tests/Future-class.R

In future: Unified Parallel and Distributed Processing in R for Everyone

source("incl/start.R")

message("*** Future class ...")

message("*** Future class - exception ...")

f <- Future()
print(f)

res <- tryCatch(value(f), error = identity)
print(res)
stopifnot(inherits(res, "error"))

## Invalid seed
res <- tryCatch(f <- Future(42, seed = 1:2), error = identity)
stopifnot(inherits(res, "error"))

## When no packages are exported
foo <- structure(function(...) { Future(1) }, class = "future")
plan(foo)
f <- Future()
expr <- getExpression(f)
print(expr)
stopifnot(is.call(expr))

clazzes <- list(
  sequential = SequentialFuture,
  multisession = function(...) MultisessionFuture(..., workers = I(1L)),
  sequential = SequentialFuture
)
if (supportsMulticore()) {
  clazzes$multicore = function(...) MulticoreFuture(..., workers = I(1L))
}

for (clazz in clazzes) {
  ## Calling run() more than once
  f <- clazz({ 42L })
  print(f)
  run(f)
  res <- tryCatch(run(f), error = identity)
  stopifnot(inherits(res, "error"))
  v <- value(f)
  print(v)
  stopifnot(v == 42L)

  ## Call value() without run()
  f <- clazz({ 42L })
  v <- value(f)
  print(v)
  stopifnot(v == 42L)
  
  ## To avoid 'multisession' from leaving stray workers behind
  ClusterRegistry(action = "stop")
}

message("*** Future class - exception ... DONE")

message("*** Future class ... DONE")

source("incl/end.R")