options change ignored in future_map

[Fritzimponis]

I have already asked this question in stack overflow but I didn't get any response so apologies for the cross posting. The question is updated with a reproducible example;

I am trying to use future_map from package furrr within a function I wrote. The function has a dependency on a particular option set in options(). When I change this option to something else it is completely ignored when the function runs in plan(multisession). Is there a way to "inform" every worker on the option change? If I change back to plan(sequential) the function works as expected.

Here is a reproducible example:

# Two functions 
abc <- function(n) {
   n * getOption("tst_value")
}
      
future_abc_mult <- function(n) {
   future_map(n, ~abc(.))
}

# Load packages:
library(furrr)

# Set options:
options(tst_value = 1)

# Try using default plan; sequential  
n = c(1,2,3,4)
future_abc_mult(n)

# Try using multiprocess plan  
plan(multiprocess)
future_abc_mult(n)

Here is my sessionInfo

sessionInfo()
R version 3.4.2 (2017-09-28)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_United Kingdom.1252 LC_CTYPE=English_United Kingdom.1252
[3] LC_MONETARY=English_United Kingdom.1252 LC_NUMERIC=C
[5] LC_TIME=English_United Kingdom.1252

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] furrr_0.1.0 future_1.9.0 dplyr_0.7.4 purrr_0.2.5 readr_1.1.1
[6] tidyr_0.7.2 tibble_1.3.4 ggplot2_2.2.1 tidyverse_1.1.1

loaded via a namespace (and not attached):
[1] Rcpp_0.12.13 cellranger_1.1.0 compiler_3.4.2 plyr_1.8.4 bindr_0.1
[6] forcats_0.2.0 tools_3.4.2 digest_0.6.15 lubridate_1.6.0 jsonlite_1.5
[11] nlme_3.1-131 gtable_0.2.0 lattice_0.20-35 pkgconfig_2.0.1 rlang_0.2.1
[16] psych_1.7.8 yaml_2.1.14 parallel_3.4.2 haven_1.1.0 bindrcpp_0.2
[21] xml2_1.1.1 stringr_1.2.0 httr_1.3.1 globals_0.12.1 hms_0.3
[26] grid_3.4.2 glue_1.1.1 listenv_0.7.0 R6_2.2.2 readxl_1.0.0
[31] foreign_0.8-69 modelr_0.1.1 reshape2_1.4.3 magrittr_1.5 codetools_0.2-15
[36] scales_0.5.0 rvest_0.3.2 assertthat_0.2.0 mnormt_1.5-5 colorspace_1.3-2
[41] stringi_1.1.5 lazyeval_0.2.0 munsell_0.4.3 broom_0.4.2

[DavisVaughan]

future actually documents this as a still open issue over there. Look there for a few examples of how to do this manually. I agree that it might should be easier, or made more clear, but its not anything that furrr will be able to do so I'm going to close!

futureverse/future#134