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ocsigen
Deprecate Lwt_main.yield and Lwt_unix.yield?
This is a suggestion. After talking to @aantron on Discourse, I feel we should officially deprecate yield and related functions using [@@alert deprecate], in hope that one day we will merge the two pools into one.
Lwt.pause () will do the job. There are currently two pools in the codebase due to the two almost identical mechanisms, but I believe they can be safely merged once every Lwt_unix.yield () and Lwt_main.yield () is replaced by Lwt.pause ().
See
https://github.com/ocsigen/lwt/blob/9cbf3a9c21f181dcd78dabf2117f87a62a2d65cc/src/unix/lwt_main.mli#L45-L52
and https://discuss.ocaml.org/t/lwt-pause-versus-yield/7875.
See https://github.com/ocsigen/lwt/pull/784 for some earlier discussion of this.
TL;DR:
-
Lwt_main.runtreats paused and yielded promises differently: it resolves paused promises twice as often as yielded promises. - This is not an intended difference, but it's a significant difference and it may be significant for several binaries.
I think that, before we release this we should:
- run the tests of all the opam packages that depend on lwt with the modified lwt (I think this is possible through the opam CI in some way)
- notify packages that we break or even give them some patches
- advertise the possibility of the change on discuss (and maybe other channels)
Then if all of that goes well, we can release. It'll need a "breaking change" mention in the changelog.
Maybe we could leverage the opam infrastructure to test if we break some of the tests of the opam packages. I think we should do this (if possible), make upstream commits to all possibly broken packages, and we should make a special mention of this in the changelog (and advertise it in advance on discuss too).
I just updated CHANGES in the #858 but need help in all other actionable items.
I'll ask some opam wizards about the general test of all dependencies.