Run a function (job) in another session

Usage

start_job(
  fun,
  fun_args = list(),
  packages = NULL,
  workdir = NULL,
  method = c("callr", "rs_job", "mirai"),
  name = NULL,
  ensure_init = TRUE,
  digest_key = NULL,
  envvars = NULL
)

check_job(job_id)

resolve_job(
  job_id,
  timeout = Inf,
  auto_remove = TRUE,
  must_init = TRUE,
  unresolved = c("warning", "error", "silent")
)

remove_job(job_id)

Arguments

fun: function to evaluate
fun_args: list of function arguments
packages: list of packages to load
workdir: working directory; default is temporary path
method: job type; choices are 'rs_job' (only used in 'RStudio' environment), 'mirai' (when package 'mirai' is installed), and 'callr' (default).
name: name of the job
ensure_init: whether to make sure the job has been started; default is true
digest_key: a string that will affect how job ID is generated; used internally
envvars: additional environment variables to set; must be a named list of environment variables
job_id: job identification number
timeout: timeout in seconds before the resolve ends; jobs that are still running are subject to unresolved policy
auto_remove: whether to automatically remove the job if resolved; default it true
must_init: whether the resolve should error out if the job is not initialized: typically meaning the either the resolving occurs too soon (only when ensure_init=FALSE) or the job files are corrupted; default is true
unresolved: what to do if the job is still running after timing-out; default is 'warning' and return NULL, other choices are 'error' or 'silent'

Value

For start_job, a string of job identification number; check_job returns the job status; resolve_job returns the function result.

Examples


if (FALSE) { # \dontrun{

# Basic use
job_id <- start_job(function() {
  Sys.sleep(1)
  Sys.getpid()
})

check_job(job_id)

result <- resolve_job(job_id)


# As promise
library(promises)
as.promise(
  start_job(function() {
    Sys.sleep(1)
    Sys.getpid()
  })
) %...>%
  print()

} # }