45 lines
2.0 KiB
OCaml
45 lines
2.0 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy and Pascal Cuoq, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1995 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the GNU Library General Public License. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Module [Mutex]: locks for mutual exclusion *)
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(* Mutexes (mutual-exclusion locks) are used to implement critical sections
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and protect shared mutable data structures against concurrent accesses.
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The typical use is (if [m] is the mutex associated with the data structure
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[D]):
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[
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Mutex.lock m;
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(* Critical section that operates over D *);
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Mutex.unlock m
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]
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*)
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type t
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(* The type of mutexes. *)
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external create: unit -> t = "caml_mutex_new"
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(* Return a new mutex. *)
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external lock: t -> unit = "caml_mutex_lock"
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(* Lock the given mutex. Only one thread can have the mutex locked
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at any time. A thread that attempts to lock a mutex already locked
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by another thread will suspend until the other thread unlocks
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the mutex. *)
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external try_lock: t -> bool = "caml_mutex_try_lock"
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(* Same as [try_lock], but does not suspend the calling thread if
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the mutex is already locked: just return [false] immediately
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in that case. If the mutex is unlocked, lock it and
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return [true]. *)
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external unlock: t -> unit = "caml_mutex_unlock"
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(* Unlock the given mutex. Other threads suspended trying to lock
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the mutex will restart. *)
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