X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/10f0429366b11cb6697ce0c0cb200943b0181bd0..d96c801afcc9beac00274914682f4ce28f54ed7f:/examples/lua/chord/chord.lua

diff --git a/examples/lua/chord/chord.lua b/examples/lua/chord/chord.lua
index d8f308977e..523b15017c 100644
--- a/examples/lua/chord/chord.lua
+++ b/examples/lua/chord/chord.lua
@@ -13,7 +13,7 @@ fix_fingers_delay = 120
 check_predecessor_delay = 120
 lookup_delay = 10
 
--- current node (don't worry, globals are duplicated in each process)
+-- current node (don't worry, globals are duplicated in each simulated process)
 my_node = {
   id = my_id,
   next_finger_to_fix = 1,
@@ -28,7 +28,7 @@ my_node = {
 -- - the id of a guy I know in the system (except for the first node)
 function node(...)
 
-  -- TODO simplify the parameters
+  -- TODO simplify the deployment file
   local known_id
   local args = {...}
   my_node.id = tonumber(args[1])
@@ -36,7 +36,11 @@ function node(...)
     known_id = tonumber(args[2])
   end
 
-  simgrid.debug("Hello, I'm a node")
+  -- initialize the node
+  for i = 1, nb_bits do
+    my_node.fingers[i] = my_node.id
+  end
+  my_node.comm_recv = simgrid.task.irecv(my_node.id)
 
   -- join the ring
   local join_success = false
@@ -57,18 +61,17 @@ function node(...)
     local next_check_predecessor_date = now + check_predecessor_delay
     local next_lookup_date = now + lookup_delay
 
-    local task, success
-    my_node.comm_recv = simgrid.task.irecv(my_node.id)
+    local task, err
 
     while now < max_simulation_time do
 
-      task, success = simgrid.comm.test(my_node.comm_recv)
+      task, err = my_node.comm_recv:test()
 
       if task then
 	-- I received a task: answer it
         my_node.comm_recv = simgrid.task.irecv(my_node.id)
 	handle_task(task)
-      elseif failed then
+      elseif err then
         -- the communication has failed: nevermind
         my_node.comm_recv = simgrid.task.irecv(my_node.id)
       else
@@ -84,6 +87,7 @@ function node(...)
 	elseif now >= next_check_predecessor_date then
 	  check_predecessor()
 	  next_check_predecessor_date = simgrid.get_clock() + check_predecessor_delay
+
 	elseif now >= next_lookup_date then
 	  random_lookup()
 	  next_lookup_date = simgrid.get_clock() + lookup_delay
@@ -101,6 +105,13 @@ function node(...)
   end
 end
 
+-- Makes the current node leave the ring
+function leave()
+
+  simgrid.info("Leaving the ring")
+  -- TODO: notify others
+end
+
 -- This function is called when the current node receives a task.
 -- - task: the task received
 function handle_task(task)
@@ -109,17 +120,28 @@ function handle_task(task)
 
   if type == "find successor" then
 
+    simgrid.info("Received a 'find successor' request from " .. task.answer_to ..
+        " for id " .. task.request_id)
+
     -- is my successor the successor?
     if is_in_interval(task.request_id, my_node.id + 1, my_node.fingers[1]) then
+
+      simgrid.info("Sending back a 'find successor answer' to " ..
+          task.answer_to .. ": the successor of " .. task.request_id ..
+	  " is " .. my_node.fingers[1])
+
       task.type = "find successor answer"
       task.answer = my_node.fingers[1]
       task:dsend(task.answer_to)
     else
       -- forward the request to the closest preceding finger in my table
+
+      simgrid.info("Forwarding the 'find successor' request to my closest preceding finger")
       task:dsend(closest_preceding_node(task.request_id))
     end
 
   elseif type == "get predecessor" then
+    task.type = "get predecessor answer"
     task.answer = my_node.predecessor
     task:dsend(task.answer_to)
 
@@ -171,9 +193,16 @@ function is_in_interval(id, a, b)
   return id <= b
 end
 
+-- Returns whether the current node is in the ring.
+function has_joined()
+
+  return my_node.fingers[1] ~= nil
+end
+
 -- Creates a new Chord ring.
 function create()
   my_node.predecessor = nil
+  my_node.fingers[1] = my_node.id
 end
 
 -- Attemps to join the Chord ring.
@@ -181,12 +210,16 @@ end
 -- - return value: true if the join was successful
 function join(known_id)
 
+  simgrid.info("Joining the ring with id " .. my_node.id .. ", knowing node " .. known_id)
+
   local successor = remote_find_successor(known_id, my_node.id)
   if successor == nil then
+    simgrid.info("Cannot join the ring.")
     return false
   end
 
-  my_node.finger[1] = successor
+  my_node.predecessor = nil
+  my_node.fingers[1] = successor
   return true
 end
 
@@ -197,16 +230,16 @@ end
 function closest_preceding_node(id)
 
   for i = nb_bits, 1, -1 do
-    if is_in_interval(my_node.fingers[i].id, my_node.id + 1, id - 1) then
+    if is_in_interval(my_node.fingers[i], my_node.id + 1, id - 1) then
       -- finger i is the first one before id
-      return my_node.fingers[i].id
+      return my_node.fingers[i]
     end
   end
 end
 
 -- Finds the successor of an id
 -- id: the id to find
--- return value: the id of the successor, or -1 if the request failed
+-- return value: the id of the successor, or nil if the request failed
 function find_successor(id)
 
   if is_in_interval(id, my_node.id + 1, my_node.fingers[1]) then
@@ -230,26 +263,38 @@ function remote_find_successor(ask_to, id)
   task.request_id = id
   task.answer_to = my_node.id
 
+  simgrid.info("Sending a 'find successor' request to " .. ask_to .. " for id " .. id)
   if task:send(ask_to, timeout) then
     -- request successfully sent: wait for an answer
+
+    simgrid.info("Sent the 'find successor' request to " .. ask_to ..
+        " for id " .. id .. ", waiting for the answer")
+
     while true do
-      task = simgrid.comm.wait(my_node.comm_recv, timeout)
+      task = my_node.comm_recv:wait(timeout)
       my_node.comm_recv = simgrid.task.irecv(my_node.id)
     
       if not task then
 	-- failed to receive the answer
+	simgrid.info("Failed to receive the answer to my 'find successor' request")
 	return nil
       else
 	-- a task was received: is it the expected answer?
-	if task.type ~= "find successor answer" or task[request_id] ~= id then
+	if task.type ~= "find successor answer" or task.request_id ~= id then
           -- this is not our answer
+	  simgrid.info("Received another request of type " .. task.type)
 	  handle_task(task)
 	else
 	  -- this is our answer
+	  simgrid.info("Received the answer to my 'find successor' request for id " ..
+	      id .. ": the successor is " .. task.answer)
 	  return task.answer
 	end
       end
     end
+  else
+    simgrid.info("Failed to send the 'find successor' request to " .. ask_to ..
+        " for id " .. id)
   end
 
   return successor
@@ -267,7 +312,7 @@ function remote_get_predecessor(ask_to)
   if task:send(ask_to, timeout) then
     -- request successfully sent: wait for an answer
     while true do
-      task = simgrid.comm.wait(my_node.comm_recv, timeout)
+      task = my_node.comm_recv:wait(timeout)
       my_node.comm_recv = simgrid.task.irecv(my_node.id)
     
       if not task then
@@ -302,7 +347,7 @@ function stabilize()
   end
 
   -- this node is a candidate to become my new successor
-  if candidate ~= nil and is_in_interval(candidate, my_node.id + 1, successor -1) then
+  if candidate ~= nil and is_in_interval(candidate, my_node.id + 1, successor - 1) then
     my_node.fingers[1] = candidate
   end
 
@@ -339,7 +384,7 @@ function fix_fingers()
   local id = find_successor(my_node.id + 2^i)
   if id ~= nil then
     if id ~= my_node.fingers[i] then
-      fingers[i] = id
+      my_node.fingers[i] = id
     end
     my_node.next_finger_to_fix = (i % nb_bits) + 1
   end