ofp_event: Timestamp when OpenFlow event was generated

This patch introduces "timestamp" attribute for OpenFlow event classes
which shows when that event was generated by Datapath instance and nearly
equivalent to when Ryu finished receiving the message contained in that
event instance.

Suggested-by: Matthew Hayes <matthew_john_hayes@hotmail.com>
Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 3 insertions, 1 deletions

diff --git a/ryu/controller/ofp_event.py b/ryu/controller/ofp_event.py
index 6b1c8b3e..6eb8e5f8 100644
--- a/ryu/controller/ofp_event.py
+++ b/ryu/controller/ofp_event.py
@@ -19,10 +19,10 @@ OpenFlow event definitions.
 """
 
 import inspect
+import time
 
 from ryu.controller import handler
 from ryu import ofproto
-from ryu import utils
 from . import event
 
 
@@ -41,12 +41,14 @@ class EventOFPMsgBase(event.EventBase):
     msg.datapath A ryu.controller.controller.Datapath instance
                  which describes an OpenFlow switch from which we received
                  this OpenFlow message.
+    timestamp    Timestamp when Datapath instance generated this event.
     ============ ==============================================================
 
     The msg object has some more additional members whose values are extracted
     from the original OpenFlow message.
     """
     def __init__(self, msg):
+        self.timestamp = time.time()
         super(EventOFPMsgBase, self).__init__()
         self.msg = msg