Horton

Re: Add non-blocking version of PQcancel

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Jacob Champion <pchampion@vmware.com>, "Jelte.Fennema@microsoft.com" <Jelte.Fennema@microsoft.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-03-25T19:34:50Z
Lists: pgsql-hackers 
Robert Haas <robertmhaas@gmail.com> writes:
> Well, that's a fair point, but it's somewhat orthogonal to the one I'm
> making, which is that a non-blocking version of function X might be
> expected to share code or at least functionality with X itself. Having
> something that is named in a way that implies asynchrony without other
> differences but which is actually different in other important ways is
> no good.

Yeah.  We need to choose a name for these new function(s) that is
sufficiently different from "PQcancel" that people won't expect them
to behave exactly the same as that does.  I lack any good ideas about
that, how about you?

>> Yeah, I don't think it's anywhere near fully baked yet.  On the other
>> hand, we do have a couple of weeks left.

> We do?

Um, you did read the psql-release discussion about setting the feature
freeze deadline, no?

			regards, tom lane

Commits

  1. postgres_fdw: re-issue cancel requests a few times if necessary.

  2. Make postgres_fdw's query_cancel test less flaky.

  3. postgres_fdw: Split out the query_cancel test to its own file

  4. Fix copy-paste mistake in PQcancelCreate

  5. Make libpqsrv_cancel's return const char *, not char *

  6. Stabilize postgres_fdw test

  7. libpq-be-fe-helpers.h: wrap new cancel APIs

  8. dblink/isolationtester/fe_utils: Use new cancel API

  9. Put libpq_pipeline cancel test back

  10. Hopefully make libpq_pipeline's new cancel test more reliable

  11. libpq: Add encrypted and non-blocking query cancellation routines

  12. libpq: Move pg_cancel to fe-cancel.c

  13. Add tests for libpq query cancellation APIs

  14. Add missing connection statuses to docs

  15. libpq: Change some static functions to extern

  16. libpq: Add pqReleaseConnHosts function

  17. libpq: Move cancellation related functions to fe-cancel.c

  18. Make spelling of cancelled/cancellation consistent

  19. Be more wary about OpenSSL not setting errno on error.

  20. libpq: Use modern socket flags, if available.

  21. Drop test view when done with it.

  22. Doc: add some doco about using the libpq_pipeline test module.

  23. postgres_fdw: Allow cancellation of transaction control commands.