How to use Lwt_pool

I want to have a pool of Redis database connections with a max number of connections. It looks like Lwt_pool is the solution I am looking for, but I don't quite grasp how it should work. For example, some questions I have:

The docs talk about Lwt_pool being great to reuse open connections, but how does the pool know what connections are available for reuse? As far as I see, there is no particular way to signal that and the API only provides the use method.
Is there any resource better than the Lwt docs to learn how it works? I can't easily find code examples or many resources available about it.

Solution

The function you pass to use returns a thread. When the thread finishes, the connection is released back to the pool.

The source code is fairly easy to read. In this case:

let use p f =
  acquire p >>= fun c ->
  Lwt.catch
    (fun () ->
       let t = f c in
       t >>= fun _ ->
       release p c;
       t)
    (fun e ->
       checked_release p c;
       Lwt.fail e)