事件Demo"/>
上层监听Kernel上报的UEvent事件Demo
最近的项目需要上层判断新外挂的mcu的连接状态 , 其节点自定义为 /sys/class/lgy_class/lgy/lgy。
在kernel中创建节好点的时候,其实已经有了uevent事件了。
上层需要监听的是这个节点虚拟出来的
1,在自定义的NeoManagerService.java 服务中添加监听动作;
private static final String LGY_STATE_MATCH ="DEVPATH=/devices/virtual/lgy_class/lgy";
/** Listens for uevent messages from the kernel to monitor the lgy state*/
private final class LgyUEventObserver extends UEventObserver {@Overridepublic void onUEvent(UEventObserver.UEvent event) {Log.d("lgy_debug","onUEvent 1111111111111");Log.d("lgy_debug","onUEvent 2222222222222");String state = event.get("LGY_STATE");Log.d("lgy_debug","onUEvent 2222222222222 state ="+state);doSomeThing();}
}
private static final String LGY_STATE_MATCH ="DEVPATH=/devices/virtual/lgy_class/lgy";private static UEventObserver mUEventObserver;public NeoManagerService(Context context) {//super(context);mContext = context; try {myService = ILgytestDevice.getService(); mLgytestCallback = new LgytestCallback();myService.registerCallback(mLgytestCallback);mUEventObserver = new LgyUEventObserver();mUEventObserver.startObserving(LGY_STATE_MATCH);} catch (Exception e) {Log.e ("lgy_debug","ILgytestDevice getService error!");e.printStackTrace();} }
kernel层使用kobject_uevent_env函数上报uevent事件
char *disconnected[2] = { "LGY_STATE=DISCONNECTED", NULL };
char *connected[2] = { "LGY_STATE=CONNECTED", NULL };
char **uevent_envp = NULL;uevent_envp = dev->connected ? connected : disconnected;//设备连接状态kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, uevent_envp);//开始上报事件
//kobject_uevent(&dev->kobj, KOBJ_CHANGE);//这种方式上层得不到LGY_STATE的值
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上层监听Kernel上报的UEvent事件Demo
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