Get the number of workers available

nbrOfWorkers(evaluator = NULL)

nbrOfFreeWorkers(evaluator = NULL, background = FALSE, ...)

Arguments

evaluator: A future evaluator function. If NULL (default), the current evaluator as returned by plan() is used.
background: If TRUE, only workers that can process a future in the background are considered. If FALSE, also workers running in the main R process are considered, e.g. when using the 'sequential' backend.
...: Not used; reserved for future use.

nbrOfWorkers() returns a positive number in \({1, 2, 3, ...}\), which for some future backends may also be +Inf.

nbrOfFreeWorkers() returns a non-negative number in \({0, 1, 2, 3, ...}\) which is less than or equal to nbrOfWorkers().

plan(multisession)
nbrOfWorkers()  ## == availableCores()
#> system 
#>      8 

plan(sequential)
nbrOfWorkers()  ## == 1
#> [1] 1