set_num_threads: Set the number of OpenMP threads OpenFHE may use

In openfhe.R: R Interface to the 'OpenFHE' Fully Homomorphic Encryption Library

Set the number of OpenMP threads OpenFHE may use

Description

OpenFHE parallelizes its core arithmetic with OpenMP and, by default, uses every hardware thread the machine reports. set_num_threads() sets the cap through OpenFHE's own thread controls, which every parallel region in the library consults when it starts, so the change takes effect immediately, on every platform, and regardless of which thread the work runs on. It is a no-op when the package was built without OpenMP.

Usage

set_num_threads(n)

Arguments

n	integer; the requested maximum number of threads (at least 1).

Details

Requests above the number of threads available when the library was loaded (the hardware count, or OMP_NUM_THREADS if that was set before R started) are reduced to that number. The value in effect is returned, so a reduced request is visible to the caller; get_num_threads() reports the same value later.

The package default is uncapped, so interactive users get full parallelism. Under ⁠R CMD check⁠, which sets ⁠_R_CHECK_LIMIT_CORES_⁠, the package caps itself at two threads when it is loaded, in line with CRAN's two-thread policy. This also covers packages that depend on 'openfhe.R', which therefore need no thread handling of their own.

Value

integer; the cap now in effect, invisibly.

See Also

get_num_threads()

Examples

old <- get_num_threads()
set_num_threads(2L)
set_num_threads(old)

openfhe.R documentation built on Nov. 13, 2026, 5:07 p.m.