70 lines
1.8 KiB
OCaml
70 lines
1.8 KiB
OCaml
(* Copyright 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>. *)
|
|
|
|
(* This file is part of Ocamlmsg. *)
|
|
|
|
(* Ocamlmsg is free software: you can redistribute it and/or modify it *)
|
|
(* under the terms of the GNU General Public License as published by the *)
|
|
(* Free Software Foundation, either version 3 of the License, or (at your *)
|
|
(* option) any later version. *)
|
|
|
|
(* Ocamlmsg is distributed in the hope that it will be useful, but *)
|
|
(* WITHOUT ANY WARRANTY; without even the implied warranty of *)
|
|
(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *)
|
|
(* General Public License for more details. *)
|
|
|
|
(* You should have received a copy of the GNU General Public License *)
|
|
(* along with Ocamlmsg. If not, see <http://www.gnu.org/licenses/>. *)
|
|
|
|
(* Shared queue *)
|
|
|
|
type 'a t = {
|
|
mtx: Mutex.t;
|
|
mutable capacity: int;
|
|
nonfull: Condition.t;
|
|
nonempty: Condition.t;
|
|
queue: 'a Queue.t
|
|
}
|
|
|
|
let create n = {
|
|
mtx = Mutex.create ();
|
|
capacity = n;
|
|
nonfull = Condition.create ();
|
|
nonempty = Condition.create ();
|
|
queue = Queue.create ()
|
|
}
|
|
|
|
let approx_capacity q = q.capacity
|
|
|
|
let add v q =
|
|
Mutex.lock q.mtx;
|
|
while q.capacity < 1 do
|
|
Condition.wait q.nonfull q.mtx
|
|
done;
|
|
q.capacity <- q.capacity - 1;
|
|
Queue.add v q.queue;
|
|
Condition.signal q.nonempty;
|
|
Mutex.unlock q.mtx
|
|
|
|
let pop q =
|
|
Mutex.lock q.mtx;
|
|
while Queue.is_empty q.queue do
|
|
Condition.wait q.nonempty q.mtx
|
|
done;
|
|
let result = Queue.pop q.queue in
|
|
q.capacity <- q.capacity + 1;
|
|
Condition.signal q.nonfull;
|
|
Mutex.unlock q.mtx;
|
|
result
|
|
|
|
let peek q =
|
|
Mutex.lock q.mtx;
|
|
let result =
|
|
if Queue.is_empty q.queue
|
|
then None
|
|
else (q.capacity <- q.capacity + 1;
|
|
Condition.signal q.nonfull;
|
|
Some (Queue.pop q.queue))
|
|
in
|
|
Mutex.unlock q.mtx;
|
|
result
|