Hello,
We are currently making lots of changes to Rcpp (see the open Rcpp
mailing list if interested [1] in the details).
We are now using [2] R_PreserveObject and R_ReleaseObject to manage
garbage collection instead of the PROTECT/UNPROTECT dance. This seems to
work well, but I was wondering if there was documentation about it.
In particular, if we preserve the same SEXP twice (or more), should we
implement some sort of reference counting ?
Reading the source (below, from memory.c) I think not, but some
confirmation would help.
void R_PreserveObject(SEXP object)
{
R_PreciousList = CONS(object, R_PreciousList);
}
static SEXP RecursiveRelease(SEXP object, SEXP list)
{
if (!isNull(list)) {
if (object == CAR(list))
return CDR(list);
else
CDR(list) = RecursiveRelease(object, CDR(list));
}
return list;
}
void R_ReleaseObject(SEXP object)
{
R_PreciousList = RecursiveRelease(object, R_PreciousList);
}
I'd also be interested if there is some ideas on the relative efficiency
of the preserve/release mechanism compared to PROTECT/UNPROTECT.
Thanks,
Romain
[1] http://lists.r-forge.r-project.org/pipermail/rcpp-devel/
[2]
http://r-forge.r-project.org/plugins/scmsvn/viewcvs.php/pkg/src/RObject.cpp?rev=255&root=rcpp&view=markup
--
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
|- http://tr.im/IW9B : C++ exceptions at the R level
|- http://tr.im/IlMh : CPP package: exposing C++ objects
`- http://tr.im/HlX9 : new package : bibtex
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
