diff --git a/src/TensorFlowNET.Core/APIs/tf.array.cs b/src/TensorFlowNET.Core/APIs/tf.array.cs
index 1d2e55a7..8288c94c 100644
--- a/src/TensorFlowNET.Core/APIs/tf.array.cs
+++ b/src/TensorFlowNET.Core/APIs/tf.array.cs
@@ -116,6 +116,9 @@ namespace Tensorflow
         public Tensor fill<T>(Tensor dims, T value, string name = null)
             => gen_array_ops.fill(dims, value, name: name);
 
+        public Tensor fill<T>(Shape dims, T value, string name = null)
+            => array_ops.fill(dims, value, name: name);
+
         /// <summary>
         /// Return a tensor with the same shape and contents as input.
         /// </summary>
diff --git a/src/TensorFlowNET.Core/Eager/EagerRunner.RecordGradient.cs b/src/TensorFlowNET.Core/Eager/EagerRunner.RecordGradient.cs
index afa30811..cfcea55a 100644
--- a/src/TensorFlowNET.Core/Eager/EagerRunner.RecordGradient.cs
+++ b/src/TensorFlowNET.Core/Eager/EagerRunner.RecordGradient.cs
@@ -68,12 +68,12 @@ namespace Tensorflow.Eager
                      Tensor[] op_inputs,
                      object[] attrs,
                      Tensor[] op_outputs)
-            => (output_grads, unneeded_gradients) =>
+            => (out_grads, unneeded_gradients) =>
             {
                 if (ops.gradientFunctions[op_name] == null)
                     return new Tensor[op_inputs.Length];
 
-                var op = new EagerOperation
+                var oper = new EagerOperation
                 {
                     Name = op_name,
                     NumInputs = op_inputs.Length,
@@ -84,7 +84,40 @@ namespace Tensorflow.Eager
                     Attrs = attrs
                 };
 
-                return ops.gradientFunctions[op_name](op, output_grads);
+                /*return op_name switch
+                {
+                    "Add" => math_grad._AddGrad(oper, out_grads),
+                    "AddV2" => math_grad._AddV2Grad(oper, out_grads),
+                    "BiasAdd" => nn_grad._BiasAddGrad(oper, out_grads),
+                    "Cast" => math_grad._CastGrad(oper, out_grads),
+                    "ConcatV2" => array_grad._ConcatV2Grad(oper, out_grads),
+                    "Conv2D" => nn_grad._Conv2DGrad(oper, out_grads),
+                    "ExpandDims" => array_grad._ExpandDimsGrad(oper, out_grads),
+                    "Exp" => math_grad._ExpGrad(oper, out_grads),
+                    "FusedBatchNormV3" => nn_grad._FusedBatchNormV3Grad(oper, out_grads),
+                    "Id" => math_grad._IdGrad(oper, out_grads),
+                    "LeakyRelu" => nn_grad._LeakyReluGrad(oper, out_grads),
+                    "Log1p" => math_grad._Log1pGrad(oper, out_grads),
+                    "Maximum" => math_grad._MaximumGrad(oper, out_grads),
+                    "Mean" => math_grad._MeanGrad(oper, out_grads),
+                    "Minimum" => math_grad._MinimumGrad(oper, out_grads),
+                    "Mul" => math_grad._MulGrad(oper, out_grads),
+                    "Neg" => math_grad._NegGrad(oper, out_grads),
+                    "Pad" => array_grad._PadGrad(oper, out_grads),
+                    "Pow" => math_grad._PowGrad(oper, out_grads),
+                    "RealDiv" => math_grad._RealDivGrad(oper, out_grads),
+                    "Read" => resource_variable_grad._ReadGrad(oper, out_grads),
+                    "Reshape" => array_grad._ReshapeGrad(oper, out_grads),
+                    "ResizeNearestNeighbor" => image_grad._ResizeNearestNeighborGrad(oper, out_grads),
+                    "Select" => math_grad._SelectGrad(oper, out_grads),
+                    "Sigmoid" => math_grad._SigmoidGrad(oper, out_grads),
+                    "Sum" => math_grad._SumGrad(oper, out_grads),
+                    "Sub" => math_grad._SubGrad(oper, out_grads),
+                    "StridedSlice" => array_grad._StridedSliceGrad(oper, out_grads),
+                    _ => ops.gradientFunctions[op_name](oper, out_grads)
+                };*/
+
+                return ops.gradientFunctions[op_name](oper, out_grads);
             };
 
         bool CouldForwardprop()
diff --git a/src/TensorFlowNET.Core/Eager/EagerRunner.TFE_FastPathExecute.cs b/src/TensorFlowNET.Core/Eager/EagerRunner.TFE_FastPathExecute.cs
index 7d5c4645..20049952 100644
--- a/src/TensorFlowNET.Core/Eager/EagerRunner.TFE_FastPathExecute.cs
+++ b/src/TensorFlowNET.Core/Eager/EagerRunner.TFE_FastPathExecute.cs
@@ -15,7 +15,7 @@ namespace Tensorflow.Eager
     /// </summary>
     public partial class EagerRunner
     {
-        UnorderedMap<string, SafeOpHandle> thread_local_eager_operation_map = new UnorderedMap<string, SafeOpHandle>();
+        UnorderedMap<string, SafeEagerOpHandle> thread_local_eager_operation_map = new UnorderedMap<string, SafeEagerOpHandle>();
         public void ClearEagerOperationMap()
             => thread_local_eager_operation_map.Clear();
 
@@ -157,7 +157,7 @@ namespace Tensorflow.Eager
             return flat_result;
         }
 
-        SafeOpHandle GetOp(Context ctx, string op_or_function_name, Status status)
+        SafeEagerOpHandle GetOp(Context ctx, string op_or_function_name, Status status)
         {
             if (thread_local_eager_operation_map.find(op_or_function_name, out var op))
                 c_api.TFE_OpReset(op, op_or_function_name, ctx.DeviceName, status.Handle);
@@ -205,7 +205,7 @@ namespace Tensorflow.Eager
             ArgDef input_arg,
             List<object> flattened_attrs,
             List<Tensor> flattened_inputs,
-            SafeOpHandle op,
+            SafeEagerOpHandle op,
             Status status)
         {
             var tensor = tf.convert_to_tensor(inputs);
@@ -225,7 +225,7 @@ namespace Tensorflow.Eager
             return true;
         }
 
-        public void SetOpAttrs(SafeOpHandle op, params object[] attrs)
+        public void SetOpAttrs(SafeEagerOpHandle op, params object[] attrs)
         {
             var status = tf.Status;
             var len = attrs.Length;
@@ -258,7 +258,7 @@ namespace Tensorflow.Eager
         /// <param name="attr_value"></param>
         /// <param name="attr_list_sizes"></param>
         /// <param name="status"></param>
-        void SetOpAttrWithDefaults(Context ctx, SafeOpHandle op, AttrDef attr,
+        void SetOpAttrWithDefaults(Context ctx, SafeEagerOpHandle op, AttrDef attr,
             string attr_name, object attr_value,
             Dictionary<string, long> attr_list_sizes,
             Status status)
@@ -280,7 +280,7 @@ namespace Tensorflow.Eager
             }
         }
 
-        bool SetOpAttrList(Context ctx, SafeOpHandle op,
+        bool SetOpAttrList(Context ctx, SafeEagerOpHandle op,
             string key, object values, TF_AttrType type,
             Dictionary<string, long> attr_list_sizes,
             Status status)
@@ -326,7 +326,7 @@ namespace Tensorflow.Eager
             return true;
         }
 
-        bool SetOpAttrScalar(Context ctx, SafeOpHandle op,
+        bool SetOpAttrScalar(Context ctx, SafeEagerOpHandle op,
             string key, object value, TF_AttrType type,
             Dictionary<string, long> attr_list_sizes,
             Status status)
diff --git a/src/TensorFlowNET.Core/Eager/SafeOpHandle.cs b/src/TensorFlowNET.Core/Eager/SafeEagerOpHandle.cs
similarity index 86%
rename from src/TensorFlowNET.Core/Eager/SafeOpHandle.cs
rename to src/TensorFlowNET.Core/Eager/SafeEagerOpHandle.cs
index 073638ec..66c84d74 100644
--- a/src/TensorFlowNET.Core/Eager/SafeOpHandle.cs
+++ b/src/TensorFlowNET.Core/Eager/SafeEagerOpHandle.cs
@@ -16,18 +16,17 @@
 
 using System;
 using Tensorflow.Util;
-using static Tensorflow.Binding;
 
 namespace Tensorflow.Eager
 {
-    public sealed class SafeOpHandle : SafeTensorflowHandle
+    public sealed class SafeEagerOpHandle : SafeTensorflowHandle
     {
-        private SafeOpHandle()
+        private SafeEagerOpHandle()
         {
 
         }
 
-        public SafeOpHandle(IntPtr handle)
+        public SafeEagerOpHandle(IntPtr handle)
             : base(handle)
         {
 
diff --git a/src/TensorFlowNET.Core/Eager/c_api.eager.cs b/src/TensorFlowNET.Core/Eager/c_api.eager.cs
index 419f14c9..f8911bd4 100644
--- a/src/TensorFlowNET.Core/Eager/c_api.eager.cs
+++ b/src/TensorFlowNET.Core/Eager/c_api.eager.cs
@@ -59,7 +59,7 @@ namespace Tensorflow
         /// <param name="status">TF_Status*</param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern TF_AttrType TFE_OpGetAttrType(SafeOpHandle op, string attr_name, ref byte is_list, SafeStatusHandle status);
+        public static extern TF_AttrType TFE_OpGetAttrType(SafeEagerOpHandle op, string attr_name, ref byte is_list, SafeStatusHandle status);
 
         [DllImport(TensorFlowLibName)]
         public static extern TF_AttrType TFE_OpNameGetAttrType(SafeContextHandle ctx, string op_or_function_name, string attr_name, ref byte is_list, SafeStatusHandle status);
@@ -72,7 +72,7 @@ namespace Tensorflow
         /// <param name="input_name">const char*</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern int TFE_OpGetInputLength(SafeOpHandle op, string input_name, SafeStatusHandle status);
+        public static extern int TFE_OpGetInputLength(SafeEagerOpHandle op, string input_name, SafeStatusHandle status);
 
         /// <summary>
         /// Returns the length (number of tensors) of the output argument `output_name`
@@ -83,7 +83,7 @@ namespace Tensorflow
         /// <param name="status"></param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern int TFE_OpGetOutputLength(SafeOpHandle op, string input_name, SafeStatusHandle status);
+        public static extern int TFE_OpGetOutputLength(SafeEagerOpHandle op, string input_name, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -94,7 +94,7 @@ namespace Tensorflow
         /// <param name="status">TF_Status*</param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern int TFE_OpAddInputList(SafeOpHandle op, [In, MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(SafeHandleArrayMarshaler))] SafeTensorHandleHandle[] inputs, int num_inputs, SafeStatusHandle status);
+        public static extern int TFE_OpAddInputList(SafeEagerOpHandle op, [In, MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(SafeHandleArrayMarshaler))] SafeTensorHandleHandle[] inputs, int num_inputs, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -161,7 +161,7 @@ namespace Tensorflow
         /// <param name="retvals"></param>
         /// <param name="num_retvals"></param>
         /// <param name="status"></param>
-        public static void TFE_Execute(SafeOpHandle op, SafeTensorHandleHandle[] retvals, out int num_retvals, SafeStatusHandle status)
+        public static void TFE_Execute(SafeEagerOpHandle op, SafeTensorHandleHandle[] retvals, out int num_retvals, SafeStatusHandle status)
         {
             unsafe
             {
@@ -187,7 +187,7 @@ namespace Tensorflow
         /// <param name="num_retvals">int*</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        private static unsafe extern void TFE_Execute(SafeOpHandle op, IntPtr* retvals, ref int num_retvals, SafeStatusHandle status);
+        private static unsafe extern void TFE_Execute(SafeEagerOpHandle op, IntPtr* retvals, ref int num_retvals, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -197,7 +197,7 @@ namespace Tensorflow
         /// <param name="status">TF_Status*</param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern SafeOpHandle TFE_NewOp(SafeContextHandle ctx, string op_or_function_name, SafeStatusHandle status);
+        public static extern SafeEagerOpHandle TFE_NewOp(SafeContextHandle ctx, string op_or_function_name, SafeStatusHandle status);
 
         /// <summary>
         /// Resets `op_to_reset` with `op_or_function_name` and `raw_device_name`. This
@@ -213,7 +213,7 @@ namespace Tensorflow
         /// <param name="raw_device_name">const char*</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpReset(SafeOpHandle op_to_reset, string op_or_function_name, string raw_device_name, SafeStatusHandle status);
+        public static extern void TFE_OpReset(SafeEagerOpHandle op_to_reset, string op_or_function_name, string raw_device_name, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -229,13 +229,13 @@ namespace Tensorflow
         /// <param name="attr_name">const char*</param>
         /// <param name="value">TF_DataType</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrType(SafeOpHandle op, string attr_name, TF_DataType value);
+        public static extern void TFE_OpSetAttrType(SafeEagerOpHandle op, string attr_name, TF_DataType value);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrInt(SafeOpHandle op, string attr_name, long value);
+        public static extern void TFE_OpSetAttrInt(SafeEagerOpHandle op, string attr_name, long value);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrFloat(SafeOpHandle op, string attr_name, float value);
+        public static extern void TFE_OpSetAttrFloat(SafeEagerOpHandle op, string attr_name, float value);
 
         /// <summary>
         /// 
@@ -246,19 +246,19 @@ namespace Tensorflow
         /// <param name="num_dims">const int</param>
         /// <param name="out_status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrShape(SafeOpHandle op, string attr_name, long[] dims, int num_dims, SafeStatusHandle out_status);
+        public static extern void TFE_OpSetAttrShape(SafeEagerOpHandle op, string attr_name, long[] dims, int num_dims, SafeStatusHandle out_status);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrShapeList(SafeOpHandle op, string attr_name, IntPtr[] dims, int[] num_dims, int num_values, SafeStatusHandle out_status);
+        public static extern void TFE_OpSetAttrShapeList(SafeEagerOpHandle op, string attr_name, IntPtr[] dims, int[] num_dims, int num_values, SafeStatusHandle out_status);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrStringList(SafeOpHandle op, string attr_name, string[] values, ulong[] lengths, int num_values);
+        public static extern void TFE_OpSetAttrStringList(SafeEagerOpHandle op, string attr_name, string[] values, ulong[] lengths, int num_values);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrBool(SafeOpHandle op, string attr_name, bool value);
+        public static extern void TFE_OpSetAttrBool(SafeEagerOpHandle op, string attr_name, bool value);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrFunctionName(SafeOpHandle op, string attr_name, string data, int length);
+        public static extern void TFE_OpSetAttrFunctionName(SafeEagerOpHandle op, string attr_name, string data, int length);
 
         /// <summary>
         /// 
@@ -268,16 +268,16 @@ namespace Tensorflow
         /// <param name="value">const void*</param>
         /// <param name="length">size_t</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrString(SafeOpHandle op, string attr_name, string value, ulong length);
+        public static extern void TFE_OpSetAttrString(SafeEagerOpHandle op, string attr_name, string value, ulong length);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrTypeList(SafeOpHandle op, string attr_name, TF_DataType[] values, int num_values);
+        public static extern void TFE_OpSetAttrTypeList(SafeEagerOpHandle op, string attr_name, TF_DataType[] values, int num_values);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrIntList(SafeOpHandle op, string attr_name, long[] values, int num_values);
+        public static extern void TFE_OpSetAttrIntList(SafeEagerOpHandle op, string attr_name, long[] values, int num_values);
 
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetAttrValueProto(SafeOpHandle op, string attr_name, IMessage[] proto, int proto_len, SafeStatusHandle status);
+        public static extern void TFE_OpSetAttrValueProto(SafeEagerOpHandle op, string attr_name, IMessage[] proto, int proto_len, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -286,7 +286,7 @@ namespace Tensorflow
         /// <param name="device_name"></param>
         /// <param name="status"></param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpSetDevice(SafeOpHandle op, string device_name, SafeStatusHandle status);
+        public static extern void TFE_OpSetDevice(SafeEagerOpHandle op, string device_name, SafeStatusHandle status);
 
         /// <summary>
         /// 
@@ -295,7 +295,7 @@ namespace Tensorflow
         /// <param name="h">TFE_TensorHandle*</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TFE_OpAddInput(SafeOpHandle op, SafeTensorHandleHandle h, SafeStatusHandle status);
+        public static extern void TFE_OpAddInput(SafeEagerOpHandle op, SafeTensorHandleHandle h, SafeStatusHandle status);
 
         /// <summary>
         /// 
diff --git a/src/TensorFlowNET.Core/Gradients/array_grad.cs b/src/TensorFlowNET.Core/Gradients/array_grad.cs
index 528b5208..c4cb9fbd 100644
--- a/src/TensorFlowNET.Core/Gradients/array_grad.cs
+++ b/src/TensorFlowNET.Core/Gradients/array_grad.cs
@@ -51,7 +51,7 @@ namespace Tensorflow.Gradients
         }
 
         [RegisterGradient("ConcatV2")]
-        public static Tensor[] _ConcatGradV2(Operation op, Tensor[] grads)
+        public static Tensor[] _ConcatV2Grad(Operation op, Tensor[] grads)
         {
             var grad = grads[0];
             return _ConcatGradHelper(op, grad, start_value_index: 0, end_value_index: -1, dim_index: -1);
diff --git a/src/TensorFlowNET.Core/Gradients/ops.gradient_function_mapping.cs b/src/TensorFlowNET.Core/Gradients/ops.gradient_function_mapping.cs
index 044ae9fe..e5831f25 100644
--- a/src/TensorFlowNET.Core/Gradients/ops.gradient_function_mapping.cs
+++ b/src/TensorFlowNET.Core/Gradients/ops.gradient_function_mapping.cs
@@ -50,42 +50,11 @@ namespace Tensorflow
                             {
                                 // tf.Logger.Debug($"Caculate Gradient: {oper.name} {m.Name}");
 
-                                var results = m.Name switch
-                                {
-                                    /*"_AddGrad" => math_grad._AddGrad(oper, out_grads),
-                                    "_AddV2Grad" => math_grad._AddV2Grad(oper, out_grads),
-                                    "_BiasAddGrad" => nn_grad._BiasAddGrad(oper, out_grads),
-                                    "_CastGrad" => math_grad._CastGrad(oper, out_grads),
-                                    "_ConcatGradV2" => array_grad._ConcatGradV2(oper, out_grads),
-                                    "_Conv2DGrad" => nn_grad._Conv2DGrad(oper, out_grads),
-                                    "_ExpandDimsGrad" => array_grad._ExpandDimsGrad(oper, out_grads),
-                                    "_ExpGrad" => math_grad._ExpGrad(oper, out_grads),
-                                    "_FusedBatchNormV3Grad" => nn_grad._FusedBatchNormV3Grad(oper, out_grads),
-                                    "_IdGrad" => math_grad._IdGrad(oper, out_grads),
-                                    "_LeakyReluGrad" => nn_grad._LeakyReluGrad(oper, out_grads),
-                                    "_Log1pGrad" => math_grad._Log1pGrad(oper, out_grads),
-                                    "_MaximumGrad" => math_grad._MaximumGrad(oper, out_grads),
-                                    "_MeanGrad" => math_grad._MeanGrad(oper, out_grads),
-                                    "_MinimumGrad" => math_grad._MinimumGrad(oper, out_grads),
-                                    "_MulGrad" => math_grad._MulGrad(oper, out_grads),
-                                    "_NegGrad" => math_grad._NegGrad(oper, out_grads),
-                                    "_PadGrad" => array_grad._PadGrad(oper, out_grads),
-                                    "_PowGrad" => math_grad._PowGrad(oper, out_grads),
-                                    "_RealDivGrad" => math_grad._RealDivGrad(oper, out_grads),
-                                    "_ReadGrad" => resource_variable_grad._ReadGrad(oper, out_grads),
-                                    "_ReshapeGrad" => array_grad._ReshapeGrad(oper, out_grads),
-                                    "_ResizeNearestNeighborGrad" => image_grad._ResizeNearestNeighborGrad(oper, out_grads),
-                                    "_SelectGrad" => math_grad._SelectGrad(oper, out_grads),
-                                    "_SigmoidGrad" => math_grad._SigmoidGrad(oper, out_grads),
-                                    "_SumGrad" => math_grad._SumGrad(oper, out_grads),
-                                    "_SubGrad" => math_grad._SubGrad(oper, out_grads),
-                                    "_StridedSliceGrad" => array_grad._StridedSliceGrad(oper, out_grads),*/
-                                    _ => g.InvokeMember(m.Name,
-                                           BindingFlags.InvokeMethod,
-                                           null,
-                                           null,
-                                           args: new object[] { oper, out_grads }) as Tensor[]
-                                };
+                                var results = g.InvokeMember(m.Name,
+                                    BindingFlags.InvokeMethod,
+                                    null,
+                                    null,
+                                    args: new object[] { oper, out_grads }) as Tensor[];
 
                                 // foreach (var result in results.Where(x => x != null))
                                     // tf.Logger.Debug($"Gradient: {result.name} {result.shape}");
diff --git a/src/TensorFlowNET.Core/Operations/Operation.Control.cs b/src/TensorFlowNET.Core/Operations/Operation.Control.cs
index 5c10f59e..89145e41 100644
--- a/src/TensorFlowNET.Core/Operations/Operation.Control.cs
+++ b/src/TensorFlowNET.Core/Operations/Operation.Control.cs
@@ -39,7 +39,7 @@ namespace Tensorflow
 
         public void _add_control_input(Operation op)
         {
-            c_api.TF_AddControlInput(OpDesc, op);
+            // c_api.TF_AddControlInput(_opDesc, op);
             //c_api.AddControlInput(graph, _handle, op);
         }
 
diff --git a/src/TensorFlowNET.Core/Operations/Operation.cs b/src/TensorFlowNET.Core/Operations/Operation.cs
index a3bfcdf0..cb018700 100644
--- a/src/TensorFlowNET.Core/Operations/Operation.cs
+++ b/src/TensorFlowNET.Core/Operations/Operation.cs
@@ -46,7 +46,6 @@ namespace Tensorflow
         private readonly IntPtr _handle; // _c_op in python
 
         private readonly Graph _graph;
-        private NodeDef _node_def;
 
         public string type => OpType;
 
@@ -57,24 +56,14 @@ namespace Tensorflow
         public int _id_value { get; set; }
         public Operation op => this;
         public TF_DataType dtype => TF_DataType.DtInvalid;
-        public virtual string name => _handle == IntPtr.Zero ? null : c_api.StringPiece(c_api.TF_OperationName(_handle));
-        public string OpType => _handle == IntPtr.Zero ? null : c_api.StringPiece(c_api.TF_OperationOpType(_handle));
+        public virtual string name => _handle == IntPtr.Zero ? "" : c_api.StringPiece(c_api.TF_OperationName(_handle));
+        public string OpType => _handle == IntPtr.Zero ? "" : c_api.StringPiece(c_api.TF_OperationOpType(_handle));
 
-        public string Device => _handle == IntPtr.Zero ? null : c_api.StringPiece(c_api.TF_OperationDevice(_handle));
+        public string Device => _handle == IntPtr.Zero ? "" : c_api.StringPiece(c_api.TF_OperationDevice(_handle));
 
-        bool _is_stateful;
-        public OperationDescription OpDesc { get; set; }
+        // OperationDescription _opDesc;
 
-        public NodeDef node_def
-        {
-            get
-            {
-                if (_node_def == null)
-                    _node_def = GetNodeDef();
-
-                return _node_def;
-            }
-        }
+        public NodeDef node_def => GetNodeDef();
 
         public Operation(IntPtr handle, Graph g = null)
         {
@@ -168,8 +157,7 @@ namespace Tensorflow
             if (op_def == null)
                 op_def = g.GetOpDef(node_def.Op);
 
-            (_handle, OpDesc) = ops._create_c_op(g, node_def, inputs, control_input_ops.ToArray(), op_def);
-            _is_stateful = op_def.IsStateful;
+            (_handle, _) = ops._create_c_op(g, node_def, inputs, control_input_ops.ToArray(), op_def);
 
             // Initialize self._outputs.
             output_types = new TF_DataType[NumOutputs];
@@ -199,16 +187,11 @@ namespace Tensorflow
             if (tf.executing_eagerly())
                 return (T[])get_attr(name);
 
-            AttrValue x = null;
+            using var buf = new Buffer();
+            c_api.TF_OperationGetAttrValueProto(_handle, name, buf.Handle, tf.Status.Handle);
+            tf.Status.Check(true);
 
-            lock (Locks.ProcessWide)
-            {
-                using var buf = new Buffer();
-                c_api.TF_OperationGetAttrValueProto(_handle, name, buf.Handle, tf.Status.Handle);
-                tf.Status.Check(true);
-
-                x = AttrValue.Parser.ParseFrom(buf.ToArray());
-            }
+            var x = AttrValue.Parser.ParseFrom(buf.ToArray());
 
             string oneof_value = x.ValueCase.ToString();
             if (string.IsNullOrEmpty(oneof_value))
@@ -227,16 +210,11 @@ namespace Tensorflow
 
         public virtual object get_attr(string name)
         {
-            AttrValue x = null;
-
-            lock (Locks.ProcessWide)
-            {
-                using var buf = new Buffer();
-                c_api.TF_OperationGetAttrValueProto(_handle, name, buf.Handle, tf.Status.Handle);
-                tf.Status.Check(true);
+            using var buf = new Buffer();
+            c_api.TF_OperationGetAttrValueProto(_handle, name, buf.Handle, tf.Status.Handle);
+            tf.Status.Check(true);
 
-                x = AttrValue.Parser.ParseFrom(buf.ToArray());
-            }
+            var x = AttrValue.Parser.ParseFrom(buf.ToArray());
 
             string oneof_value = x.ValueCase.ToString();
             if (string.IsNullOrEmpty(oneof_value))
@@ -262,15 +240,10 @@ namespace Tensorflow
 
         private NodeDef GetNodeDef()
         {
-            lock (Locks.ProcessWide)
-                using (var s = new Status())
-                using (var buffer = new Buffer())
-                {
-                    c_api.TF_OperationToNodeDef(_handle, buffer.Handle, s.Handle);
-                    s.Check();
-
-                    return NodeDef.Parser.ParseFrom(buffer.ToArray());
-                }
+            using var buffer = new Buffer();
+            c_api.TF_OperationToNodeDef(_handle, buffer.Handle, tf.Status.Handle);
+            tf.Status.Check(throwException: true);
+            return NodeDef.Parser.ParseFrom(buffer.ToArray());
         }
 
         /// <summary>
@@ -284,21 +257,21 @@ namespace Tensorflow
         {
             _assert_same_graph(tensor);
 
-            var input = _tf_input(index);
-            var output = tensor._as_tf_output();
+            // var input = _tf_input(index);
+            // var output = tensor._as_tf_output();
 
             // Reset cached inputs.
             _inputs_val = null;
-            _node_def = null;
+            // _node_def = null;
             // after the c_api call next time _inputs is accessed 
             // the updated inputs are reloaded from the c_api
-            lock (Locks.ProcessWide)
-            {
+            // lock (Locks.ProcessWide)
+            // {
                 // disable
                 // c_api.TF_UpdateEdge(_graph, output, input, tf.Status.Handle);
                 //var updated_inputs = inputs;
-                tf.Status.Check();
-            }
+                // tf.Status.Check();
+            // }
         }
 
         private void _assert_same_graph(Tensor tensor)
@@ -311,7 +284,7 @@ namespace Tensorflow
         /// </summary>
         public TF_Output _tf_output(int output_idx)
         {
-            return new TF_Output(op, output_idx);
+            return new TF_Output(_handle, output_idx);
         }
 
         /// <summary>
@@ -319,7 +292,7 @@ namespace Tensorflow
         /// </summary>
         public TF_Input _tf_input(int input_idx)
         {
-            return new TF_Input(op, input_idx);
+            return new TF_Input(_handle, input_idx);
         }
 
         public NDArray numpy() => throw new NotImplementedException("");
diff --git a/src/TensorFlowNET.Core/Operations/array_ops.cs b/src/TensorFlowNET.Core/Operations/array_ops.cs
index d13e0005..71ae89bd 100644
--- a/src/TensorFlowNET.Core/Operations/array_ops.cs
+++ b/src/TensorFlowNET.Core/Operations/array_ops.cs
@@ -80,27 +80,16 @@ namespace Tensorflow
                 return tf_with(ops.name_scope(name, "zeros", shape), scope =>
                 {
                     name = scope;
-                    var shape_tensor = constant_op._tensor_shape_tensor_conversion_function(shape);
-                    Tensor zeros = null;
-                    switch (dtype)
+                    // var shape_tensor = constant_op._tensor_shape_tensor_conversion_function(shape);
+                    Tensor zeros = dtype switch
                     {
-                        case TF_DataType.TF_DOUBLE:
-                            zeros = constant(0d);
-                            break;
-                        case TF_DataType.TF_FLOAT:
-                            zeros = constant(0f);
-                            break;
-                        case TF_DataType.TF_INT8:
-                            zeros = constant((sbyte)0);
-                            break;
-                        case TF_DataType.TF_UINT8:
-                            zeros = constant((byte)0);
-                            break;
-                        default:
-                            zeros = constant(0);
-                            break;
-                    }
-                    return fill(shape_tensor, zeros, name: name);
+                        TF_DataType.TF_DOUBLE => constant(0d),
+                        TF_DataType.TF_FLOAT => constant(0f),
+                        TF_DataType.TF_INT8 => constant((sbyte)0),
+                        TF_DataType.TF_UINT8 => constant((byte)0),
+                        _ => constant(0)
+                    };
+                    return fill(shape, zeros, name: name);
                 });
             }
             else
@@ -311,12 +300,8 @@ namespace Tensorflow
         /// <param name="value">A value to fill the returned `tf.Tensor`.</param>
         /// <param name="name">Optional string. The name of the output `tf.Tensor`.</param>
         /// <returns>A `tf.Tensor` with shape `dims` and the same dtype as `value`.</returns>
-        public static Tensor fill(Tensor dims, Tensor value, string name = null)
-        {
-            var result = gen_array_ops.fill(dims, value, name: name);
-            // tensor_util.maybe_set_static_shape(result, dims)
-            return result;
-        }
+        public static Tensor fill<T>(Shape dims, T value, string name = null)
+            => gen_array_ops.fill(dims, value, name: name);
 
         /// <summary>
         /// Returns the rank of a tensor.
@@ -425,25 +410,18 @@ namespace Tensorflow
                 dtype = dtype.as_base_dtype();
                 name = scope;
 
-                Tensor ones = null;
-                switch (dtype)
+                Tensor ones = dtype switch
                 {
-                    case TF_DataType.TF_DOUBLE:
-                        ones = constant(1.0d);
-                        break;
-                    case TF_DataType.TF_FLOAT:
-                        ones = constant(1.0f);
-                        break;
-                    default:
-                        ones = constant(1);
-                        break;
-                }
+                    TF_DataType.TF_DOUBLE => constant(1.0d),
+                    TF_DataType.TF_FLOAT => constant(1.0f),
+                    _ => constant(1)
+                };
 
                 if (shape.ndim == 0)
                     return ones;
 
-                var shape_tensor = constant_op._tensor_shape_tensor_conversion_function(shape);
-                return fill(shape_tensor, ones, name: name);
+                // var shape_tensor = constant_op._tensor_shape_tensor_conversion_function(shape);
+                return fill(shape, ones, name: name);
             });
 
         public static Tensor one_hot(Tensor indices, Tensor depth,
diff --git a/src/TensorFlowNET.Core/Operations/image_ops_impl.cs b/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
index 4085a1b5..f9e9061c 100644
--- a/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
+++ b/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
@@ -2086,8 +2086,7 @@ new_height, new_width");
                                     gather_idx),
                     new[] { batch_size, -1 });
             }
-            var invalid_index = array_ops.fill(ops.convert_to_tensor(new object[] { batch_size, max_output_size }),
-                                                                    tf.constant(0));
+            var invalid_index = array_ops.fill(new Shape((int)batch_size, (int)max_output_size), 0);
             var idx_index = array_ops.expand_dims(math_ops.range(max_output_size), 0);
             var num_valid_expanded = array_ops.expand_dims(num_valid, 1);
             idx = array_ops.where(idx_index < num_valid_expanded,
diff --git a/src/TensorFlowNET.Core/ops.cs b/src/TensorFlowNET.Core/ops.cs
index 0141b74b..95e8db57 100644
--- a/src/TensorFlowNET.Core/ops.cs
+++ b/src/TensorFlowNET.Core/ops.cs
@@ -223,42 +223,39 @@ namespace Tensorflow
 
             var input_tensors = _reconstruct_sequence_inputs(op_def, inputs, node_def.Attr);
 
-            lock (Locks.ProcessWide)
-            {
-                var op_desc = graph.NewOperation(node_def.Op, node_def.Name);
+            var op_desc = graph.NewOperation(node_def.Op, node_def.Name);
 
-                if (!string.IsNullOrEmpty(node_def.Device))
-                    c_api.TF_SetDevice(op_desc, node_def.Device);
+            if (!string.IsNullOrEmpty(node_def.Device))
+                c_api.TF_SetDevice(op_desc, node_def.Device);
 
-                // Add inputs
-                foreach (var op_input in input_tensors)
-                {
-                    if (op_input.IsList)
-                        c_api.TF_AddInputList(op_desc, op_input.Select(x => x._as_tf_output()).ToArray(), op_input.Count());
-                    else if (op_input.Count() == 1)
-                        c_api.TF_AddInput(op_desc, op_input[0]._as_tf_output());
-                }
+            // Add inputs
+            foreach (var op_input in input_tensors)
+            {
+                if (op_input.IsList)
+                    c_api.TF_AddInputList(op_desc, op_input.Select(x => x._as_tf_output()).ToArray(), op_input.Count());
+                else if (op_input.Count() == 1)
+                    c_api.TF_AddInput(op_desc, op_input[0]._as_tf_output());
+            }
 
-                var status = tf.Status;
+            var status = tf.Status;
 
-                // Add control inputs
-                foreach (var control_input in control_inputs)
-                    c_api.TF_AddControlInput(op_desc, control_input);
+            // Add control inputs
+            foreach (var control_input in control_inputs)
+                c_api.TF_AddControlInput(op_desc, control_input);
 
-                // Add attrs
-                foreach (var attr in node_def.Attr)
-                {
-                    var bytes = attr.Value.ToByteArray();
-                    c_api.TF_SetAttrValueProto(op_desc, attr.Key, bytes, proto_len: bytes.Length, status: status.Handle);
-                    status.Check(true);
-                }
+            // Add attrs
+            foreach (var attr in node_def.Attr)
+            {
+                var bytes = attr.Value.ToByteArray();
+                c_api.TF_SetAttrValueProto(op_desc, attr.Key, bytes, proto_len: bytes.Length, status: status.Handle);
+                status.Check(true);
+            }
 
-                var c_op = c_api.TF_FinishOperation(op_desc, status.Handle);
+            var c_op = op_desc.FinishOperation(status);
 
-                status.Check(true);
+            status.Check(true);
 
-                return (c_op, op_desc);
-            }
+            return (c_op, op_desc);
         }
 
         public static Tensors[] _reconstruct_sequence_inputs(OpDef op_def, Tensor[] inputs, MapField<string, AttrValue> attrs)
diff --git a/src/TensorFlowNET.Keras/Engine/Model.Fit.cs b/src/TensorFlowNET.Keras/Engine/Model.Fit.cs
index 41eaecd0..ab4ba0de 100644
--- a/src/TensorFlowNET.Keras/Engine/Model.Fit.cs
+++ b/src/TensorFlowNET.Keras/Engine/Model.Fit.cs
@@ -101,9 +101,9 @@ namespace Tensorflow.Keras.Engine
                         var result_pairs = string.Join(", ", results.Select(x => $"{x.Item1}: {(float)x.Item2:F6}"));
                         Binding.tf_output_redirect.WriteLine($"Epoch: {epoch + 1:D3}/{epochs:D3}, Step: {step + 1:D4}/{data_handler.Inferredsteps:D4}, {result_pairs}");
                     }
-                }
 
-                GC.Collect();
+                    GC.Collect();
+                }
                 GC.WaitForPendingFinalizers();
             }
         }
diff --git a/src/TensorFlowNET.Keras/Layers/Activation/Tanh.cs b/src/TensorFlowNET.Keras/Layers/Activation/Tanh.cs
index e64365de..99b80394 100644
--- a/src/TensorFlowNET.Keras/Layers/Activation/Tanh.cs
+++ b/src/TensorFlowNET.Keras/Layers/Activation/Tanh.cs
@@ -5,18 +5,23 @@ using Tensorflow.Keras.ArgsDefinition;
 using Tensorflow.Keras.Engine;
 using static Tensorflow.Binding;
 
-namespace Tensorflow.Keras.Layers {
-      public class Tanh : Layer {
-            public Tanh ( LayerArgs args ) : base(args) {
-                  // Tanh has no arguments
-            }
-            protected override Tensors Call ( Tensors inputs, Tensor state = null, bool? training = null ) {
-                  Tensor x = inputs;
+namespace Tensorflow.Keras.Layers
+{
+    public class Tanh : Layer
+    {
+        public Tanh(LayerArgs args) : base(args)
+        {
+            // Tanh has no arguments
+        }
+        protected override Tensors Call(Tensors inputs, Tensor state = null, bool? training = null)
+        {
+            Tensor x = inputs;
 
-                  return tf.tanh(x);
-            }
-            public override Shape ComputeOutputShape ( Shape input_shape ) {
-                  return input_shape;
-            }
-      }
+            return tf.tanh(x);
+        }
+        public override Shape ComputeOutputShape(Shape input_shape)
+        {
+            return input_shape;
+        }
+    }
 }
diff --git a/test/TensorFlowNET.Native.UnitTest/CApiTest.cs b/test/TensorFlowNET.Native.UnitTest/CApiTest.cs
index 5f9da347..781d29ee 100644
--- a/test/TensorFlowNET.Native.UnitTest/CApiTest.cs
+++ b/test/TensorFlowNET.Native.UnitTest/CApiTest.cs
@@ -80,25 +80,25 @@ namespace Tensorflow.Native.UnitTest
         protected ulong TF_TensorByteSize(SafeTensorHandle t)
             => c_api.TF_TensorByteSize(t);
 
-        protected void TFE_OpAddInput(SafeOpHandle op, SafeTensorHandleHandle h, SafeStatusHandle status)
+        protected void TFE_OpAddInput(SafeEagerOpHandle op, SafeTensorHandleHandle h, SafeStatusHandle status)
             => c_api.TFE_OpAddInput(op, h, status);
 
-        protected void TFE_OpSetAttrType(SafeOpHandle op, string attr_name, TF_DataType value)
+        protected void TFE_OpSetAttrType(SafeEagerOpHandle op, string attr_name, TF_DataType value)
             => c_api.TFE_OpSetAttrType(op, attr_name, value);
 
-        protected void TFE_OpSetAttrShape(SafeOpHandle op, string attr_name, long[] dims, int num_dims, SafeStatusHandle out_status)
+        protected void TFE_OpSetAttrShape(SafeEagerOpHandle op, string attr_name, long[] dims, int num_dims, SafeStatusHandle out_status)
             => c_api.TFE_OpSetAttrShape(op, attr_name, dims, num_dims, out_status);
 
-        protected void TFE_OpSetAttrString(SafeOpHandle op, string attr_name, string value, uint length)
+        protected void TFE_OpSetAttrString(SafeEagerOpHandle op, string attr_name, string value, uint length)
             => c_api.TFE_OpSetAttrString(op, attr_name, value, length);
 
-        protected SafeOpHandle TFE_NewOp(SafeContextHandle ctx, string op_or_function_name, SafeStatusHandle status)
+        protected SafeEagerOpHandle TFE_NewOp(SafeContextHandle ctx, string op_or_function_name, SafeStatusHandle status)
             => c_api.TFE_NewOp(ctx, op_or_function_name, status);
 
         protected SafeTensorHandleHandle TFE_NewTensorHandle(SafeTensorHandle t, SafeStatusHandle status)
             => c_api.TFE_NewTensorHandle(t, status);
 
-        protected void TFE_Execute(SafeOpHandle op, SafeTensorHandleHandle[] retvals, out int num_retvals, SafeStatusHandle status)
+        protected void TFE_Execute(SafeEagerOpHandle op, SafeTensorHandleHandle[] retvals, out int num_retvals, SafeStatusHandle status)
             => c_api.TFE_Execute(op, retvals, out num_retvals, status);
 
         protected SafeContextOptionsHandle TFE_NewContextOptions()
@@ -107,13 +107,13 @@ namespace Tensorflow.Native.UnitTest
         protected SafeContextHandle TFE_NewContext(SafeContextOptionsHandle opts, SafeStatusHandle status)
             => c_api.TFE_NewContext(opts, status);
 
-        protected int TFE_OpGetInputLength(SafeOpHandle op, string input_name, SafeStatusHandle status)
+        protected int TFE_OpGetInputLength(SafeEagerOpHandle op, string input_name, SafeStatusHandle status)
             => c_api.TFE_OpGetInputLength(op, input_name, status);
 
-        protected int TFE_OpAddInputList(SafeOpHandle op, SafeTensorHandleHandle[] inputs, int num_inputs, SafeStatusHandle status)
+        protected int TFE_OpAddInputList(SafeEagerOpHandle op, SafeTensorHandleHandle[] inputs, int num_inputs, SafeStatusHandle status)
             => c_api.TFE_OpAddInputList(op, inputs, num_inputs, status);
 
-        protected int TFE_OpGetOutputLength(SafeOpHandle op, string input_name, SafeStatusHandle status)
+        protected int TFE_OpGetOutputLength(SafeEagerOpHandle op, string input_name, SafeStatusHandle status)
             => c_api.TFE_OpGetOutputLength(op, input_name, status);
 
         protected void TFE_DeleteTensorHandle(IntPtr h)
@@ -149,7 +149,7 @@ namespace Tensorflow.Native.UnitTest
         protected SafeTensorHandleHandle TFE_TensorHandleCopyToDevice(SafeTensorHandleHandle h, SafeContextHandle ctx, string device_name, SafeStatusHandle status)
             => c_api.TFE_TensorHandleCopyToDevice(h, ctx, device_name, status);
 
-        protected void TFE_OpSetDevice(SafeOpHandle op, string device_name, SafeStatusHandle status)
+        protected void TFE_OpSetDevice(SafeEagerOpHandle op, string device_name, SafeStatusHandle status)
             => c_api.TFE_OpSetDevice(op, device_name, status);
     }
 }
diff --git a/test/TensorFlowNET.Native.UnitTest/Eager/Eager.cs b/test/TensorFlowNET.Native.UnitTest/Eager/Eager.cs
index 40e2d064..864c09f0 100644
--- a/test/TensorFlowNET.Native.UnitTest/Eager/Eager.cs
+++ b/test/TensorFlowNET.Native.UnitTest/Eager/Eager.cs
@@ -25,7 +25,7 @@ namespace Tensorflow.Native.UnitTest.Eager
             return th;
         }
 
-        SafeOpHandle MatMulOp(SafeContextHandle ctx, SafeTensorHandleHandle a, SafeTensorHandleHandle b)
+        SafeEagerOpHandle MatMulOp(SafeContextHandle ctx, SafeTensorHandleHandle a, SafeTensorHandleHandle b)
         {
             using var status = TF_NewStatus();
 
@@ -63,7 +63,7 @@ namespace Tensorflow.Native.UnitTest.Eager
             return false;
         }
 
-        SafeOpHandle ShapeOp(SafeContextHandle ctx, SafeTensorHandleHandle a)
+        SafeEagerOpHandle ShapeOp(SafeContextHandle ctx, SafeTensorHandleHandle a)
         {
             using var status = TF_NewStatus();