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| 1 | (**************************************************************************) |
| 2 | (* *) |
| 3 | (* OCaml *) |
| 4 | (* *) |
| 5 | (* Xavier Leroy and Damien Doligez, INRIA Rocquencourt *) |
| 6 | (* *) |
| 7 | (* Copyright 1996 Institut National de Recherche en Informatique et *) |
| 8 | (* en Automatique. *) |
| 9 | (* *) |
| 10 | (* All rights reserved. This file is distributed under the terms of *) |
| 11 | (* the GNU Lesser General Public License version 2.1, with the *) |
| 12 | (* special exception on linking described in the file LICENSE. *) |
| 13 | (* *) |
| 14 | (**************************************************************************) |
| 15 | |
| 16 | (** Locks for mutual exclusion. |
| 17 | |
| 18 | Mutexes (mutual-exclusion locks) are used to implement critical sections |
| 19 | and protect shared mutable data structures against concurrent accesses. |
| 20 | The typical use is (if [m] is the mutex associated with the data structure |
| 21 | [D]): |
| 22 | {[ |
| 23 | Mutex.lock m; |
| 24 | (* Critical section that operates over D *); |
| 25 | Mutex.unlock m |
| 26 | ]} |
| 27 | *) |
| 28 | |
| 29 | type t |
| 30 | (** The type of mutexes. *) |
| 31 | |
| 32 | val create : unit -> t |
| 33 | (** Return a new mutex. *) |
| 34 | |
| 35 | val lock : t -> unit |
| 36 | (** Lock the given mutex. Only one thread can have the mutex locked |
| 37 | at any time. A thread that attempts to lock a mutex already locked |
| 38 | by another thread will suspend until the other thread unlocks |
| 39 | the mutex. *) |
| 40 | |
| 41 | val try_lock : t -> bool |
| 42 | (** Same as {!Mutex.lock}, but does not suspend the calling thread if |
| 43 | the mutex is already locked: just return [false] immediately |
| 44 | in that case. If the mutex is unlocked, lock it and |
| 45 | return [true]. *) |
| 46 | |
| 47 | val unlock : t -> unit |
| 48 | (** Unlock the given mutex. Other threads suspended trying to lock |
| 49 | the mutex will restart. *) |
| 50 |