future.globals does not seem to work when variables are "created" in the named list

[DavisVaughan]

Kind of an obscure issue but definitely an issue:

library(future.apply)

plan(sequential)
future_lapply(
  X = 1, 
  FUN = function(x) {y}, 
  future.globals = list(y = 4)
)
#> Error in ...future.FUN(...future.X_jj, ...): object 'y' not found

z <- 1
future_lapply(
  X = 1, 
  FUN = function(x) {y}, 
  future.globals = list(y = z)
)
#> Error in ...future.FUN(...future.X_jj, ...): object 'y' not found

Created on 2018-05-09 by the reprex package (v0.2.0).

Interestingly, the y value is recognized as a global, and makes it into the environment that the expression is evaluated in. You can see this by debugging and making your way to this line of run.UniprocessFuture(). Not sure why it can't be seen inside the lapply() after that

[DavisVaughan]

Seems to not be a problem with pure futures

library(future.apply)
#> Loading required package: future
#> 
#> Attaching package: 'future.apply'
#> The following object is masked from 'package:future':
#> 
#>     future_lapply
plan(sequential)
value(future({y}, globals = list(y = 4)))
#> [1] 4

value(future(
  expr = { lapply(1, function(x) {y}) }, 
  globals = list(y = 4)
))
#> [[1]]
#> [1] 4

Created on 2018-05-09 by the reprex package (v0.2.0).

[HenrikBengtsson]

Thxs. Here's an example of the problem using plain futures:

> library(future)
> plan(sequential)
> f <- futureCall(function(x) y, args = list(x = 1), future.globals = list(y = 3))
> value(f)
Error in (function (x)  : object 'y' not found

It'll be solved over at HenrikBengtsson/future#225. Closing this one.

[HenrikBengtsson]

My futureCall() example was invalid. Re-opening this future.apply issue for now (though the solution to it will still be in the future package).

[DavisVaughan]

FYI this affects multicore for me as well. multisession works though.

library(future.apply)

plan(multicore)
future_lapply(
  X = 1, 
  FUN = function(x) {y}, 
  future.globals = list(y = 4)
)
#> Error in ...future.FUN(...future.X_jj, ...): object 'y' not found

plan(multisession)
future_lapply(
  X = 1, 
  FUN = function(x) {y}, 
  future.globals = list(y = 4)
)
#> [[1]]
#> [1] 4

Created on 2018-05-14 by the reprex package (v0.2.0).

[HenrikBengtsson]

Turns out that I just fixed this in future (>= 1.21.0-9003) in HenrikBengtsson/future@6a87881, cf. HenrikBengtsson/future#515.