Correct inotify usage and fix strong count accounting error

Fix an error in polling of inotify fd to avoid 100% CPU usage.
Refactored code to use android Looper.

Fix a string count accounting error that causes unpaired decStrong
crashing sensor hidl service.

Bug: 37719320
Bug: 37714835
Test: no longer have 100% CPU usage.
Test: tested connection of a few mouse/keyboard/usb disk/gnubby
      no crash observed.
Test: cts still working properly after fix.
Change-Id: Ibaa026151e5e4919d8dd134c16f5865d5e30ef8a

1 files changed, 5 insertions, 1 deletions

diff --git a/modules/sensors/dynamic_sensor/ConnectionDetector.h b/modules/sensors/dynamic_sensor/ConnectionDetector.h
index 712d832f..0ee1df29 100644
--- a/modules/sensors/dynamic_sensor/ConnectionDetector.h
+++ b/modules/sensors/dynamic_sensor/ConnectionDetector.h
@@ -19,6 +19,7 @@
 
 #include "BaseDynamicSensorDaemon.h"
 #include <utils/Thread.h>
+#include <utils/Looper.h>
 
 #include <regex>
 
@@ -62,17 +63,20 @@ public:
             BaseDynamicSensorDaemon *d, const std::string &path, const std::string &regex);
     virtual ~FileConnectionDetector();
 private:
+    static constexpr int POLL_IDENT = 1;
     // implement virtual of Thread
     virtual bool threadLoop();
 
     bool matches(const std::string &name) const;
     void processExistingFiles() const;
+    void handleInotifyData(ssize_t len, const char *data);
+    bool readInotifyData();
     std::string getFullName(const std::string name) const;
 
     std::string mPath;
     std::regex mRegex;
+    sp<Looper> mLooper;
     int mInotifyFd;
-    struct pollfd mPollFd;
 };
 
 } // namespace SensorHalExt