[JASS] Very basic question regarding handles

[Molekyle]

This is probably an incredibly stupid question.. but at what point should I null handles for max efficiency? I'd like to use my script as a reference.

It seemed natural to me that the handles should be null'ed only once they have been declared - as shown below:

function SH_OL_conditions takes nothing returns nothing
    local trigger trig
    local unit caster
    local integer trigid
    local integer stats
    local effect sfx

    if GetSpellAbilityId() == SH_OL_spellid() then
        set caster = GetTriggerUnit()
        set stats = SH_OL_stats(SH_OL_getlevel(caster))
        set sfx = AddSpecialEffectTarget("Abilities\\Spells\\Orc\\Purge\\PurgeBuffTarget.mdl", caster, "origin")
        call SetHeroInt(caster, (GetHeroInt(caster, false)) + stats, true)
        call SetHeroAgi(caster, (GetHeroAgi(caster, false)) + stats, true)
        set trig = CreateTrigger()
        set trigid = GetHandleId (trig)
        call TriggerRegisterTimerEvent(trig, 0.2, true)
        call SaveTriggerActionHandle(udg_SH_hashtable , trigid, 0, TriggerAddAction(trig, function SH_OL_periodic))
        call SaveUnitHandle(udg_SH_hashtable, trigid, 1, caster)
        call SaveReal(udg_SH_hashtable, trigid, 2, 0.)
        call SaveReal(udg_SH_hashtable, trigid, 3, SH_OL_duration())
        call SaveInteger(udg_SH_hashtable, trigid, 4, stats)
        call SaveEffectHandle(udg_SH_hashtable, trigid, 5, sfx)
        set trig = null 
        set caster = null
        set sfx = null
    endif

endfunction

But looking at other people's code I tend to see this:

function SH_OL_conditions takes nothing returns nothing
    local trigger trig
    local unit caster
    local integer trigid
    local integer stats
    local effect sfx

    if GetSpellAbilityId() == SH_OL_spellid() then
        set caster = GetTriggerUnit()
        set stats = SH_OL_stats(SH_OL_getlevel(caster))
        set sfx = AddSpecialEffectTarget("Abilities\\Spells\\Orc\\Purge\\PurgeBuffTarget.mdl", caster, "origin")
        call SetHeroInt(caster, (GetHeroInt(caster, false)) + stats, true)
        call SetHeroAgi(caster, (GetHeroAgi(caster, false)) + stats, true)
        set trig = CreateTrigger()
        set trigid = GetHandleId (trig)
        call TriggerRegisterTimerEvent(trig, 0.2, true)
        call SaveTriggerActionHandle(udg_SH_hashtable , trigid, 0, TriggerAddAction(trig, function SH_OL_periodic))
        call SaveUnitHandle(udg_SH_hashtable, trigid, 1, caster)
        call SaveReal(udg_SH_hashtable, trigid, 2, 0.)
        call SaveReal(udg_SH_hashtable, trigid, 3, SH_OL_duration())
        call SaveInteger(udg_SH_hashtable, trigid, 4, stats)
        call SaveEffectHandle(udg_SH_hashtable, trigid, 5, sfx)
    endif

    set trig = null 
    set caster = null
    set sfx = null

endfunction

 

[Maker]

The first method.

 

[Molekyle]

Alright, thank you Maker : )

 

[Mr_Bean]

The first method is better, because in the second one you are assigning null to the handles that already aren't referencing anything, so it's a pointless operation

 

[Spartipilo]

Wait... the variable may be created without a value, but still created. Wouldn't they leak if the "if" conditions aren't met?

And the value these variables get inside the "if" doesn't remain on the variable outside/after the "if"? It does, it has to.

I always tough on using these variables in all the trigger (even the same for different stuff) and nullying at the end just those that aren't nulled during the trigger (like first of group unit)

Does this means that local variables are harmless until you assign them a value?

 

[Maker]

Does this means that local variables are harmless until you assign them a value?

Yes.

Additionally if you compare an unassigned variable to 0 or null, depending on variable type, the function will abort.

 

[Imp Midna]

Handle Variables don't leak. The Handles those Variables are assigned to leak because the internal refernce counter of wc is too dumb to decrease itself when a local gets out of scope. No Handle assigned, no leak.