floodlight/ivs — pull request #218 by rlane (2014-11-13 18:37:19+00:00)
Title: use processes instead of threads for handling upcalls

Reviewer: @harshsin

This has several advantages:

- The main process will not block upcall processes while writing to forwarding
datastructures.
- Upcalls see the forwarding state changed atomically between barriers, as is
already the case with kflows.
- The LuaJIT pipeline can use multiple cores.
- Pipeline implementors don't need to worry about locking.

The complicated port quiescing code is completely removed. The forwarding state rwlock is also removed.