% Generated by roxygen2: do not edit by hand % Please edit documentation in R/options.R \name{setThreadOptions} \alias{setThreadOptions} \alias{defaultNumThreads} \title{Thread options for RcppParallel} \usage{ setThreadOptions(numThreads = "auto", stackSize = "auto") defaultNumThreads() } \arguments{ \item{numThreads}{Number of threads to use for task scheduling. Call \code{defaultNumThreads()} to determine the the default value used for "auto".} \item{stackSize}{Stack size (in bytes) to use for worker threads. The default used for "auto" is 2MB on 32-bit systems and 4MB on 64-bit systems (note that this parameter has no effect on Windows).} } \value{ \code{defaultNumThreads()} returns the default number of threads used by RcppParallel, if another value isn't specified either via \code{setThreadOptions()} or explicitly in calls to \code{parallelFor()} and \code{parallelReduce()}. } \description{ Set thread options (number of threads to use for task scheduling and stack size per-thread) for RcppParallel. } \details{ RcppParallel is automatically initialized with the default number of threads and thread stack size when it loads. You can call \code{setThreadOptions()} at any time to change the defaults. The \code{parallelFor()} and \code{parallelReduce()} also accept \code{numThreads} as an argument, if you'd like to control the number of threads specifically to be made available for a particular parallel function call. Note that this value is advisory, and TBB may choose a smaller number of threads if the number of requested threads cannot be honored on the system. } \examples{ \dontrun{ library(RcppParallel) setThreadOptions(numThreads = 4) defaultNumThreads() } }