Cheat Engine

[jgoemat]

I'm working through some LUA stuff and updating the wiki and was wondering if and when to destroy objects and what needs to be destroyed.

For instance if I use "createMemScan()" and then "createFoundList()" when the scan is compete, do I need to destroy both objects to free the memory?

If I use getCurrentMemscan() to access the main window scan, should I avoid destroying that? If I call createFoundList() on it should I destroy that?

[Dark Byte]

Things you create should be destroyed yes. So both the foundlist and memscan object

getCurrentMemscan() doesn't create it, so don't destroy this
If you attach a foundlist to that unspecified behaviour will occur. Just get the current foundlist of that memscan object.(or at least restore it when done)

One thing to note are objects on a form. If you destroy a form the objects on it will be destroyed as well, so do nt free those after having freed the form

[fingersmith]

I am under the impression that LUA automatically perform garbage collection...aka no need to destroy object explicitly.

FS

[Dark Byte]

it garbage collects lua things yes, but the objects you create with create* functions are just wrappers for native code objects. Those do need to get destroyed manually

[panraven]

In Lua 5.3 so ce 6.5, there is a metamethod __gc to handle ce object with Lua's garbage collecting.
https://www.lua.org/manual/5.3/manual.html#2.5.1

[Dark Byte]

yeah, but keeping track of all lua variables that reference a specific object is quite taxing.

e.g: you can get an reference to a form, a button on the form, and edit field on a form.

when you close the form, and it's close action is caFree, the form, button and edit field need to be dereferenced as well, and the garbage collector needs to be told to NOT free them

there is some testing implemented in ce with regard to garbage collecting
e.g this script:

[panraven]

[akumakuja28]

I would recommend just using collectgarbage() but it is fucking notorious for breaking things. Even if using destroy().

Things I have often experienced from garbage collecting are.
-- Breaking of the address list
Injection templates cause access violations
Unable to edit names or values on the address list.
Loss of the file menu
Random access violations when searching.
And plenty of other things.

The memory leak with LUA is ridiculous. Your best bet is to build your forms and never destroy just use hide().

Easy code for hiding a form
If Form~= nil
then
Form.Visible = true
Else
Whatever your formcreate() function is.
End

function CloseForm()
Form.Visible = false
End


Form.OnClose = CloseForm


Dont use an embedded function like

Form.OnClose = function()
Form.Visible = false
End

As these tend to break them selfs also.








Running that arguement works great to reduce the memory impact of
Create and Destroy(). As eventually you WILL create an access violation with this practice. At some time CE will eventually write over a section
Of code it needs for something else. Now while this experience maybe
Anecdotal it is just my experience from writing a CE extension to Manage games and cheat tables. And in this I have defined well over 400 things in LUA.

I know this sounds rant like. But honestly whenever you create something in CE lua environment try your hardest to reuse that asset vs recreation. Which brings me to another point stay away from any "local" variable as these things are notorious for memory leaks.

[mgr.inz.Player]

[akumakuja28]

[mgr.inz.Player]

OK, send it.

PS: do not attach any file to PM. Just paste a link to googledrive, onedrive or whatever you are using.