On Tue, Jan 26, 2021 at 1:23 PM Matthew Flatt <[email protected]> wrote:
> At Tue, 26 Jan 2021 10:25:42 +0100, Ryan Culpepper wrote: > > This "works", but is it reliably safe to use place-channel-put from an OS > > thread? > > No. It's not intended to work from an arbitrary OS thread, and because > `place-channel-put` touches the thread scheduler to enter atomic mode, > I can imagine that it might go wrong either now or with some small > future change. > > > Or is there a better way to do this? > > Probably the only way currently is to use `unsafe-poller`. See > "rktrl.rkt" in "readline" for an example. It would make sense to make > that part of `ffi/unsafe/thread` or a new `ffi/unsafe` library. (It > would also be good to add `unsafe-make-signal-received` to > `ffi/unsafe/schedule`.) > Thanks for the pointer! Those sound useful, but in the spirit of maximum caution, is there a guarantee that the write to the box from the new OS thread will be visible to the original Racket OS thread when the poller tries to read it? Is `box-cas!` or one of the memory-order operations needed? Ryan -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CANy33qm9Fu%3DxPWSG%2BPRoG9Pbfddo0FJQLnb_CWr8isvCmGNSfQ%40mail.gmail.com.
