What does 'adb shell start/stop' do?

Question

Question

What do adb shell start and adb shell stop actually do?

Description

I think they call /system/bin/start<

Answer 1

Basically, all your Android services are restarted; those that are created and registered in SystemServer.java. This is called within the "Context of Zygote". So yes, Zygote is stopped.

All your services registered with ServiceManager in Android will get removed within ServiceManager. To restart them, do adb shell start.

Also note that SystemServer is started by Zygote, so init.rc tells that if Zygote is stopped, then even SystemServer must be stopped. Even SurfaceFlinger dies, since it's started from SystemServer but natively.

Answer 2

Run this on your device

grep ^service /init*rc

Answer 3

I have been wondering what "stop" does on Android too. Learned from someone that "stop" stops AP being rendered by SurfaceFlinger.

Had a try with the command like below. Execute the command, wait for a few seconds and then execute "stop" on Android. The command keeps printing increased number and creating .txt files. So maybe it only stops the Android part while the Linux part remains active. Just FYI.

busybox sh -c 'i=0;while [ $i -ne 100 ]; do echo $i >> count.txt; sleep 1; i=$(($i + 1)); echo $i; touch "$i.txt"; done;'