I just encountered a very confusing julia behavior. I always thought that variables defined inside a function remain local to that function. But in the following example, the scope changes.
I define a simple function as below
using Distributed
addprocs(2)
function f()
@everywhere x = myid()
@everywhere println("x = ", x)
end
Executing the following code
f()
gives the result
x = 1
From worker 2: x = 2
From worker 3: x = 3
But since x is defined inside the function, I would expect the variable x to be not defined outside the function. However, upon executing the following code
x
I get the result
1
Even more confusing is the execution of the following code
@fetchfrom 3 x
which again gives
1
This is super confusing behavior. First, how does x become available outside the function? Second, why are all the processors/cores returning the same value of x? Thank you for your help.