Re: Retain dynamic shared memory segments for postmaster lifetime

On Mon, Jan 27, 2014 at 7:48 PM, Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> On Mon, Jan 13, 2014 at 2:50 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> I have extended test (contrib) module dsm_demo such that now user
>> can specify during dsm_demo_create the lifespan of segment.
>
> Applied dsm_keep_segment_v1.patch and dsm_demo_v1.patch.
> Got the following warning when I tried above example:
>
> postgres=# select dsm_demo_create('this message is from session-new', 1);
> WARNING: dynamic shared memory leak: segment 1402373971 still referenced
> WARNING: dynamic shared memory leak: segment 1402373971 still referenced
> dsm_demo_create
> -----------------
> 1402373971
> (1 row)

Thanks for verification.
The reason is that resource owner has reference to segment till commit time
which leads to this warning. The fix is to remove reference from
resource owner when user calls this new API dsm_keep_segment, similar
to what currently dsm_keep_mapping does.

Find the updated patch to fix this problem attached with this mail.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com