In official documentation, two examples are used:
julia> function rand2(dims...)
return 2*rand(dims...)
end
julia> rand2(2,2)
2×2 Array{Float64,2}:
0.153756 0.368514
1.15119 0.918912
julia> fetch(@spawn rand2(2,2))
ERROR: RemoteException(2, CapturedException(UndefVarError(Symbol("#rand2"))
[...]
julia> A = rand(1000,1000);
julia> Bref = @spawn A^2;
[...]
julia> fetch(Bref);
These two examples seem to be very similiar. However, in the first example, rand2 is not available on worker’s process while in the second example, A is available on worker’s process. The only difference is rand2 is a function and A is a variable. What’s the essential difference between a function and a variable such that they behave differently in macro @spawn?