Strange memory leaks

[EdgeOfChaos]

So, I decided to use the function from this thread to discover whether I had memory leaks: http://www.hiveworkshop.com/forums/triggers-scripts-269/things-leak-35124/

Specifically, this is what I wrote.

library Debug initializer onInit
    
    globals
        private boolean debugOn = true
        private boolean handleCountOn = true
        private timer t
        private constant real PERIOD = 1.
    endglobals
    
    private function handleCount takes nothing returns nothing
        local location L = Location(0,0)
        call BJDebugMsg(I2S(GetHandleId(L)-0x100000))
        call RemoveLocation(L)
        set L = null
    endfunction
    
    private function onInit takes nothing returns nothing
        if(debugOn and handleCountOn)then
           set t = CreateTimer()
           call TimerStart(t,PERIOD,true,function handleCount)
       endif
    endfunction
    
endlibrary

This works fine, and it shows the number of handles I have. The confusing thing was when it said that the number of handles were increasing by thousands every second - i.e. thousands of memory leaks. I had been coding carefully, so I went through and disabled all the triggers until I found what caused it.

This caused the leaks:

    private function bSleep takes nothing returns nothing
        local group g = CreateGroup()
        call GroupEnumUnitsInRect(g,GetPlayableMapRect(),Filter(function sleepFilter))
        call DestroyGroup(g)
        set g = null
    endfunction

I messed around with it for a while and found that if I removed the DestroyGroup call, it would no longer leak, like this:

    private function bSleep takes nothing returns nothing
        local group g = CreateGroup()
        call GroupEnumUnitsInRect(g,GetPlayableMapRect(),Filter(function sleepFilter))
        set g = null
    endfunction

But from my knowledge of JASS, I would have expected the first one would not leak, and the second one would. It turned out to be the opposite when I coded it. I'm wondering why, or if there is some problem with the code that showed the handle count in the first place.

 

[Anitarf]

What does the surrounding code look like, like the sleepFilter and whichever function calls bSleep? Can you reproduce this bug in an empty map with just this code?

 

[EdgeOfChaos]

I removed all code from sleepFilter (just has a return false)
This is the code that calls the function

    private function onInit takes nothing returns nothing
        call TimerStart(t,1,true,function bSleep)
    endfunction

I'll try it in an empty map.

 

[Aniki]

The handleCount function you are using

    function handleCount takes nothing returns nothing
        local location L = Location(0,0)
        call BJDebugMsg(I2S(GetHandleId(L)-0x100000))
        call RemoveLocation(L)
        set L = null
    endfunction

is not correct.

See this resource for an example of a better implementation.

 

[EdgeOfChaos]

Thanks - working much better now!