[Rd] [External] Something is wrong with the unserialize function

[Jiefei Wang]

Thanks for the fix! I will wait for the update and try it again.

Best,
Jiefei

On Fri, Oct 30, 2020 at 1:42 AM <luke-tierney using uiowa.edu> wrote:

> I found that also; fixed in r79386 in the trunk. Will port to R-patched
> shortly.
>
> Best,
>
> luke
>
> On Thu, 29 Oct 2020, Martin Morgan wrote:
>
> > This
> >
> > Index: src/main/altrep.c
> > ===================================================================
> > --- src/main/altrep.c (revision 79385)
> > +++ src/main/altrep.c (working copy)
> > @@ -275,10 +275,11 @@
> >       SEXP psym = ALTREP_SERIALIZED_CLASS_PKGSYM(info);
> >       SEXP class = LookupClass(csym, psym);
> >       if (class == NULL) {
> > -         SEXP pname = ScalarString(PRINTNAME(psym));
> > +         SEXP pname = PROTECT(ScalarString(PRINTNAME(psym)));
> >           R_tryCatchError(find_namespace, pname,
> >                           handle_namespace_error, NULL);
> >           class = LookupClass(csym, psym);
> > +         UNPROTECT(1);
> >       }
> >       return class;
> >     }
> >
> > seems to remove the warning; I'm guessing that the other SEXP already
> exist so don't need protecting?
> >
> > Martin Morgan
> >
> >
> > On 10/29/20, 12:47 PM, "R-devel on behalf of luke-tierney using uiowa.edu" <
> r-devel-bounces using r-project.org on behalf of luke-tierney using uiowa.edu> wrote:
> >
> >    Thanks for the report. Will look into it when I get a chance unless
> >    someone else gets there first.
> >
> >    A simpler reprex:
> >
> >    ## create and serialize a memmory-mapped file object
> >    filePath <- "x.dat"
> >    con <- file(filePath, "wrb")
> >    writeBin(rep(0.0,10),con)
> >    close(con)
> >
> >    library(simplemmap)
> >    x <- mmap(filePath, "double")
> >    saveRDS(x, file = "x.Rds")
> >
> >    ## in a separate R process:
> >    gctorture()
> >    readRDS("x.Rds")
> >
> >    Looks like a missing PROTECT somewhere.
> >
> >    Best,
> >
> >    luke
> >
> >    On Thu, 29 Oct 2020, Jiefei Wang wrote:
> >
> >    > Hi all,
> >    >
> >    > I am not able to export an ALTREP object when `gctorture` is on in
> the
> >    > worker. The package simplemmap can be used to reproduce the
> problem. See
> >    > the example below
> >    > ```
> >    > ## Create a temporary file
> >    > filePath <- tempfile()
> >    > con <- file(filePath, "wrb")
> >    > writeBin(rep(0.0,10),con)
> >    > close(con)
> >    >
> >    > library(simplemmap)
> >    > library(parallel)
> >    > cl <- makeCluster(1)
> >    > x <- mmap(filePath, "double")
> >    > ## Turn gctorture on
> >    > clusterEvalQ(cl, gctorture())
> >    > clusterExport(cl, "x")
> >    > ## x is an 0-length vector on the worker
> >    > clusterEvalQ(cl, x)
> >    > stopCluster(cl)
> >    > ```
> >    >
> >    > you can find more info on the problem if you manually build a
> connection
> >    > between two R processes and export the ALTREP object. See output
> below
> >    > ```
> >    >> con <- socketConnection(port = 1234,server = FALSE)
> >    >> gctorture()
> >    >> x <- unserialize(con)
> >    > Warning message:
> >    > In unserialize(con) :
> >    >  cannot unserialize ALTVEC object of class 'mmap_real' from package
> >    > 'simplemmap'; returning length zero vector
> >    > ```
> >    > It seems like  simplemmap did not get loaded correctly on the
> worker. If
> >    > you run `library( simplemmap)` before unserializing the ALTREP,
> there will
> >    > be no problem. But I suppose we should be able to unserialize
> objects
> >    > without preloading the library?
> >    >
> >    > This issue can be reproduced on Ubuntu with R version 4.0.2
> (2020-06-22)
> >    > and Windows with R Under development (unstable) (2020-09-03 r79126).
> >    >
> >    > Here is the link to simplemmap:
> >    > https://github.com/ALTREP-examples/Rpkg-simplemmap
> >    >
> >    > Best,
> >    > Jiefei
> >    >
> >    >  [[alternative HTML version deleted]]
> >    >
> >    > ______________________________________________
> >    > R-devel using r-project.org mailing list
> >    > https://stat.ethz.ch/mailman/listinfo/r-devel
> >    >
> >
> >    --
> >    Luke Tierney
> >    Ralph E. Wareham Professor of Mathematical Sciences
> >    University of Iowa                  Phone:             319-335-3386
> >    Department of Statistics and        Fax:               319-335-3017
> >        Actuarial Science
> >    241 Schaeffer Hall                  email:   luke-tierney using uiowa.edu
> >    Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu
> >
> >    ______________________________________________
> >    R-devel using r-project.org mailing list
> >    https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
> --
> Luke Tierney
> Ralph E. Wareham Professor of Mathematical Sciences
> University of Iowa                  Phone:             319-335-3386
> Department of Statistics and        Fax:               319-335-3017
>     Actuarial Science
> 241 Schaeffer Hall                  email:   luke-tierney using uiowa.edu
> Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu

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