Re: Detecting libpq connections improperly shared via fork()

On Wed, Oct 3, 2012 at 3:14 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On Thursday, October 04, 2012 12:08:18 AM Daniel Farina wrote:
>> It would be fantastic for libpq to somehow monitor use of a connection
>> from multiple PIDs that share a parent and deliver an error indicating
>> what is wrong. Unfortunately detecting that would require either a
>> file or some kind of shared memory map, AFAIK, and I don't know how
>> keen anyone is on accepting that patch. So, may I ask: how keen is
>> anyone on accepting such a patch, and under what conditions of
>> mechanism?
> Hm. An easier version of this could just be storing the pid of the process
> that did the PQconnectdb* in the PGconn struct. You can then check that
> PGconn->pid == getpid() at relatively few places and error out on a mismatch.
> That should be doable with only minor overhead.

I suppose this might needlessly eliminate someone who forks and hands
off the PGconn struct to exactly one child, but it's hard to argue
with its simplicity and portability of mechanism.

--
fdr