Did nulling unit group cause leak?

Asuna Tichondrius · Jun 29, 2025

Because i want merge one MUI trigger in one trigger loop with other, i decide to merge it to one variable but the problem (maybe) i'm afraid to it cause leak if i nullified since i don't use it on other trigger , I'm curious if that cause leak or not if i'm nulling one of unit group?

Custom script: set udg_AquaKonoGroupDummy[udg_AquaKono[0]] = null

Here for example i merge the trigger

Exocirm
- Events
  - Unit - A unit Starts the effect of an ability
- Conditions
  - (Ability being cast) Equal to Exorcism
- Actions
  - Set HeroAbilityLevel = (Level of (Ability being cast) for (Triggering unit))
  - Set HeroAttribute = (Intelligence of (Triggering unit) (Include bonuses))
  - Set HeroLevel = (Hero level of (Triggering unit))
  - Set HeroBaseDamage = (Base Damage of (Triggering unit) for weapon index 1)
  - Set HeroTrait = Magical[(Custom value of (Triggering unit))]
  - Set SongOfPearlBonus = (SongOfPearlDamageMultiplier[SongOfPearlLevel[(Custom value of (Triggering unit))]] x (Max life of (Triggering unit)))
  - Set HeroAllinOne = (((HeroBaseDamage + HeroAttribute) + HeroLevel) + HeroTrait)
  - Set Point[0] = (Position of (Triggering unit))
  - Set AquaKono[0] = (AquaKono[0] + 1)
  - Custom script: set udg_AquaKonoGroupDummy[udg_AquaKono[0]] = CreateGroup()
  - For each (Integer A) from 1 to 5, do (Actions)
    - Loop - Actions
      - Set Point[1] = (Point[0] offset by 400.00 towards (72.00 x (Real((Integer A)))) degrees)
      - Set AquaKonoAngle[AquaKono[0]] = (Angle from Point[1] to Point[0])
      - Unit - Create 1 Aqua Ion Beam for (Owner of (Triggering unit)) at Point[1] facing AquaKonoAngle[AquaKono[0]] degrees
      - Set AquaKonoDummy[AquaKono[0]] = (Last created unit)
      - Unit Group - Add AquaKonoDummy[AquaKono[0]] to AquaKonoGroupDummy[AquaKono[0]]
      - Custom script: call RemoveLocation(udg_Point[1])
  - If (All Conditions are True) then do (Then Actions) else do (Else Actions)
    - If - Conditions
      - ((Triggering unit) has buff SongOfPearlBuff) Equal to True
    - Then - Actions
      - Set AquaKonoDamage[AquaKono[0]] = (AquaExorcismB[HeroAbilityLevel] + (SongOfPearlBonus + ((Real(HeroAllinOne)) x AquaExorcismM[HeroAbilityLevel])))
    - Else - Actions
      - Set AquaKonoDamage[AquaKono[0]] = (AquaExorcismB[HeroAbilityLevel] + (0.00 + ((Real(HeroAllinOne)) x AquaExorcismM[HeroAbilityLevel])))
  - Set AquaKonoCaster[AquaKono[0]] = (Triggering unit)
  - Set AquaKonoDelay[AquaKono[0]] = 0.00
  - Set AquaKonoRun[AquaKono[0]] = 0.00
  - Set AquaKonoSpeed[AquaKono[0]] = 15.00
  - Set AquaKonoX[AquaKono[0]] = 0.00
  - Set AquaKonoY[AquaKono[0]] = 0.00
  - Set AquaKonoStage[AquaKono[0]] = 1
  - Set AquaKonoX[AquaKono[0]] = 0.00
  - Set AquaKonoY[AquaKono[0]] = 0.00
  - Set AquaBoolean[AquaKono[0]] = False
  - If (All Conditions are True) then do (Then Actions) else do (Else Actions)
    - If - Conditions
      - AquaKono[0] Equal to 1
    - Then - Actions
      - Trigger - Turn on ExocirmLoop <gen>
    - Else - Actions
  - Custom script: call RemoveLocation(udg_Point[0])

WaterSplash
- Events
  - Unit - A unit Starts the effect of an ability
- Conditions
  - (Ability being cast) Equal to Sacred Water Splash
- Actions
  - Set HeroAbilityLevel = (Level of (Ability being cast) for (Triggering unit))
  - Set HeroAttribute = (Intelligence of (Triggering unit) (Include bonuses))
  - Set HeroLevel = (Hero level of (Triggering unit))
  - Set HeroBaseDamage = (Base Damage of (Triggering unit) for weapon index 1)
  - Set HeroTrait = Magical[(Custom value of (Triggering unit))]
  - Set SongOfPearlBonus = (SongOfPearlDamageMultiplier[SongOfPearlLevel[(Custom value of (Triggering unit))]] x (Max life of (Triggering unit)))
  - Set HeroAllinOne = (((HeroBaseDamage + HeroAttribute) + HeroLevel) + HeroTrait)
  - Set Point[0] = (Target point of ability being cast)
  - Set AquaKono[0] = (AquaKono[0] + 1)
  - Set AquaKonoX[AquaKono[0]] = (X of Point[0])
  - Set AquaKonoY[AquaKono[0]] = (Y of Point[0])
  - Set AquaKonoCaster[AquaKono[0]] = (Triggering unit)
  - Set AquaKonoDummy[AquaKono[0]] = No unit
  - Set AquaKonoDelay[AquaKono[0]] = 1.98
  - Set AquaKonoRun[AquaKono[0]] = 0.00
  - Set AquaKonoSpeed[AquaKono[0]] = 15.00
  - Set AquaKonoStage[AquaKono[0]] = 2
  - Custom script: set udg_AquaKonoGroupDummy[udg_AquaKono[0]] = null
  - Set AquaBoolean[AquaKono[0]] = False
  - If (All Conditions are True) then do (Then Actions) else do (Else Actions)
    - If - Conditions
      - ((Triggering unit) has buff SongOfPearlBuff) Equal to True
    - Then - Actions
      - Set AquaKonoDamage[AquaKono[0]] = (AquaWaterSplash[HeroAbilityLevel] + (SongOfPearlBonus + ((Real(HeroAllinOne)) x AquaWaterSplash2[HeroAbilityLevel])))
    - Else - Actions
      - Set AquaKonoDamage[AquaKono[0]] = (AquaWaterSplash[HeroAbilityLevel] + (0.00 + ((Real(HeroAllinOne)) x AquaWaterSplash2[HeroAbilityLevel])))
  - If (All Conditions are True) then do (Then Actions) else do (Else Actions)
    - If - Conditions
      - AquaKono[0] Equal to 1
    - Then - Actions
      - Trigger - Turn on ExocirmLoop <gen>
    - Else - Actions
  - Custom script: call RemoveLocation(udg_Point[0])

Nichilus · Jun 30, 2025

Yes, it does leak.

Custom script: set udg_AquaKonoGroupDummy[udg_AquaKono[0]] = CreateGroup()

This creates an object (a unit group) and assigns its handleId to variable/array AquaKonoGroupDummy under index X.
Now handleId stored in AquaKonoGroupDummy[X] references the unit group object. Note that it is not the object itself that is stored in the variable, it is only a reference to the object.

Following action:

Custom script: set udg_AquaKonoGroupDummy[udg_AquaKono[0]] = null

just removes the reference. So AquaKonoGroupDummy[X] will no longer refence unit group object.
However there is nothing destroying said object, so it causes memory leak.

Custom script: call DestroyGroup(udg_AquaKonoGroupDummy[udg_AquaKono[0]])

will destroy the unit group object referenced by AquaKonoGroupDummy.

---
Also, I do not understand the relationship between Exocirm and WaterSplash triggers. I only see that one is creating unit group while other nulls reference to it.
However what I would like to point is following: If your intention is to create unit group in Exocirm and WaterSplash should destroy that unit group, then what you have currently will not work and it will always leak.

Asuna Tichondrius · Jul 1, 2025

Okay, thanks for information, i guess i will revamp my spell because i add too much refernce too merge trigger, because i though it will efficient to track the unit group (because one of trigger didn't actually need unit group, but if i not use that reference it will nasty bug on the spell)

Also, one question are udg_UnitVariable = No Unit cause leak?

Nichilus said:
Also, I do not understand the relationship between Exocirm and WaterSplash triggers. I only see that one is creating unit group while other nulls reference to it.
However what I would like to point is following: If your intention is to create unit group in Exocirm and WaterSplash should destroy that unit group, then what you have currently will not work and it will always leak.

Because i want to merge it to this loop and destroy it in this loop, i didn't want create too much variable because performance issue.

ExocirmLoop
- Events
  - Time - Every 0.03 seconds of game time
- Conditions
- Actions
  - For each (Integer AquaKono[1]) from 1 to AquaKono[0], do (Actions)
    - Loop - Actions
      - If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoStage[AquaKono[1]] Equal to 0
        
        Then - Actions
        
        Set AquaKonoDummy[AquaKono[1]] = AquaKonoDummy[AquaKono[0]]
        
        Set AquaKonoCaster[AquaKono[1]] = AquaKonoCaster[AquaKono[0]]
        
        Set AquaKonoDelay[AquaKono[1]] = AquaKonoDelay[AquaKono[0]]
        
        Set AquaKonoRun[AquaKono[1]] = AquaKonoRun[AquaKono[0]]
        
        Set AquaKonoStage[AquaKono[1]] = AquaKonoStage[AquaKono[0]]
        
        Set AquaKonoDamage[AquaKono[1]] = AquaKonoDamage[AquaKono[0]]
        
        Set AquaKonoGroupDummy[AquaKono[1]] = AquaKonoGroupDummy[AquaKono[0]]
        
        Set AquaBoolean[AquaKono[1]] = AquaBoolean[AquaKono[0]]
        
        Set AquaKonoChance[AquaKono[1]] = AquaKonoChance[AquaKono[0]]
        
        Set AquaKonoX[AquaKono[1]] = AquaKonoX[AquaKono[0]]
        
        Set AquaKonoY[AquaKono[1]] = AquaKonoY[AquaKono[0]]
        
        Set AquaKono[1] = (AquaKono[1] - 1)
        
        Set AquaKono[0] = (AquaKono[0] - 1)
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKono[0] Equal to 0
        
        Then - Actions
        
        Trigger - Turn off (This trigger)
        
        Else - Actions
        
        Else - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoStage[AquaKono[1]] Equal to 1
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoDelay[AquaKono[1]] Greater than or equal to 1.80
        
        Then - Actions
        
        Set Point[2] = (Position of AquaKonoCaster[AquaKono[1]])
        
        Unit Group - Pick every unit in AquaKonoGroupDummy[AquaKono[1]] and do (Actions)
        
        Loop - Actions
        
        Set Point[3] = (Position of (Picked unit))
        
        Set AquaKonoRun[AquaKono[1]] = (Distance between Point[2] and Point[3])
        
        Set AquaKonoAngle[AquaKono[1]] = (Angle from Point[3] to Point[2])
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoRun[AquaKono[1]] Greater than or equal to AquaKonoSpeed[AquaKono[1]]
        
        Then - Actions
        
        Set Point[4] = (Point[3] offset by AquaKonoSpeed[AquaKono[1]] towards (AquaKonoAngle[AquaKono[1]] + 30.00) degrees)
        
        Unit - Move (Picked unit) instantly to Point[4], facing AquaKonoAngle[AquaKono[1]] degrees
        
        Custom script: call RemoveLocation(udg_Point[4])
        
        Else - Actions
        
        Unit - Kill (Picked unit)
        
        Unit Group - Remove (Picked unit) from AquaKonoGroupDummy[AquaKono[1]]
        
        Custom script: call RemoveLocation(udg_Point[3])
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        (AquaKonoGroupDummy[AquaKono[1]] is empty) Equal to True
        
        Then - Actions
        
        Set GenericGroup = (Units within 400.00 of Point[2] matching ((((Matching unit) is alive) Equal to True) and (((Matching unit) belongs to an enemy of (Owner of AquaKonoCaster[AquaKono[1]])) Equal to True)))
        
        Special Effect - Create a special effect at Point[2] using Objects\Spawnmodels\Other\NeutralBuildingExplosion\NeutralBuildingExplosion.mdl
        
        Special Effect - Destroy (Last created special effect)
        
        Unit Group - Pick every unit in GenericGroup and do (Actions)
        
        Loop - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        ((Picked unit) is Undead) Equal to True
        
        Then - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage (Picked unit), dealing (2.00 x AquaKonoDamage[AquaKono[1]]) damage of attack type Spells and damage type Magic
        
        Else - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage (Picked unit), dealing AquaKonoDamage[AquaKono[1]] damage of attack type Spells and damage type Magic
        
        Custom script: call DestroyGroup(udg_GenericGroup)
        
        Custom script: call DestroyGroup(udg_AquaKonoGroupDummy[udg_AquaKono[1]])
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Else - Actions
        
        Custom script: call RemoveLocation(udg_Point[2])
        
        Else - Actions
        
        Set AquaKonoDelay[AquaKono[1]] = (AquaKonoDelay[AquaKono[1]] + 0.03)
        
        Else - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoStage[AquaKono[1]] Equal to 2
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoRun[AquaKono[1]] Greater than or equal to AquaKonoDelay[AquaKono[1]]
        
        Then - Actions
        
        Set Point[2] = (Point(AquaKonoX[AquaKono[1]], AquaKonoY[AquaKono[1]]))
        
        Special Effect - Create a special effect at Point[2] using Objects\Spawnmodels\Naga\NagaDeath\NagaDeath.mdl
        
        Special Effect - Set Scale of (Last created special effect) to 2.00
        
        Special Effect - Destroy (Last created special effect)
        
        Set GenericGroup = (Units within 400.00 of Point[2] matching ((((Matching unit) is alive) Equal to True) and (((Matching unit) belongs to an enemy of (Owner of AquaKonoCaster[AquaKono[1]])) Equal to True)))
        
        Unit Group - Pick every unit in GenericGroup and do (Actions)
        
        Loop - Actions
        
        Set Chance = (Random integer number between 1 and 10)
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        Chance Less than or equal to 5
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        ((Picked unit) is Undead) Equal to True
        
        Then - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage (Picked unit), dealing (2.00 x AquaKonoDamage[AquaKono[1]]) damage of attack type Spells and damage type Magic
        
        Else - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage (Picked unit), dealing AquaKonoDamage[AquaKono[1]] damage of attack type Spells and damage type Magic
        
        Else - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage (Picked unit), dealing AquaKonoDamage[AquaKono[1]] damage of attack type Spells and damage type Magic
        
        Custom script: call RemoveLocation(udg_Point[2])
        
        Custom script: call DestroyGroup(udg_GenericGroup)
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Else - Actions
        
        Set AquaKonoRun[AquaKono[1]] = (AquaKonoRun[AquaKono[1]] + 0.03)
        
        Else - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoStage[AquaKono[1]] Equal to 3
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        (AquaKonoCaster[AquaKono[1]] is alive) Equal to True
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoRun[AquaKono[1]] Greater than or equal to AquaKonoDelay[AquaKono[1]]
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaBoolean[AquaKono[1]] Equal to True
        
        Then - Actions
        
        Unit - Set life of AquaKonoCaster[AquaKono[1]] to ((Percentage life of AquaKonoCaster[AquaKono[1]]) - 20.00)%
        
        Special Effect - Create a special effect attached to the origin of AquaKonoCaster[AquaKono[1]] using war3mapImported\WhiteChakraExplosion.mdx
        
        Special Effect - Destroy (Last created special effect)
        
        Else - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage AquaKonoDummy[AquaKono[1]], dealing AquaKonoDamage[AquaKono[1]] damage of attack type Spells and damage type Magic
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Unit - Unpause AquaKonoCaster[AquaKono[1]]
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoChance[AquaKono[1]] Equal to 1
        
        Then - Actions
        
        Special Effect - Create a special effect attached to the origin of AquaKonoDummy[AquaKono[1]] using war3mapImported\Shining Flare.mdx
        
        Special Effect - Destroy (Last created special effect)
        
        Else - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoChance[AquaKono[1]] Equal to 2
        
        Then - Actions
        
        Special Effect - Create a special effect attached to the origin of AquaKonoDummy[AquaKono[1]] using Abilities\Spells\Human\HolyBolt\HolyBoltSpecialArt.mdl
        
        Special Effect - Destroy (Last created special effect)
        
        Else - Actions
        
        Special Effect - Create a special effect attached to the origin of AquaKonoDummy[AquaKono[1]] using war3mapImported\Valiant Charge Holy.mdx
        
        Special Effect - Destroy (Last created special effect)
        
        Animation - Reset AquaKonoCaster[AquaKono[1]]'s animation
        
        Else - Actions
        
        Set AquaKonoRun[AquaKono[1]] = (AquaKonoRun[AquaKono[1]] + 0.03)
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoRun[AquaKono[1]] Equal to AquaKonoSpeed[AquaKono[1]]
        
        Then - Actions
        
        Animation - Play AquaKonoCaster[AquaKono[1]]'s spell two animation
        
        Else - Actions
        
        Else - Actions
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Else - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoStage[AquaKono[1]] Equal to 4
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        (Current order of AquaKonoCaster[AquaKono[1]]) Equal to (Order(blink))
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaKonoRun[AquaKono[1]] Greater than or equal to AquaKonoDelay[AquaKono[1]]
        
        Then - Actions
        
        Special Effect - Create a special effect attached to the origin of AquaKonoDummy[AquaKono[1]] using war3mapImported\WaterEnchant.mdx
        
        Special Effect - Destroy (Last created special effect)
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        (AquaKonoDummy[AquaKono[1]] belongs to an ally of (Owner of AquaKonoCaster[AquaKono[1]])) Equal to True
        
        Then - Actions
        
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
        
        If - Conditions
        
        AquaBoolean[AquaKono[1]] Equal to True
        
        Then - Actions
        
        Set GenericPoint = (Position of AquaKonoDummy[AquaKono[1]])
        
        Unit - Create 1 Peasant Caster for (Owner of AquaKonoCaster[AquaKono[1]]) at GenericPoint facing Default building facing degrees
        
        Unit - Add Inner Fire (Water of Regeneration) to (Last created unit)
        
        Unit - Set level of Inner Fire (Water of Regeneration) for (Last created unit) to AquaKonoChance[AquaKono[1]]
        
        Unit - Order (Last created unit) to Human Priest - Inner Fire AquaKonoDummy[AquaKono[1]]
        
        Unit - Add a 1.00 second Generic expiration timer to (Last created unit)
        
        Custom script: call RemoveLocation(udg_GenericPoint)
        
        Else - Actions
        
        Unit - Set life of AquaKonoDummy[AquaKono[1]] to ((Life of AquaKonoDummy[AquaKono[1]]) + AquaKonoDamage[AquaKono[1]])
        
        Floating Text - Create floating text that reads (+ + (String((Integer(AquaKonoDamage[AquaKono[1]]))))) above AquaKonoDummy[AquaKono[1]] with Z offset 0.00, using font size 13.00, color (0.00%, 100.00%, 0.00%), and 0.00% transparency
        
        Floating Text - Set the velocity of (Last created floating text) to 270.00 towards 90.00 degrees
        
        Floating Text - Change (Last created floating text): Disable permanence
        
        Floating Text - Change the lifespan of (Last created floating text) to 2.50 seconds
        
        Floating Text - Change the fading age of (Last created floating text) to 1.50 seconds
        
        Special Effect - Create a special effect attached to the origin of Elaina_Target[Elaina[1]] using Abilities\Spells\Human\Resurrect\ResurrectTarget.mdl
        
        Else - Actions
        
        Unit - Cause AquaKonoCaster[AquaKono[1]] to damage AquaKonoDummy[AquaKono[1]], dealing (0.50 x AquaKonoDamage[AquaKono[1]]) damage of attack type Spells and damage type Magic
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Else - Actions
        
        Set AquaKonoRun[AquaKono[1]] = (AquaKonoRun[AquaKono[1]] + 0.03)
        
        Else - Actions
        
        Set AquaKonoStage[AquaKono[1]] = 0
        
        Else - Actions

Uncle · Jul 1, 2025

When working in GUI you'll mostly encounter leaks related to these variable types: Unit Group, Player Group, Point, and Special Effect.

Local variables need to be "nulled" to avoid a leak as well, but the only way to use them in GUI is through Custom Script which people rarely do:

Custom script: local unit u = GetTriggerUnit()
Custom script: call KillUnit(u)
Custom script: set u = null

Global variables do NOT have to be "nulled" since they're permanent. Note that variables made in the Variable Editor are Global variables. The reason for the name is that they can be used in any trigger, so they're accessible from anywhere (globally). Local variables are only accessible from within the trigger that created them (locally).

With that in mind, it's easy to avoid memory leaks in GUI by using these functions:

Custom script: call RemoveLocation( udg_PointVariable )
Custom script: call DestroyGroup( udg_UnitGroupVariable )
Custom script: call DestroyForce( udg_PlayerGroupVariable )
Special Effect - Destroy (Last created special effect)

There might be some I'm forgetting about, but the above functions should be your primary solution for dealing with ~90% of your memory leaks.

So even if you're confused about "dealing with memory leaks" as a concept, you can follow the above rule of thumb for safely managing the majority of your memory leaks. Just remember that you don't need to remove/destroy something that is intended to be permanent, you only want to clean up your "trash".

Nichilus · Jul 1, 2025

Asuna Tichondrius said:
Also, one question are udg_UnitVariable = No Unit cause leak?

Strictly speaking, no. But not because setting unit variable to "No unit" would magically remove unit's memory leak. Memory leak definition is "an object allocated in memory which was not deallocated/destroyed and you lost all references to it" - meaning you cannot destroy it anymore and it keeps hanging in the memory.
But you can in most cases remove unit - for example by killing it or by giving it timed life. You can also get units using "Pick every unit" action.
The only cases where units would be considered memory leaks would be for example if you hid a unit and then kept it hidden until the end of the game. That unit would no longer be part of the game, but still be allocated in memory. Or a dummy unit with locust that is not properly removed and has no timed life. Such dummy would keep hanging on in the game.

Asuna Tichondrius said:
i didn't want create too much variable because performance issue.

What performance issues?

Asuna Tichondrius · Jul 1, 2025

Uncle said:
When working in GUI you'll mostly encounter leaks related to these variable types: Unit Group, Player Group, Point, and Special Effect.

Local variables need to be "nulled" to avoid a leak as well, but the only way to use them in GUI is through Custom Script which people rarely do:

Custom script: local unit u = GetTriggerUnit()

Custom script: call KillUnit(u)

Custom script: set u = null

Global variables do not have to be "nulled" since they're permanent. Note that variables made in the Variable Editor are Global variables. The reason for the name is that they can be used in any trigger, so they're accessible from anywhere (globally). Local variables are only accessible from within the trigger that created them (locally).

Anyway, it's pretty easy to avoid memory leaks in GUI. If you're not doing anything too advanced then this is basically all you need to worry about:

Custom script: call RemoveLocation( udg_PointVariable )

Custom script: call DestroyGroup( udg_UnitGroupVariable )

Custom script: call DestroyForce( udg_PlayerGroupVariable )

Special Effect - Destroy (Last created special effect)

There might be some I'm forgetting about, but the above functions should be your primary solution for dealing with ~90% of your memory leaks.

So it safe if i use like this or don't null it after all?

Untitled Trigger 002
- Events
- Conditions
- Actions
  - Set UnitVariable = (Triggering unit)
  - Custom script: do something
  - Set UnitVariable = No unit

Nichilus said:
What performance issues?

There are so long loading to load variable espically in Real variable one, because i have 600 of them.

Uncle · Jul 1, 2025

Asuna Tichondrius said:
So it safe if i use like this or don't null it after all?

Untitled Trigger 002

Events

Conditions

Actions

Set UnitVariable = (Triggering unit)

Custom script: do something

Set UnitVariable = No unit

Think back to what I said in my previous post:

These are your main leaks: Unit Group, Player Group, Point, Special Effect, Local variable.

Did you create one of the above?

No -> It's NOT a memory leak.
Yes -> It's a memory leak.

Of course there's some unmentioned cases but I left them out because I believe they're not worth worrying about yet. You'll encounter them if you start working with Hashtables/Local variables/Jass/Lua, etc... in which case you'll probably be following a tutorial that mentions the potential leaks.

Asuna Tichondrius · Jul 1, 2025

Uncle said:
Think back to what I said:

These are what leak: Unit Group, Player Group, Point, Special Effect, Local variable.

Did you create one of the above? No? Then it's not a memory leak.

Of course there's some unmentioned cases but I left them out because I believe they're not worth worrying about yet. You'll encounter them when you start working with Hashtables/Local variables/Jass/Lua, etc... in which case you'll probably be following a tutorial which mentions the potential leaks.

Alright alright thanks to make it clear? i'm just really confused hahaha

Uncle · Jul 1, 2025

Asuna Tichondrius said:
Alright alright thanks to make it clear? i'm just really confused hahaha

What type of variable is this?

Set UnitVariable = (Triggering unit)

Is it a Unit Group, Player Group, Point, Special Effect, or Local variable?
No.

Does the function it uses -> (Triggering unit) have anything to do with the above variable types?
No.

I'm oversimplifying things here since it can be confusing, but you really just need to memorize a few keywords and how to deal with them.

So setting UnitVariable = "No unit" is unnecessary since it's not a Local variable. Only Local variables need to be "nulled" when you're done with them. You also don't have any temporary objects to destroy/remove which Nichilus went into detail about.

Nichilus · Jul 1, 2025

Asuna Tichondrius said:
There are so long loading to load variable espically in Real variable one, because i have 600 of them.

I don't think this is any issue, to be honest. Most likely you had some triggers that were badly using those variables.
If the issue would be memory allocation for those 600 variables, then I think a more pressing issue would be using arrays, as each array always allocates space for 32768 different values (for indexes from 0 up to 32767).

You could consider:

using temp variables if you are having performance issues with world editor rather than during map gameplay. You would basically reuse a set of variables in multiple triggers, decreasing the amount of variables world editor has to track.
using local variables when you need to track some stuff in simple triggers. The only disadvantage is that you need to write them using vJASS/lua language inside Custom Script trigger action.
rewriting critical systems of your map into vJASS/lua, since GUI transformation to map script creates a lot of bloated code. This, of course, gives you easy access to local variables, but you need to learn vJASS/lua.

Did nulling unit group cause leak?

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