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Specify the number of threads that SimInf should use

Source: R/openmp.R
set_num_threads.Rd

Set the number of threads to be used in SimInf code that is parallelized with OpenMP (if available).

Usage

set_num_threads(threads = NULL)

Arguments

threads

Integer specifying the maximum number of threads to use in OpenMP-parallelized functions. If NULL (default), SimInf attempts to use all available processors, subject to the limits imposed by the environment variables listed above.

Value

The previous value of the thread count is returned invisibly.

Details

The number of threads is initialized when SimInf is first loaded in the R session, based on optional environment variables (see ‘Details’). It can also be explicitly set by calling set_num_threads. If the environment variables affecting the thread count change, set_num_threads must be called again for the new values to take effect.

The function determines the number of available processors using omp_get_num_procs() and limits the thread count based on omp_get_thread_limit() and the following environment variables (checked in order of precedence):

  • SIMINF_NUM_THREADS: Specific limit for SimInf.

  • OMP_NUM_THREADS: General OpenMP limit.

  • OMP_THREAD_LIMIT: Maximum thread limit.

The threads argument allows you to override these limits, provided the requested value does not exceed the maximum allowed by the environment or hardware constraints.