Wait for the DRb server to be ready instead of waiting an arbitrary s…

…econd.

bin/play.rb

@@ -1,6 +1,7 @@
 $:.unshift File.expand_path("../../lib", __FILE__)
 require "battleship/game"
 require "battleship/console_renderer"
+require "battleship/util"
 require "stringio"
 require "digest/sha1"
 require "forwardable"
@@ -39,8 +40,8 @@ def kill
     port = PORT + i
     secret = Digest::SHA1.hexdigest("#{Time.now}#{rand}#{i}")
     system %{ruby #{player_server} "#{path}" #{port} #{secret} &}
+    Battleship::Util.wait_for_socket("localhost", port)
     players << PlayerClient.new(secret, DRbObject.new(nil, "druby://localhost:#{port}"))
-    sleep 1
   end
 
   winners = []

lib/battleship/util.rb

@@ -1,3 +1,5 @@
+require "socket"
+
 module Battleship
   module Util
     PLAYER_METHODS = [:name, :new_game, :take_turn]
@@ -10,5 +12,23 @@ def find_player_classes
           (klass.instance_methods & PLAYER_METHODS) == PLAYER_METHODS
         }
     end
+
+    def wait_for_socket(host, port, timeout=1)
+      socket  = Socket.new(:INET, :STREAM)
+      address = Socket.pack_sockaddr_in(port, host)
+      optval = [timeout, 0].pack("l_2")
+      socket.setsockopt :SOCKET, :RCVTIMEO, optval
+      socket.setsockopt :SOCKET, :SNDTIMEO, optval
+
+      loop do
+        begin
+          socket.connect(address)
+          return
+        rescue SystemCallError => e
+        end
+      end
+    end
+
+    extend self
   end
 end