Content-Type: multipart/mixed;
 boundary=5ae4ba4c466da4b3a4842affd55f0cccceffa06d9b6773f36fe46ef17f9c
Mime-Version: 1.0
Date: Mon, 24 Jul 2023 14:57:58 -0500
Cc: <pgsql-hackers@postgresql.org>
Subject: Re: psql not responding to SIGINT upon db reconnection
To: "Tom Lane" <tgl@sss.pgh.pa.us>
From: "Tristan Partin" <tristan@neon.tech>
Message-Id: <CUAO24Z1Y72E.2069AD01EB4LO@gonk>
References: <CUAJJDVD8L61.2AH6VEEDMTXX3@gonk>
 <CUAKHCX5472I.SJP0AWQRYVFA@gonk> <CUAKIOVISECO.2S7MSQFOP1304@gonk>
 <1588058.1690220636@sss.pgh.pa.us>
In-Reply-To: <1588058.1690220636@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/CUAO24Z1Y72E.2069AD01EB4LO%40gonk>
Precedence: bulk

--5ae4ba4c466da4b3a4842affd55f0cccceffa06d9b6773f36fe46ef17f9c
Content-Type: multipart/alternative;
 boundary=f51172faf984fc3d2ce4319469b3aee7d23da8297bf93dd899b35131ef18

--f51172faf984fc3d2ce4319469b3aee7d23da8297bf93dd899b35131ef18
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
Content-Type: text/plain; charset=UTF-8; format=Flowed

On Mon Jul 24, 2023 at 12:43 PM CDT, Tom Lane wrote:
> "Tristan Partin" <tristan@neon.tech> writes:
> > v3 is attached which fixes up some code comments I added which I hadn't=
=20
> > attached to the commit already, sigh.
>
> I don't care for this patch at all.  You're bypassing the pqsignal
> abstraction layer that the rest of psql goes through, and the behavior
> you're implementing isn't very nice.  People do not expect ^C to
> kill psql - it should just stop the \c attempt and leave you as you
> were.
>
> Admittedly, getting PQconnectdbParams to return control on SIGINT
> isn't too practical.  But you could probably replace that with a loop
> around PQconnectPoll and test for CancelRequested in the loop.

That sounds like a much better solution. Attached you will find a v4=20
that implements your suggestion. Please let me know if there is=20
something that I missed. I can confirm that the patch works.

	$ ./build/src/bin/psql/psql -h pg.neon.tech
	NOTICE:  Welcome to Neon!
	Authenticate by visiting:
	    https://console.neon.tech/psql_session/xxx
=09
=09
	NOTICE:  Connecting to database.
	psql (17devel, server 15.3)
	SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compres=
sion: off)
	Type "help" for help.
=09
	tristan957=3D> \c
	NOTICE:  Welcome to Neon!
	Authenticate by visiting:
	    https://console.neon.tech/psql_session/yyy
=09
=09
	^Cconnection to server at "pg.neon.tech" (3.18.6.96), port 5432 failed:=20
	Previous connection kept
	tristan957=3D>=20

--=20
Tristan Partin
Neon (https://neon.tech)

--f51172faf984fc3d2ce4319469b3aee7d23da8297bf93dd899b35131ef18--

--5ae4ba4c466da4b3a4842affd55f0cccceffa06d9b6773f36fe46ef17f9c
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename=v4-0001-Allow-SIGINT-to-cancel-psql-database-reconnection.patch
Content-Type: text/x-patch; charset=utf-8;
 name=v4-0001-Allow-SIGINT-to-cancel-psql-database-reconnection.patch
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--5ae4ba4c466da4b3a4842affd55f0cccceffa06d9b6773f36fe46ef17f9c--