Implement SafeImportGraphDefOptionsHandle as a wrapper for TF_ImportGraphDefOptions

src/TensorFlowNET.Core/Framework/Models/ScopedTFImportGraphDefOptions.cs

@@ -1,10 +0,0 @@
-namespace Tensorflow.Framework.Models
-{
-    public class ScopedTFImportGraphDefOptions : ImportGraphDefOptions
-    {
-        public ScopedTFImportGraphDefOptions() : base()
-        {
-
-        }
-    }
-}

src/TensorFlowNET.Core/Framework/Models/ScopedTFImportGraphDefResults.cs

@@ -1,17 +0,0 @@
-using System;
-
-namespace Tensorflow.Framework.Models
-{
-    public class ScopedTFImportGraphDefResults : ImportGraphDefOptions
-    {
-        public ScopedTFImportGraphDefResults() : base()
-        {
-            
-        }
-
-        public ScopedTFImportGraphDefResults(IntPtr results) : base(results)
-        {
-
-        }
-    }
-}

src/TensorFlowNET.Core/Framework/importer.cs

@@ -62,7 +62,7 @@ namespace Tensorflow
             {
                 _PopulateTFImportGraphDefOptions(scoped_options, prefix, input_map, return_elements);
                 // need to create a class ImportGraphDefWithResults with IDisposal
-                results = c_api.TF_GraphImportGraphDefWithResults(graph, buffer, scoped_options, status.Handle);
+                results = c_api.TF_GraphImportGraphDefWithResults(graph, buffer, scoped_options.Handle, status.Handle);
                 status.Check(true);
             }
 
@@ -114,8 +114,8 @@ namespace Tensorflow
             Dictionary<string, Tensor> input_map,
             string[] return_elements)
         {
-            c_api.TF_ImportGraphDefOptionsSetPrefix(options, prefix);
-            c_api.TF_ImportGraphDefOptionsSetUniquifyNames(options, (char)1);
+            c_api.TF_ImportGraphDefOptionsSetPrefix(options.Handle, prefix);
+            c_api.TF_ImportGraphDefOptionsSetUniquifyNames(options.Handle, (char)1);
 
             foreach(var input in input_map)
             {
@@ -130,11 +130,11 @@ namespace Tensorflow
                 if(name.Contains(":"))
                 {
                     var (op_name, index) = _ParseTensorName(name);
-                    c_api.TF_ImportGraphDefOptionsAddReturnOutput(options, op_name, index);
+                    c_api.TF_ImportGraphDefOptionsAddReturnOutput(options.Handle, op_name, index);
                 }
                 else
                 {
-                    c_api.TF_ImportGraphDefOptionsAddReturnOperation(options, name);
+                    c_api.TF_ImportGraphDefOptionsAddReturnOperation(options.Handle, name);
                 }
             }
 

src/TensorFlowNET.Core/Graphs/Graph.Import.cs

@@ -29,7 +29,7 @@ namespace Tensorflow
             int size = Marshal.SizeOf<TF_Output>();
             var return_output_handle = Marshal.AllocHGlobal(size * num_return_outputs);
 
-            c_api.TF_GraphImportGraphDefWithReturnOutputs(_handle, graph_def, opts, return_output_handle, num_return_outputs, s.Handle);
+            c_api.TF_GraphImportGraphDefWithReturnOutputs(_handle, graph_def, opts.Handle, return_output_handle, num_return_outputs, s.Handle);
 
             var tf_output_ptr = (TF_Output*) return_output_handle;
             for (int i = 0; i < num_return_outputs; i++) 
@@ -53,8 +53,8 @@ namespace Tensorflow
             using (var graph_def = new Buffer(bytes))
             {
                 as_default();
-                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, prefix);
-                c_api.TF_GraphImportGraphDef(_handle, graph_def, opts, status.Handle);
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts.Handle, prefix);
+                c_api.TF_GraphImportGraphDef(_handle, graph_def, opts.Handle, status.Handle);
                 status.Check(true);
                 return status.Code == TF_Code.TF_OK;
             }

src/TensorFlowNET.Core/Graphs/ImportGraphDefOptions.cs

@@ -18,30 +18,24 @@ using System;
 
 namespace Tensorflow
 {
-    public class ImportGraphDefOptions : DisposableObject
+    public sealed class ImportGraphDefOptions : IDisposable
     {
+        public SafeImportGraphDefOptionsHandle Handle { get; }
+
         public int NumReturnOutputs 
-            => c_api.TF_ImportGraphDefOptionsNumReturnOutputs(_handle);
+            => c_api.TF_ImportGraphDefOptionsNumReturnOutputs(Handle);
 
         public ImportGraphDefOptions()
         {
-            _handle = c_api.TF_NewImportGraphDefOptions();
-        }
-
-        public ImportGraphDefOptions(IntPtr handle)
-        {
-            _handle = handle;
+            Handle = c_api.TF_NewImportGraphDefOptions();
         }
 
         public void AddReturnOutput(string name, int index)
         {
-            c_api.TF_ImportGraphDefOptionsAddReturnOutput(_handle, name, index);
+            c_api.TF_ImportGraphDefOptionsAddReturnOutput(Handle, name, index);
         }
 
-        protected override void DisposeUnmanagedResources(IntPtr handle)
-            => c_api.TF_DeleteImportGraphDefOptions(handle);
-
-        public static implicit operator IntPtr(ImportGraphDefOptions opts) => opts._handle;
-        public static implicit operator ImportGraphDefOptions(IntPtr handle) => new ImportGraphDefOptions(handle);
+        public void Dispose()
+            => Handle.Dispose();
     }
 }

src/TensorFlowNET.Core/Graphs/SafeImportGraphDefOptionsHandle.cs

@@ -0,0 +1,40 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET Authors. All Rights Reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+******************************************************************************/
+
+using System;
+using Tensorflow.Util;
+
+namespace Tensorflow
+{
+    public sealed class SafeImportGraphDefOptionsHandle : SafeTensorflowHandle
+    {
+        public SafeImportGraphDefOptionsHandle()
+        {
+        }
+
+        public SafeImportGraphDefOptionsHandle(IntPtr handle)
+            : base(handle)
+        {
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            c_api.TF_DeleteImportGraphDefOptions(handle);
+            SetHandle(IntPtr.Zero);
+            return true;
+        }
+    }
+}

src/TensorFlowNET.Core/Graphs/c_api.graph.cs

@@ -78,7 +78,7 @@ namespace Tensorflow
         /// <param name="num_return_outputs">int</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern unsafe void TF_GraphImportGraphDefWithReturnOutputs(IntPtr graph, IntPtr graph_def, IntPtr options, IntPtr return_outputs, int num_return_outputs, SafeStatusHandle status);
+        public static extern unsafe void TF_GraphImportGraphDefWithReturnOutputs(IntPtr graph, IntPtr graph_def, SafeImportGraphDefOptionsHandle options, IntPtr return_outputs, int num_return_outputs, SafeStatusHandle status);
 
         /// <summary>
         /// Import the graph serialized in `graph_def` into `graph`.  Returns nullptr and
@@ -92,7 +92,7 @@ namespace Tensorflow
         /// <param name="status">TF_Status*</param>
         /// <returns>TF_ImportGraphDefResults*</returns>
         [DllImport(TensorFlowLibName)]
-        public static extern IntPtr TF_GraphImportGraphDefWithResults(IntPtr graph, IntPtr graph_def, IntPtr options, SafeStatusHandle status);
+        public static extern IntPtr TF_GraphImportGraphDefWithResults(IntPtr graph, IntPtr graph_def, SafeImportGraphDefOptionsHandle options, SafeStatusHandle status);
 
         /// <summary>
         /// Import the graph serialized in `graph_def` into `graph`.
@@ -102,7 +102,7 @@ namespace Tensorflow
         /// <param name="options">TF_ImportGraphDefOptions*</param>
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_GraphImportGraphDef(IntPtr graph, IntPtr graph_def, IntPtr options, SafeStatusHandle status);
+        public static extern void TF_GraphImportGraphDef(IntPtr graph, IntPtr graph_def, SafeImportGraphDefOptionsHandle options, SafeStatusHandle status);
         
         /// <summary>
         /// Iterate through the operations of a graph.
@@ -160,7 +160,7 @@ namespace Tensorflow
         /// <param name="opts"></param>
         /// <param name="oper"></param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsAddControlDependency(IntPtr opts, IntPtr oper);
+        public static extern void TF_ImportGraphDefOptionsAddControlDependency(SafeImportGraphDefOptionsHandle opts, IntPtr oper);
 
         /// <summary>
         /// Set any imported nodes with input `src_name:src_index` to have that input
@@ -173,7 +173,7 @@ namespace Tensorflow
         /// <param name="src_index">int</param>
         /// <param name="dst">TF_Output</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsAddInputMapping(IntPtr opts, string src_name, int src_index, TF_Output dst);
+        public static extern void TF_ImportGraphDefOptionsAddInputMapping(SafeImportGraphDefOptionsHandle opts, string src_name, int src_index, TF_Output dst);
 
         /// <summary>
         /// Add an operation in `graph_def` to be returned via the `return_opers` output
@@ -183,7 +183,7 @@ namespace Tensorflow
         /// <param name="opts">TF_ImportGraphDefOptions* opts</param>
         /// <param name="oper_name">const char*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsAddReturnOperation(IntPtr opts, string oper_name);
+        public static extern void TF_ImportGraphDefOptionsAddReturnOperation(SafeImportGraphDefOptionsHandle opts, string oper_name);
 
         /// <summary>
         /// Add an output in `graph_def` to be returned via the `return_outputs` output
@@ -195,7 +195,7 @@ namespace Tensorflow
         /// <param name="oper_name">const char*</param>
         /// <param name="index">int</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsAddReturnOutput(IntPtr opts, string oper_name, int index);
+        public static extern void TF_ImportGraphDefOptionsAddReturnOutput(SafeImportGraphDefOptionsHandle opts, string oper_name, int index);
 
         /// <summary>
         /// Returns the number of return operations added via
@@ -204,7 +204,7 @@ namespace Tensorflow
         /// <param name="opts"></param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern int TF_ImportGraphDefOptionsNumReturnOperations(IntPtr opts);
+        public static extern int TF_ImportGraphDefOptionsNumReturnOperations(SafeImportGraphDefOptionsHandle opts);
 
         /// <summary>
         /// Returns the number of return outputs added via
@@ -213,7 +213,7 @@ namespace Tensorflow
         /// <param name="opts">const TF_ImportGraphDefOptions*</param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern int TF_ImportGraphDefOptionsNumReturnOutputs(IntPtr opts);
+        public static extern int TF_ImportGraphDefOptionsNumReturnOutputs(SafeImportGraphDefOptionsHandle opts);
 
         /// <summary>
         /// Set any imported nodes with control input `src_name` to have that input
@@ -225,7 +225,7 @@ namespace Tensorflow
         /// <param name="src_name">const char*</param>
         /// <param name="dst">TF_Operation*</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsRemapControlDependency(IntPtr opts, string src_name, IntPtr dst);
+        public static extern void TF_ImportGraphDefOptionsRemapControlDependency(SafeImportGraphDefOptionsHandle opts, string src_name, IntPtr dst);
 
         /// <summary>
         /// Set the prefix to be prepended to the names of nodes in `graph_def` that will
@@ -234,7 +234,7 @@ namespace Tensorflow
         /// </summary>
         /// <param name="ops"></param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsSetPrefix(IntPtr ops, string prefix);
+        public static extern void TF_ImportGraphDefOptionsSetPrefix(SafeImportGraphDefOptionsHandle ops, string prefix);
 
         /// <summary>
         /// Set whether to uniquify imported operation names. If true, imported operation
@@ -246,7 +246,7 @@ namespace Tensorflow
         /// <param name="ops">TF_ImportGraphDefOptions*</param>
         /// <param name="uniquify_prefix">unsigned char</param>
         [DllImport(TensorFlowLibName)]
-        public static extern void TF_ImportGraphDefOptionsSetUniquifyNames(IntPtr ops, char uniquify_prefix);
+        public static extern void TF_ImportGraphDefOptionsSetUniquifyNames(SafeImportGraphDefOptionsHandle ops, char uniquify_prefix);
 
         /// <summary>
         /// Fetches the return operations requested via
@@ -295,7 +295,7 @@ namespace Tensorflow
         public static extern IntPtr TF_NewGraph();
 
         [DllImport(TensorFlowLibName)]
-        public static extern IntPtr TF_NewImportGraphDefOptions();
+        public static extern SafeImportGraphDefOptionsHandle TF_NewImportGraphDefOptions();
 
         /// <summary>
         /// Updates 'dst' to consume 'new_src'.

test/TensorFlowNET.UnitTest/GraphTest.cs

@@ -222,10 +222,12 @@ namespace TensorFlowNET.UnitTest.NativeAPI
             // Import it, with a prefix, in a fresh graph.
             graph.Dispose();
             graph = new Graph().as_default();
-            var opts = c_api.TF_NewImportGraphDefOptions();
-            c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported");
-            c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
-            EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            using (var opts = c_api.TF_NewImportGraphDefOptions())
+            {
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported");
+                c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
+                EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            }
 
             Operation scalar = graph.OperationByName("imported/scalar");
             Operation feed = graph.OperationByName("imported/feed");
@@ -258,17 +260,19 @@ namespace TensorFlowNET.UnitTest.NativeAPI
 
             // Import it again, with an input mapping, return outputs, and a return
             // operation, into the same graph.
-            c_api.TF_DeleteImportGraphDefOptions(opts);
-            opts = c_api.TF_NewImportGraphDefOptions();
-            c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported2");
-            c_api.TF_ImportGraphDefOptionsAddInputMapping(opts, "scalar", 0, new TF_Output(scalar, 0));
-            c_api.TF_ImportGraphDefOptionsAddReturnOutput(opts, "feed", 0);
-            c_api.TF_ImportGraphDefOptionsAddReturnOutput(opts, "scalar", 0);
-            EXPECT_EQ(2, c_api.TF_ImportGraphDefOptionsNumReturnOutputs(opts));
-            c_api.TF_ImportGraphDefOptionsAddReturnOperation(opts, "scalar");
-            EXPECT_EQ(1, c_api.TF_ImportGraphDefOptionsNumReturnOperations(opts));
-            var results = c_api.TF_GraphImportGraphDefWithResults(graph, graph_def, opts, s.Handle);
-            EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            IntPtr results;
+            using (var opts = c_api.TF_NewImportGraphDefOptions())
+            {
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported2");
+                c_api.TF_ImportGraphDefOptionsAddInputMapping(opts, "scalar", 0, new TF_Output(scalar, 0));
+                c_api.TF_ImportGraphDefOptionsAddReturnOutput(opts, "feed", 0);
+                c_api.TF_ImportGraphDefOptionsAddReturnOutput(opts, "scalar", 0);
+                EXPECT_EQ(2, c_api.TF_ImportGraphDefOptionsNumReturnOutputs(opts));
+                c_api.TF_ImportGraphDefOptionsAddReturnOperation(opts, "scalar");
+                EXPECT_EQ(1, c_api.TF_ImportGraphDefOptionsNumReturnOperations(opts));
+                results = c_api.TF_GraphImportGraphDefWithResults(graph, graph_def, opts, s.Handle);
+                EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            }
 
             Operation scalar2 = graph.OperationByName("imported2/scalar");
             Operation feed2 = graph.OperationByName("imported2/feed");
@@ -294,13 +298,14 @@ namespace TensorFlowNET.UnitTest.NativeAPI
             c_api.TF_DeleteImportGraphDefResults(results);
 
             // Import again, with control dependencies, into the same graph.
-            c_api.TF_DeleteImportGraphDefOptions(opts);
-            opts = c_api.TF_NewImportGraphDefOptions();
-            c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported3");
-            c_api.TF_ImportGraphDefOptionsAddControlDependency(opts, feed);
-            c_api.TF_ImportGraphDefOptionsAddControlDependency(opts, feed2);
-            c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
-            EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            using (var opts = c_api.TF_NewImportGraphDefOptions())
+            {
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported3");
+                c_api.TF_ImportGraphDefOptionsAddControlDependency(opts, feed);
+                c_api.TF_ImportGraphDefOptionsAddControlDependency(opts, feed2);
+                c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
+                EXPECT_EQ(TF_Code.TF_OK, s.Code);
+            }
 
             var scalar3 = graph.OperationByName("imported3/scalar");
             var feed3 = graph.OperationByName("imported3/feed");
@@ -327,12 +332,13 @@ namespace TensorFlowNET.UnitTest.NativeAPI
             EXPECT_EQ(TF_Code.TF_OK, s.Code);
 
             // Import again, with remapped control dependency, into the same graph
-            c_api.TF_DeleteImportGraphDefOptions(opts);
-            opts = c_api.TF_NewImportGraphDefOptions();
-            c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported4");
-            c_api.TF_ImportGraphDefOptionsRemapControlDependency(opts, "imported/feed", feed);
-            c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
-            ASSERT_EQ(TF_Code.TF_OK, s.Code);
+            using (var opts = c_api.TF_NewImportGraphDefOptions())
+            {
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, "imported4");
+                c_api.TF_ImportGraphDefOptionsRemapControlDependency(opts, "imported/feed", feed);
+                c_api.TF_GraphImportGraphDef(graph, graph_def, opts, s.Handle);
+                ASSERT_EQ(TF_Code.TF_OK, s.Code);
+            }
 
             var scalar4 = graph.OperationByName("imported4/imported3/scalar");
             var feed4 = graph.OperationByName("imported4/imported2/feed");
@@ -344,8 +350,6 @@ namespace TensorFlowNET.UnitTest.NativeAPI
             EXPECT_EQ(feed, control_inputs[0]);
             EXPECT_EQ(feed4, control_inputs[1]);
 
-            c_api.TF_DeleteImportGraphDefOptions(opts);
-
             // Can add nodes to the imported graph without trouble.
             c_test_util.Add(feed, scalar, graph, s);
             ASSERT_EQ(TF_Code.TF_OK, s.Code);