Delete stuff to free RAM

Sat, 29 Jun 2019 15:29:35 UTC

Hi everyone,

I am tinkering with procedural generation and I inevitably run out of memory. I expected to be able to delete some obsolete data to free some memory but I do not succeed. It looks like deleting variables does not free RAM. What did I miss?

I isolated that in the following script that just fill a global variable named STATE with random data, then set it to NIL, and track that it does not free any RAM. It outputs as such:

RAM: 0%
 FILL STATE WITH DATA...
RAM: 41%
 DELETE STATE...
RAM: 41%

The code:

state = {}

function _init()
 cls()
 print("ram: "..flr(stat(0)/20.48).."%")
 print(" fill state with data...")

 -- fill state with dumb data
 fill_state()

 -- test ram
 print("ram: "..flr(stat(0)/20.48).."%")
 print(" delete state...")
 state=nil
 print("ram: "..flr(stat(0)/20.48).."%")
end

function fill_state()
 state.data = {}
 local str=""
 for i=1,1000 do
  str=str.."abcdefghijklmnopqrstuvwxyz"..i
 end
 for i=1,100 do
  state.data[i] = {}
  for j=1,1000 do
   state.data[i][j] = str
  end  
 end
end

Isn't the garbage collector supposed to help me here? What did I miss? What is the way around the issue?
Thanks :)

jacomyma [Lexaloffle Blog Feed]

Delete stuff to free RAM