Re: psql not responding to SIGINT upon db reconnection

Tristan Partin <tristan@neon.tech>

From: "Tristan Partin" <tristan@neon.tech>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: <pgsql-hackers@postgresql.org>
Date: 2023-07-24T19:57:58Z
Lists: pgsql-hackers

Attachments

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 
> > 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 
that implements your suggestion. Please let me know if there is 
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
	
	
	NOTICE:  Connecting to database.
	psql (17devel, server 15.3)
	SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
	Type "help" for help.
	
	tristan957=> \c
	NOTICE:  Welcome to Neon!
	Authenticate by visiting:
	    https://console.neon.tech/psql_session/yyy
	
	
	^Cconnection to server at "pg.neon.tech" (3.18.6.96), port 5432 failed: 
	Previous connection kept
	tristan957=> 

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

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix old, misleading comment for PGRES_POLLING_ACTIVE.

  2. Remove reachable call to pg_unreachable().

  3. Allow SIGINT to cancel psql database reconnections.

  4. Expose PQsocketPoll via libpq

  5. Fix query cancellation handling in psql