1/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15#ifndef TENSORFLOW_CORE_FRAMEWORK_FUNCTION_HANDLE_CACHE_H_
16#define TENSORFLOW_CORE_FRAMEWORK_FUNCTION_HANDLE_CACHE_H_
17
18#include <string>
19
20#include "tensorflow/core/framework/function.h"
21
22namespace tensorflow {
23
24// Thread-safe data structure for caching function instantiations.
25class FunctionHandleCache {
26 public:
27 explicit FunctionHandleCache(FunctionLibraryRuntime* lib);
28
29 ~FunctionHandleCache();
30
31 // Looks up the function to be instantiated in the cache first. If present,
32 // returns handle from there. Otherwise, instantiates a new function
33 // and stores handle in the cache.
34 //
35 // The cache retains the ownership of the handle. In particular, the caller
36 // should not invoke `ReleaseHandle`.
37 Status Instantiate(const string& function_name, AttrSlice attrs,
38 FunctionLibraryRuntime::InstantiateOptions options,
39 FunctionLibraryRuntime::Handle* handle);
40
41 // Releases all the handles in the cache, clearing out the state for all
42 // functions involved.
43 Status Clear();
44
45 private:
46 mutex mu_;
47 FunctionLibraryRuntime* lib_ = nullptr; // not owned
48 const string state_handle_;
49 std::unordered_map<string, FunctionLibraryRuntime::Handle> handles_
50 TF_GUARDED_BY(mu_);
51};
52
53} // namespace tensorflow
54
55#endif // TENSORFLOW_CORE_FRAMEWORK_FUNCTION_HANDLE_CACHE_H_
56