[systemd-devel] systemctl how to stop a service

[liuxueping]

Hi:
I have a test in arm64,my test case try to start/stop a ntp service 
frequently,like that:

  #!/bin/bash
  i=0
  while [ 1 ];do
  echo "========$((i++))========"
  systemctl restart ntpd &
  kill -9 $!
  sleep 10
  systemctl stop ntpd
  echo "stop status:$?"
  systemctl start ntpd
  ps aux >> file
  sleep 5
  ps aux >> file
  status_ntpd_result=$(systemctl status ntpd.service|grep Active|awk 
'{print($2)}')
  if [ "${status_ntpd_result}" != "active" ]
  then
          echo "The status_ntpd_result is error, is not active."
          ps aux |grep ntp |grep -v grep
          exit 1
  fi
  ps aux |grep ntpd |grep -v grep
  sleep 10
  done


A few minutes later, the ntpd service failed to start,ant systemctl 
status ntpd shows:
ntpd[6698]: unable to bind to wildcard address 0.0.0.0 - another process 
may be running - EXITING

The result of "ps aux" before sleep 5 shows:
root      6698  0.0  0.0      0     0 ?        Ds   08:45   0:00 [ntpd]
After 5 seconds,there is no ntpd process in system.

the stop status is 0,the execution of the stop command is successful,the 
PID of the ntpd process is 1.

I would like to know if the systemctl command will wait for all the 
processes to exit completely before returning the result.