From b5c22a8a96203ad6b656524fe5ecf246a89efb58 Mon Sep 17 00:00:00 2001
From: Nathan Lasseter <nathan.je.lasseter@googlemail.com>
Date: Fri, 23 Dec 2011 10:11:48 +0000
Subject: Started work on erlbal_n. Changed names to reflect.

---
 erlbal_p.erl | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 erlbal_p.erl

(limited to 'erlbal_p.erl')

diff --git a/erlbal_p.erl b/erlbal_p.erl
new file mode 100644
index 0000000..ed43e0e
--- /dev/null
+++ b/erlbal_p.erl
@@ -0,0 +1,59 @@
+-module(erlbal_p).
+-export([make_request/2, start_bal/0, stop_bal/1, start_server/4, stop_server/2, list_servers/1]).
+
+start_server(Balancer, Node, Fun, INITSTATE) when is_function(Fun, 2) andalso is_list(INITSTATE) ->
+	PID = spawn(Node, fun() -> server_loop(Fun, INITSTATE) end),
+	Balancer ! {add_node, PID}.
+
+stop_server(Balancer, PID) ->
+	Balancer ! {del_node, PID},
+	PID ! die.
+
+list_servers(Balancer) ->
+	Balancer ! {list_nodes, self()},
+	receive Nodes -> Nodes end.
+
+server_loop(Fun, STATE) ->
+	receive
+		{request, From, ARGS} ->
+			{Ret, NEWSTATE} = Fun(ARGS, STATE),
+			From ! Ret,
+			server_loop(Fun, NEWSTATE);
+		die ->
+			ok
+	end.
+
+start_bal() ->
+	spawn(fun() -> bal_loop([], 1) end).
+
+stop_bal(Balancer) ->
+	Balancer ! die.
+
+bal_loop(Serverlist, Nextserver) ->
+	receive
+		{add_node, PID} ->
+			bal_loop(Serverlist ++ [PID], Nextserver);
+		{del_node, PID} ->
+			bal_loop(Serverlist -- [PID], Nextserver);
+		{list_nodes, From} ->
+			From ! Serverlist,
+			bal_loop(Serverlist, Nextserver);
+		{request, From, ARGS} ->
+			Serv = lists:nth(Nextserver, Serverlist),
+			Serv ! {request, From, ARGS},
+			NS = Nextserver + 1,
+			SLL = length(Serverlist),
+			if
+				NS > SLL ->
+					bal_loop(Serverlist, 1);
+				true ->
+					bal_loop(Serverlist, NS)
+			end;
+		die ->
+			ok
+	end.
+
+
+make_request(Balancer, ARGS) when is_list(ARGS)->
+	Balancer ! {request, self(), ARGS},
+	receive Ret -> Ret end.
-- 
cgit v1.2.1