[julia-users] Garbage collection outside the global scope

[Andrew B. Martin]

I'm having a hard time figuring out how to free up memory by zeroing and 
garbage collecting objects in a function.

function runModel()
    d = generateData()
    d = 0
    gc()
end


When I run runModel() in the REPL memory usage remains as if d is still 
stored in memory.

Even if I do:

for i in 1:5
   d = generateData();
   d = 0
   gc()
end

Memory is not freed by the garbage collection.

If I enter:

julia> d = generateData();

julia> d = 0

julia> gc()

Then memory from d is freed up.

I've looked at this SO 
question: 
http://stackoverflow.com/questions/25871711/julia-garbage-collection-inside-functions-works-differently-than-in-global-spac
 
but it doesn't provide any answers.


Why is memory freed when run garbage collection is done in the global 
scope, but not in a function or for-loop?