Horton

Re: Probable memory leak with ECPG and AIX

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Noah Misch <noah@leadboat.com>
Cc: Guillaume Lelarge <guillaume@lelarge.info>, Benoit Lobréau <benoit.lobreau@gmail.com>, PostgreSQL Developers <pgsql-hackers@postgresql.org>, "Dr. Michael Meskes" <michael.meskes@credativ.com>
Date: 2022-07-02T18:53:34Z
Lists: pgsql-hackers 
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 called
> newlocale() while ECPGconnect() holds connections_mutex.  See log message and
> comments for details.  I tested "./configure ac_cv_func_uselocale=no ..." 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/ecpglib/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, const 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

Commits

  1. Fix previous commit's ecpg_clocale for ppc Darwin.

  2. ecpglib: call newlocale() once per process.