tree b9a37b4765cbd16ff140c7c8bb09069148306678
parent f9161caaf39634c7047ded2d14d6f536aa76557e
author Pavlin Radoslavov <pavlin@onlab.us> 1383265472 -0700
committer Pavlin Radoslavov <pavlin@onlab.us> 1383265472 -0700

Use TreeMap instead of HashMap to store topology-related state.
The latter doesn't guarantee the ordering of the items, hence the
computation result (e.g., choosing between two shortest paths with
same cost) could depend on the ordering of events.