Domain(3)                        OCaml library                       Domain(3)

NAME
       Domain - no description

Module
       Module   Domain

Documentation
       Module Domain
        : sig end


       Alert unstable.  The Domain interface may change in incompatible ways
       in the future.







       Domains.

       See 'Parallel programming' chapter in the manual.

       type !'a t


       A domain of type 'a t runs independently, eventually producing a result
       of type 'a, or an exception



       val spawn : (unit -> 'a) -> 'a t


       spawn f creates a new domain that runs in parallel with the current
       domain.


       Raises Failure if the program has insufficient resources to create
       another domain.



       val join : 'a t -> 'a


       join d blocks until domain d runs to completion. If d results in a
       value, then that is returned by join d . If d raises an uncaught
       exception, then that is re-raised by join d .


       type id = private int


       Domains have unique integer identifiers



       val get_id : 'a t -> id


       get_id d returns the identifier of the domain d




       val self : unit -> id


       self () is the identifier of the currently running domain



       val before_first_spawn : (unit -> unit) -> unit


       before_first_spawn f registers f to be called before the first domain
       is spawned by the program. The functions registered with
       before_first_spawn are called on the main (initial) domain. The
       functions registered with before_first_spawn are called in 'first in,
       first out' order: the oldest function added with before_first_spawn is
       called first.


       Raises Invalid_argument if the program has already spawned a domain.



       val at_exit : (unit -> unit) -> unit


       at_exit f registers f to be called when the current domain exits. Note
       that at_exit callbacks are domain-local and only apply to the calling
       domain. The registered functions are called in 'last in, first out'
       order: the function most recently added with at_exit is called first.
       An example:


       let temp_file_key = Domain.DLS.new_key (fun _ ->
         let tmp = snd (Filename.open_temp_file "" "") in
         Domain.at_exit (fun () -> close_out_noerr tmp);
         tmp)


       The snippet above creates a key that when retrieved for the first time
       will open a temporary file and register an at_exit callback to close
       it, thus guaranteeing the descriptor is not leaked in case the current
       domain exits.



       val cpu_relax : unit -> unit

       If busy-waiting, calling cpu_relax () between iterations will improve
       performance on some CPU architectures



       val is_main_domain : unit -> bool


       is_main_domain () returns true if called from the initial domain.



       val recommended_domain_count : unit -> int

       The recommended maximum number of domains which should be running
       simultaneously (including domains already running).

       The value returned is at least 1 .


       module DLS : sig end





OCamldoc                          2024-02-29                         Domain(3)