Mark Morgan Lloyd <markMLl.pgsql-general@telemetry.co.uk> writes:
> Do any special precautions need to be taken when PQNotifies is being
> called, to make sure that nothing else is referencing the handle?
It's pretty much the same as any other operation on a PGconn: if there
could be more than one thread touching the connection object
concurrently, you'd be well advised to add some application-level
locking.
http://www.postgresql.org/docs/9.2/static/libpq-threading.html
The lack of any such locking inside libpq is partly historical, and
partly because in many practical situations you'll need application-side
locks anyway to protect application data structures associated with the
connection.
regards, tom lane