;; Copyright (c) Tim Dysinger tim <[<-on->]> dysinger.net ;; Permission is hereby granted, free of charge, to any person obtaining a copy ;; of this software and associated documentation files (the "Software"), to deal ;; in the Software without restriction, including without limitation the rights ;; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell ;; copies of the Software, and to permit persons to whom the Software is ;; furnished to do so, subject to the following conditions: ;; The above copyright notice and this permission notice shall be included in ;; all copies or substantial portions of the Software. ;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR ;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, ;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE ;; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER ;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, ;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN ;; THE SOFTWARE. (defmodule ping_pong (export (start_link 0) (ping 0)) (export (init 1) (handle_call 3) (handle_cast 2) (handle_info 2) (terminate 2) (code_change 3)) (behaviour gen_server)) ;Just indicates intent (defun start_link () (: gen_server start_link (tuple 'local 'ping_pong) 'ping_pong (list) (list))) ;; Client API (defun ping () (: gen_server call 'ping_pong 'ping)) ;; Gen_server callbacks (defrecord state (pings 0)) (defun init (args) (tuple 'ok (make-state pings 0))) (defun handle_call (req from state) (let* ((new-count (+ (state-pings state) 1)) (new-state (set-state-pings state new-count))) (tuple 'reply (tuple 'pong new-count) new-state))) (defun handle_cast (msg state) (tuple 'noreply state)) (defun handle_info (info state) (tuple 'noreply state)) (defun terminate (reason state) 'ok) (defun code_change (old-vers state extra) (tuple 'ok state))