Hey @miwroblewski thank you for your contribution and sorry for the very late reply - I haven't been looking after the project for a while.
Honestly, the change is looking good to me. I can't remember why there was so many dances with the pid file etc. Are you using it for your projects, does it work fine with just setting Pid from the Process?

Hi,
It worked pretty well, but I am not using the project anymore as I did face some issues with my Integration tests. Worth to mention I was testing it on my Linux Fedora 28, so not sure about other platforms (like Windows) so maybe it will require further testing for Windows.

@miwroblewski, @smecsia - I strongly suggest to rethink this.
As far as I understand, the complex code here is because the 'postgres.exe' is not the process which is executed. Instead pg_ctl or the 'runas' on Windows is executed, and they executed the postgres.exe.
This causes problems during shutdown.
@acommuni
This is explained in #129 in great detail. There's something odd in flapdoodle in how is uses the pid.

Doing this change here will make things even worse.