70 lines
1.7 KiB
OCaml
70 lines
1.7 KiB
OCaml
(* Copyright 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>. *)
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(* This file is part of Hop. *)
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(* Hop is free software: you can redistribute it and/or modify it *)
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(* under the terms of the GNU General Public License as published by the *)
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(* Free Software Foundation, either version 3 of the License, or (at your *)
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(* option) any later version. *)
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(* Hop 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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(* General Public License for more details. *)
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(* You should have received a copy of the GNU General Public License *)
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(* along with Hop. If not, see <http://www.gnu.org/licenses/>. *)
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(* Shared queue *)
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type 'a t = {
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mtx: Mutex.t;
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mutable capacity: int;
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nonfull: Condition.t;
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nonempty: Condition.t;
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queue: 'a Queue.t
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}
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let create n = {
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mtx = Mutex.create ();
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capacity = n;
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nonfull = Condition.create ();
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nonempty = Condition.create ();
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queue = Queue.create ()
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}
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let approx_capacity q = q.capacity
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let add v q =
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Mutex.lock q.mtx;
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while q.capacity < 1 do
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Condition.wait q.nonfull q.mtx
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done;
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q.capacity <- q.capacity - 1;
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Queue.add v q.queue;
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Condition.signal q.nonempty;
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Mutex.unlock q.mtx
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let pop q =
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Mutex.lock q.mtx;
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while Queue.is_empty q.queue do
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Condition.wait q.nonempty q.mtx
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done;
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let result = Queue.pop q.queue in
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q.capacity <- q.capacity + 1;
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Condition.signal q.nonfull;
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Mutex.unlock q.mtx;
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result
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let peek q =
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Mutex.lock q.mtx;
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let result =
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if Queue.is_empty q.queue
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then None
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else (q.capacity <- q.capacity + 1;
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Condition.signal q.nonfull;
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Some (Queue.pop q.queue))
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in
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Mutex.unlock q.mtx;
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result
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