51 lines
992 B
OCaml
51 lines
992 B
OCaml
(* 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 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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