agora inbox for pljava-dev@postgresql.org
help / color / mirror / Atom feedSubject: [Pljava-dev] stack depth limit exceeded - patch possible?
Date: Wed, 16 Apr 2008 10:16:15 -0600
Message-ID: <4806264F.1060800@ejurka.com> (raw)
In-Reply-To: <48060EE6.9040009@par.univie.ac.at>
References: <48010499.30000@par.univie.ac.at>
<Pine.BSO.4.64.0804131023000.9928@leary.csoft.net>
<58782.88.116.137.78.1208177811.squirrel@www.par.univie.ac.at>
<Pine.BSO.4.64.0804141112330.5378@leary.csoft.net>
<48060EE6.9040009@par.univie.ac.at>
Alexander W?hrer wrote:
> 2304DEBUG: Changed stack_base_ptr from 00BDFC9A to 0B1EFAF4
> 2304DEBUG: Restored stack_base_ptr to 00BDFC9A
> 2304DEBUG: Changed stack_base_ptr from 00BDFC9A to 0B1EFAC8
> 2304DEBUG: Restored stack_base_ptr to 00BDFC9A
> 2304DEBUG: Exception in function SPI_cursor_fetch
> org.postgresql.pljava.internal.ServerException: stack depth limit exceeded
> at org.postgresql.pljava.internal.Portal._fetch(Native Method)
> at org.postgresql.pljava.internal.Portal.fetch(Portal.java:91)
So you can see the initial stack_base_ptr being adjusted when the query
is initially executed. Unfortunately pljava is not adjusting it again
later when rs.next() is being called. So if the portal fetch needs to
do any actual work (that is the results were not materialized by the
initial execution) it needs to adjust the stack as well. Can you try
the attached patch to see if it fixes things for you?
In general it seems that anything operating inside of
synchronized(Backend.THREADLOCK) might need to adjust the stack unless
it's certain the work it's doing is trivial and won't invoke
check_stack_depth. Unfortunately I don't know enough about when pg
calls check_stack_depth to know offhand what is/is not safe. A more
thorough audit is required here. Let's start with this patch and see
where that gets us.
Kris Jurka
-------------- next part --------------
A non-text attachment was scrubbed...
Name: portal-stack-adjust.patch
Type: text/x-patch
Size: 4358 bytes
Desc: not available
URL: <http://lists.pgfoundry.org/pipermail/pljava-dev/attachments/20080416/73b24a12/attachment.bin;
view thread (11+ messages) latest in thread
Message-ID: <4806264F.1060800@ejurka.com>
Permalink: ../4806264F.1060800@ejurka.com/
Also on: postgresql.org/message-id/4806264F.1060800@ejurka.com
reply
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: pljava-dev@postgresql.org
Subject: Re: [Pljava-dev] stack depth limit exceeded - patch possible?
In-Reply-To: <4806264F.1060800@ejurka.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox