Incremental update to the TFLite C API

PiperOrigin-RevId: 208273960

9 files changed, 317 insertions, 33 deletions

diff --git a/tensorflow/contrib/lite/experimental/c/BUILD b/tensorflow/contrib/lite/experimental/c/BUILD
index 50f8da66d0..8fc07e8eb7 100644
--- a/tensorflow/contrib/lite/experimental/c/BUILD
+++ b/tensorflow/contrib/lite/experimental/c/BUILD
@@ -26,17 +26,33 @@ tflite_cc_shared_object(
     }),
     deps = [
         ":c_api",
+        ":c_api_experimental",
         ":exported_symbols.lds",
         ":version_script.lds",
     ],
 )
 
 cc_library(
+    name = "c_api_internal",
+    srcs = ["c_api.h"],
+    hdrs = ["c_api_internal.h"],
+    copts = tflite_copts(),
+    visibility = [
+        "//tensorflow/contrib/lite/experimental/c:__subpackages__",
+    ],
+    deps = [
+        "//tensorflow/contrib/lite:context",
+        "//tensorflow/contrib/lite:framework",
+    ],
+)
+
+cc_library(
     name = "c_api",
     srcs = ["c_api.cc"],
     hdrs = ["c_api.h"],
     copts = tflite_copts(),
     deps = [
+        ":c_api_internal",
         "//tensorflow/contrib/lite:context",
         "//tensorflow/contrib/lite:framework",
         "//tensorflow/contrib/lite:schema_fbs_version",
@@ -44,6 +60,17 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "c_api_experimental",
+    srcs = ["c_api_experimental.cc"],
+    hdrs = ["c_api_experimental.h"],
+    copts = tflite_copts(),
+    deps = [
+        ":c_api",
+        ":c_api_internal",
+    ],
+)
+
 cc_test(
     name = "c_api_test",
     size = "small",
@@ -51,9 +78,21 @@ cc_test(
     data = ["//tensorflow/contrib/lite:testdata/add.bin"],
     deps = [
         ":c_api",
-        "//tensorflow/contrib/lite:framework",
         "//tensorflow/contrib/lite:kernel_api",
         "//tensorflow/contrib/lite/testing:util",
         "@com_google_googletest//:gtest",
     ],
 )
+
+cc_test(
+    name = "c_api_experimental_test",
+    size = "small",
+    srcs = ["c_api_experimental_test.cc"],
+    data = ["//tensorflow/contrib/lite:testdata/add.bin"],
+    deps = [
+        ":c_api",
+        ":c_api_experimental",
+        "//tensorflow/contrib/lite/testing:util",
+        "@com_google_googletest//:gtest",
+    ],
+)
diff --git a/tensorflow/contrib/lite/experimental/c/c_api.cc b/tensorflow/contrib/lite/experimental/c/c_api.cc
index 9d29e8b3e0..a4ab0e8c30 100644
--- a/tensorflow/contrib/lite/experimental/c/c_api.cc
+++ b/tensorflow/contrib/lite/experimental/c/c_api.cc
@@ -15,6 +15,7 @@ limitations under the License.
 #include "tensorflow/contrib/lite/experimental/c/c_api.h"
 
 #include "tensorflow/contrib/lite/context.h"
+#include "tensorflow/contrib/lite/experimental/c/c_api_internal.h"
 #include "tensorflow/contrib/lite/interpreter.h"
 #include "tensorflow/contrib/lite/kernels/register.h"
 #include "tensorflow/contrib/lite/model.h"
@@ -23,28 +24,55 @@ limitations under the License.
 extern "C" {
 #endif  // __cplusplus
 
-struct _TFL_Interpreter {
-  std::unique_ptr<tflite::Interpreter> impl;
-};
-
 // LINT.IfChange
 
-TFL_Interpreter* TFL_NewInterpreter(const void* model_data,
-                                    int32_t model_size) {
+TFL_Model* TFL_NewModel(const void* model_data, size_t model_size) {
   auto model = tflite::FlatBufferModel::BuildFromBuffer(
-      static_cast<const char*>(model_data), static_cast<size_t>(model_size));
-  if (!model) {
+      static_cast<const char*>(model_data), model_size);
+  return model ? new TFL_Model{std::move(model)} : nullptr;
+}
+
+TFL_Model* TFL_NewModelFromFile(const char* model_path) {
+  auto model = tflite::FlatBufferModel::BuildFromFile(model_path);
+  return model ? new TFL_Model{std::move(model)} : nullptr;
+}
+
+void TFL_DeleteModel(TFL_Model* model) { delete model; }
+
+TFL_InterpreterOptions* TFL_NewInterpreterOptions() {
+  return new TFL_InterpreterOptions{};
+}
+
+void TFL_DeleteInterpreterOptions(TFL_InterpreterOptions* options) {
+  delete options;
+}
+
+void TFL_InterpreterOptionsSetNumThreads(TFL_InterpreterOptions* options,
+                                         int32_t num_threads) {
+  options->num_threads = num_threads;
+}
+
+TFL_Interpreter* TFL_NewInterpreter(
+    const TFL_Model* model, const TFL_InterpreterOptions* optional_options) {
+  if (!model || !model->impl) {
     return nullptr;
   }
 
   tflite::ops::builtin::BuiltinOpResolver resolver;
-  tflite::InterpreterBuilder builder(*model, resolver);
-  std::unique_ptr<tflite::Interpreter> interpreter_impl;
-  if (builder(&interpreter_impl) != kTfLiteOk) {
+  tflite::InterpreterBuilder builder(*model->impl, resolver);
+  std::unique_ptr<tflite::Interpreter> interpreter;
+  if (builder(&interpreter) != kTfLiteOk) {
     return nullptr;
   }
 
-  return new TFL_Interpreter{std::move(interpreter_impl)};
+  if (optional_options) {
+    if (optional_options->num_threads !=
+        TFL_InterpreterOptions::kDefaultNumThreads) {
+      interpreter->SetNumThreads(optional_options->num_threads);
+    }
+  }
+
+  return new TFL_Interpreter{std::move(interpreter)};
 }
 
 void TFL_DeleteInterpreter(TFL_Interpreter* interpreter) { delete interpreter; }
@@ -97,9 +125,13 @@ int32_t TFL_TensorDim(const TFL_Tensor* tensor, int32_t dim_index) {
 
 size_t TFL_TensorByteSize(const TFL_Tensor* tensor) { return tensor->bytes; }
 
+void* TFL_TensorData(const TFL_Tensor* tensor) {
+  return static_cast<void*>(tensor->data.raw);
+}
+
 TFL_Status TFL_TensorCopyFromBuffer(TFL_Tensor* tensor, const void* input_data,
-                                    int32_t input_data_size) {
-  if (tensor->bytes != static_cast<size_t>(input_data_size)) {
+                                    size_t input_data_size) {
+  if (tensor->bytes != input_data_size) {
     return kTfLiteError;
   }
   memcpy(tensor->data.raw, input_data, input_data_size);
@@ -107,8 +139,8 @@ TFL_Status TFL_TensorCopyFromBuffer(TFL_Tensor* tensor, const void* input_data,
 }
 
 TFL_Status TFL_TensorCopyToBuffer(const TFL_Tensor* tensor, void* output_data,
-                                  int32_t output_data_size) {
-  if (tensor->bytes != static_cast<size_t>(output_data_size)) {
+                                  size_t output_data_size) {
+  if (tensor->bytes != output_data_size) {
     return kTfLiteError;
   }
   memcpy(output_data, tensor->data.raw, output_data_size);
diff --git a/tensorflow/contrib/lite/experimental/c/c_api.h b/tensorflow/contrib/lite/experimental/c/c_api.h
index 070f1add13..3757349b55 100644
--- a/tensorflow/contrib/lite/experimental/c/c_api.h
+++ b/tensorflow/contrib/lite/experimental/c/c_api.h
@@ -30,6 +30,9 @@ limitations under the License.
 //
 // Conventions:
 // * We use the prefix TFL_ for everything in the API.
+// * size_t is used to represent byte sizes of objects that are
+//   materialized in the address space of the calling process.
+// * int is used as an index into arrays.
 
 #ifdef SWIG
 #define TFL_CAPI_EXPORT
@@ -54,15 +57,50 @@ typedef TfLiteStatus TFL_Status;
 typedef TfLiteType TFL_Type;
 
 // --------------------------------------------------------------------------
+// TFL_Model wraps a loaded TensorFlow Lite model.
+typedef struct TFL_Model TFL_Model;
+
+// Returns a model from the provided buffer, or null on failure.
+TFL_CAPI_EXPORT extern TFL_Model* TFL_NewModel(const void* model_data,
+                                               size_t model_size);
+
+// Returns a model from the provided file, or null on failure.
+TFL_CAPI_EXPORT extern TFL_Model* TFL_NewModelFromFile(const char* model_path);
+
+// Destroys the model instance.
+TFL_CAPI_EXPORT extern void TFL_DeleteModel(TFL_Model* model);
+
+// --------------------------------------------------------------------------
+// TFL_InterpreterOptions allows customized interpreter configuration.
+typedef struct TFL_InterpreterOptions TFL_InterpreterOptions;
+
+// Returns a new interpreter options instances.
+TFL_CAPI_EXPORT extern TFL_InterpreterOptions* TFL_NewInterpreterOptions();
+
+// Destroys the interpreter options instance.
+TFL_CAPI_EXPORT extern void TFL_DeleteInterpreterOptions(
+    TFL_InterpreterOptions* options);
+
+// Sets the number of CPU threads to use for the interpreter.
+TFL_CAPI_EXPORT extern void TFL_InterpreterOptionsSetNumThreads(
+    TFL_InterpreterOptions* options, int32_t num_threads);
+
+// --------------------------------------------------------------------------
 // TFL_Interpreter provides inference from a provided model.
-typedef struct _TFL_Interpreter TFL_Interpreter;
+typedef struct TFL_Interpreter TFL_Interpreter;
 
-// Returns an interpreter for the provided model, or null on failure.
+// Returns a new interpreter using the provided model and options, or null on
+// failure.
+//
+// * `model` must be a valid model instance. The caller retains ownership of the
+//   object, and can destroy it immediately after creating the interpreter.
+// * `optional_options` may be null. The caller retains ownership of the object,
+//   and can safely destroy it immediately after creating the interpreter.
 //
 // NOTE: The client *must* explicitly allocate tensors before attempting to
 // access input tensor data or invoke the interpreter.
 TFL_CAPI_EXPORT extern TFL_Interpreter* TFL_NewInterpreter(
-    const void* model_data, int32_t model_size);
+    const TFL_Model* model, const TFL_InterpreterOptions* optional_options);
 
 // Destroys the interpreter.
 TFL_CAPI_EXPORT extern void TFL_DeleteInterpreter(TFL_Interpreter* interpreter);
@@ -76,7 +114,8 @@ TFL_CAPI_EXPORT extern int TFL_InterpreterGetInputTensorCount(
 TFL_CAPI_EXPORT extern TFL_Tensor* TFL_InterpreterGetInputTensor(
     const TFL_Interpreter* interpreter, int32_t input_index);
 
-// Attempts to resize the specified input tensor.
+// Resizes the specified input tensor.
+//
 // NOTE: After a resize, the client *must* explicitly allocate tensors before
 // attempting to access the resized tensor data or invoke the interpreter.
 // REQUIRES: 0 <= input_index < TFL_InterpreterGetInputTensorCount(tensor)
@@ -131,16 +170,24 @@ TFL_CAPI_EXPORT extern int32_t TFL_TensorDim(const TFL_Tensor* tensor,
 // Returns the size of the underlying data in bytes.
 TFL_CAPI_EXPORT extern size_t TFL_TensorByteSize(const TFL_Tensor* tensor);
 
+// Returns a pointer to the underlying data buffer.
+//
+// Note: The result may be null if tensors have not yet been allocated, e.g.,
+// if the Tensor has just been created or resized and `TFL_AllocateTensors()`
+// has yet to be called, or if the output tensor is dynamically sized and the
+// interpreter hasn't been invoked.
+TFL_CAPI_EXPORT extern void* TFL_TensorData(const TFL_Tensor* tensor);
+
 // Copies from the provided input buffer into the tensor's buffer.
 // REQUIRES: input_data_size == TFL_TensorByteSize(tensor)
 TFL_CAPI_EXPORT extern TFL_Status TFL_TensorCopyFromBuffer(
-    TFL_Tensor* tensor, const void* input_data, int32_t input_data_size);
+    TFL_Tensor* tensor, const void* input_data, size_t input_data_size);
 
 // Copies to the provided output buffer from the tensor's buffer.
 // REQUIRES: output_data_size == TFL_TensorByteSize(tensor)
 TFL_CAPI_EXPORT extern TFL_Status TFL_TensorCopyToBuffer(
     const TFL_Tensor* output_tensor, void* output_data,
-    int32_t output_data_size);
+    size_t output_data_size);
 
 #ifdef __cplusplus
 }  // extern "C"
diff --git a/tensorflow/contrib/lite/experimental/c/c_api_experimental.cc b/tensorflow/contrib/lite/experimental/c/c_api_experimental.cc
new file mode 100644
index 0000000000..c4dbc55cbf
--- /dev/null
+++ b/tensorflow/contrib/lite/experimental/c/c_api_experimental.cc
@@ -0,0 +1,31 @@
+/* Copyright 2018 The TensorFlow 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.
+==============================================================================*/
+
+#include "tensorflow/contrib/lite/experimental/c/c_api_experimental.h"
+
+#include "tensorflow/contrib/lite/experimental/c/c_api_internal.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+TFL_Status TFL_InterpreterResetVariableTensorsToZero(
+    TFL_Interpreter* interpreter) {
+  return interpreter->impl->ResetVariableTensorsToZero();
+}
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif  // __cplusplus
diff --git a/tensorflow/contrib/lite/experimental/c/c_api_experimental.h b/tensorflow/contrib/lite/experimental/c/c_api_experimental.h
new file mode 100644
index 0000000000..b0ac258dcf
--- /dev/null
+++ b/tensorflow/contrib/lite/experimental/c/c_api_experimental.h
@@ -0,0 +1,32 @@
+/* Copyright 2018 The TensorFlow 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.
+==============================================================================*/
+#ifndef TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_EXPERIMENTAL_H_
+#define TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_EXPERIMENTAL_H_
+
+#include "tensorflow/contrib/lite/experimental/c/c_api.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+// Resets all variable tensors to zero.
+TFL_CAPI_EXPORT extern TFL_Status TFL_InterpreterResetVariableTensorsToZero(
+    TFL_Interpreter* interpreter);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif  // __cplusplus
+
+#endif  // TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_EXPERIMENTAL_H_
diff --git a/tensorflow/contrib/lite/experimental/c/c_api_experimental_test.cc b/tensorflow/contrib/lite/experimental/c/c_api_experimental_test.cc
new file mode 100644
index 0000000000..db6e5251de
--- /dev/null
+++ b/tensorflow/contrib/lite/experimental/c/c_api_experimental_test.cc
@@ -0,0 +1,46 @@
+/* Copyright 2018 The TensorFlow 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.
+==============================================================================*/
+
+#include "tensorflow/contrib/lite/experimental/c/c_api_experimental.h"
+
+#include <gtest/gtest.h>
+#include "tensorflow/contrib/lite/experimental/c/c_api.h"
+#include "tensorflow/contrib/lite/testing/util.h"
+
+namespace {
+
+TEST(CApiExperimentalSimple, Smoke) {
+  TFL_Model* model = TFL_NewModelFromFile(
+      "tensorflow/contrib/lite/testdata/add.bin");
+  ASSERT_NE(model, nullptr);
+
+  TFL_Interpreter* interpreter =
+      TFL_NewInterpreter(model, /*optional_options=*/nullptr);
+  ASSERT_NE(interpreter, nullptr);
+  ASSERT_EQ(TFL_InterpreterAllocateTensors(interpreter), kTfLiteOk);
+
+  EXPECT_EQ(TFL_InterpreterResetVariableTensorsToZero(interpreter), kTfLiteOk);
+
+  TFL_DeleteModel(model);
+  TFL_DeleteInterpreter(interpreter);
+}
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  ::tflite::LogToStderr();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/tensorflow/contrib/lite/experimental/c/c_api_internal.h b/tensorflow/contrib/lite/experimental/c/c_api_internal.h
new file mode 100644
index 0000000000..c5c612a4c6
--- /dev/null
+++ b/tensorflow/contrib/lite/experimental/c/c_api_internal.h
@@ -0,0 +1,41 @@
+/* Copyright 2018 The TensorFlow 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.
+==============================================================================*/
+#ifndef TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_INTERNAL_H_
+#define TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_INTERNAL_H_
+
+#include "tensorflow/contrib/lite/experimental/c/c_api.h"
+
+#include "tensorflow/contrib/lite/interpreter.h"
+#include "tensorflow/contrib/lite/model.h"
+
+// Internal structures used by the C API. These are likely to change and should
+// not be depended on.
+
+struct TFL_Model {
+  std::unique_ptr<tflite::FlatBufferModel> impl;
+};
+
+struct TFL_InterpreterOptions {
+  enum {
+    kDefaultNumThreads = -1,
+  };
+  int num_threads = kDefaultNumThreads;
+};
+
+struct TFL_Interpreter {
+  std::unique_ptr<tflite::Interpreter> impl;
+};
+
+#endif  // TENSORFLOW_CONTRIB_LITE_EXPERIMENTAL_C_C_API_INTERNAL_H_
diff --git a/tensorflow/contrib/lite/experimental/c/c_api_test.cc b/tensorflow/contrib/lite/experimental/c/c_api_test.cc
index bc925e00a6..a631dae890 100644
--- a/tensorflow/contrib/lite/experimental/c/c_api_test.cc
+++ b/tensorflow/contrib/lite/experimental/c/c_api_test.cc
@@ -18,22 +18,28 @@ limitations under the License.
 #include "tensorflow/contrib/lite/experimental/c/c_api.h"
 
 #include <gtest/gtest.h>
-#include "tensorflow/contrib/lite/allocation.h"
 #include "tensorflow/contrib/lite/context.h"
 #include "tensorflow/contrib/lite/testing/util.h"
 
 namespace {
 
 TEST(CApiSimple, Smoke) {
-  tflite::FileCopyAllocation model_file(
-      "tensorflow/contrib/lite/testdata/add.bin",
-      tflite::DefaultErrorReporter());
+  TFL_Model* model = TFL_NewModelFromFile(
+      "tensorflow/contrib/lite/testdata/add.bin");
+  ASSERT_NE(model, nullptr);
 
-  TFL_Interpreter* interpreter =
-      TFL_NewInterpreter(model_file.base(), model_file.bytes());
+  TFL_InterpreterOptions* options = TFL_NewInterpreterOptions();
+  ASSERT_NE(options, nullptr);
+  TFL_InterpreterOptionsSetNumThreads(options, 2);
+
+  TFL_Interpreter* interpreter = TFL_NewInterpreter(model, options);
   ASSERT_NE(interpreter, nullptr);
-  ASSERT_EQ(TFL_InterpreterAllocateTensors(interpreter), kTfLiteOk);
 
+  // The options/model can be deleted immediately after interpreter creation.
+  TFL_DeleteInterpreterOptions(options);
+  TFL_DeleteModel(model);
+
+  ASSERT_EQ(TFL_InterpreterAllocateTensors(interpreter), kTfLiteOk);
   ASSERT_EQ(TFL_InterpreterGetInputTensorCount(interpreter), 1);
   ASSERT_EQ(TFL_InterpreterGetOutputTensorCount(interpreter), 1);
 
diff --git a/tensorflow/contrib/lite/experimental/examples/unity/TensorFlowLitePlugin/Assets/TensorFlowLite/SDK/Scripts/Interpreter.cs b/tensorflow/contrib/lite/experimental/examples/unity/TensorFlowLitePlugin/Assets/TensorFlowLite/SDK/Scripts/Interpreter.cs
index ab966bae2e..b6905b5fbf 100644
--- a/tensorflow/contrib/lite/experimental/examples/unity/TensorFlowLitePlugin/Assets/TensorFlowLite/SDK/Scripts/Interpreter.cs
+++ b/tensorflow/contrib/lite/experimental/examples/unity/TensorFlowLitePlugin/Assets/TensorFlowLite/SDK/Scripts/Interpreter.cs
@@ -16,6 +16,8 @@ using System;
 using System.Runtime.InteropServices;
 
 using TFL_Interpreter = System.IntPtr;
+using TFL_InterpreterOptions = System.IntPtr;
+using TFL_Model = System.IntPtr;
 using TFL_Tensor = System.IntPtr;
 
 namespace TensorFlowLite
@@ -32,7 +34,9 @@ namespace TensorFlowLite
     public Interpreter(byte[] modelData) {
       GCHandle modelDataHandle = GCHandle.Alloc(modelData, GCHandleType.Pinned);
       IntPtr modelDataPtr = modelDataHandle.AddrOfPinnedObject();
-      handle = TFL_NewInterpreter(modelDataPtr, modelData.Length);
+      TFL_Model model = TFL_NewModel(modelDataPtr, modelData.Length);
+      handle = TFL_NewInterpreter(model, /*options=*/IntPtr.Zero);
+      TFL_DeleteModel(model);
       if (handle == IntPtr.Zero) throw new Exception("Failed to create TensorFlowLite Interpreter");
     }
 
@@ -89,9 +93,15 @@ namespace TensorFlowLite
     #region Externs
 
     [DllImport (TensorFlowLibrary)]
+    private static extern unsafe TFL_Interpreter TFL_NewModel(IntPtr model_data, int model_size);
+
+    [DllImport (TensorFlowLibrary)]
+    private static extern unsafe TFL_Interpreter TFL_DeleteModel(TFL_Model model);
+
+    [DllImport (TensorFlowLibrary)]
     private static extern unsafe TFL_Interpreter TFL_NewInterpreter(
-        IntPtr model_data,
-        int model_size);
+        TFL_Model model,
+        TFL_InterpreterOptions optional_options);
 
     [DllImport (TensorFlowLibrary)]
     private static extern unsafe void TFL_DeleteInterpreter(TFL_Interpreter interpreter);