Listener

A dedicated, self-healing LISTEN on a pool's database. listen(pool, "jobs") takes a connection out of the pool for as long as the listener lives, LISTENs on it, and reads notifications on a fiber of its own into a queue. If the connection fails (the server restarts, the backend is terminated, the network drops) the listener returns it to the pool, takes another, LISTENs again and carries on. Postgres keeps no notifications for a session that is not connected, so those sent while the listener is reconnecting are lost; code that must not miss any should read its table again after reconnects changes.

listener, error := Pg.listen(pool, "jobs", "mail");
while true {
    n, error := Pg.receive(listener);
    if error.kind != .NONE break;
    defer Pg.free_notification(*n);
    print("% on %\n", n.payload, n.channel);
}
Pg.close_listener(listener);

Not run: it needs a PostgreSQL server.