summaryrefslogtreecommitdiffstats
path: root/media/gmp-clearkey/0.1/RefCounted.h
blob: 6da69429586489b8a8784455826db0d2793e45d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
/*
 * Copyright 2015, Mozilla Foundation and contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __RefCount_h__
#define __RefCount_h__

#include <stdint.h>
#include <assert.h>
#include "ClearKeyUtils.h"

#if defined(_MSC_VER)
#include <atomic>
typedef std::atomic<uint32_t> AtomicRefCount;
#else
class AtomicRefCount {
public:
  explicit AtomicRefCount(uint32_t aValue)
    : mCount(aValue)
    , mMutex(GMPCreateMutex())
  {
    assert(mMutex);
  }
  ~AtomicRefCount()
  {
    if (mMutex) {
      mMutex->Destroy();
    }
  }
  uint32_t operator--() {
    AutoLock lock(mMutex);
    return --mCount;
  }
  uint32_t operator++() {
    AutoLock lock(mMutex);
    return ++mCount;
  }
  operator uint32_t() {
    AutoLock lock(mMutex);
    return mCount;
  }
private:
  uint32_t mCount;
  GMPMutex* mMutex;
};
#endif

// Note: Thread safe.
class RefCounted {
public:
  void AddRef() {
    ++mRefCount;
  }

  uint32_t Release() {
    uint32_t newCount = --mRefCount;
    if (!newCount) {
      delete this;
    }
    return newCount;
  }

protected:
  RefCounted()
    : mRefCount(0)
  {
  }
  virtual ~RefCounted()
  {
    assert(!mRefCount);
  }
  AtomicRefCount mRefCount;
};

template<class T>
class RefPtr {
public:
  explicit RefPtr(T* aPtr) : mPtr(nullptr) {
    Assign(aPtr);
  }
  ~RefPtr() {
    Assign(nullptr);
  }
  T* operator->() const { return mPtr; }

  RefPtr& operator=(T* aVal) {
    Assign(aVal);
    return *this;
  }

private:
  void Assign(T* aPtr) {
    if (mPtr) {
      mPtr->Release();
    }
    mPtr = aPtr;
    if (mPtr) {
      aPtr->AddRef();
    }
  }
  T* mPtr;
};

#endif // __RefCount_h__