From: mehdi <mido.peace@gmail.com>
Date: Wed, 27 Apr 2011 16:02:51 +0000 (+0200)
Subject: chord implementation in splay/lua
X-Git-Tag: v3_6_rc3~82
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/6eac7a5107a6946d8d3141da743c5e5971a89347?ds=sidebyside

chord implementation in splay/lua
---

diff --git a/examples/lua/SimSplay/chord.lua b/examples/lua/SimSplay/chord.lua
new file mode 100644
index 0000000000..7e2295428c
--- /dev/null
+++ b/examples/lua/SimSplay/chord.lua
@@ -0,0 +1,73 @@
+dofile "sim_splay.lua"
+between, call, thread, ping = misc.between_c, rpc.call, events.thread, rpc.ping
+n, predecessor, finger, timeout, m = {}, nil, {}, 5, 24
+function join(n0) -- n0: some node in the ring
+	simgrid.info("Euh...")
+	predecessor = nil
+	finger[1] = call(n0, {'find_successor', n.id})
+	simgrid.info("8Here..")
+	call(finger[1], {'notify', n})
+end
+
+function closest_preceding_node(id)
+	for i = m, 1, -1 do
+		if finger[i] and between(finger[i].id, n.id, id) then 
+			return finger[i]
+		end
+	end
+	return n
+end
+
+function find_successor(id)
+	if finger[1].id == n.id or between(id, n.id, (finger[1].id + 1) % 2^m) then
+		return finger[1]
+	else
+		local n0 = closest_preceding_node(id)
+		return call(n0, {'find_successor', id})
+	end
+end
+function stabilize()
+	local x = call(finger[1], 'predecessor')
+	if x and between(x.id, n.id, finger[1].id) then
+		finger[1] = x -- new successor
+		call(finger[1], {'notify', n})
+	end
+end
+function notify(n0)
+	if n0.id ~= n.id and
+			(not predecessor or between(n0.id, predecessor.id, n.id)) then
+		predecessor = n0
+	end
+end
+function fix_fingers()
+	refresh = (refresh and (refresh % m) + 1) or 1 -- 1 <= next <= m
+	finger[refresh] = find_successor((n.id + 2^(refresh - 1)) % 2^m)
+end
+function check_predecessor()
+	if predecessor and not rpc.ping(predecessor) then
+		predecessor = nil
+	end
+end
+
+n.id = math.random(1, 2^m)
+finger[1] = n
+if job then
+	n.ip, n.port = job.me.ip, job.me.port
+	join({ip = "192.42.43.42", port = 20000})
+else
+	simgrid.info("bizzaaaaaar...")
+	n.ip, n.port = "127.0.0.1", 20000
+	if arg[1] then n.ip = arg[1] end
+	if arg[2] then n.port = tonumber(arg[2]) end
+	if not arg[3] then
+		print("RDV")
+	else
+		print("JOIN")
+		thread(function() join({ip = arg[3], port = tonumber(arg[4])}) end)
+	end
+end
+rpc.server(n.port)
+events.periodic(stabilize, timeout)
+events.periodic(check_predecessor, timeout)
+events.periodic(fix_fingers, timeout)
+events.loop()