urbanairship/datacube — pull request #46 by todd534 (2013-05-14 20:57:23+00:00)
Title: make the readCombineCas retries re-read between failures

Currently it does this:

get old value
compute new value as (old val + update)
for 1 .. casRetries
try to checkAndPut(.., old val, new value)

if the value in the table changes, this will fail between reading and updating. Retrying won't help, because we don't read a new old value. This change helps that by rereading the old value between retries.