Module type
Class type

A pool implementation for the current concurrency library.

type ('a, +'e) t
val create : ?max_size:int -> ?max_idle_size:int -> ?check:('a -> (bool -> unit) -> unit) -> ?validate:('a -> bool Lwt.t) -> ?log_src:Logs.Src.t -> (unit -> ('a, 'e) result Lwt.t) -> ('a -> unit Lwt.t) -> ('a, 'e) t

Internal: create alloc free is a pool of resources allocated by alloc and freed by free. This is primarily intended for implementing the connect_pool functions.

  • parameter max_size

    The maximum number of allocated resources.

  • parameter max_idle_size

    The maximum number of resources to pool for later use. Defaults to max_size.

  • parameter check

    A function used to check a resource after use.

  • parameter validate

    A function to check before use that a resource is still valid.

val size : ('a, 'e) t -> int

size pool is the current number of open resources in pool.

val use : ?priority:float -> ('a -> ('b, 'e) result Lwt.t) -> ('a, 'e) t -> ('b, 'e) result Lwt.t

use f pool calls f on a resource drawn from pool, handing back the resource to the pool when f exits.

  • parameter priority

    Requests for the resource are handled in decreasing order of priority. The default priority is 0.0.

val drain : ('a, 'e) t -> unit Lwt.t

drain pool closes all resources in pool. The pool is still usable, as new resources will be created on demand.