Can't solve Valgrind memory issues in Rcpp code

Question

I have posted my package on CRAN and recived Valgrind's check results revealing some memory leaks (link). Unfortunately, I can't reproduce these errors. Therefore, I have some hypothesis why these errors occur but can't test them. So I need an advice whether I am going in a right direction and how it is possible to fix corresponding errors.

There are lots of problem's indicated by Valgrind but some of them are similar in a sense that they refer to the same or similar lines of code. Therefore below I have described just some problems (error message) which are representative to others. Other messages could be found via above mentioned link.

Problem 1

When running the following example code (R call to function which uses Rcpp code i.e. C++ functions in some places):

# ... some preceding code with data preparation
pgn <- mvoprobit(z ~ w1 + w2,
                 data = data,
                 marginal = list("PGN" = 3))

Valgrind produces the error message:

==2563572== Invalid read of size 8
==2563572==    at 0x52B841: STRING_ELT (svn/R-devel/src/main/memory.c:3923)
==2563572==    by 0x175F1952: begin (R-devel/site-library/Rcpp/include/Rcpp/vector/string_proxy.h:167)
==2563572==    by 0x175F1952: operator!= (R-devel/site-library/Rcpp/include/Rcpp/vector/string_proxy.h:194)
==2563572==    by 0x175F1952: pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/pmnorm.cpp:384)
==2563572==    by 0x175C2584: _mnorm_pmnorm_try(SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/RcppExports.cpp:232)
==2563572==    by 0x1767C9B3: mnorm::pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (R-devel/site-library/mnorm/include/mnorm_RcppExports.h:138)
==2563572==    by 0x176867DE: lnL_mvoprobit(arma::Col<double>, Rcpp::Vector<19, Rcpp::PreserveStorage>, Rcpp::String, int, int) (packages/tests-vg/switchSelection/src/mvoprobit.cpp:399)
==2563572==    by 0x17663D34: _switchSelection_lnL_mvoprobit (packages/tests-vg/switchSelection/src/RcppExports.cpp:75)
==2563572==    by 0x4A268D: R_doDotCall (svn/R-devel/src/main/dotcode.c:880)
==2563572==    by 0x4E126C: bcEval (svn/R-devel/src/main/eval.c:8002)
==2563572==    by 0x4F43CF: Rf_eval (svn/R-devel/src/main/eval.c:1013)
==2563572==    by 0x4F620E: R_execClosure (svn/R-devel/src/main/eval.c:2187)
==2563572==    by 0x4F6F42: Rf_applyClosure (svn/R-devel/src/main/eval.c:2113)
==2563572==    by 0x4E45FD: bcEval (svn/R-devel/src/main/eval.c:7414)

After reading some tutorials on interpreting the results of Valgrind's check I have come to the conclusion that it is reasonable to read the error message from the down up. First, I see that the problem starts from the line 399 of the code in mvoprobit.cpp file which contains function lnL_mvoprobit. This line of code uses the other function pmnorm. Therefore I conclude that the problem occurs on line 384 of pmnorm.cpp which has the following line of code (Valgrind's mention of operator!= reinforce the hypothesis that it mentions exactly this line of code):

if (marginal_names[i] != "normal")

where marginal_names is a CharacterVector. I thought that Invalid read of size 8 message indicates that I am trying to read marginal_names[i] while it is empty (reinforce this hypothesis with begin mention by Valgrand) . However intensive check (including the check on other examples including other example code and various appropriate alternative input specifications) have revealed that when the example is running i inside a cycle where marginal_names[i] occures is always 0 (and never other value) while marginal_names is a character vector of a single (one) element. Therefore I can't understand the source of the problem.

Problem 2

The next Valgrind's message going straight after the first one is as follows:

==2563572==  Address 0x1920c570 is 7,840 bytes inside a block of size 7,960 alloc'd
==2563572==    at 0x484086F: malloc (/builddir/build/BUILD/valgrind-3.18.1/coregrind/m_replacemalloc/vg_replace_malloc.c:381)
==2563572==    by 0x5318D0: GetNewPage (svn/R-devel/src/main/memory.c:972)
==2563572==    by 0x533503: Rf_allocVector3 (svn/R-devel/src/main/memory.c:2812)
==2563572==    by 0x175C7ADA: SEXPREC* Rcpp::internal::primitive_range_wrap__impl__nocast<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, int>(__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, __gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, std::random_access_iterator_tag) [clone .isra.0] (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:116)
==2563572==    by 0x175CBFB2: primitive_range_wrap__impl<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, int> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:167)
==2563572==    by 0x175CBFB2: range_wrap_dispatch___impl<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, int> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:179)
==2563572==    by 0x175CBFB2: range_wrap_dispatch<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > >, int> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:419)
==2563572==    by 0x175CBFB2: range_wrap<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > > > (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:429)
==2563572==    by 0x175CBFB2: wrap<__gnu_cxx::__normal_iterator<int const*, std::vector<int, std::allocator<int> > > > (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:941)
==2563572==    by 0x175CBFB2: operator SEXP (R-devel/site-library/Rcpp/include/Rcpp/api/meat/Dimension.h:26)
==2563572==    by 0x175CBFB2: wrap_dispatch_unknown<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:503)
==2563572==    by 0x175CBFB2: wrap_dispatch_eigen<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:770)
==2563572==    by 0x175CBFB2: wrap_dispatch_unknown_importable<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:787)
==2563572==    by 0x175CBFB2: wrap_dispatch<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap.h:807)
==2563572==    by 0x175CBFB2: wrap<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/internal/wrap_end.h:30)
==2563572==    by 0x175CBFB2: operator=<Rcpp::Dimension> (R-devel/site-library/Rcpp/include/Rcpp/api/meat/proxy.h:33)
==2563572==    by 0x175CBFB2: arma_wrap<arma::Mat<double> > (R-devel/site-library/RcppArmadillo/include/RcppArmadillo/interface/RcppArmadilloWrap.h:33)
==2563572==    by 0x175CBFB2: SEXPREC* Rcpp::wrap<double>(arma::Mat<double> const&) (R-devel/site-library/RcppArmadillo/include/RcppArmadillo/interface/RcppArmadilloWrap.h:72)
==2563572==    by 0x175C7E23: get<arma::Mat<double> > (R-devel/site-library/Rcpp/include/Rcpp/vector/converter.h:80)
==2563572==    by 0x175C7E23: replace_element__dispatch__isArgument<Rcpp::traits::named_object<arma::Mat<double> > > (R-devel/site-library/Rcpp/include/Rcpp/vector/Vector.h:532)
==2563572==    by 0x175C7E23: replace_element__dispatch<Rcpp::traits::named_object<arma::Mat<double> > > (R-devel/site-library/Rcpp/include/Rcpp/vector/Vector.h:525)
==2563572==    by 0x175C7E23: replace_element<Rcpp::traits::named_object<arma::Mat<double> > > (R-devel/site-library/Rcpp/include/Rcpp/vector/Vector.h:514)
==2563572==    by 0x175C7E23: Rcpp::Vector<19, Rcpp::PreserveStorage> Rcpp::Vector<19, Rcpp::PreserveStorage>::create__dispatch<Rcpp::traits::named_object<Rcpp::Matrix<14, Rcpp::PreserveStorage> >, Rcpp::traits::named_object<Rcpp::Matrix<14, Rcpp::PreserveStorage> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> > >(Rcpp::traits::integral_constant<bool, true>, Rcpp::traits::named_object<Rcpp::Matrix<14, Rcpp::PreserveStorage> > const&, Rcpp::traits::named_object<Rcpp::Matrix<14, Rcpp::PreserveStorage> > const&, Rcpp::traits::named_object<arma::Mat<double> > const&, Rcpp::traits::named_object<arma::Mat<double> > const&, Rcpp::traits::named_object<arma::Mat<double> > const&, Rcpp::traits::named_object<arma::Mat<double> > const&, Rcpp::traits::named_object<arma::Mat<double> > const&) [clone .isra.0] (R-devel/site-library/Rcpp/include/Rcpp/generated/Vector__create.h:378)
==2563572==    by 0x175CAA52: create<Rcpp::traits::named_object<Rcpp::Matrix<14> >, Rcpp::traits::named_object<Rcpp::Matrix<14> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> >, Rcpp::traits::named_object<arma::Mat<double> > > (R-devel/site-library/Rcpp/include/Rcpp/generated/Vector__create.h:343)
==2563572==    by 0x175CAA52: cmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/cmnorm.cpp:261)
==2563572==    by 0x175F38F7: pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/pmnorm.cpp:638)
==2563572==    by 0x175FBAA4: pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/pmnorm.cpp:1343)
==2563572==    by 0x175C2584: _mnorm_pmnorm_try(SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/RcppExports.cpp:232)
==2563572==    by 0x1767C9B3: mnorm::pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (R-devel/site-library/mnorm/include/mnorm_RcppExports.h:138)
==2563572==    by 0x17670748: lnL_mnprobit(arma::Col<double>, Rcpp::Vector<19, Rcpp::PreserveStorage>, Rcpp::String, int, int) (packages/tests-vg/switchSelection/src/mnprobit.cpp:287)

Since it mentiones lnL_mnprobit function that does not related to mvoprobit function from the abovementioned example code (instead lnL_mnprobit associated with mnprobit function) I conclude that despite the fact where the error message located it is associated with another part of example code (that is going before the example code I have posted above):

# some data preparation code
model <- mnprobit(z ~ w1 + w2,
                  data = data)
summary(model)

Using the same logic as before I think that the problem associated with line 261 of cmnorm.cpp file that is as follows:

  List return_list = List::create(Named("mean") = mean_cond_numeric,
                                  Named("sigma") = sigma_cond_numeric,
                                  Named("s12s22") = s12s22,
                                  Named("sigma_d") = sigma_d,
                                  Named("sigma_g") = sigma_g,
                                  Named("sigma_dg") = sigma_dg,
                                  Named("sigma_g_inv") = sigma_g_inv);

where mean_cond_numeric and sigma_cond_numeric are Rcpp::NumericMatrix while s12s22, sigma_d, sigma_dg and sigma_g_inv are arma::mat. By running the example code I have checked that these matrices are always non-empty and contain correct values. My only hypothesis that the problem is that Rcpp::List contains both Rcpp::NumericMatrix and arma::mat. Could it be the source of memory problems?

Problem 3

The error message is as follows:

==2563572== 352 bytes in 1 blocks are possibly lost in loss record 94 of 1,822
==2563572==    at 0x4845464: calloc (/builddir/build/BUILD/valgrind-3.18.1/coregrind/m_replacemalloc/vg_replace_malloc.c:1328)
==2563572==    by 0x401364B: UnknownInlinedFun (/usr/src/debug/glibc-2.33-21.fc34.x86_64/elf/../include/rtld-malloc.h:44)
==2563572==    by 0x401364B: allocate_dtv (/usr/src/debug/glibc-2.33-21.fc34.x86_64/elf/../elf/dl-tls.c:366)
==2563572==    by 0x401364B: _dl_allocate_tls (/usr/src/debug/glibc-2.33-21.fc34.x86_64/elf/../elf/dl-tls.c:612)
==2563572==    by 0x53C8008: pthread_create@@GLIBC_2.2.5 (in /usr/lib64/libpthread-2.33.so)
==2563572==    by 0x5395283: ??? (in /usr/lib64/libgomp.so.1.0.0)
==2563572==    by 0x538C2D0: GOMP_parallel (in /usr/lib64/libgomp.so.1.0.0)
==2563572==    by 0x17607F70: normcdf_helper<arma::Mat<double>, arma::Gen<arma::Mat<double>, arma::gen_zeros>, arma::Gen<arma::Mat<double>, arma::gen_ones> > (R-devel/site-library/RcppArmadillo/include/armadillo_bits/fn_normcdf.hpp:67)
==2563572==    by 0x17607F70: arma::enable_if2<arma::is_real<arma::Mat<double>::elem_type>::value, arma::Mat<arma::Mat<double>::elem_type> >::result arma::normcdf<arma::Mat<double> >(arma::Base<arma::Mat<double>::elem_type, arma::Mat<double> > const&) (R-devel/site-library/RcppArmadillo/include/armadillo_bits/fn_normcdf.hpp:153)
==2563572==    by 0x175F4C5B: pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/pmnorm.cpp:725)
==2563572==    by 0x175C2584: _mnorm_pmnorm_try(SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*, SEXPREC*) (/tmp/RtmpvZ7OOy/R.INSTALL331e2639ef54f9/mnorm/src/RcppExports.cpp:232)
==2563572==    by 0x1767C9B3: mnorm::pmnorm(Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, Rcpp::Matrix<14, Rcpp::PreserveStorage>, Rcpp::Vector<14, Rcpp::PreserveStorage>, int, Rcpp::String, Rcpp::String, bool, bool, bool, bool, bool, bool, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, int, Rcpp::Nullable<Rcpp::Vector<19, Rcpp::PreserveStorage> >, bool, bool) (R-devel/site-library/mnorm/include/mnorm_RcppExports.h:138)
==2563572==    by 0x17670748: lnL_mnprobit(arma::Col<double>, Rcpp::Vector<19, Rcpp::PreserveStorage>, Rcpp::String, int, int) (packages/tests-vg/switchSelection/src/mnprobit.cpp:287)
==2563572==    by 0x17662A54: _switchSelection_lnL_mnprobit (packages/tests-vg/switchSelection/src/RcppExports.cpp:47)
==2563572==    by 0x4A268D: R_doDotCall (svn/R-devel/src/main/dotcode.c:880)

I think that the problem associated with 725 line of code from pmnorm.cpp:

arma::vec prob0 = (arma::normcdf(upr1) - arma::normcdf(lwr1)) %
                  (arma::normcdf(upr2) - arma::normcdf(lwr2));

Unfortunatelly I have no hypothesis why the error message occurs since arguments of arma::normcdf are always well defined.

I will be extremelly greatful for any help in understanding the source of abovementioned problems and comments on how to fix them!

This points from your package using your `mnorm` package to you `mnorm` package. Maybe you are doing something there that is not thread-safe. I do not have time right now to dig into this but have you considered _not_ doing OpenMP automatically but maybe just optionally and then maybe default to the option being 'off' to simply not trigger the issue? `valgrind` is a good and trusted tool, and R is known to _not_ be thread-safe. We can use OpenMP in R (and Rcpp) code, but only very carefully. — Dirk Eddelbuettel, May 05 '23 at 14:17
@DirkEddelbuettel thank you very much for the advice it was very helpfull. I have installed Valgrind on wsl (for Windows) and been able to reproduce the errors from CRAN. The source of problems was probably due to automatic OMP multithreading by some RcppArmadillo functions. After I have add: #define ARMA_DONT_USE_OPENMP #include to my .cpp files in mnorm and switchSelection packages Valgrind do not show any memory errors. — Bogdan, May 07 '23 at 16:39
Nice to hear! I have found over the year that those reports by CRAN using valgrind and/or UBSAN checkers can be trusted, they often reveal actual issues and it is worth honing in with smallest possible examples. That said, we also trust (Rcpp)Armadillo: it should not leak and does use OpenMP well by default on appropriate OSs. Maybe keep digging in case you have found a (rare, I would think bug) but it is possibly. I often find more often than not it was my use or setup as the root cause. — Dirk Eddelbuettel, May 07 '23 at 16:43

score 2 · Answer 1 · answered May 06 '23 at 06:29

"After reading some tutorials on interpreting the results of Valgrind's check I have come to the conclusion that it is reasonable to read the error message from the down up."

I would not recommend that.

Do not turn on leak checking initially.
Fix all errors from the top down.
When you have no more errors, turn on leak checking.
Fix the leaks from the bottom up (the largest leaks are at the end).

Assuming that

==2563572== Invalid read of size 8
==2563572==    at 0x52B841: STRING_ELT (svn/R-devel/src/main/memory.c:3923)

does refer to

if (marginal_names[i] != "normal")

it probably means that i is negative or larger than the number of elements that marginal_names was allocated to hold. The memcheck error should give more information as to how many bytes before or after the array the invalid write was.

But note that the assignment to `marginal_names[i]` comes from a call of a complex-enough R function that evaluates a formulates. All sorts of things could be going on. Also note two lines down we get `operator !=` -- but your overall points are very valid so I upvoted your answer. — Dirk Eddelbuettel, May 06 '23 at 13:40

Can't solve Valgrind memory issues in Rcpp code

1 Answers1