add SafeStringTensorHandle

Author: Oceania2018

src/TensorFlowNET.Core/NumPy/NDArray.Index.cs

@@ -64,9 +64,9 @@ NDArray GetData(IEnumerable<Slice> slices)
             if (tensor.Handle == null)
             {
                 if (tf.executing_eagerly())
-                    return new NDArray(tensor);
-                else
                     tensor = tf.defaultSession.eval(tensor);
+                else
+                    return new NDArray(tensor);
             }
 
             return new NDArray(tensor);

src/TensorFlowNET.Core/Tensors/SafeStringTensorHandle.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Tensorflow.Util;
+
+namespace Tensorflow
+{
+    public sealed class SafeStringTensorHandle : SafeTensorHandle
+    {
+        Shape _shape;
+        SafeTensorHandle _handle;
+        const int TF_TSRING_SIZE = 24;
+
+        protected SafeStringTensorHandle()
+        {
+        }
+
+        public SafeStringTensorHandle(SafeTensorHandle handle, Shape shape)
+            : base(handle.DangerousGetHandle())
+        {
+            _handle = handle;
+            _shape = shape;
+        }
+
+        protected override bool ReleaseHandle()
+        {
+#if TRACK_TENSOR_LIFE
+            print($"Delete StringTensorHandle 0x{handle.ToString("x16")}");
+#endif
+
+            long size = 1;
+            foreach (var s in _shape.dims)
+                size *= s;
+            var tstr = c_api.TF_TensorData(_handle);
+
+            for (int i = 0; i < size; i++)
+            {
+                c_api.TF_StringDealloc(tstr);
+                tstr += TF_TSRING_SIZE;
+            }
+
+            SetHandle(IntPtr.Zero);
+
+            return true;
+        }
+    }
+}

src/TensorFlowNET.Core/Tensors/SafeTensorHandle.cs

@@ -20,9 +20,9 @@ limitations under the License.
 
 namespace Tensorflow
 {
-    public sealed class SafeTensorHandle : SafeTensorflowHandle
+    public class SafeTensorHandle : SafeTensorflowHandle
     {
-        private SafeTensorHandle()
+        protected SafeTensorHandle()
         {
         }
 

src/TensorFlowNET.Core/Tensors/TStringHandle.cs

@@ -10,7 +10,7 @@ public partial class Tensor
     {
         const int TF_TSRING_SIZE = 24;
 
-        public SafeTensorHandle StringTensor(string[] strings, Shape shape)
+        public SafeStringTensorHandle StringTensor(string[] strings, Shape shape)
         {
             // convert string array to byte[][]
             var buffer = new byte[strings.Length][];
@@ -20,7 +20,7 @@ public SafeTensorHandle StringTensor(string[] strings, Shape shape)
             return StringTensor(buffer, shape);
         }
 
-        public SafeTensorHandle StringTensor(byte[][] buffer, Shape shape)
+        public SafeStringTensorHandle StringTensor(byte[][] buffer, Shape shape)
         {
             var handle = c_api.TF_AllocateTensor(TF_DataType.TF_STRING,
                 shape.ndim == 0 ? null : shape.dims,
@@ -39,7 +39,7 @@ public SafeTensorHandle StringTensor(byte[][] buffer, Shape shape)
                 tstr += TF_TSRING_SIZE;
             }
 
-            return handle;
+            return new SafeStringTensorHandle(handle, shape);
         }
 
         public string[] StringData()

src/TensorFlowNET.Core/Tensors/Tensor.String.cs

@@ -255,19 +255,7 @@ public override string ToString()
 
         protected override void DisposeUnmanagedResources(IntPtr handle)
         {
-            if (dtype == TF_DataType.TF_STRING)
-            {
-                long size = 1;
-                foreach (var s in shape.dims)
-                    size *= s;
-                var tstr = TensorDataPointer;
 
-                for (int i = 0; i < size; i++)
-                {
-                    c_api.TF_StringDealloc(tstr);
-                    tstr += TF_TSRING_SIZE;
-                }
-            }
         }
 
         public bool IsDisposed => _disposed;