setupProcessing and setActive memory barriers

Both the setupProcessing() and setActive() seems to be called from the main thread while process() is of course called from Audio Thread, are there specified any memory barriers to ensure update order?

the host has to guaranty that the order is respected…

UI Thread: setupProcessing (…)
UI Thread: setActive (true)

Audio Thread: setProcessing (true)
Audio Thread: process (…)

Audio Thread: setProcessing (false)

UI Thread: setActive (true)

no specific way to do this correctly is specified.