tree 8d27fc0d6b2b3f5ff9d4192a9ba4ea03a71eed30
parent dafae19ef6f775b43d488e728fa213fef50c797f
author Sangho Shin <sangho@onlab.us> 1412727203 -0700
committer Sangho Shin <sangho@onlab.us> 1412727203 -0700

 - More null check when getting switch object
 - More efficeint topology event handling
 - When switch is gone, remove all neighbor ports

Change-Id: Ie071906e98b6c8c2b300b8c87ce5157803aaa2df