1/*
2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef SYSTEM_WRAPPERS_INTERFACE_REF_COUNT_H_
12#define SYSTEM_WRAPPERS_INTERFACE_REF_COUNT_H_
13
14#include "webrtc/system_wrappers/interface/atomic32.h"
15
16namespace webrtc {
17
18// This class can be used for instantiating
19// reference counted objects.
20// int32_t AddRef() and int32_t Release().
21// Usage:
22// RefCountImpl<T>* implementation = new RefCountImpl<T>(p);
23//
24// Example:
25// class MyInterface {
26//  public:
27//   virtual void DoSomething() = 0;
28//   virtual int32_t AddRef() = 0;
29//   virtual int32_t Release() = 0:
30//  private:
31//   virtual ~MyInterface(){};
32// }
33// class MyImplementation : public MyInterface {
34//  public:
35//   virtual DoSomething() { printf("hello"); };
36// };
37// MyImplementation* CreateMyImplementation() {
38//   RefCountImpl<MyImplementation>* implementation =
39//       new RefCountImpl<MyImplementation>();
40//   return implementation;
41// }
42
43template <class T>
44class RefCountImpl : public T {
45 public:
46  RefCountImpl() : ref_count_(0) {}
47
48  template<typename P>
49  explicit RefCountImpl(P p) : T(p), ref_count_(0) {}
50
51  template<typename P1, typename P2>
52  RefCountImpl(P1 p1, P2 p2) : T(p1, p2), ref_count_(0) {}
53
54  template<typename P1, typename P2, typename P3>
55  RefCountImpl(P1 p1, P2 p2, P3 p3) : T(p1, p2, p3), ref_count_(0) {}
56
57  template<typename P1, typename P2, typename P3, typename P4>
58  RefCountImpl(P1 p1, P2 p2, P3 p3, P4 p4) : T(p1, p2, p3, p4), ref_count_(0) {}
59
60  template<typename P1, typename P2, typename P3, typename P4, typename P5>
61  RefCountImpl(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5)
62      : T(p1, p2, p3, p4, p5), ref_count_(0) {}
63
64  virtual int32_t AddRef() {
65    return ++ref_count_;
66  }
67
68  virtual int32_t Release() {
69    int32_t ref_count;
70    ref_count = --ref_count_;
71    if (ref_count == 0)
72      delete this;
73    return ref_count;
74  }
75
76 protected:
77  Atomic32 ref_count_;
78};
79
80}  // namespace webrtc
81
82#endif  // SYSTEM_WRAPPERS_INTERFACE_REF_COUNT_H_
83