I'm developing an external that starts a separate pthread to poll some hardware inputs. When the outputs change, I need to send a message like [34 56( to one of two outlets in the external from my thread. 

Do I need to use my own mutex? or the sys_lock(), sys_unlock() calls around the outlet_whatever() calls? or nothing at all, just call outlet_whatever()?

Anyone cares to give a two line explanation of the logic around this?

Thanks!

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