Parallel Memory Leak

module RemoteHelpers

using Base: sync_add

function remote_call_from_module(w, expression::Expr)
    call_expr = :(remotecall($w, eval, Main, $(Expr(:quote, expression))))
    eval(Main, call_expr)
end

remote_eval(w, expression::Expr) = remote_call_from_module(w, expression)

function remote_eval(expression::Expr)
    @sync begin
        for w in workers()
            sync_add(remote_eval(w,expression))
        end
    end
end

end


# Below is an example of some of the operations that are being done. The example
# may not make complete sense but these are the basic operations:
# Create/Update a variable on each worker
# Run a loop on each worker which should replace a row of an existing matrix

using RemoteHelpers
using Base: sync_add

a = addprocs(4)

# This type of call has a memory leak on the workers.

for j = 1:250
  c = rand(50, 5000)
  @sync begin
    for i in a
       sync_add(remote_eval(i, :(begin
                                 n = 50
                                 b = 5000
                                 c = $c
                                 result = zeros(n, b)  
                               
                                 for j = 1:n
                                   result[j, :] = rand(1, b)
                                 end
                                end)))
    end
  end
end


rmprocs(a)
## But calling doing this does not result in a memory leak
a = addprocs(4)

for j = 1:250
  c = rand(50, 5000)
  @sync begin
    for i in a
       sync_add(remote_eval(i, quote
                                 n = 50
                                 b = 5000
                                 c = $c
                                 result = zeros(n, b)  
                                end))
    end
  end
  
  @sync remote_eval(quote
                      for j = 1:n
                        result[j, :] = rand(1, b)
                      end
                    end)
end  # module