Set up or stop parallel processing plan

Configures parallel processing with future::plan() or stops an existing plan. When stopping, it resets to sequential mode.

Usage

set_parallel(
  n_cores = 1L,
  strategy = "multisession",
  stop_cluster = FALSE,
  show_log = TRUE,
  future_max_size = 500L,
  ...
)

Arguments

n_cores

Integer. Number of cores to use. If NULL, defaults to sequential mode. Default is 1.

strategy

Character. The parallel processing strategy to use. Valid options are "sequential", "multisession" (default), "multicore", and "cluster". See future::plan() and set_parallel() for details.

stop_cluster

Logical. If TRUE, stops any parallel cluster and resets to sequential mode. If FALSE (default), sets up a new plan.

show_log

Logical. If TRUE (default), logs messages via cat_time().

future_max_size

Numeric. Maximum allowed total size (in megabytes) of global variables identified. See future.globals.maxSize argument of future::future.options for more details. Default is 500L for 500 MB.

...

Additional arguments to pass to cat_time.

Author

Ahmed El-Gabbas

Examples

load_packages(future)

# number of workers available
future::nbrOfWorkers()
#> [1] 1

# ---------------------------------------------
# `multisession`
# ---------------------------------------------

# Prepare working in parallel
set_parallel(n_cores = 2)
#> Setting up parallel processing using 2 cores (strategy: `multisession`) - 14:50:19
future::plan("list")
#> List of future strategies:
#> 1. multisession:
#>    - args: function (..., workers = 2L, gc = TRUE, envir = parent.frame())
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = strategy, workers = n_cores, gc = TRUE)
future::nbrOfWorkers()
#> [1] 2

# Stopping parallel processing
set_parallel(stop_cluster = TRUE)
#> Stopping parallel processing - 14:50:20
future::plan("list")
#> List of future strategies:
#> 1. sequential:
#>    - args: function (..., gc = TRUE, envir = parent.frame(), workers = "<NULL>")
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = "sequential", gc = TRUE)
future::nbrOfWorkers()
#> [1] 1

# ---------------------------------------------
# `cluster`
# ---------------------------------------------

# Prepare working in parallel
set_parallel(n_cores = 2, strategy = "cluster")
#> Setting up parallel processing using 2 cores (strategy: `cluster`) - 14:50:20
future::plan("list")
#> List of future strategies:
#> 1. cluster:
#>    - args: function (..., workers = 2L, gc = TRUE, envir = parent.frame())
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = strategy, workers = n_cores, gc = TRUE)
future::nbrOfWorkers()
#> [1] 2

# Stopping parallel processing
set_parallel(stop_cluster = TRUE)
#> Stopping parallel processing - 14:50:21
future::plan("list")
#> List of future strategies:
#> 1. sequential:
#>    - args: function (..., gc = TRUE, envir = parent.frame(), workers = "<NULL>")
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = "sequential", gc = TRUE)
future::nbrOfWorkers()
#> [1] 1

# ---------------------------------------------
# `multicore`
# ---------------------------------------------

# Prepare working in parallel
set_parallel(n_cores = 2, strategy = "multicore")
#> Setting up parallel processing using 2 cores (strategy: `multicore`) - 14:50:21
future::plan("list")
#> List of future strategies:
#> 1. multicore:
#>    - args: function (..., workers = 2L, gc = TRUE, envir = parent.frame())
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = strategy, workers = n_cores, gc = TRUE)
future::nbrOfWorkers()
#> [1] 2
#> attr(,"class")
#> [1] "integer"

# Stopping parallel processing
set_parallel(stop_cluster = TRUE)
#> Stopping parallel processing - 14:50:21
future::plan("list")
#> List of future strategies:
#> 1. sequential:
#>    - args: function (..., gc = TRUE, envir = parent.frame(), workers = "<NULL>")
#>    - tweaked: TRUE
#>    - call: future::plan(strategy = "sequential", gc = TRUE)
future::nbrOfWorkers()
#> [1] 1

# ---------------------------------------------
# `sequential`
# ---------------------------------------------

set_parallel(n_cores = 1, strategy = "sequential")
future::nbrOfWorkers()
#> [1] 1