Jan Midtgaard

> @jmid also argued that spawning a pair of Domains for each pair of parallel command sequences allows to test them for a clean state. Although it’s true that it...

This is excellent Olivier, thanks a bunch! :pray: I was hoping to pull off something like this initially, but couldn't quite get the type-encoding working... As much as I love...

Saw this again - but now in MSVC native mode - and causing a crash: https://github.com/ocaml-multicore/multicoretests/actions/runs/9126100215/job/25093649961?pr=458 ``` random seed: 251075488 generated error fail pass / total time test name [...

Note to self: Exit code `-1073741819` corresponds to `c0000005` ```ocaml Printf.sprintf "%lx" (-1073741819l);; - : string = "c0000005" ``` which indicates `STATUS_ACCESS_VIOLATION`, i.e., to Windows correspondent of a segfault: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/596a1078-e883-4972-9bbc-49e60bebca55

We are seeing several Cygwin timeouts during Dynlink, which may well be this bug being triggered - https://github.com/ocaml-multicore/multicoretests/actions/runs/6049285277/job/16416279067 5.1 - https://github.com/ocaml-multicore/multicoretests/actions/runs/5950931125/job/16139719760 5.1 - https://github.com/ocaml-multicore/multicoretests/actions/runs/5942185755/job/16114588868 5.1 - https://github.com/ocaml-multicore/multicoretests/actions/runs/6042013562/job/16396215009 trunk

Seen again on Cygwin `5.1.0~rc2` when merging #389 into `main` https://github.com/ocaml-multicore/multicoretests/actions/runs/6077015167/job/16485985404 ``` random seed: 153981 generated error fail pass / total time test name [ ] 0 0 0 0...

This triggered again on the 0.3 branch for Cygwin trunk part1 https://github.com/ocaml-multicore/multicoretests/actions/runs/6481561492/job/17599326796 ``` random seed: 406303381 generated error fail pass / total time test name [ ] 0 0 0...

I've spent some time creating a reproducer for this: libB.ml: ```ocaml let value = 34 ``` repro.ml: ```ocaml let loadfile f = try Dynlink.loadfile (Dynlink.adapt_filename f) with Dynlink.Error (Dynlink.Module_already_loaded _)...

The weekly 5.1.1 run triggered a `Dynlink stress test` crash on MinGW: https://github.com/ocaml-multicore/multicoretests/actions/runs/8406318839/job/23020071322 ``` random seed: 398767628 generated error fail pass / total time test name [ ] 0 0...

FTR, while dusting off #399 for merging, I discovered that the parallel Dynlink issue also affects MSVC - because it also uses FlexDLL under the surface. Here's an example MSVC...