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 <utils/String8.h>
29 #include <utils/Vector.h>
30 #include "EmulatedCamera2.h"
31 
32 namespace android {
33 class EmulatedCameraHotplugThread : public Thread {
34  public:
35   EmulatedCameraHotplugThread(size_t totalCameraCount);
36   ~EmulatedCameraHotplugThread();
37 
38   virtual void requestExit();
39   virtual status_t requestExitAndWait();
40 
41  private:
42   virtual status_t readyToRun();
43   virtual bool threadLoop();
44 
45   struct SubscriberInfo {
46     int CameraID;
47     int WatchID;
48   };
49 
50   bool addWatch(int cameraId);
51   bool removeWatch(int cameraId);
52   SubscriberInfo* getSubscriberInfo(int cameraId);
53 
54   int getCameraId(String8 filePath) const;
55   int getCameraId(int wd) const;
56 
57   String8 getFilePath(int cameraId) const;
58   int readFile(String8 filePath) const;
59 
60   bool createFileIfNotExists(int cameraId) const;
61 
62   Vector<int> mSubscribedCameraIds;
63   Vector<SubscriberInfo> mSubscribers;
64 
65   // variables above are unguarded:
66   // -- accessed in thread loop or in constructor only
67 
68   Mutex mMutex;
69 
70   bool mRunning;  // guarding only when it's important
71 };
72 }  // namespace android
73 
74 #endif
75