I wanted to see how long nim held on to unused memory and I wrote a simple
program that assigns a new seq to the same variable in a loop that runs twice
every second. The seq needs under 200k but every once in a while getTotalMem
reports double the previous high. After a while it gets up to over 8 billion on
a 16 GB system arch linux system. It goes back down after a few more loops but
it again doubles after a while. I wonder if nim really tried to grab that much
memory for a short while. The follwing program shows the problem in a few
minutes.
import os
proc fmt(x:int):string =
var s = $x
var ll = s.len
var j,l2:int
result = newstring(ll + (ll-1) div 3)
for i in 0..<ll:
result[j] = s[i]
inc j
if (ll-i) mod 3 == 1 and (ll-i)>1:
result[j] = ','
inc j
proc mtest() =
var imax = 0
while true:
var n = 20000
var v=newseq[int](n)
for i in 0..<n: v[i]+=i
sleep(500)
var t = getTotalMem()
if t > imax: imax = t
echo "Total = ", t.fmt
echo "Free = ", getFreeMem().fmt
echo "Occu = ", getOccupiedMem().fmt
echo "Max = ", imax.fmt
echo v[1] + v[2], "\n"
when isMainModule:
mtest()
