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1 /* Copyright 2017 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 /// \file
16 /// Memory management for TF Lite.
17 #ifndef TENSORFLOW_LITE_ALLOCATION_H_
18 #define TENSORFLOW_LITE_ALLOCATION_H_
19 
20 #include <stddef.h>
21 
22 #include <cstdio>
23 #include <cstdlib>
24 #include <memory>
25 #include <vector>
26 
27 #include "tensorflow/lite/c/common.h"
28 #include "tensorflow/lite/core/api/error_reporter.h"
29 #include "tensorflow/lite/string_type.h"
30 
31 namespace tflite {
32 
33 // A memory allocation handle. This could be a mmap or shared memory.
34 class Allocation {
35  public:
~Allocation()36   virtual ~Allocation() {}
37 
38   enum class Type {
39     kMMap,
40     kFileCopy,
41     kMemory,
42   };
43 
44   // Base pointer of this allocation
45   virtual const void* base() const = 0;
46   // Size in bytes of the allocation
47   virtual size_t bytes() const = 0;
48   // Whether the allocation is valid
49   virtual bool valid() const = 0;
50   // Return the type of the Allocation.
type()51   Type type() const { return type_; }
52 
53  protected:
Allocation(ErrorReporter * error_reporter,Type type)54   Allocation(ErrorReporter* error_reporter, Type type)
55       : error_reporter_(error_reporter), type_(type) {}
56   ErrorReporter* error_reporter_;
57 
58  private:
59   const Type type_;
60 };
61 
62 class MMAPAllocation : public Allocation {
63  public:
64   MMAPAllocation(const char* filename, ErrorReporter* error_reporter);
65   virtual ~MMAPAllocation();
66   const void* base() const override;
67   size_t bytes() const override;
68   bool valid() const override;
69 
fd()70   int fd() const { return mmap_fd_; }
71 
72   static bool IsSupported();
73 
74  protected:
75   // Data required for mmap.
76   int mmap_fd_ = -1;  // mmap file descriptor
77   const void* mmapped_buffer_;
78   size_t buffer_size_bytes_ = 0;
79 };
80 
81 class FileCopyAllocation : public Allocation {
82  public:
83   FileCopyAllocation(const char* filename, ErrorReporter* error_reporter);
84   virtual ~FileCopyAllocation();
85   const void* base() const override;
86   size_t bytes() const override;
87   bool valid() const override;
88 
89  private:
90   // Data required for mmap.
91   std::unique_ptr<const char[]> copied_buffer_;
92   size_t buffer_size_bytes_ = 0;
93 };
94 
95 class MemoryAllocation : public Allocation {
96  public:
97   // Allocates memory with the pointer and the number of bytes of the memory.
98   // The pointer has to remain alive and unchanged until the destructor is
99   // called.
100   MemoryAllocation(const void* ptr, size_t num_bytes,
101                    ErrorReporter* error_reporter);
102   virtual ~MemoryAllocation();
103   const void* base() const override;
104   size_t bytes() const override;
105   bool valid() const override;
106 
107  private:
108   const void* buffer_;
109   size_t buffer_size_bytes_ = 0;
110 };
111 
112 }  // namespace tflite
113 
114 #endif  // TENSORFLOW_LITE_ALLOCATION_H_
115