[Rd] Stack checking, core dumps, and embedding R

[Prof Brian Ripley]

On Tue, 11 Apr 2006, Simon Urbanek wrote:

> On Apr 11, 2006, at 5:34 AM, A.J. Rossini wrote:
>
>> I've been experiencing some interesting stack warnings recently
>> when moving from R 2.2.x to the R 2.3.0 series and the R 2.4.0
>> series.  In particular, I'm getting warnings of "Error: C stack
>> usage is too close to the limit" before segfaulting, and this
>> wasn't happening under the 2.2.x series.
>>
>> Here's the question statement:  (ONLY) In the situation where one
>> is embedding R, is anyone else seeing this occur with recent (past
>> 2 weeks) versions of R (both the 2.3.x and 2.4.x series)?
>>
>
> When embedding R, the stack base is set to -1 (which is almost
> certainly wrong) if R cannot find the stack base using some system
> method.

Setting it to -1 means stack checking is disabled, so _no_ harm is done.
The test is

     if(R_CStackLimit != -1 && usage > 0.95 * R_CStackLimit) {

in errors.c.

> I have just fixed the detection for OS X, so you shouldn't
> get that message there anymore. However, I was wondering why to not
> set it to something reasonable - even if we are not the main
> application, IMHO less harm is done setting it to something based on
> the current stack pointer than using -1. The status quo relies on the
> embedding application to set the stack base - I don't know if that's
> a good idea. Opinions?

Wrong premise, wrong conclusion.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595