[Rcpp-devel] Using Rcpp::Function in parallel with TBB mutex lock & a reference.

[Dirk Eddelbuettel]

On 7 February 2025 at 14:01, Kumar MS wrote:
| Thank you Dirk. Your observation is correct. I am left with two questions. As
| always, I appreciate your answers.
| 
| 1. Except for this single step of calling an R function (model matrix-like
| objects that are being created by an external library in R), all my other
| computations are now implemented in C++ & thread friendly. Does this mean I
| would have no other option but to go serial if I need to call R an function? Do
| you have any alternative recommendations? I would really love to take advantage
| of RcppParallel/TBB here, as I have heavily exploited RcppParallel to
| parallelize everything else. 

Not to ruin your day (again) as I believe we have been over this a few times
between here and your StackOverflow questions: Nomatter how much you want it
to be possible you still cannot call back to R from the parallel code.

| 2. Your RInside calculations in the Boost thread example are multi-threaded,
| with a locking interface to RInside instance too. I wonder what makes that work
| well without R reporting issues, while the TBB/rcppParallel implementation
| taking a similar approach has trouble. 

RInside is not really a relevant example as it operates the other way around
where you have a `main()` function and want to embed R.  What we do with Rcpp
is typically a running R process from which we call extensions. Not the same.

Dirk

-- 
dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org