Why does this short piece of code use up memory and does not release

Solar2D General Questions/Discussion
#1

Code is showing as below. What I am doing is create lots of group and then remove all of them. I expect they shouldn’t take up memory. However, the result isn’t like that. Am I missing anything here?

for i = 1, 100000 do

 local fff = display.newGroup()

 fff:removeSelf()

 fff = nil

end

i = nil

collectgarbage(“collect”)

timer.performWithDelay(1000, function()

 print(collectgarbage(“count”))

end, 0)

#2

put another collectgarbage(“collect”) inside your timer callback before printing the count – i think all you’re seeing is some residual junk from the timer callback itself that isn’t getting collected immediately.

(that is, i don’t think you’re seeing residual from the display groups – in fact, you can probably comment out that entire first section and still see the residual timer junk unless you add that additional collect inside the callback)

#3

Try this:

print(collectgarbage(“count”))
for i = 1, 100000 do
 local fff = display.newGroup()
 fff:removeSelf()
 fff = nil
 collectgarbage(“collect”)
end
i = nil
collectgarbage(“collect”)

print(collectgarbage(“count”))
timer.performWithDelay(1000, function()
 collectgarbage(“collect”)
 print(collectgarbage(“count”))
end, 0)

The timer executing creates some memory and since you never reclaim it, it appears to go up until GC runs again. 

#4

put another collectgarbage(“collect”) inside your timer callback before printing the count – i think all you’re seeing is some residual junk from the timer callback itself that isn’t getting collected immediately.

(that is, i don’t think you’re seeing residual from the display groups – in fact, you can probably comment out that entire first section and still see the residual timer junk unless you add that additional collect inside the callback)

#5

Try this:

print(collectgarbage(“count”))
for i = 1, 100000 do
 local fff = display.newGroup()
 fff:removeSelf()
 fff = nil
 collectgarbage(“collect”)
end
i = nil
collectgarbage(“collect”)

print(collectgarbage(“count”))
timer.performWithDelay(1000, function()
 collectgarbage(“collect”)
 print(collectgarbage(“count”))
end, 0)

The timer executing creates some memory and since you never reclaim it, it appears to go up until GC runs again.