Re: Issue with PGC_BACKEND parameters

On 01/30/2014 03:12 PM, Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>> On 12/22/2013 11:30 PM, Amit Kapila wrote:
>> -                 * backend start.
>> +                 * backend start. However for windows, we need to process
>> +                 * config file during backend start for non-default
>> parameters,
>> +                 * so we need to allow change of PGC_BACKEND during backend
>> +                 * startup.
>>                     */
>> -                if (IsUnderPostmaster)
>> +                if (IsUnderPostmaster && !IsInitProcessingMode())
>>                        return -1;
>>                }
>> I think this change looks OK.
> The comment is pretty awful, since this is neither Windows-specific nor
> a read of the config file.  Perhaps more like "However, in EXEC_BACKEND
> builds we load nondefault settings from the CONFIG_EXEC_PARAMS file during
> backend start.  In that situation we should accept PGC_SIGHUP
> settings, so as to have the same value as if we'd forked from the
> postmaster."
>
> Also, I think that the extra test should only be made #ifdef EXEC_BACKEND,
> so as to minimize the risk of breaking things.  Not that this isn't pretty
> darn fragile anyway; I think testing IsInitProcessingMode here is a very
> random way to detect this case.  I wonder if it'd be better to pass down
> an explicit flag indicating that we're doing read_nondefault_variables().
> If we don't do that, maybe an Assert(IsInitProcessingMode()) in
> read_nondefault_variables() would be a good thing.
>
>             


OK, I've added your comment to the commitfest item and marked it as 
"Waiting on Author".

cheers

andrew