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