1 /*
2  * Copyright (c) 2021-2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef POWERMGR_SP_SINGLETON_H
17 #define POWERMGR_SP_SINGLETON_H
18 
19 #include <mutex>
20 #include <memory>
21 #include <refbase.h>
22 
23 #include "nocopyable.h"
24 
25 namespace OHOS {
26 namespace DisplayPowerMgr {
27 template<typename T>
28 class DelayedSpSingleton : public NoCopyable {
29 public:
30     static sptr<T> GetInstance();
31     static void DestroyInstance();
32 
33 private:
34     static sptr<T> instance_;
35     static std::mutex mutex_;
36 };
37 
38 template<typename T>
39 sptr<T> DelayedSpSingleton<T>::instance_ = nullptr;
40 
41 template<typename T>
42 std::mutex DelayedSpSingleton<T>::mutex_;
43 
44 template<typename T>
GetInstance()45 sptr<T> DelayedSpSingleton<T>::GetInstance()
46 {
47     if (!instance_) {
48         std::lock_guard<std::mutex> lock(mutex_);
49         if (instance_ == nullptr) {
50             instance_ = new T();
51         }
52     }
53 
54     return instance_;
55 }
56 
57 template<typename T>
DestroyInstance()58 void DelayedSpSingleton<T>::DestroyInstance()
59 {
60     std::lock_guard<std::mutex> lock(mutex_);
61     if (instance_) {
62         instance_.clear();
63         instance_ = nullptr;
64     }
65 }
66 } // namespace PowerMgr
67 } // namespace OHOS
68 #endif
69