Adding a UDP echo benchmark.

extra/benchmark/echo/echo.factor

@@ -0,0 +1,20 @@
+! Copyright (C) 2010 John Benediktsson
+! See http://factorcode.org/license.txt for BSD license
+
+USING: accessors destructors kernel io.binary io.sockets
+sequences ;
+
+IN: benchmark.echo
+
+: send/recv ( packet server client -- )
+    [ over over addr>> ] [ send ] bi* receive drop assert= ;
+
+: udp-echo ( -- )
+    [
+        10000 iota [ 4 >be ] map
+        f 0 <inet4> <datagram>
+        f 0 <inet4> <datagram>
+        [ send/recv ] 2curry each
+    ] with-destructors ;
+
+MAIN: udp-echo