blob: 703487d87405d5ebe61e5899ae63bdf3fe19b5f8 (
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
|
// Copyright (C) 2014 The Android Open Source Project
//
// 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.
#include "emugl/common/smart_ptr.h"
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
namespace emugl {
// Thread-safe atomic reference-counting type.
class RefCount {
public:
RefCount() : mCount(1) {}
~RefCount() {}
// Technically not thread-safe, use only for testing.
int count() const { return (int)mCount; }
void increment() {
#ifdef _WIN32
InterlockedIncrement(&mCount);
#else
__sync_fetch_and_add(&mCount, 1);
#endif
}
bool decrement() {
#ifdef _WIN32
return InterlockedDecrement(&mCount) == 0;
#else
return __sync_add_and_fetch(&mCount, -1) == 0;
#endif
}
private:
#ifdef _WIN32
LONG mCount;
#else
int mCount;
#endif
};
// SmartPtrBase implementation.
SmartPtrBase::SmartPtrBase(void* ptr) : mPtr(ptr), mRefCount(NULL) {
if (mPtr)
mRefCount = new RefCount();
}
SmartPtrBase::SmartPtrBase(const SmartPtrBase& other)
: mPtr(other.mPtr), mRefCount(other.mRefCount) {
if (mRefCount)
mRefCount->increment();
}
int SmartPtrBase::getRefCount() const {
return mRefCount ? mRefCount->count() : 0;
}
void SmartPtrBase::addRef() {
if (mRefCount)
mRefCount->increment();
}
void* SmartPtrBase::copyFrom(const SmartPtrBase& other) {
void* old_ptr = release();
mPtr = other.mPtr;
mRefCount = other.mRefCount;
if (mRefCount)
mRefCount->increment();
return old_ptr;
}
void* SmartPtrBase::release() {
void* old_ptr = mPtr;
RefCount* old_refcount = mRefCount;
if (old_refcount) {
mPtr = NULL;
mRefCount = NULL;
if (old_refcount->decrement()) {
delete old_refcount;
return old_ptr;
}
}
return NULL;
}
} // namespace emugl
|
