Re: signal handling in plpython

Hi!

Following your ideas I've made a test [here
<https://github.com/CartoDB/postgres/commit/d587d8a6e4f035cc45e1d84fc46aa7c3ab0344c3>],
only in plpython and seems to works pretty well. I've to make more tests
and execute the postgres regress too.

This ad-hoc solution could be enough for now, we don't have
shared_preload_libraries
as Heikki pointed, because in the next week we need to be able to interrupt
plpython functions.

But, I would REALLY LOVE to implement a proper solution for this case,
making hooks in Postgres for extensions like Heikki propose or any other
proposal. I'm really enjoying to work in the Postgres internals
and at least I'd like to finish this PATCH.

Any suggestion on what do I need to read, similar cases, advices, etc?

Again thank you very much for your time and you invaluable help.

Mario

2016-10-14 15:22 GMT+02:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Heikki Linnakangas <hlinnaka(at)iki(dot)fi> writes:
> > On 10/14/2016 04:05 PM, Tom Lane wrote:
> >> I wrote:
> >>> Py_AddPendingCall is safe to call from a signal handler? That would
> >>> be ... quite remarkable.
>
> > Yes, I believe it is.
>
> > https://github.com/python/cpython/blob/4b71e63b0616aa2a44c9b13675e4c8
> e3c0157481/Python/ceval.c#L422
>
> I don't know whether to laugh or cry, but that code is a joke. Just
> silently fail if you can't get the lock?
>
> regards, tom lane
>