title: corona : memory issue?
body: <p>actually i'm having few question here, hope someone can help me out.</p>
  
  <p>1) what is the different between </p>
  
  <pre><code>print(collectgarbage("count"))
  </code></pre>
  
  <p>and </p>
  
  <pre><code>print(system.getInfo( "textureMemoryUse" ))
  </code></pre>
  
  <p>2) i have a game that after u finish it, it will jump back to 1st page and you can just play it again, i try to out put textureMemoryUse it doesn't show me memory leak, but yet the game become more lag each time i play it, is there any other reason would make it lag other than memory leak ? </p>
  
  <p>3) what is the correct way to remove an object ? what i try to do is :</p>
  
  <pre><code>object:removeSelf()
  object = nil
  </code></pre>
  
  <p>but if i out put by using collectgarbage("count") it doesn't show any different before and after i use it.</p>
  
  <p>game being lagging for each time playing have been suffer me for 2 days, really can't find what's wrong in my code, hope to get some help here.</p>
  
  <hr>
  
  <p>here is my code on remove all the memory </p>
  
  <pre><code>--remove all the transition that store in a table
  local k, v
  for k,v in pairs(transitionTable) do
      --print(k)
      timer.cancel( v )
      v = nil; k = nil 
  end
  
  transitionTable = nil
  transitionTable = {}
  
  -- remove movie clip
  playButtonAnim:removeSelf()
  playButtonAnim = nil
  
  -- remove displayGroup and it's child
  displayGroup.x = display.contentHeight + 10
  displayGroup.x = display.contentWidth + 10
  if(displayGroup ~= nil and displayGroup.numChildren ~= nil) then
      for i=1,displayGroup.numChildren do
          print("child on display group : "..displayGroup.numChildren)
          displayGroup:remove(1)
      end
      displayGroup:removeSelf()
  end
  </code></pre>
  
  <p>i try to :</p>
  
  <pre><code>    collectgarbage("collect")
  print( "collectgarbage is " .. collectgarbage("count")  )
  </code></pre>
  
  <p>on each line and found that remove movie clip part din release any memory, i think it is not a proper way to remove it?</p>