From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@enterprisedb.com>
cc: Robert Haas <robertmhaas@gmail.com>, Jakub Glapa <jakub.glapa@gmail.com>,
        Justin Pryzby <pryzby@telsasoft.com>,
        Fabio Isabettini <fisabettini@voipfuture.com>,
        Arne Roland <A.Roland@index.de>, Sand Stone <sand.m.stone@gmail.com>,
        Rick Otten <rottenwindfish@gmail.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: dsa_allocate() faliure
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Comments: In-reply-to Thomas Munro <thomas.munro@enterprisedb.com>
	message dated "Mon, 11 Feb 2019 11:24:38 +1100"
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Date: Sun, 10 Feb 2019 20:22:45 -0500
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Thomas Munro <thomas.munro@enterprisedb.com> writes:
> On Mon, Feb 11, 2019 at 10:33 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I observe from
>> https://coverage.postgresql.org/src/backend/utils/mmgr/freepage.c.gcov.=
html
>> that the edge cases in this function aren't too well exercised by
>> our regression tests, meaning that the buildfarm might not prove
>> much either way about the correctness of this patch.  That is one
>> factor pushing me to think we shouldn't risk it.  But, taking a
>> longer view, is that something that's practical to improve?

> Yeah.  This is a nice example of code that really deserves unit tests
> written in C.  Could be good motivation to built the infrastructure I
> mentioned here:
> https://www.postgresql.org/message-id/flat/CAEepm%3D2heu%2B5zwB65jWap3XY=
-UP6PpJZiKLQRSV2UQH9BmVRXQ%40mail.gmail.com

Meh.  I think if you hold out for that, you're going to be waiting a
long time.  I was thinking more along the lines of making a test API
in src/test/modules/, akin to what we've got for predtest or rbtree.

			regards, tom lane