On Wed, Aug 11, 2010 at 10:15 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>> On 08/11/2010 09:43 AM, Tom Lane wrote:
>>> Andrew Dunstan<andrew@dunslane.net> writes:
>>>> Why not just add the configured port (DEF_PGPORT) into the calculation
>>>> of the port to run on?
>
>>> No, that would be just about the worst possible choice. It'd be
>>> guaranteed to fail in the standard scenario that you are running
>>> "make check" before updating an existing installation.
>
>> One of us is missing something. I didn't say to run the checks using the
>> configured port. I had in mind something like:
>
>> port = 0xC000 | ((PG_VERSION_NUM + DEF_PGPORT) & 0x3FFF);
>
> Oh, I see, modify the DEF_PGPORT don't just use it as-is. OK, except
> that I think something like the above is still pretty risky for the
> buildfarm, because you would still have conflicts for assorted
> combinations of version numbers and branch_port settings.
>
> How about just this:
>
> port = 0xC000 | (DEF_PGPORT & 0x3FFF);
>
> If anyone was actually using a DEF_PGPORT above 0xC000, this would mean
> that they couldn't run "make check" on the same machine as their running
> installation (at least not without adjusting pg_regress's port choice,
> which I still think we need to tweak the makefiles to make easier).
> But for ordinary buildfarm usage, this would be guaranteed not to
> conflict as long as you'd chosen nonconflicting branch_ports for all
> your branches and animals.
>
> Or we could do something like
>
> port = 0xC000 ^ (DEF_PGPORT & 0x7FFF);
>
> which is absolutely guaranteed not to conflict with DEF_PGPORT, at the
> cost of possibly shifting into the 32K-48K port number range if you
> had set DEF_PGPORT above 48K.
I like XOR a lot better than OR.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company