Re: libpq/async notifications - Mailing list pgsql-interfaces

From Tom Lane
Subject Re: libpq/async notifications
Date
Msg-id 9884.1066147821@sss.pgh.pa.us
Whole thread Raw
In response to libpq/async notifications  (Igor Shevchenko <igor@carcass.ath.cx>)
Responses Re: libpq/async notifications  (Igor Shevchenko <igor@carcass.ath.cx>)
List pgsql-interfaces
Igor Shevchenko <igor@carcass.ath.cx> writes:
> Is there a way to only check if there's any pending async notifications ?
> I've found only PQnotifies(..) but it also removes the first notification from 
> the list.
> A function for only checking this can be used in a gui app to setup async 
> notifications processing so it happens only after an app reaches it's main 
> loop (which is a good idea since it won't happen in the middle of another 
> app's handler function which happens to use pgsql database interface).
> Currently I have to check for notifications with PQnotifies every time my app 
> returns to the main loop after using any of PGexec, etc, which is not very 
> efficient.

"Not very efficient"?  This seems like a very weak argument.  The actual
cost of running the function is no different from PQnotifies in the case
where no notify event is found; and in the case where one is found, it'd
be slower because you'd then have to call PQnotifies anyway to remove
the item from the list.

Yes, I know the function is only five lines, but there are also
documentation and other maintenance costs to consider anytime we add
something to libpq's API.  I don't think you've made enough of a case
for it.
        regards, tom lane


pgsql-interfaces by date:

Previous
From: Jan Wieck
Date:
Subject: Re: more on undefined reference to 'pg_detoast_datum'
Next
From: "Brett Maton"
Date:
Subject: Intercept database Connection request