bixo/bixo — pull request #63 by rockwalrus (2014-04-30 15:43:45+00:00)
Title: Only call TupleEntryCollectors when Cascading allows it.

Cascading expects the TupleEntryCollectors to only be called when a thread is currently in a method such as operate or cleanup. This patch adds a semaphore to prevent other threads from calling a collector if one of the appropriate methods is not being executed. Not doing this resulted in ConcurrentModificationExceptions and other spurious problems.