,20 +823,20 @@ class DistributedConnection extends NetworkConnection with IStore {
               //    packet.callbackId, packet.resourceId, packet.content, false);
               break;
 
-
             case IIPPacketAction.KeepAlive:
-                iipRequestKeepAlive(packet.callbackId, packet.currentTime, packet.interval);
+              iipRequestKeepAlive(
+                  packet.callbackId, packet.currentTime, packet.interval);
               break;
 
             case IIPPacketAction.ProcedureCall:
-                iipRequestProcedureCall(packet.callbackId, packet.procedure, packet.dataType as TransmissionType, msg);
+              iipRequestProcedureCall(packet.callbackId, packet.procedure,
+                  packet.dataType as TransmissionType, msg);
               break;
 
             case IIPPacketAction.StaticCall:
-                iipRequestStaticCall(packet.callbackId, packet.classId, packet.methodIndex, packet.dataType as TransmissionType, msg);
+              iipRequestStaticCall(packet.callbackId, packet.classId,
+                  packet.methodIndex, packet.dataType as TransmissionType, msg);
               break;
-
-
           }
         } else if (packet.command == IIPPacketCommand.Reply) {
           switch (packet.action) {
@@ -823,7 +903,6 @@ class DistributedConnection extends NetworkConnection with IStore {
             case IIPPacketAction.InvokeFunction:
             case IIPPacketAction.StaticCall:
             case IIPPacketAction.ProcedureCall:
-
               iipReplyInvoke(packet.callbackId,
                   packet.dataType ?? TransmissionType.Null, msg);
               break;
@@ -1038,10 +1117,11 @@ class DistributedConnection extends NetworkConnection with IStore {
               emitArgs("ready", []);
 
               // start perodic keep alive timer
-              _keepAliveTimer = Timer(Duration(seconds: KeepAliveInterval), _keepAliveTimer_Elapsed);
+              _keepAliveTimer = Timer(Duration(seconds: KeepAliveInterval),
-              
+                  _keepAliveTimer_Elapsed);
             }
           } else if (_authPacket.command == IIPAuthPacketCommand.Error) {
+            _invalidCredentials = true;
             var ex = AsyncException(ErrorType.Management, _authPacket.errorCode,
                 _authPacket.errorMessage);
             _openReply?.triggerError(ex);
@@ -1096,7 +1176,7 @@ class DistributedConnection extends NetworkConnection with IStore {
   /// <returns></returns>
   AsyncReply<bool> put(IResource resource) {
     if (Codec.isLocalResource(resource, this))
-      _resources.add(
+      _neededResources.add(
           (resource as DistributedResource).distributedResourceInstanceId
               as int,
           resource);
@@ -1190,7 +1270,21 @@ class DistributedConnection extends NetworkConnection with IStore {
     return reply;
   }
 
-  AsyncReply<dynamic>? sendDetachRequest(int instanceId) {
+  void detachResource(int instanceId) async {
+    try {
+      if (_attachedResources.containsKey(instanceId))
+        _attachedResources.remove(instanceId);
+
+      if (_suspendedResources.containsKey(instanceId))
+        _suspendedResources.remove(instanceId);
+
+      await _sendDetachRequest(instanceId);
+    } catch (ex) {
+      // do nothing
+    }
+  }
+
+  AsyncReply<dynamic>? _sendDetachRequest(int instanceId) {
     try {
       return (sendRequest(IIPPacketAction.DetachResource)
             ..addUint32(instanceId))
@@ -1277,11 +1371,16 @@ class DistributedConnection extends NetworkConnection with IStore {
   void iipEventResourceReassigned(int resourceId, int newResourceId) {}
 
   void iipEventResourceDestroyed(int resourceId) {
-    if (_resources.contains(resourceId)) {
+    var r = _attachedResources[resourceId]?.target;
-      var r = _resources[resourceId];
+    if (r != null) {
-      _resources.remove(resourceId);
+      r.destroy();
-      r?.destroy();
+      return;
+    } else if (_neededResources.contains(resourceId)) {
+      // @TODO: handle this mess
+      _neededResources.remove(resourceId);
     }
+
+    _attachedResources.remove(resourceId);
   }
 
   // @TODO: Check for deadlocks
@@ -1532,17 +1631,15 @@ class DistributedConnection extends NetworkConnection with IStore {
     _subscriptions.remove(resource);
   }
 
-void _unsubscribeAll(){
+  void _unsubscribeAll() {
     _subscriptions.forEach((resource, value) {
       resource.instance?.off("resourceEventOccurred", _instance_EventOccurred);
       resource.instance?.off("resourceModified", _instance_PropertyModified);
       resource.instance?.off("resourceDestroyed", _instance_ResourceDestroyed);
-    
     });
 
     _subscriptions.clear();
-}
+  }
-
 
   void iipRequestReattachResource(
       int callback, int resourceId, int resourceAge) {
@@ -2071,11 +2168,11 @@ void _unsubscribeAll(){
     });
   }
 
-
+  void iipRequestProcedureCall(int callback, String procedureCall,
-    void iipRequestProcedureCall(int callback, String procedureCall, TransmissionType transmissionType, DC content)
+      TransmissionType transmissionType, DC content) {
-    {
     // server not implemented
-        sendError(ErrorType.Management, callback, ExceptionCode.GeneralFailure.index);
+    sendError(
+        ErrorType.Management, callback, ExceptionCode.GeneralFailure.index);
 
     // if (server == null)
     // {
@@ -2116,22 +2213,22 @@ void _unsubscribeAll(){
     // });
   }
 
-    void iipRequestStaticCall(int callback, Guid classId, int index, TransmissionType transmissionType, DC content)
+  void iipRequestStaticCall(int callback, Guid classId, int index,
-    {
+      TransmissionType transmissionType, DC content) {
     var template = Warehouse.getTemplateByClassId(classId);
 
-        if (template == null)
+    if (template == null) {
-        {
+      sendError(
-            sendError(ErrorType.Management, callback, ExceptionCode.TemplateNotFound.index);
+          ErrorType.Management, callback, ExceptionCode.TemplateNotFound.index);
       return;
     }
 
     var ft = template.getFunctionTemplateByIndex(index);
 
-        if (ft == null)
+    if (ft == null) {
-        {
       // no function at this index
-            sendError(ErrorType.Management, callback, ExceptionCode.MethodNotFound.index);
+      sendError(
+          ErrorType.Management, callback, ExceptionCode.MethodNotFound.index);
       return;
     }
 
@@ -2169,7 +2266,6 @@ void _unsubscribeAll(){
     // });
   }
 
-
   void iipRequestResourceAttribute(int callback, int resourceId) {}
 
 // @TODO: Check for deadlocks
@@ -2404,14 +2500,7 @@ void _unsubscribeAll(){
                   sendError(x.type, callback, x.code, x.message);
                 });
             } else {
-              /*
+              var pi = null;
-#if NETSTANDARD1_5
-                              var pi = r.GetType().GetTypeInfo().GetProperty(pt.Name);
-#else
-                              var pi = r.GetType().GetProperty(pt.Name);
-#endif*/
-
-              var pi = null; // pt.Info;
 
               if (pi != null) {
                 if (r.instance?.applicable(_session as Session,
@@ -2549,16 +2638,16 @@ void _unsubscribeAll(){
     return rt;
   }
 
-  /// <summary>
+  // /// <summary>
-  /// Retrive a resource by its instance Id.
+  // /// Retrive a resource by its instance Id.
-  /// </summary>
+  // /// </summary>
-  /// <param name="iid">Instance Id</param>
+  // /// <param name="iid">Instance Id</param>
-  /// <returns>Resource</returns>
+  // /// <returns>Resource</returns>
-  AsyncReply<IResource?> retrieve(int iid) {
+  // AsyncReply<IResource?> retrieve(int iid) {
-    for (var r in _resources.values)
+  //   for (var r in _resources.values)
-      if (r.instance?.id == iid) return new AsyncReply<IResource>.ready(r);
+  //     if (r.instance?.id == iid) return new AsyncReply<IResource>.ready(r);
-    return new AsyncReply<IResource?>.ready(null);
+  //   return new AsyncReply<IResource?>.ready(null);
-  }
+  // }
 
   AsyncReply<List<TypeTemplate>> getLinkTemplates(String link) {
     var reply = new AsyncReply<List<TypeTemplate>>();
@@ -2603,7 +2692,13 @@ void _unsubscribeAll(){
   /// <param name="id">Resource Id</param>Guid classId
   /// <returns>DistributedResource</returns>
   AsyncReply<DistributedResource> fetch(int id, List<int>? requestSequence) {
-    var resource = _resources[id];
+    var resource = _attachedResources[id]?.target;
+
+    if (resource != null)
+      return AsyncReply<DistributedResource>.ready(resource);
+
+    resource = _neededResources[id];
+
     var request = _resourceRequests[id];
 
     //print("fetch $id");
@@ -2612,8 +2707,11 @@ void _unsubscribeAll(){
       if (resource != null && (requestSequence?.contains(id) ?? false))
         return AsyncReply<DistributedResource>.ready(resource);
       return request;
-    } else if (resource != null && !resource.distributedResourceSuspended)
+    } else if (resource != null && !resource.distributedResourceSuspended) {
+      // @REVIEW: this should never happen
+      print("DCON: Resource not moved to attached.");
       return new AsyncReply<DistributedResource>.ready(resource);
+    }
 
     var reply = new AsyncReply<DistributedResource>();
     _resourceRequests.add(id, reply);
@@ -2652,8 +2750,10 @@ void _unsubscribeAll(){
             dr = new DistributedResource();
             dr.internal_init(this, id, rt[1] as int, rt[2] as String);
           }
-        } else
+        } else {
           dr = resource;
+          template = resource.instance?.template;
+        }
 
         TransmissionType transmissionType = rt[3] as TransmissionType;
         DC content = rt[4] as DC;
@@ -2674,8 +2774,12 @@ void _unsubscribeAll(){
                   ar[i + 2], ar[i] as int, ar[i + 1] as DateTime));
 
             dr.internal_attach(pvs);
-
             _resourceRequests.remove(id);
+
+            // move from needed to attached.
+            _neededResources.remove(id);
+            _attachedResources[id] = WeakReference<DistributedResource>(dr);
+
             reply.trigger(dr);
           })
             ..error((ex) => reply.triggerError(ex));
@@ -3042,18 +3146,16 @@ void _unsubscribeAll(){
   TemplateDescriber get template =>
       TemplateDescriber("Esiur.Net.IIP.DistributedConnection");
 
-
+  AsyncReply<dynamic> staticCall(
-
+      Guid classId, int index, Map<UInt8, dynamic> parameters) {
-  AsyncReply<dynamic> staticCall(Guid classId, int index, Map<UInt8, dynamic> parameters)
-  {
     var pb = Codec.compose(parameters, this);
 
     var reply = AsyncReply<dynamic>();
     var c = _callbackCounter++;
     _requests.add(c, reply);
 
-
+    sendParams()
-      sendParams()..addUint8((0x40 | IIPPacketAction.StaticCall))
+      ..addUint8((0x40 | IIPPacketAction.StaticCall))
       ..addUint32(c)
       ..addGuid(classId)
       ..addUint8(index)
@@ -3063,16 +3165,20 @@ void _unsubscribeAll(){
     return reply;
   }
 
-    // AsyncReply<dynamic> Call(String procedureCall, params object[] parameters)
+  AsyncReply<dynamic> call(String procedureCall, [List? parameters = null]) {
-    // {
+    if (parameters == null) {
-    //     var args = new Map<byte, object>();
+      return callArgs(procedureCall, Map<UInt8, dynamic>());
-    //     for (byte i = 0; i < parameters.Length; i++)
+    } else {
-    //         args.Add(i, parameters[i]);
+      var map = Map<UInt8, dynamic>();
-    //     return Call(procedureCall, args);
+      parameters.forEachIndexed((index, element) {
-    // }
+        map[UInt8(index)] = element;
+      });
+      return callArgs(procedureCall, map);
+    }
+  }
 
-    AsyncReply<dynamic> call(String procedureCall, Map<UInt8, dynamic> parameters)
+  AsyncReply<dynamic> callArgs(
-    {
+      String procedureCall, Map<UInt8, dynamic> parameters) {
     var pb = Codec.compose(parameters, this);
 
     var reply = new AsyncReply<dynamic>();
@@ -3081,7 +3187,8 @@ void _unsubscribeAll(){
 
     var callName = DC.stringToBytes(procedureCall);
 
-        sendParams()..addUint8(0x40 | IIPPacketAction.ProcedureCall)
+    sendParams()
+      ..addUint8(0x40 | IIPPacketAction.ProcedureCall)
       ..addUint32(c)
       ..addUint16(callName.length)
       ..addDC(callName)
@@ -3091,19 +3198,16 @@ void _unsubscribeAll(){
     return reply;
   }
 
-    void iipRequestKeepAlive(int callbackId, DateTime peerTime, int interval)
+  void iipRequestKeepAlive(int callbackId, DateTime peerTime, int interval) {
-    {
-
     int jitter = 0;
 
     var now = DateTime.now().toUtc();
 
-        if (_lastKeepAliveReceived != null)
+    if (_lastKeepAliveReceived != null) {
-        {
       var diff = now.difference(_lastKeepAliveReceived!).inMicroseconds;
       //Console.WriteLine("Diff " + diff + " " + interval);
 
-            jitter =(diff -interval).abs();
+      jitter = (diff - interval).abs();
     }
 
     sendParams()
@@ -3115,5 +3219,4 @@ void _unsubscribeAll(){
 
     _lastKeepAliveReceived = now;
   }
-
 }

lib/src/Net/IIP/DistributedResource.dart

@@ -76,6 +76,7 @@ class DistributedResource extends IResource {
   /// Instance Id given by the other end.
   /// </summary>
   int? get distributedResourceInstanceId => _instanceId;
+  set distributedResourceInstanceId(value) => _instanceId = value;
 
   //bool get destroyed => _destroyed;
 
@@ -90,7 +91,7 @@ class DistributedResource extends IResource {
   void destroy() {
     _destroyed = true;
     _attached = false;
-    _connection?.sendDetachRequest(_instanceId as int);
+    _connection?.detachResource(_instanceId as int);
     emitArgs("destroy", [this]);
   }
 
@@ -194,8 +195,8 @@ class DistributedResource extends IResource {
   }
 
   AsyncReply<dynamic> listen(event) {
-    if (_destroyed) throw new Exception("Trying to access destroyed object");
+    if (_destroyed) throw new Exception("Trying to access a destroyed object.");
-    if (_suspended) throw new Exception("Trying to access suspended object");
+    if (_suspended) throw new Exception("Trying to access a suspended object.");
 
     EventTemplate? et = event is EventTemplate
         ? event
@@ -214,8 +215,8 @@ class DistributedResource extends IResource {
   }
 
   AsyncReply<dynamic> unlisten(event) {
-    if (_destroyed) throw new Exception("Trying to access destroyed object");
+    if (_destroyed) throw new Exception("Trying to access a destroyed object.");
-    if (_suspended) throw new Exception("Trying to access suspended object");
+    if (_suspended) throw new Exception("Trying to access a suspended object.");
 
     EventTemplate? et = event is EventTemplate
         ? event
@@ -245,7 +246,7 @@ class DistributedResource extends IResource {
   }
 
   AsyncReply<dynamic> internal_invoke(int index, Map<UInt8, dynamic> args) {
-    if (_destroyed) throw new Exception("Trying to access a destroyed object");
+    if (_destroyed) throw new Exception("Trying to access a destroyed object.");
 
     if (_suspended) throw new Exception("Trying to access a suspended object.");
     if (instance == null) throw Exception("Object not initialized.");
@@ -290,6 +291,10 @@ class DistributedResource extends IResource {
 
   @override //overring noSuchMethod
   noSuchMethod(Invocation invocation) {
+    if (_destroyed) throw new Exception("Trying to access a destroyed object.");
+
+    if (_suspended) throw new Exception("Trying to access a suspended object.");
+
     var memberName = _getMemberName(invocation.memberName);
 
     if (invocation.isMethod) {
@@ -365,6 +370,10 @@ class DistributedResource extends IResource {
   /// <param name="value">Value</param>
   /// <returns>Indicator when the property is set.</returns>
   AsyncReply<dynamic> set(int index, dynamic value) {
+    if (_destroyed) throw new Exception("Trying to access a destroyed object.");
+
+    if (_suspended) throw new Exception("Trying to access a suspended object.");
+
     if (index >= _properties.length)
       throw Exception("Property with index `${index}` not found.");
 

lib/src/Net/NetworkConnection.dart

@@ -100,7 +100,6 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
       if (_sock != null) _sock?.close();
     } catch (ex) {
       //Global.Log("NetworkConenction:Close", LogType.Error, ex.ToString());
-
     }
   }
 

lib/src/Net/Sockets/TCPSocket.dart

@@ -153,6 +153,8 @@ class TCPSocket extends ISocket {
   }
 
   void close() {
+    if (state == SocketState.Closed) return;
+
     if (state != SocketState.Closed && state != SocketState.Terminated)
       _state = SocketState.Closed;
 

lib/src/Net/Sockets/WSocket.dart

@@ -126,6 +126,8 @@ class WSocket extends ISocket {
   }
 
   void close() {
+    if (state == SocketState.Closed) return;
+
     if (state != SocketState.Closed && state != SocketState.Terminated)
       _state = SocketState.Closed;
 

lib/src/Resource/IStore.dart

@@ -33,7 +33,7 @@ import '../Data/PropertyValue.dart';
 // new
 abstract class IStore implements IResource {
   AsyncReply<IResource?> get(String path);
-  AsyncReply<IResource?> retrieve(int iid);
+  // AsyncReply<IResource?> retrieve(int iid);
   AsyncReply<bool> put(IResource resource);
   String? link(IResource resource);
   bool record(IResource resource, String propertyName, dynamic value, int? age,

lib/src/Resource/Warehouse.dart

@@ -22,6 +22,7 @@ SOFTWARE.
 
 */
 
+ 
 import '../Data/IntType.dart';
 
 import '../Data/TransmissionType.dart';
@@ -55,7 +56,8 @@ import '../Net/IIP/DistributedConnection.dart';
 // Centeral Resource Issuer
 class Warehouse {
   static AutoList<IStore, Instance> _stores = AutoList<IStore, Instance>();
-  static Map<int, IResource> _resources = new Map<int, IResource>();
+  static Map<int, WeakReference<IResource>> _resources =
+      new Map<int, WeakReference<IResource>>();
   static int resourceCounter = 0;
 
   static KeyList<TemplateType, KeyList<Guid, TypeTemplate>> _templates =
@@ -100,7 +102,7 @@ class Warehouse {
   /// <returns></returns>
   static AsyncReply<IResource?> getById(int id) {
     if (_resources.containsKey(id))
-      return new AsyncReply<IResource?>.ready(_resources[id]);
+      return new AsyncReply<IResource?>.ready(_resources[id]?.target);
     else
       return new AsyncReply<IResource?>.ready(null);
   }
@@ -155,15 +157,19 @@ class Warehouse {
   static AsyncReply<bool> close() {
     var bag = new AsyncBag<bool>();
 
-    for (var resource in _resources.values)
+    for (var resource in _resources.values) {
-      if (!(resource is IStore))
+      var r = resource.target;
-        bag.add(resource.trigger(ResourceTrigger.Terminate));
+      if ((r != null) && !(r is IStore))
+        bag.add(r.trigger(ResourceTrigger.Terminate));
+    }
 
     for (var s in _stores) bag.add(s.trigger(ResourceTrigger.Terminate));
 
-    for (var resource in _resources.values)
+    for (var resource in _resources.values) {
-      if (!(resource is IStore))
+      var r = resource.target;
-        bag.add(resource.trigger(ResourceTrigger.SystemTerminated));
+      if ((r != null) && !(resource is IStore))
+        bag.add(r.trigger(ResourceTrigger.SystemTerminated));
+    }
 
     for (var store in _stores)
       bag.add(store.trigger(ResourceTrigger.SystemTerminated));
@@ -451,7 +457,7 @@ class Warehouse {
     var initResource = () {
       if (resource.instance == null) return;
 
-      _resources[(resource.instance as Instance).id] = resource;
+      _resources[(resource.instance as Instance).id] = WeakReference(resource);
 
       if (_warehouseIsOpen) {
         resource.trigger(ResourceTrigger.Initialize)
@@ -644,8 +650,15 @@ class Warehouse {
       _stores.remove(resource);
 
       // remove all objects associated with the store
-      var toBeRemoved =
+      //var toBeRemoved =
-          _resources.values.where((x) => x.instance?.store == resource);
+      //  _resources.values.where((x) => x.target?.instance?.store == resource);
+
+      var toBeRemoved = <IResource>[];
+      for (var wr in _resources.values) {
+        var r = wr.target;
+        if (r != null && r.instance?.store == resource) toBeRemoved.add(r);
+      }
+
       for (var o in toBeRemoved) remove(o);
 
       // StoreDisconnected?.Invoke(resource as IStore);