[asterisk-users] While loop inside recursive calls

[Jonathan H]

Well, I've never seen dialplan like that - is this a very old version
of Asterisk, or psuedocode?

Anyway..

A subroutine MUST be balanced, and if a subroutine is aborted before
it reaches return, you'll be in all sorts of hell.

An example:

You make a subroutine of some sound files you want to loop through to
make an IVR menu.

You call it using Gosub. Someone presses two while the third of 5
tracks is playing.

The stack will then be unbalanced and you'll then be in a potential
world of stack overflow and unknown hell.

So keep the gosubs for things where they cannot be interrupted.
Playback is fine. Background and ControlPlayback is not. See?

Here's a solution to this problem which caused me HUGE amounts of
headaches early on (and I mean days and nights on end!)

Hope it helps...
https://github.com/lardconcepts/asterisk-pbx-tips-and-snips/blob/master/gotchas-and-warnings.md

On 21 March 2017 at 17:31, Ethy H. Brito <ethy.brito at inexo.com.br> wrote:
>
> Hi All
>
> What happens if I, inside of a while/endwhile loop, call recursively a
> macro that itself has another while/endwhile loop and calls exitwhile() inside the
> recursive call?
>
> [macro-recursive]
> instance=$ARG1
> if instance>3
>         macroexit
> X=1
> _var1=""
> ; recursive loop
> while(Dcondition)
>         _var1=value_${X}
>         recursive(instance+1)
>         if var1==""
>                 ExitWhile()
>         X=X+1
>         some_Dcondition_changing
>         bla...
>         bla...
> EndWhile
> macroexit
>
> [some_running_context]
> ; Main loop
> while(Zcondition)
>         recursive(1)
>         if (var1=="")
>             ExitWhile
>         some_Zcondition_changing
>         bla...
>         bla...
> endwhile
> more_intructions
> MacroExit
>
> The problem I see is if I reentry "macro-recursive" a the second time,
> Macroexit returns to "more_instructions" at "some_running_context" (just after
> the Main Loop endWhile). It should return to 'if (var1=="")' at the previous
> "macro-recursive" call.
>
> It is like the second call to "macro-recursive" overwrites the first
> "macro-recursive" while/endwhile loop return point, and the second ExitWhile
> exits from the while/endwhile at "some_running_context" and not from first
> "macro-recursive" instance.
>
> In short: second (and subsequent??) call to macro-recursive is ExitWhile()ing
> from "some_running_context" while loop. First call exits ok.
>
> Any directions to share?
>
> Is this explanation too complicated to understand?
>
> Regards
>
> Ethy
>
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