1 /* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #ifndef TENSORFLOW_CC_EXPERIMENTAL_BASE_PUBLIC_RUNTIME_H_
17 #define TENSORFLOW_CC_EXPERIMENTAL_BASE_PUBLIC_RUNTIME_H_
18 
19 #include <memory>
20 
21 #include "tensorflow/c/eager/c_api_experimental.h"
22 
23 namespace tensorflow {
24 namespace experimental {
25 namespace cc {
26 
27 // Runtime represents an opaque instance of a Tensorflow runtime, with its own
28 // resources, threadpools, etc. Clients are expected to construct a Runtime
29 // object through tensorflow::cc::RuntimeBuilder::Build, after setting any
30 // relevant configuration options. Many Tensorflow functions take a reference to
31 // the runtime as an argument (eg: tensorflow::cc::SavedModelAPI::Load), and
32 // may have different implementations depending on the runtime. For many of
33 // these Runtime-attached objects (such as tensorflow::cc::TensorHandle), the
34 // Runtime must outlive these objects.
35 class Runtime {
36  public:
37   // Runtime is movable, but not copyable.
38   Runtime(Runtime&&) = default;
39   Runtime& operator=(Runtime&&) = default;
40 
41  private:
42   friend class RuntimeBuilder;
43   friend class SavedModelAPI;
44   friend class TensorHandle;
45 
46   // Wraps a TFE_Context. Takes ownership of ctx.
Runtime(TFE_Context * ctx)47   explicit Runtime(TFE_Context* ctx) : ctx_(ctx) {}
48 
49   // Deletes the currently wrapped TFE_Context, swaps it with ctx,
50   // and takes ownership of ctx.
Reset(TFE_Context * ctx)51   void Reset(TFE_Context* ctx) { ctx_.reset(ctx); }
52 
53   // Returns the TFE_Context that this object wraps. This object
54   // retains ownership of the pointer.
GetTFEContext()55   TFE_Context* GetTFEContext() const { return ctx_.get(); }
56 
57   // Runtime is not copyable
58   Runtime(const Runtime&) = delete;
59   Runtime& operator=(const Runtime&) = delete;
60 
61   struct TFEContextDeleter {
operatorTFEContextDeleter62     void operator()(TFE_Context* p) const { TFE_DeleteContext(p); }
63   };
64   std::unique_ptr<TFE_Context, TFEContextDeleter> ctx_;
65 };
66 
67 }  // namespace cc
68 }  // namespace experimental
69 }  // namespace tensorflow
70 
71 #endif  // TENSORFLOW_CC_EXPERIMENTAL_BASE_PUBLIC_RUNTIME_H_
72