blob: 793a3f10b504e5e414c4eca7dd683594541e4996 [file] [log] [blame]
;; Copyright (c) Rich Hickey and contributors. All rights reserved.
;; The use and distribution terms for this software are covered by the
;; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
;; which can be found in the file epl-v10.html at the root of this distribution.
;; By using this software in any fashion, you are agreeing to be bound by
;; the terms of this license.
;; You must not remove this notice, or any other, from this software.
(ns cljs.core.async.impl.protocols)
(def ^:const MAX-QUEUE-SIZE 1024)
(defprotocol ReadPort
(take! [port fn1-handler] "derefable val if taken, nil if take was enqueued"))
(defprotocol WritePort
(put! [port val fn1-handler] "derefable boolean (false if already closed) if handled, nil if put was enqueued.
Must throw on nil val."))
(defprotocol Channel
(close! [chan])
(closed? [chan]))
(defprotocol Handler
(active? [h] "returns true if has callback. Must work w/o lock")
(blockable? [h] "returns true if this handler may be blocked, otherwise it must not block")
#_(lock-id [h] "a unique id for lock acquisition order, 0 if no lock")
(commit [h] "commit to fulfilling its end of the transfer, returns cb. Must be called within lock"))
(defprotocol Buffer
(full? [b] "returns true if buffer cannot accept put")
(remove! [b] "remove and return next item from buffer, called under chan mutex")
(add!* [b itm] "if room, add item to the buffer, returns b, called under chan mutex")
(close-buf! [b] "called on chan closed under chan mutex, return ignored"))
(defn add!
([b] b)
([b itm]
(assert (not (nil? itm)))
(add!* b itm)))
;; Defines a buffer that will never block (return true to full?)
(defprotocol UnblockingBuffer)