Re: PL/TCL Patch to prevent postgres from becoming multithreaded

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Marshall, Steve" <smarshall(at)wsi(dot)com>
Cc: pgsql-patches(at)postgresql(dot)org
Subject: Re: PL/TCL Patch to prevent postgres from becoming multithreaded
Date: 2007-09-21 00:32:57
Message-ID: 17334.1190334777@sss.pgh.pa.us
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"Marshall, Steve" <smarshall(at)wsi(dot)com> writes:
> There is a problem in PL/TCL that can cause the postgres backend to
> become multithreaded. Postgres is not designed to be multithreaded, so
> this causes downstream errors in signal handling. We have seen this
> cause a number of "unexpected state" errors associated with notification
> handling; however, unpredictable signal handling would be likely to
> cause other errors as well.

I've applied this patch to CVS HEAD (8.3-to-be). I'm a bit hesitant
to back-patch it however, at least not till it gets through some beta
testing.

Thanks for the detailed explanation, test case, and patch!

regards, tom lane

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