From ripley at stats.ox.ac.uk  Mon Jan 16 09:08:16 2006
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Mon, 16 Jan 2006 08:08:16 +0000 (GMT)
Subject: [Rd] Provide both shlib and standard versions of R?
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On Mon, 16 Jan 2006, Bo Peng wrote:

>> then either build your own with correct options or talk to your
>> distribution's packaging team.
>
> It seems that my knowledge about this option is outdated.  When I
> first encountered this problem two years ago, the R/rpm distribution
> came with no libR.so. I was told that --enable-R-shlib would lead to
> 10% - 20% performance loss, and I had to re-compile R if I need to
> embed it.
>
> So I guess performance is no longer an issue and shared libraries are
> provided as default on all platforms now? I certainly welcome this
> change and I apologize for my unfounded accusation to R.

Why guess?  There are accurate statements in the R-admin manual, and the 
RH RPM change was discussed on this list in 2006:

https://stat.ethz.ch/pipermail/r-devel/2006-January/036118.html

> BTW, shouldn't --enable-R-shlib be yes by default during ./configure?.

No, for the reasons given in the R-admin manual.  They include that there 
are platforms on which --enable-R-shlib cannot be used.

We have been working (in R-devel) on changes which are designed to reduce 
the overhead of the shlib version of R: they do, but it is still over 10% 
on the platforms checked.  (The figures given earlier are optimistic in 
the sense that they include time spent in compiled code in packages such 
as stats in a typical R session: worst-case scenarios have up to double 
that.)

Please do think hard before you tell other people what they `should' do 
for you.

-- 
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



[Rd] Provide both shlib and standard versions of R?
Prof Brian Ripley