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refCount.h
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1 //
2 // Copyright 2016 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
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8 //
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14 // You may obtain a copy of the Apache License at
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24 #ifndef PXR_BASE_TF_REF_COUNT_H
25 #define PXR_BASE_TF_REF_COUNT_H
26 
29 
30 #include "pxr/pxr.h"
31 
32 #include "pxr/base/arch/inttypes.h"
33 #include "pxr/base/tf/api.h"
34 #include <atomic>
35 
36 PXR_NAMESPACE_OPEN_SCOPE
37 
38 template <typename T> class TfRefPtr;
39 
71 class TfRefCount {
72 public:
74  TfRefCount() : _counter(1) {
75  }
76 
81  TfRefCount(const TfRefCount&) : _counter(1) {
82  }
83 
85  int Get() const {
86  return _counter;
87  }
88 
90  const TfRefCount& operator=(const TfRefCount&) const {
91  return *this;
92  }
93 private:
95  bool _DecrementAndTestIfZero() const {
96  return (--_counter == 0);
97  }
98 
100  int _FetchAndAdd(int amount) const {
101  return _counter.fetch_add(amount);
102  }
103 
104 private:
105  mutable std::atomic<int> _counter;
106  template <typename T> friend class TfRefPtr;
107  friend struct Tf_RefPtr_UniqueChangedCounter;
108  friend struct Tf_RefPtr_Counter;
109 };
110 
111 PXR_NAMESPACE_CLOSE_SCOPE
112 
113 #endif // PXR_BASE_TF_REF_COUNT_H
const TfRefCount & operator=(const TfRefCount &) const
Assignment to a reference counter has no effect.
Definition: refCount.h:90
int Get() const
Returns counter&#39;s value.
Definition: refCount.h:85
Reference counter class.
Definition: refCount.h:71
Define integral types.
TfRefCount()
Initialize counter to one.
Definition: refCount.h:74
TfRefCount(const TfRefCount &)
Initialize counter to one.
Definition: refCount.h:81
Reference-counted smart pointer utility class.
Definition: refBase.h:37