Process priority for Android

There was a phone interview a few days ago, and was asked about the priority of the Android process, which almost didn't come back at the time, fortunately, when the interviewer was about to skip the problem.

Android divides the process into priority levels, from high to low, respectively:

1. Foreground process (Foreground)

For example, we are reading a book, then the procedure is the foreground process , these processes will not be the system priority to end . when I cut it into the background , it turned into a background process .

2, visible process (visible)

IME program , desktop clock this, visible. The visual process will not be killed by the system unless it is necessary to ensure that the foreground process is running.

3. Service Process

The process contains the service that was started. the dialing function of the telephone , the service will not be automatically ended by the system, unless you have to turn it off, it will reload itself. This is also why you can see the memory available and slow down after a while after you completely release the memory.

4. Background process (hidden)

after startup is switched to the background of the process , when hanging QQ.

5. Null process (empty)

There is nothing running in the process , some programs after exiting , will still reside in the process of an empty process , the process is not any data running , The effect is often to improve the program's next startup speed or some historical information of the recording program .

Process priority for Android