GroupClear

[Vinz]

Would a unit group leak if only used GroupClear? Because for me, DestroyGroup either a.) makes the next ForGroup only pick one unit, b.) does not pick at all, or c.) messes with add/remove unit.

 

[deathismyfriend]

If you reuse the group and don't recreate it then you never need to destroy it. You can use a firstofgroup loop to then empty then unit group and do your actions.

 

[IcemanBo]

You only leak in case you make following line more often without destroying group:

• Set Unitgroup = Units ...

So if you only set it once, and then use add/remove/clear.. there won't be any leak. Only if you set UnitGroup more often it may leak.

 

[Dr Super Good]

Would a unit group leak if only used GroupClear? Because for me, DestroyGroup either a.) makes the next ForGroup only pick one unit, b.) does not pick at all, or c.) messes with add/remove unit.

Well if you try and use something that has been destroyed what do you expect? I mean you would hardly go back to living in a building after it has been demolished would you? Once a group has been destroyed all variables pointing at it will have a destroyed handle and so any operations that use such variables will not work. You will need to set the variable to a new, freshly created group for them to work again.

 

[Vinz]

Well if you try and use something that has been destroyed what do you expect? I mean you would hardly go back to living in a building after it has been demolished would you? Once a group has been destroyed all variables pointing at it will have a destroyed handle and so any operations that use such variables will not work. You will need to set the variable to a new, freshly created group for them to work again.

The variables are set. So why do those even happen?

 

[IcemanBo]

You don't use this bj_destroy with combination of a varibale or?

• Custom script: set bj_wantDestroyGroup = true
• Unit Group - Pick every unit in UnitgroupVariable and do Actions:

After this you would be not able to use it anymore.

 

[deathismyfriend]

You don't use this bj_destroy with combination of a varibale or?

• Custom script: set bj_wantDestroyGroup = true
• Unit Group - Pick every unit in UnitgroupVariable and do Actions:

After this you would be not able to use it anymore.

Actually that would not do anything since it does not call the function that creates a unit group. So yes you would be able to use it again.

 

[Dr Super Good]

If you keep clearing a unit group that you recycle (use again and again) it will not leak. Be aware that GUI does not support this well as most group fill methods (except individual units or from other groups) create a new group.

 

[IcemanBo]

Actually that would not do anything since it does not call the function that creates a unit group. So yes you would be able to use it again.

Hm yes I guess that's right. But I had once the case I could not use it anymore, if I remember I will post.

 

[Vinz]

If you keep clearing a unit group that you recycle (use again and again) it will not leak. Be aware that GUI does not support this well as most group fill methods (except individual units or from other groups) create a new group.

How about local groups?

 

[TriggerHappy]

If you keep clearing a unit group that you recycle (use again and again) it will not leak. Be aware that GUI does not support this well as most group fill methods (except individual units or from other groups) create a new group.

Groups are cleared upon enumeration if I remember correctly.

 

[Dr Super Good]

Groups are cleared upon enumeration if I remember correctly.

Yes if you are using the natives directly. GUI's BJs create a new group...

function GetUnitsInRangeOfLocMatching takes real radius,location whichLocation,boolexpr filter returns group
    local group g = CreateGroup()
    call GroupEnumUnitsInRangeOfLoc(g, whichLocation, radius, filter)
    call DestroyBoolExpr(filter)
    return g
endfunction

function GetUnitsInRectMatching takes rect r,boolexpr filter returns group
    local group g = CreateGroup()
    call GroupEnumUnitsInRect(g, r, filter)
    call DestroyBoolExpr(filter)
    return g
endfunction

function GetUnitsInRectOfPlayer takes rect r,player whichPlayer returns group
    local group g = CreateGroup()
    set bj_groupEnumOwningPlayer = whichPlayer
    call GroupEnumUnitsInRect(g, r, filterGetUnitsInRectOfPlayer)
    return g
endfunction

function GetUnitsOfPlayerAndTypeId takes player whichPlayer,integer unitid returns group
    local group g = CreateGroup()
    set bj_groupEnumTypeId = unitid
    call GroupEnumUnitsOfPlayer(g, whichPlayer, filterGetUnitsOfPlayerAndTypeId)
    return g
endfunction

function GetUnitsOfPlayerMatching takes player whichPlayer,boolexpr filter returns group
    local group g = CreateGroup()
    call GroupEnumUnitsOfPlayer(g, whichPlayer, filter)
    call DestroyBoolExpr(filter)
    return g
endfunction

function GetUnitsOfTypeIdAll takes integer unitid returns group
    local group   result = CreateGroup()
    local group   g      = CreateGroup()
    local integer index
    set index = 0
    loop
        set bj_groupEnumTypeId = unitid
        call GroupClear(g)
        call GroupEnumUnitsOfPlayer(g, Player(index), filterGetUnitsOfTypeIdAll)
        call GroupAddGroup(g, result)
        set index = index + 1
        exitwhen index == bj_MAX_PLAYER_SLOTS
    endloop
    call DestroyGroup(g)
    return result
endfunction

function GetUnitsSelectedAll takes player whichPlayer returns group
    local group g = CreateGroup()
    call SyncSelections()
    call GroupEnumUnitsSelected(g, whichPlayer, null)
    return g
endfunction

Yeh so in JASS it is no problem to recycle groups, but GUI does not really support it.

 

[Vinz]

Weird as it is, I use JASS in GUI. Nothing in JASS trigger works for me, so I have to translate them to custom scripts.

Speaking of my problem, can someone explain why that happens?

 

[Dr Super Good]

Speaking of my problem, can someone explain why that happens?

Maybe if you post the trigger that has problems we could? By the sounds of what you posted it brings back the first point, you cannot expect to use groups after you destroy them, you should only destroy groups you no longer need to use.

 

[Vinz]

I'll find such samples. Meanwhile, can you please clarify if creating locals at either of these will take much memory:

- Unit dies
- Unit takes damage

 

[Dr Super Good]

Meanwhile, can you please clarify if creating locals at either of these will take much memory:

Why would you be concerned about the memory use? I mean JASS variables are only a couple dozen bytes and all locals are removed when the thread dies anyway. Locals do not and cannot leak in WC3 (as far as I know).

What does leak with locals are handle indexes. When a function returns it does not decrement the reference counter of local handles resulting in a reference leak so the index can never be recycled. Logically only applies to types which can be recycled such as units, locations, groups etc. This does not apply to local handles declared as function arguments since they operate correctly and do decrement reference counters on function return.

 

[Vinz]

Oh.. alright, thanks for clarifying.