options.cpp

#include<RcppParallel.h>

#include<Rinternals.h>

#if RCPP_PARALLEL_USE_TBB // TBB support turned on

#include<string>
#include<exception>

extern"C" SEXP defaultNumThreads() {
 SEXP threadsSEXP = Rf_allocVector(INTSXP, 1);
#ifdef __TBB_task_arena_H
INTEGER(threadsSEXP)[0] = tbb::this_task_arena::max_concurrency();
#else
INTEGER(threadsSEXP)[0] = tbb::task_scheduler_init::default_num_threads();
#endif
return threadsSEXP;
}

#else// TBB support not turned on

#include<tthread/tinythread.h>

extern"C" SEXP defaultNumThreads() {
 SEXP threadsSEXP = Rf_allocVector(INTSXP, 1);
INTEGER(threadsSEXP)[0] = tthread::thread::hardware_concurrency();
return threadsSEXP;
}

#endif