From 3b4edbdddf8af55f63c22bb3ba80fffa46156dd2 Mon Sep 17 00:00:00 2001 From: Alexander Sulfrian Date: Wed, 13 Oct 2010 11:53:17 +0200 Subject: added some modules for server --- server/server.erl | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 server/server.erl (limited to 'server/server.erl') diff --git a/server/server.erl b/server/server.erl new file mode 100644 index 0000000..42b1822 --- /dev/null +++ b/server/server.erl @@ -0,0 +1,45 @@ +%% --- +%% Excerpted from "Programming Erlang", +%% published by The Pragmatic Bookshelf. +%% Copyrights apply to this code. It may not be used to create training material, +%% courses, books, articles, and the like. Contact us if you are in doubt. +%% We make no guarantees that this code is fit for any purpose. +%% Visit http://www.pragmaticprogrammer.com/titles/jaerlang for more book information. +%%--- +-module(server). +-export([start/2, rpc/2, swap_code/2]). + +start(Name, Mod) -> + register(Name, spawn(fun() -> loop(Name,Mod,Mod:init()) end)). + +swap_code(Name, Mod) -> rpc(Name, {swap_code, Mod}). + +rpc(Name, Request) -> + Name ! {self(), Request}, + receive + {Name, crash} -> exit(rpc); + {Name, ok, Response} -> Response + end. + +loop(Name, Mod, OldState) -> + receive + {From, {swap_code, NewCallbackMod}} -> + From ! {Name, ok, ack}, + loop(Name, NewCallbackMod, OldState); + {From, Request} -> + try Mod:handle(From, Request, OldState) of + {Response, NewState} -> + From ! {Name, ok, Response}, + loop(Name, Mod, NewState) + catch + _: Why -> + log_the_error(Name, Request, Why), + From ! {Name, crash}, + loop(Name, Mod, OldState) + end + end. + +log_the_error(Name, Request, Why) -> + io:format("Server ~p request ~p ~n" + "caused exception ~p~n", + [Name, Request, Why]). -- cgit v1.2.3