Hi all, According to the ZeroMQ docs[1]: "Individual ØMQ sockets are not thread safe except in the case where full memory barriers are issued when migrating a socket from one thread to another." The Haskell ZeroMQ binding [2] is a fairly thin wrapper around the C API, and in particular doesn't seem to do much to enforce thread safety as described above. My question: do I need to use bound threads to call functions on sockets to ensure that all the foreign calls happen on the same OS thread, or is it the case that two consecutive foreign calls in a single Haskell thread have a "full memory barrier" between them if they end up being called from different OS threads? Thanks in advance, David [1] http://api.zeromq.org/4-0:zmq [2] http://hackage.haskell.org/package/zeromq4-haskell