Re: [HACKERS] Optional message to user when terminating/cancellingbackend

> On 23 Aug 2018, at 20:53, Tom Lane  wrote:

> I think this is just a timing problem: the signal gets sent,
> but it might or might not get received before the current statement ends.
> It's possible that a signal-sent-to-self can be expected to be received
> synchronously on all Unix platforms, but I wouldn't entirely bet on that
> (in particular, the POSIX text for kill(2) does NOT guarantee it); and
> our Windows signal implementation certainly doesn't guarantee anything
> of the sort.

That makes a lot of sense, I was thinking about it in too simplistic terms.
Thanks for the clarification.

> I don't think there's necessarily anything wrong with the code, but
> you can't test it with such a simplistic test as this and expect
> stable results.  If you feel an urgent need to have a test case,
> try building an isolationtester script.

During hacking on it I preferred to have tests for it.  Iff this makes it in,
the tests can be omitted per the judgement of the committers of course.  Since
the printed pid will vary between runs it’s hard to test more interesting
scenarios so they are of questionable worth.

cheers ./daniel