From: Tom Lane <tgl@sss.pgh.pa.us>
To: Noah Misch <noah@leadboat.com>
cc: Guillaume Lelarge <guillaume@lelarge.info>,
        Benoit =?iso-8859-1?Q?Lobr=E9au?= <benoit.lobreau@gmail.com>,
        PostgreSQL Developers <pgsql-hackers@postgresql.org>,
        "Dr. Michael Meskes" <michael.meskes@credativ.com>
Subject: Re: Probable memory leak with ECPG and AIX
In-reply-to: <20220418041645.GA1134228@rfd.leadboat.com>
References: 
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 <20211212073411.GA2218865@rfd.leadboat.com>
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 <20220101074055.GA54621@rfd.leadboat.com> <2865639.1641054902@sss.pgh.pa.us>
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Comments: In-reply-to Noah Misch <noah@leadboat.com>
	message dated "Sun, 17 Apr 2022 21:16:45 -0700"
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Date: Sat, 02 Jul 2022 14:53:34 -0400
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Noah Misch <noah@leadboat.com> writes:
> I had expected to use pthread_once() for the newlocale() call, but there=
 would
> be no useful way to report failure and try again later.  Instead, I call=
ed
> newlocale() while ECPGconnect() holds connections_mutex.  See log messag=
e and
> comments for details.  I tested "./configure ac_cv_func_uselocale=3Dno .=
.." and
> tested the scenario of newlocale() failing every time.

This looks solid to me.  The only nit I can find to pick is that I'd
have added one more comment, along the lines of

diff --git a/src/interfaces/ecpg/ecpglib/connect.c b/src/interfaces/ecpg/e=
cpglib/connect.c
index 9f958b822c..96f99ae072 100644
--- a/src/interfaces/ecpg/ecpglib/connect.c
+++ b/src/interfaces/ecpg/ecpglib/connect.c
@@ -508,6 +508,11 @@ ECPGconnect(int lineno, int c, const char *name, cons=
t char *user, const char *p
 #ifdef ENABLE_THREAD_SAFETY
 	pthread_mutex_lock(&connections_mutex);
 #endif
+
+	/*
+	 * ... but first, make certain we have created ecpg_clocale.  Rely on
+	 * holding connections_mutex to ensure this is done by only one thread.
+	 */
 #ifdef HAVE_USELOCALE
 	if (!ecpg_clocale)
 	{

I've marked it RFC.

			regards, tom lane