47 lines
1.7 KiB
Scheme
47 lines
1.7 KiB
Scheme
;;; Guile Knots
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;;; Copyright © 2020 Christopher Baines <mail@cbaines.net>
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;;;
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;;; This file is part of Guile Knots.
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;;;
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;;; The Guile Knots is free software; you can redistribute it and/or
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;;; modify it under the terms of the GNU General Public License as
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;;; published by the Free Software Foundation; either version 3 of the
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;;; License, or (at your option) any later version.
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;;;
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;;; The Guile Knots is distributed in the hope that it will be useful,
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;;; but 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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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with the guix-data-service. If not, see
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;;; <http://www.gnu.org/licenses/>.
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(define-module (knots queue)
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#:use-module (ice-9 q)
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#:use-module (fibers)
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#:use-module (fibers channels)
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#:use-module (fibers operations)
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#:export (spawn-queueing-fiber))
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(define (spawn-queueing-fiber dest-channel)
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(define queue (make-q))
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(let ((queue-channel (make-channel)))
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(spawn-fiber
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(lambda ()
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(while #t
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(if (q-empty? queue)
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(enq! queue
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(perform-operation
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(get-operation queue-channel)))
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(let ((front (q-front queue)))
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(perform-operation
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(choice-operation
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(wrap-operation (get-operation queue-channel)
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(lambda (val)
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(enq! queue val)))
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(wrap-operation (put-operation dest-channel front)
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(lambda _
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(q-pop! queue))))))))))
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queue-channel))
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