1 /*
2  * Copyright (c) 2021 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 FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_BACKGROUND_TASK_EXECUTOR_H
17 #define FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_BACKGROUND_TASK_EXECUTOR_H
18 
19 #include <condition_variable>
20 #include <functional>
21 #include <list>
22 #include <mutex>
23 #include <thread>
24 
25 #include "base/utils/noncopyable.h"
26 
27 namespace OHOS::Ace {
28 
29 enum class BgTaskPriority {
30     DEFAULT,
31     LOW,
32 };
33 
34 class BackgroundTaskExecutor {
35     ACE_DISALLOW_COPY_AND_MOVE(BackgroundTaskExecutor);
36 
37 public:
38     using Task = std::function<void()>;
39 
40     static BackgroundTaskExecutor& GetInstance();
41 
42     bool PostTask(Task&& task, BgTaskPriority priority = BgTaskPriority::DEFAULT);
43     bool PostTask(const Task& task, BgTaskPriority priority = BgTaskPriority::DEFAULT);
44 
45     void TriggerGarbageCollection();
46 
47 private:
48     BackgroundTaskExecutor();
49     ~BackgroundTaskExecutor();
50 
51     void StartNewThreads(size_t num = 1);
52     void ThreadLoop(uint32_t threadNo);
53 
54     std::mutex mutex_;
55     std::condition_variable condition_;
56     std::list<Task> tasks_;
57     std::list<Task> lowPriorityTasks_;
58     std::list<std::thread> threads_;
59     size_t currentThreadNum_ { 0 };
60     size_t maxThreadNum_ { 0 };
61     bool running_ { true };
62     uint32_t purgeFlags_ { 0 };
63 };
64 
65 } // namespace OHOS::Ace
66 
67 #endif // FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_BACKGROUND_TASK_EXECUTOR_H
68