MinikinRefCounted.h revision 6c60831cfce24b0749f50f37231e0a56d8fd4b85 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17// Base class for reference counted objects in Minikin
18
19#ifndef MINIKIN_REF_COUNTED_H
20#define MINIKIN_REF_COUNTED_H
21
22namespace android {
23
24class MinikinRefCounted {
25public:
26    void RefLocked() { mRefcount_++; }
27    void UnrefLocked() { if (--mRefcount_ == 0) { delete this; } }
28
29    // These refcount operations take the global lock.
30    void Ref();
31    void Unref();
32
33    MinikinRefCounted() : mRefcount_(1) { }
34
35    virtual ~MinikinRefCounted() { };
36private:
37    int mRefcount_;
38};
39
40// An RAII container for reference counted objects.
41// Note: this is only suitable for clients which are _not_ holding the global lock.
42template <typename T>
43class MinikinAutoUnref {
44public:
45    MinikinAutoUnref(T* obj) : mObj(obj) {
46    }
47    ~MinikinAutoUnref() {
48        mObj->Unref();
49    }
50    T& operator*() const { return *mObj; }
51    T* operator->() const { return mObj; }
52    T* get() const { return mObj; }
53private:
54    T* mObj;
55};
56
57}
58
59#endif   // MINIKIN_REF_COUNTED_H