Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <pgsql-committers-owner+archive@lists.postgresql.org>)
	id 1hGCTx-0002Rs-W7
	for pgsql-committers@arkaria.postgresql.org; Tue, 16 Apr 2019 01:01:54 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.89)
	(envelope-from <pgsql-committers-owner+archive@lists.postgresql.org>)
	id 1hGCTv-0005Rc-IF
	for pgsql-committers@arkaria.postgresql.org; Tue, 16 Apr 2019 01:01:51 +0000
Received: from makus.postgresql.org ([2001:4800:3e1:1::229])
	by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <tgl@sss.pgh.pa.us>)
	id 1hGCTv-0005RV-7a
	for pgsql-committers@lists.postgresql.org; Tue, 16 Apr 2019 01:01:51 +0000
Received: from sss.pgh.pa.us ([66.207.139.130])
	by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <tgl@sss.pgh.pa.us>)
	id 1hGCTr-00057N-Mi
	for pgsql-committers@lists.postgresql.org; Tue, 16 Apr 2019 01:01:48 +0000
Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1])
	by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id x3G11jhM028798;
	Mon, 15 Apr 2019 21:01:45 -0400
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Noah Misch <noah@leadboat.com>
cc: pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Consistently test for in-use shared memory.
In-reply-to: <28362.1555375956@sss.pgh.pa.us>
References: <E1hFBbx-0002OI-Pb@gemulon.postgresql.org>
 <26478.1555373328@sss.pgh.pa.us> <20190416005019.GA3296237@rfd.leadboat.com>
 <28362.1555375956@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Mon, 15 Apr 2019 20:52:36 -0400"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <28796.1555376505.1@sss.pgh.pa.us>
Content-Transfer-Encoding: quoted-printable
Date: Mon, 15 Apr 2019 21:01:45 -0400
Message-ID: <28797.1555376505@sss.pgh.pa.us>
List-Id: <pgsql-committers.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-committers@lists.postgresql.org>
List-Owner: <mailto:pgsql-committers-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-committers>
Precedence: bulk

Noah Misch <noah@leadboat.com> writes:
>> Perhaps I should write the 'SELECT 1 + 1' to a regular file and redirec=
t input
>> from that file.

Actually ... we don't need to run a query at all do we?

Although this would only help if Perl will optimize away an attempt
to write zero bytes to the pipe, which seems likely but not certain.

			regards, tom lane