similar to: Thread-safe R functions

Jiefei, Beyond the general response that Luke gave, to be a bit more specific to what you said, DATAPTR and INTEGER_GET_REGION involve ALTREP method execution (for ALTREP objects, obviously) so even they are not as simple and straightforward as they were a couple years ago. They should not (any longer) be thought of as being guaranteed to be essentially bare metal data retrieval from memory.

Hi Gabriel, Thanks for your explanation, I totally understand that it is almost impossible to change the data structure of STRSXP. However, what I'm proposing is not about changing the internal representation, but rather about how we design and use the ALTREP API. I might do not state the workarounds clearly as English is not my first language. Please let me explain them again in detail.

Hi all, I'm wondering if there is any way to define a `SET_ELT` function for an ALTREP class? I see there are ` ALTINTEGER_SET_ELT` etc. functions exported in Rinternal.h, but there is no corresponding ALTREP APIs to define them. The only way to set the value of an ALTREP is through a pointer, which will require that the ALTREP data is in memory. Is it on purpose? Will there be any plan to

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 =

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,

Hi Gabriel, thanks for your detailed explanation, that definitely clarifies the design choices that were made in setting up the ALTREP framework and I can see how those choices make sure existing code won't break. My specific use-case for wanting to check whether a vector is an ALTREP is the following: the fst package wraps an external C++ library (fstlib, independent from R) that was made

thanks for clearing that up, so these methods are actually not meant to be exported on Windows and OSX? Some of the ALTREP methods that now use 'attribute_hidden' would be very useful to packages that aim to be ALTREP aware, should the currently (exported) API be considered final? thanks for your time & best, Mark On Tue, Jun 4, 2019 at 6:52 PM Tierney, Luke <luke-tierney at

Hello, I have two related ALTREP questions. It seems like there is no way to assign attributes to an ALTREP vector without using C++ code. To be more specifically, I want to make an ALTREP matrix, I have tried the following R code but none of them work. ``` .Internal(inspect(1:6)) .Internal(inspect(matrix(1:6, 2,3))) .Internal(inspect(as.matrix(1:6))) .Internal(inspect(structure(1:6, dim =

Hi Gabriel, here is a simple package for reproducing the problem. https://github.com/Jiefei-Wang/testPkg Best, Jiefei On Thu, Oct 8, 2020 at 5:04 AM Gabriel Becker <gabembecker at gmail.com> wrote: > Jiefei, > > Where does the code for your altrep class live? > > Thanks, > ~G > > On Wed, Oct 7, 2020 at 4:25 AM Jiefei Wang <szwjf08 at gmail.com> wrote: >

I can work on this. Thanks Luke. ~G On Wed, Jul 24, 2019 at 8:25 AM Tierney, Luke <luke-tierney at uiowa.edu> wrote: > If one of you wanted to try to create a patch to support ALTREP > generic vectors here are some notes: > > The main challenge I am aware of (there might be others): Allowing > DATAPTR to return a writable pointer would be too dangerous because > the GC

Dear Listmembers, wanting to learn more about ALTREP I wrote the following function to extract a subsequence from an integer vector: #include <Rinternals.h> SEXP integer_get_region(SEXP _x, SEXP _i, SEXP _n) { int i = INTEGER(_i)[0]; int n = INTEGER(_n)[0]; SEXP result = PROTECT(Rf_allocVector(INTSXP, n)); INTEGER_GET_REGION(_x, i, n, INTEGER(result)); UNPROTECT(1); return

Hi Kylie, Is it a list with only numerics in it? (I only see REALSXPs there, but obviously inspect isn't showing all of them). If so, you could load it up into one big vector and then also keep partitioning information around. Bioconductor does this (see ?IRanges::CompressedList ). The potential benefit here being that the underlying large vector could then be a big out-of-memory altrep. How

Experimenting with altrep objects and v3 serialization, I discovered a possible bug. Calling DATAPTR on a compact_intseq object returns a pointer to the expanded integer sequence in memory. If you modify this data, the object values appear to be changed. However, if the compact_intseq object is then serialized (with version=3), only the original integer sequence info is written. For example,

Hi Jiefei and Kylie, Great to see people engaging with the ALTREP framework and identifying places we may need more tooling. Comments inline. On Thu, Jul 18, 2019 at 12:22 PM King Jiefei <szwjf08 at gmail.com> wrote: > > If that is the case and you are 100% sure the reference number should be 1 > for your variable *y*, my solution is to call *SET_NAMED *in C++ to reset > the

You should assume that NO functions or macros in the R API are thread-safe. If some happen to be now, on some platforms, they are not guaranteed to be in the future. Even if you use a global lock you need to keep in mind that any function in the R API can signal an error and execute a longjmp, so you need to make sure you have set a top level context in your thread. Best, luke On Sun, 13 Sep

Hello, I have encountered two bugs when using ALTREP APIs. 1. STDVEC_DATAPTR >From RInternal.h file it has a comment: /* ALTREP support */ > void *(STDVEC_DATAPTR)(SEXP x); However, this comment might not be true, the easiest way to verify it is to define a C++ function: void C_testFunc(SEXP a) > { > STDVEC_DATAPTR(a); > } and call it in R via > a=1:10 > >

Hi, This problem started as of r73472 ("Merged in the rest of the basic ALTREP framework."); I tested r73471 and it did not exist. I'm building R devel on Ubuntu 16.04.3 LTS (64-bit), with the following flags: CC="gcc -std=gnu99 -fsanitize=address -fno-omit-frame-pointer" CFLAGS="-fno-omit-frame-pointer -g -O2 -Wall -pedantic -mtune=native" and using

Hi all, I found that the finalizer of the externalPtr is not called when R is quitting. However, manually calling GC() works fine. This behavior is observed on devel R 2020-04-02 r78142 on Win and R 3.6.3 on Ubuntu. I make a reproducible package here: https://github.com/Jiefei-Wang/example Here is the detail of how to reproduce the problem, I create a temporary file in the package root path and

Hi, As the subject suggests, I am looking for the most robust way to call an (arbitrary) function from the R API from another but the main POSIX thread in a package's code. I know that, "[c]alling any of the R API from threaded code is ?for experts only? and strongly discouraged. Many functions in the R API modify internal R data structures and might corrupt these data structures if

Hello from Bioconductor, I'm developing a package to share R objects across clusters using boost library. The concept is similar to mmap package: https://cran.r-project.org/web/packages/mmap/index.html . However, I have a problem when I was trying to write Dataptr_method for the alternative string. Based on my understanding, the return value of the Dataptr_method function should be a vector