This needs to be confirmed:
Location based atomics do not imply a full fence of the same level. So
to get the code in dispose() read the actual data, it seems we need to
initiate a fence.
If we're idle, there might be objects pending cleanup for the last two
epochs. Unless another thread comes in and checks into a new epoch or we
shut down, they will linger forever.
If one of the objects was a connection, it wouldn't get closed and be
stuck in CLOSE_WAIT state, potentially refusing another ligitimate
connection if its socket address were to match the one we're yet to
close.
Similar to the algorithm presented in
https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-579.pdf
Not completely lock-free at the moment. Also the problems with epoch
based memory reclamation are still present - a thread actively observing
an epoch getting stuck will prevent LloadConnections and LloadOperations
being freed, potentially running out of memory.
