fix default session

src/TensorFlowNET.Core/Sessions/BaseSession.cs

@@ -43,7 +43,7 @@ namespace Tensorflow
 
         private NDArray _run<T>(T fetches, FeedItem[] feed_dict = null)
         {
-            var feed_dict_tensor = new Dictionary<Tensor, NDArray>();
+            var feed_dict_tensor = new Dictionary<object, object>();
 
             if (feed_dict != null)
                 feed_dict.ToList().ForEach(x => feed_dict_tensor.Add(x.Key, x.Value));
@@ -79,9 +79,30 @@ namespace Tensorflow
         /// name of an operation, the first Tensor output of that operation
         /// will be returned for that element.
         /// </returns>
-        private NDArray[] _do_run(List<Operation> target_list, List<Tensor> fetch_list, Dictionary<Tensor, NDArray> feed_dict)
+        private NDArray[] _do_run(List<Operation> target_list, List<Tensor> fetch_list, Dictionary<object, object> feed_dict)
         {
-            var feeds = feed_dict.Select(x => new KeyValuePair<TF_Output, Tensor>(x.Key._as_tf_output(), new Tensor(x.Value))).ToArray();
+            var feeds = feed_dict.Select(x => 
+            {
+                if(x.Key is Tensor tensor)
+                {
+                    switch (x.Value)
+                    {
+                        case Tensor t1:
+                            return new KeyValuePair<TF_Output, Tensor>(tensor._as_tf_output(), t1);
+                        case NDArray nd:
+                            return new KeyValuePair<TF_Output, Tensor>(tensor._as_tf_output(), new Tensor(nd));
+                        case int intVal:
+                            return new KeyValuePair<TF_Output, Tensor>(tensor._as_tf_output(), new Tensor(intVal));
+                        case float floatVal:
+                            return new KeyValuePair<TF_Output, Tensor>(tensor._as_tf_output(), new Tensor(floatVal));
+                        case double doubleVal:
+                            return new KeyValuePair<TF_Output, Tensor>(tensor._as_tf_output(), new Tensor(doubleVal));
+                        default:
+                            break;
+                    }
+                }
+                throw new NotImplementedException("_do_run.feed_dict");
+            }).ToArray();
             var fetches = fetch_list.Select(x => x._as_tf_output()).ToArray();
             var targets = target_list;
 

src/TensorFlowNET.Core/Sessions/FeedItem.cs

@@ -10,13 +10,13 @@ namespace Tensorflow
     /// </summary>
     public class FeedItem
     {
-        public Tensor Key { get; }
-        public NDArray Value { get; }
+        public object Key { get; }
+        public object Value { get; }
 
-        public FeedItem(Tensor tensor, NDArray nd)
+        public FeedItem(object key, object val)
         {
-            Key = tensor;
-            Value = nd;
+            Key = key;
+            Value = val;
         }
     }
 }

src/TensorFlowNET.Core/Sessions/_FetchHandler.cs

@@ -16,7 +16,7 @@ namespace Tensorflow
         private List<Tensor> _final_fetches = new List<Tensor>();
         private List<T> _targets = new List<T>();
 
-        public _FetchHandler(Graph graph, T fetches, Dictionary<Tensor, NDArray> feeds = null, Action feed_handles = null)
+        public _FetchHandler(Graph graph, T fetches, Dictionary<object, object> feeds = null, Action feed_handles = null)
         {
             _fetch_mapper = new _FetchMapper<T>().for_fetch(fetches);
             foreach(var fetch in _fetch_mapper.unique_fetches())

src/TensorFlowNET.Core/Train/Saving/Saver.cs

@@ -160,9 +160,9 @@ namespace Tensorflow
 
             if (!_is_empty)
             {
-                /*model_checkpoint_path = sess.run(_saver_def.SaveTensorName, new FeedItem[] {
+                var model_checkpoint_path1 = sess.run(_saver_def.SaveTensorName, new FeedItem[] {
                     new FeedItem(_saver_def.FilenameTensorName, checkpoint_file)
-                });*/
+                });
             }
 
             throw new NotImplementedException("");

src/TensorFlowNET.Core/ops.py.cs

@@ -289,7 +289,7 @@ namespace Tensorflow
         /// <returns>The default `Session` being used in the current thread.</returns>
         public static Session get_default_session()
         {
-            return tf.Session();
+            return tf.defaultSession;
         }
 
         public static void _run_using_default_session(Operation operation, FeedItem[] feed_dict, Graph graph, Session session)

src/TensorFlowNET.Core/tf.cs

@@ -17,7 +17,7 @@ namespace Tensorflow
         public static Context context = new Context(new ContextOptions(), new Status());
 
         public static Graph g = new Graph();
-        public static Session session = new Session();
+        public static Session defaultSession;
 
         public static RefVariable Variable<T>(T data, string name = "", TF_DataType dtype = TF_DataType.DtInvalid)
         {
@@ -49,7 +49,8 @@ namespace Tensorflow
 
         public static Session Session()
         {
-            return session;
+            defaultSession = new Session();
+            return defaultSession;
         }
     }
 }