[MITgcm-support] blocking exchange

[samar khatiwala]

Hello, I have a question about the proper use of _EXCH_XYZ_R8.

At some point in the code, I need to update overlaps for some
arrays I have created. The arrays are declared identically to
pTracer.

Can I simply call _EXCH_XYZ_R8(myArray...) or will this wreak havoc
in a multiprocessor run? I am not sure if _BARRIER or something else
needs to be declared/called before an exchange. I don't see anything
in, say, ptracers_fields_blocking_exchanges, but just want to be sure.

Thanks, Samar