The second update of the 3.6.x release of simmer, the Discrete-Event Simulator for R, is on CRAN, thus inaugurating a bi-monthly release cycle. I must thank Duncan Garmonsway (@nacnudus) for creating and now maintaining “The Bank Tutorial: Part I” vignette, Franz Fuchs for finding an important and weird memory bug (here) that prevented
simmer from freeing the allocated memory (all 3.x.x versions are affected up to this release), and the
Rcpp people for enduring me while I was helplessly searching for a solution to this. 🙂
My special thanks to Kevin Ushey (@kevinushey), who finally found the bug. As it happens, the bug was not in
Rcpp but in
magrittr, and the problem is that the pipe operator, in its inscrutable magic, creates a new environment for unnamed functions (instead of the current one, as it should be), and there it stores a reference to the first object in the pipe. More or less. Further details here.
Anyway, if somebody faces the same problem, know that there is a workaround: you just need to delete that hidden reference, as
simmer does in this release to get rid of the memory issues. Happy simmering!
Minor changes and fixes:
- Update “The Bank Tutorial: Part I” vignette (@nacnudus in #90).
trap()’s handler cloning and associated test (#91).
resourcesis a function (#92).
- Accept dynamic timeouts in batches (#93).
rollback()’s default behaviour to
times=Inf, i.e., infinite loop (#95).
- Stop and throw an error when
timeout()returns a missing value (#96 and #97).
- Fix memory management: resetting the environment was clearing but not deallocating memory (#98, fixed in #99).
- Fix object destruction: workaround for tidyverse/magrittr#146 (#98, fixed in effcb6b).
Article originally published in Enchufa2.es: simmer 3.6.2.