Control OpenMP thread count for dafr kernels.

set_num_threads(n) caps the number of OpenMP threads used by every subsequent kernel dispatch. get_num_threads() reports the current cap.

Usage

set_num_threads(n)

get_num_threads()

Arguments

n

Positive integer; the maximum number of OpenMP threads to use. Values < 1 are clamped to 1.

Value

set_num_threads invisibly returns n. get_num_threads returns the current OpenMP max-threads value.

Details

dafr's kernels default to the system's OpenMP maximum (typically OMP_NUM_THREADS or the machine's CPU count). CRAN policy allows at most two cores for package checks, and .onLoad() detects CRAN-like environments (via _R_CHECK_LIMIT_CORES_ or an OMP_THREAD_LIMIT ≤ 2) and caps to 2 automatically. Interactive users can raise or lower the cap at any time.

Examples

old <- get_num_threads()
set_num_threads(1L)   # single-thread mode
get_num_threads()     # 1
#> [1] 1
set_num_threads(old)  # restore