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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy and Damien Doligez, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License, with *)
(* the special exception on linking described in file ../../LICENSE. *)
(* *)
(***********************************************************************)
(* $Id: condition.mli 9547 2010-01-22 12:48:24Z doligez $ *)
(** Condition variables to synchronize between threads.
Condition variables are used when one thread wants to wait until another
thread has finished doing something: the former thread ``waits'' on the
condition variable, the latter thread ``signals'' the condition when it
is done. Condition variables should always be protected by a mutex.
The typical use is (if [D] is a shared data structure, [m] its mutex,
and [c] is a condition variable):
{[
Mutex.lock m;
while (* some predicate P over D is not satisfied *) do
Condition.wait c m
done;
(* Modify D *)
if (* the predicate P over D is now satified *) then Condition.signal c;
Mutex.unlock m
]}
*)
type t
(** The type of condition variables. *)
val create : unit -> t
(** Return a new condition variable. *)
val wait : t -> Mutex.t -> unit
(** [wait c m] atomically unlocks the mutex [m] and suspends the
calling process on the condition variable [c]. The process will
restart after the condition variable [c] has been signalled.
The mutex [m] is locked again before [wait] returns. *)
val signal : t -> unit
(** [signal c] restarts one of the processes waiting on the
condition variable [c]. *)
val broadcast : t -> unit
(** [broadcast c] restarts all processes waiting on the
condition variable [c]. *)
|
