1 /*
2  * Copyright (C) 2013 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 #ifndef HW_EMULATOR_CAMERA_EMULATED_CAMERA_HOTPLUG_H
18 #define HW_EMULATOR_CAMERA_EMULATED_CAMERA_HOTPLUG_H
19 
20 /**
21  * This class emulates hotplug events by inotifying on a file, specific
22  * to a camera ID. When the file changes between 1/0 the hotplug
23  * status goes between PRESENT and NOT_PRESENT.
24  *
25  * Refer to FAKE_HOTPLUG_FILE in EmulatedCameraHotplugThread.cpp
26  */
27 
28 #include <vector>
29 #include "EmulatedCamera2.h"
30 #include <utils/String8.h>
31 #include <utils/Vector.h>
32 
33 namespace android {
34 class EmulatedCameraHotplugThread : public Thread {
35   public:
36     EmulatedCameraHotplugThread(std::vector<int> subscribedCameraIds);
37     ~EmulatedCameraHotplugThread();
38 
39     virtual void requestExit();
40     virtual status_t requestExitAndWait();
41 
42   private:
43 
44 
45     virtual status_t readyToRun();
46     virtual bool threadLoop();
47 
48     struct SubscriberInfo {
49         int CameraID;
50         int WatchID;
51     };
52 
53     bool addWatch(int cameraId);
54     bool removeWatch(int cameraId);
55     SubscriberInfo* getSubscriberInfo(int cameraId);
56 
57     int getCameraId(const String8& filePath) const;
58     int getCameraId(int wd) const;
59 
60     String8 getFilePath(int cameraId) const;
61     int readFile(const String8& filePath) const;
62 
63     int mInotifyFd;
64     std::vector<int> mSubscribedCameraIds;
65     Vector<SubscriberInfo> mSubscribers;
66 
67     // variables above are unguarded:
68     // -- accessed in thread loop or in constructor only
69 
70     Mutex mMutex;
71 
72     bool mRunning;          // guarding only when it's important
73 };
74 } // namespace android
75 
76 #endif
77