Periodicity with multiple layers of ghost nodes

Right now periodicity is not possible if there are two or more ghost nodes (i.e. if FabArrayBase::m_multi_ghost is true) - per

amrex/Src/Base/AMReX_FabArrayBase.cpp

Line 879 in 930e75e

    
           AMREX_ASSERT(m_multi_ghost ? !m_period.isAnyPeriodic() : true); // this only works for non-periodic

Is it possible to update FabArrayBase to allow for periodicity with multiple layers of ghost nodes?

Sorry for taking me so long to reply. The issue is this line

https://github.com/AMReX-Codes/amrex/blame/b6ed5237987e1d5babda45a606baa6074e426272/Src/Base/AMReX_FabArrayBase.cpp#L705

complementIn is used to remove all the valid points from B ox dst_bx_ng. But the function does not take periodic boundaries into account. It's possible to do that. So let's keep this issue open. I will try to implement it. Meanwhile, you could achieve it by calling FillBoundary twice. First with multi_ghost=true and no periodic boundaries, and then with multi_ghost=false and periodic boundaries.

Thanks @WeiqunZhang. I'll keep an eye on the issue, but will implement your temporary fix when/if we need periodicity working quickly.