Module Picos_select.Intr

A mechanism to interrupt blocking Unix IO operations.

⚠️ The mechanism uses a signal which should not be used for other purposes.

⚠️ Beware that signal handling in OCaml 5.0.0 is known to be broken and several fixes were included in OCaml 5.1.0.

type t

Represents an optional interrupt request.

val nothing : t

A constant for a no request. clr nothing does nothing.

val req : seconds:float -> t

req ~seconds requests an interrupt in the form of a signal delivered to the thread that made the request within the specified number of seconds. Blocking Unix IO calls typically raise an error with the Unix.EINTR error code when they are interrupted by a signal. Regardless of whether the signal gets triggered or a system call gets interrupted, the request must be cleared exactly once!

⚠️ Due to limitations of the OCaml system modules and unlike with typical timeout mechanisms, the interrupt may also be triggered sooner.

val clr : t -> unit

clr req either cancels or acknowledges the interrupt request. Every req must be cleared exactly once!