option to wait for pid file to appear

[igor@xxxxxxxx (Igor Bukanov)]

On 17 May 2018 at 12:07, Michael Chapman <mike at very.puzzling.org> wrote:
> It _is_ better for the PID file to be written out before the initial
> process exits, but systemd will handle things correctly even if they
> happen the other way around. Essentially the service won't be considered
> to have completed activation until both events occur. If one or the other
> takes too long (i.e. longer than the TimeoutStartSec= setting), the unit
> will fail.

Does it means that even ExecStartPost and especially ExecReload can
always safely use $MAINPID? I.e. does systemd call these Execs only
after it managed to read the the pid file even when the file is
written after the initial ExecStart process exited?

And yes, Type=pid-file will be very useful. I have exactly a shell
script that will benefit from it nicely.