如何实现看门狗的功能？此为apache开发的监视某进程是否存在的包，非常好用。

如何实现看门狗的功能？此为apache开发的监视某进程是否存在的包，非常好用。-How to achieve the function of watchdog? This is apache developed to monitor the existence of a process package, very easy to use.