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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: mutex.ml 9547 2010-01-22 12:48:24Z doligez $ *)
type t = { mutable locked: bool; mutable waiting: Thread.t list }
let create () = { locked = false; waiting = [] }
let rec lock m =
if m.locked then begin (* test and set atomic *)
Thread.critical_section := true;
m.waiting <- Thread.self() :: m.waiting;
Thread.sleep();
lock m
end else begin
m.locked <- true (* test and set atomic *)
end
let try_lock m = (* test and set atomic *)
if m.locked then false else begin m.locked <- true; true end
let unlock m =
(* Don't play with Thread.critical_section here because of Condition.wait *)
let w = m.waiting in (* atomic *)
m.waiting <- []; (* atomic *)
m.locked <- false; (* atomic *)
List.iter Thread.wakeup w
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