don't allow walsender to consume superuser_reserved_connection slots, or during shutdown

On Wed, Apr 21, 2010 at 1:56 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> ...shouldn't we move the "tests", plural, rather than just the one?
>> It seems right to reject new SR connections during shutdown.
>
> Yeah; you'd also need to adjust both of them to consider am_walsender.
> (IOW, we want to treat SR connections as non-superuser for both tests.)

[ subject changed, recipient list trimmed ]

Here's the fine patch.  The actual code changes are simple and seem to
work as expected, but I struggled a bit with the phrasing of the
messages.  Feel free to suggest improvements.  Also, I wasn't sure if
there was somewhere in the documentation where we discussed the
restriction that only superusers can connect during shutdown.  If
there is such a place, we should update that, too.

...Robert