Yeah, I get that they are async. What happens is that the background process is not doing anything when the process gets a SIGINT. I.e. the background process is just listening on its standard input.
AFAICT for an interactive process such a SIGINT is just swallowed, with a newline outputted to the terminal. But apparently, for this background process, it is not swallowed, and it is triggered later. FWIW it does not happen on Windows, not very surprisingly. Gabor On Tue, Apr 30, 2019 at 9:13 PM Simon Urbanek <simon.urba...@r-project.org> wrote: > > Interrupts are not synchronous in R - the signal only flags the request for > interruption. Nothing actually happens until R_CheckUserInterrupt() is called > at an interruptible point. In you case your code is apparently not calling > R_CheckUserInterrupt() until later as a side-effect of the next evaluation. > > Cheers, > Simon > > > > On Apr 30, 2019, at 3:44 PM, Gábor Csárdi <csardi.ga...@gmail.com> wrote: > > > > Hi All, > > > > I realize that this is not a really nice reprex, but anyone has an > > idea why a background R session would "remember" an interrupt (SIGINT) > > on Unix? > > > > rs <- callr::r_session$new() > > rs$interrupt() # just sends a SIGINT > > #> [1] TRUE > > > > rs$run(function() 1+1) > > #> Error: interrupt > > > > rs$run(function() 1+1) > > #> [1] 2 > > > > It seems that the main loop somehow stores the SIGINT it receives > > while it is waiting on stdin, and then it triggers it when some input > > comes in.... Maybe. Just speculating.... > > > > Thanks, > > Gabor > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
