From 5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e Mon Sep 17 00:00:00 2001 From: Trygve Laugstøl Date: Fri, 23 Feb 2024 07:08:18 +0100 Subject: wip --- learn-you-some-erlang/kitty_server.erl | 74 ++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 learn-you-some-erlang/kitty_server.erl (limited to 'learn-you-some-erlang/kitty_server.erl') diff --git a/learn-you-some-erlang/kitty_server.erl b/learn-you-some-erlang/kitty_server.erl new file mode 100644 index 0000000..a40e20a --- /dev/null +++ b/learn-you-some-erlang/kitty_server.erl @@ -0,0 +1,74 @@ +%%%%% Naive version +-module(kitty_server). + +-export([start_link/0, order_cat/4, return_cat/2, close_shop/1]). + +-record(cat, {name, color=green, description}). + +%%% Client API +start_link() -> spawn_link(fun init/0). + +%% Synchronous call +order_cat(Pid, Name, Color, Description) -> + Ref = erlang:monitor(process, Pid), + Pid ! {self(), Ref, {order, Name, Color, Description}}, + receive + {Ref, Cat = #cat{}} -> + erlang:demonitor(Ref, [flush]), + Cat; + {'DOWN', Ref, process, Pid, Reason} -> + erlang:error(Reason) + after 5000 -> + erlang:error(timeout) + end. + +%% This call is asynchronous +return_cat(Pid, Cat = #cat{}) -> + Pid ! {return, Cat}, + ok. + +%% Synchronous call +close_shop(Pid) -> + Ref = erlang:monitor(process, Pid), + Pid ! {self(), Ref, terminate}, + receive + {Ref, ok} -> + erlang:demonitor(Ref, [flush]), + ok; + {'DOWN', Ref, process, Pid, Reason} -> + erlang:error(Reason) + after 5000 -> + erlang:error(timeout) + end. + +%%% Server functions +init() -> loop([]). + +loop(Cats) -> + receive + {Pid, Ref, {order, Name, Color, Description}} -> + if Cats =:= [] -> + Pid ! {Ref, make_cat(Name, Color, Description)}, + loop(Cats); + Cats =/= [] -> % got to empty the stock + Pid ! {Ref, hd(Cats)}, + loop(tl(Cats)) + end; + {return, Cat = #cat{}} -> + loop([Cat|Cats]); + {Pid, Ref, terminate} -> + Pid ! {Ref, ok}, + terminate(Cats); + Unknown -> + %% do some logging here too + io:format("Unknown message: ~p~n", [Unknown]), + loop(Cats) + end. + +%%% Private functions +make_cat(Name, Col, Desc) -> + #cat{name=Name, color=Col, description=Desc}. + +terminate(Cats) -> + [io:format("~p was set free.~n",[C#cat.name]) || C <- Cats], + ok. -- cgit v1.2.3