;; SPDX-License-Identifier: EUPL-1.2
;; SPDX-FileCopyrightText: 2025 Uko Kokņevičs <perkontevs@gmail.com>
(defpackage :ukkoclot/test/rw-lock
  (:documentation "Test-suite for :ukkoclot/src/rw-lock.")
  (:use :c2cl :fiveam :iterate :ukkoclot/src/rw-lock)
  (:import-from :bt2 :join-thread :make-thread :with-timeout))
(in-package :ukkoclot/test/rw-lock)

(def-suite :ukkoclot/rw-lock)
(in-suite :ukkoclot/rw-lock)

(test rw-lock.typep
  (is (typep (make-rw-lock) 'rw-lock)))

(test rw-lock-p
  (is (rw-lock-p (make-rw-lock))))

(test acquire-read-lock.no-contention
  (with-timeout (5)
    (let ((lock (make-rw-lock)))
      (is-true (acquire-read-lock lock :wait t))
      (is (rw-lock-p (release-read-lock lock)))
      (is-true (acquire-read-lock lock :wait nil))
      (is (rw-lock-p (release-read-lock lock))))))

(test acquire-read-lock.multiple
  (with-timeout (5)
    (let ((lock (make-rw-lock)))
      (is-true (acquire-read-lock lock :wait t))
      (is-true (acquire-read-lock lock :wait nil))
      (is-true (acquire-read-lock lock :wait t))
      (is (rw-lock-p (release-read-lock lock)))
      (is (rw-lock-p (release-read-lock lock)))
      (is (rw-lock-p (release-read-lock lock))))))

(test release-read-lock.failing
  (let ((lock (make-rw-lock)))
    (signals error (release-read-lock lock))
    (is-true (acquire-write-lock lock :wait nil))
    (signals error (release-read-lock lock))))

(test acquire-write-lock.no-contention
  (let ((lock (make-rw-lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))))

(test acquire-write-lock.contention
  (let ((lock (make-rw-lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is-false (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))))

(test acquire-write-lock.failing
  (let ((lock (make-rw-lock)))
    (signals error (release-write-lock lock))
    (is-true (acquire-read-lock lock :wait nil))
    (signals error (release-write-lock lock))))

(test acquire-read&write-lock.contention
  (let ((lock (make-rw-lock)))
    (is-true (acquire-read-lock lock :wait nil))
    (is-true (acquire-read-lock lock :wait nil))
    (is-false (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-read-lock lock)))
    (is (rw-lock-p (release-read-lock lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is-false (acquire-read-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))))

(test read&write-locks.contention
  (let ((lock (make-rw-lock))
        (value 0)
        reader-threads
        writer-threads)
    (flet ((reader-fn () (with-read-lock (lock)
                           (sleep (random 0.1))
                           value))
           (writer-fn () (with-write-lock (lock)
                           (incf value)
                           (sleep (random 0.1))
                           (incf value))))
      (iter (repeat 100)
            (push (make-thread #'reader-fn) reader-threads)
            (sleep (random 0.02))
            (push (make-thread #'writer-fn) writer-threads)))
    (iter (for writer-thread in writer-threads)
          (join-thread writer-thread))
    (is (every #'evenp
         (iter (for reader-thread in reader-threads)
               (collect (join-thread reader-thread)))))))

(test with-read-lock.simple
  (let ((lock (make-rw-lock)))
    (with-read-lock (lock)
      (is-true (acquire-read-lock lock :wait nil))
      (is (rw-lock-p (release-read-lock lock)))
      (is-false (acquire-write-lock lock :wait nil)))
    (is-true (acquire-read-lock lock :wait nil))
    (is (rw-lock-p (release-read-lock lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))))

(test with-write-lock.simple
  (let ((lock (make-rw-lock)))
    (with-write-lock (lock)
      (is-false (acquire-read-lock lock :wait nil))
      (is-false (acquire-write-lock lock :wait nil)))
    (is-true (acquire-read-lock lock :wait nil))
    (is (rw-lock-p (release-read-lock lock)))
    (is-true (acquire-write-lock lock :wait nil))
    (is (rw-lock-p (release-write-lock lock)))))