1 /*
2  * Copyright (c) 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 UTILS_EVENT_REACTOR_H
17 #define UTILS_EVENT_REACTOR_H
18 
19 #include <cstdint>
20 #include <atomic>
21 #include <memory>
22 #include <mutex>
23 #include <vector>
24 #include <set>
25 #include <queue>
26 #include "io_event_common.h"
27 #include "errors.h"
28 #include "io_event_handler.h"
29 
30 namespace OHOS {
31 namespace Utils {
32 
33 class IOEventEpoll;
34 
35 class IOEventReactor {
36 public:
37     static constexpr uint8_t FLAG_CHANGED = 0x01;
38     static constexpr size_t INIT_FD_NUMS = 8;
39     static constexpr int EXPANSION_COEFF = 2;
40 
41     IOEventReactor();
42     IOEventReactor(const IOEventReactor&) = delete;
43     IOEventReactor& operator=(const IOEventReactor&) = delete;
44     IOEventReactor(const IOEventReactor&&) = delete;
45     IOEventReactor& operator=(const IOEventReactor&&) = delete;
46     virtual ~IOEventReactor();
47 
48     ErrCode SetUp();
49     ErrCode CleanUp();
50     ErrCode Clean(int fd);
51 
52     ErrCode AddHandler(IOEventHandler* target);
53     ErrCode RemoveHandler(IOEventHandler* target);
54     ErrCode UpdateHandler(IOEventHandler* target);
55     ErrCode FindHandler(IOEventHandler* target);
56 
57     void Run(int timeout);
58 
Terminate()59     inline void Terminate()
60     {
61         loopReady_ = false;
62     }
63 
EnableHandling()64     inline void EnableHandling()
65     {
66         enabled_ = true;
67     }
68 
DisableHandling()69     inline void DisableHandling()
70     {
71         enabled_ = false;
72     }
73 private:
74     struct FdEvents {
75         std::shared_ptr<IOEventHandler> head;
76         EventId events;
77         uint8_t flags;
78 
FdEventsFdEvents79         FdEvents()
80         {
81             head = std::make_shared<IOEventHandler>();
82             events = Events::EVENT_NONE;
83             flags = 0u;
84         }
85     };
86 
87     bool HasHandler(IOEventHandler* target);
88     void InsertNodeFront(int fd, IOEventHandler* target);
89     void RemoveNode(IOEventHandler* target);
90 
91     void HandleAll(const std::vector<std::pair<int, EventId>>&);
92     void Execute(const std::vector<EventCallback>& tasks);
93 
94     ErrCode HandleEvents(int fd, EventId events);
95     bool UpdateToDemultiplexer(int fd);
96 
97     bool DoClean(int fd);
98 
99     std::mutex mutex_;
100     std::atomic<bool> loopReady_;
101     std::atomic<bool> enabled_;
102     std::atomic<uint32_t> count_;
103     std::vector<struct FdEvents> ioHandlers_;
104     std::unique_ptr<IOEventEpoll> backend_;
105 };
106 
107 } // namespace Utils
108 } // namespace OHOS
109 #endif