Re: Retain dynamic shared memory segments for postmaster lifetime

On Tue, Jan 28, 2014 at 6:12 AM, Kyotaro HORIGUCHI
<horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> I had a short look on this patch.
>
> - DSM implimentation seems divided into generic part (dsm.c) and
> platform dependent part(dsm_impl.c). This dsm_keep_segment
> puts WIN32 specific part directly into dms.c. I suppose it'd
> be better defining DSM_OP_KEEP_SEGMENT and calling dms_impl_op
> from dms_keep_segment, or something.

That might not be a very good fit, but maybe there should be a
separate function exposed by dsm_impl.c to do the
implementation-dependent part of the work; it would be a no-op except
on Windows.

> - Repeated calling of dsm_keep_segment even from different
> backends creates new (orphan) handles as many as it is called.
> Simplly invoking this function in some of extensions intending
> to stick segments might results in so many orphan
> handles. Something to curb that situation would be needed.

I don't really think this is a problem. Let's just document that
dsm_keep_segment() should not be called more than once per segment.

--
Robert Haas
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