63 lines
2.3 KiB
OCaml
63 lines
2.3 KiB
OCaml
(* Lightweight thread library for Objective Caml
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* http://www.ocsigen.org/lwt
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* Interface Lwt_mutex
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* Copyright (C) 2005-2008 Jérôme Vouillon
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* Laboratoire PPS - CNRS Université Paris Diderot
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation, with linking exceptions;
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* either version 2.1 of the License, or (at your option) any later
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* version. See COPYING file for details.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*)
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(** Cooperative locks for mutual exclusion *)
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type t
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(** Type of Lwt mutexes *)
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val create : unit -> t
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(** [create ()] creates a new mutex, which is initially unlocked *)
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val lock : t -> unit Lwt.t
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(** [lock mutex] lockcs the mutex, that is:
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- if the mutex is unlocked, then it is marked as locked and
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{!lock} returns immediatly
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- if it is locked, then {!lock} waits for all threads waiting on
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the mutex to terminate, then it resumes when the last one
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unlocks the mutex
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Note: threads are wake up is the same order they try to lock the
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mutex *)
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val unlock : t -> unit
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(** [unlock mutex] unlock the mutex if no threads is waiting on
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it. Otherwise it will eventually removes the first one and
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resumes it. *)
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val is_locked : t -> bool
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(** [locked mutex] returns whether [mutex] is currently locked *)
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val is_empty : t -> bool
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(** [is_empty mutex] returns [true] if they are no thread waiting on
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the mutex, and [false] otherwise *)
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val with_lock : t -> (unit -> 'a Lwt.t) -> 'a Lwt.t
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(** [with_lock lock f] is used to lock a mutex within a block scope.
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The function [f ()] is called with the mutex locked, and its
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result is returned from the call to {with_lock}. If an exception
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is raised from f, the mutex is also unlocked before the scope of
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{with_lock} is exited. *)
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