Re: [pve-devel] [RFC PATCH] fix #3106: correctly queue incoming connections

[Dietmar Maurer <dietmar@proxmox.com>]

> > +                Ok((sock, _addr)) =>  {
> > +                    sock.set_nodelay(true).unwrap();
> > +                    let _ = set_tcp_keepalive(sock.as_raw_fd(), PROXMOX_BACKUP_TCP_KEEPALIVE_TIME);
> > +                    let acceptor = Arc::clone(&acceptor);
> > +                    let mut sender = sender.clone();
> > +
> > +                    if accept_counter.load(Ordering::SeqCst) > MAX_PENDING_ACCEPTS {
> > +                        eprintln!("connection rejected - to many open connections");
> > +                        continue;
> > +                    }
> > +                    accept_counter.fetch_add(1, Ordering::SeqCst);
> 
> We should think about making a counter guard for this sort of thing,
> because from this point onward we're not allowed to use `?` anywhere,
> which is quite annoying.

I wonder if we can simply use an Arc<bool> for that? The Arc already has
an atomic counter with deref on drop!

And we can query that counter with Arc::strong_count

What do you think?