setThreadOptions.Rd

% 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()
}

}