[R] dyn.load the same code more than once?
Prof Brian Ripley
ripley at stats.ox.ac.uk
Fri Jan 5 19:09:38 CET 2001
On Fri, 5 Jan 2001, Matthew Wiener wrote:
> Hi. I'm still working on figuring out why some C code that interfaced
> nicely with R-1.1.1 is causing segmentation faults in R-1.2.0. Brian
> Ripley advised me that R-1.2.0 can be more sensitive to array overruns
> than was R-1.1.1, so I'm looking for overruns. But in the course of
> running R with a debugger I've come across something else.
> Without thinking about it much, I put the dyn.load statement loading my
> compiled code into the function immediately before the code is called.
> This means that the dyn.load call is being executed over and over. This
> has never seemed to cause a problem, but under the debugger I get an error
> after several times that some address cannot be accessed (the exact
> address changes from time to time). If I'm not in the debugger, this
> doesn't happen, but perhaps it has something to do with my eventual memory
> So my question is: can multiple loading of code cause a problem? If so,
> what kind?
Well, there are finite resources in src/unix/dynload.c, like for 100
> Also, I'll try loading the code in my .First function instead. Can this
> lead to any problems (like memory issues if I load lots of functions)?
Not at all. You only load the code, don't find all the entry points.
It is what we advise.
> I'm working on an alpha running Red Hat Linux.
> Matt Wiener
> r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> Send "info", "help", or "[un]subscribe"
> (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
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 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
More information about the R-help