[PD] What exactly is a "stack overflow" ?

IOhannes m zmoelnig zmoelnig at iem.at
Mon Dec 17 21:08:05 CET 2007

Andy Farnell wrote:
> On Mon, 17 Dec 2007 20:08:20 +0100
> Derek Holzer <derek at umatic.nl> wrote:
>> Sending a "bang" message to the [until] object, created without an 
>> argument saying how many times the bang should be done, will give 
>> roughly the same effect--
> If only!
> Objects that overflow the stack cause an exception, most of which trap
> nicely and you get a gentle report not to do that again.
> Sending an unqualified  bang to [until] will have you reaching for power
> switch because it enters a very tight loop with no exit condition and no
> hope of even seeing a SIGINT.
> I know we like to pretend this is "feature", but isn't it time to treat it
> as a bug?

so what is the behaviour you would like to see?
only allow fixed sized loops?
stop iterating after a maximum 10 bangs?
use [del 0] inbetween to make the loop interruptible?

all of the above would break a lot of my patches.

btw, Pd does not freeze for me. while i am typing this email, an 
infinite [until] is eating most of my CPU power (but not all).

now i did send it a SIGINT and this freed my CPU.


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