From: tgl@postgresql.org
To: pgsql-committers@postgresql.org
Subject: pgsql: Fix error cleanup failure caused by 8.4 changes in plpgsql to try
Date: Sat, 18 Jul 2009 19:15:50 +0000 (UTC)
Message-ID: <20090718191550.AE2AB75331E@cvs.postgresql.org> (raw)
Log Message:
-----------
Fix error cleanup failure caused by 8.4 changes in plpgsql to try to avoid
memory leakage in error recovery. We were calling FreeExprContext, and
therefore invoking ExprContextCallback callbacks, in both normal and error
exits from subtransactions. However this isn't very safe, as shown in
recent trouble report from Frank van Vugt, in which releasing a tupledesc
refcount failed. It's also unnecessary, since the resources that callbacks
might wish to release should be cleaned up by other error recovery mechanisms
(ie the resource owners). We only really want FreeExprContext to release
memory attached to the exprcontext in the error-exit case. So, add a bool
parameter to FreeExprContext to tell it not to call the callbacks.
A more general solution would be to pass the isCommit bool parameter on to
the callbacks, so they could do only safe things during error exit. But
that would make the patch significantly more invasive and possibly break
third-party code that registers ExprContextCallback callbacks. We might want
to do that later in HEAD, but for now I'll just do what seems reasonable to
back-patch.
Tags:
----
REL8_4_STABLE
Modified Files:
--------------
pgsql/src/backend/executor:
execUtils.c (r1.159 -> r1.159.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execUtils.c?r1=1.159&r2=1.15...)
nodeBitmapIndexscan.c (r1.30 -> r1.30.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeBitmapIndexscan.c?r1=1.30&am...)
nodeIndexscan.c (r1.132 -> r1.132.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeIndexscan.c?r1=1.132&r2=...)
pgsql/src/include/executor:
executor.h (r1.155 -> r1.155.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/executor.h?r1=1.155&r2=1.155...)
pgsql/src/pl/plpgsql/src:
pl_exec.c (r1.244 -> r1.244.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c?r1=1.244&r2=1.244.2....)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: tgl@postgresql.org
Subject: Re: pgsql: Fix error cleanup failure caused by 8.4 changes in plpgsql to try
In-Reply-To: <20090718191550.AE2AB75331E@cvs.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox