Misc #21877: DevMeeting-2026-03-17

• Status: Open
• Assignee: -

[mame (Yusuke Endoh)]

The next dev meeting

Date: 2026/03/17 13:00-17:00 (JST)
Log: TBD

• Dev meeting IS NOT a decision-making place. All decisions should be done at the bug tracker.
• Dev meeting is a place we can ask Matz, nobu, nurse and other developers directly.
• Matz is a very busy person. Take this opportunity to ask him. If you can not attend, other attendees can ask instead of you (if attendees can understand your issue).
• We will write a record of the discussion in the file or to each ticket in English.
• All activities are best-effort (keep in mind that most of us are volunteer developers).
• The date, time and place of the meeting are scheduled according to when/where we can reserve Matz's time.
• DO NOT discuss then on this ticket, please.

Call for agenda items

If you have a ticket that you want matz and committers to discuss, please post it into this ticket in the following format:

* [Ticket ref] Ticket title (your name)
  * Comment (A summary of the ticket, why you put this ticket here, what point should be discussed, etc.)

Example:

* [Feature #14609] `Kernel#p` without args shows the receiver (ko1)
  * I feel this feature is very useful and some people say :+1: so let discuss this feature.

• It is recommended to add a comment by 2026/03/14. We hold a preparatory meeting to create an agenda a few days before the dev-meeting.
• The format is strict. We'll use this script to automatically create an markdown-style agenda. We may ignore a comment that does not follow the format.
• Your comment is mandatory. We cannot read all discussion of the ticket in a limited time. We appreciate it if you could write a short summary and update from a previous discussion.

[mame (Yusuke Endoh)]

• Related to Misc #14770: [META] DevelopersMeeting added

[synacker (Mikhail Milovidov)]

• [Feature #21869] Add receive_all Method to Ractor API for Message Batching
  • This feature is essential for high‑load services because message batching is a highly efficient technique for reducing the number of expensive I/O requests and minimizing context switches between Ractors and business logic
  • The feature opens the way to vectorized message handlers, enabling batch processing of messages in a single handler invocation.
  • The proposal has received positive feedback from the community on GitHub, Reddit, and Discord
  • I have created a PR on GitHub: https://github.com/ruby/ruby/pull/16105

[Earlopain (Earlopain _)]

• [Feature #21875] Handling of trailing commas in lambda parameters (earlopain)
  • Followup to Feature #19107 (Allow trailing comma in method signature)
  • During implementation I noticed that lambdas in the style of ->() never came up
  • In addition to the ticket description, @Eregon (Benoit Daloze) created a good comparison in https://bugs.ruby-lang.org/issues/21875#note-2
  • There are a few ways that a trailing comma could be handled but I think it would be best to just reject it. It's confusing and I don't think there is a use-case (if one comes up, we can reconsider).

[tenderlovemaking (Aaron Patterson)]

• [Feature #21942] Allow reading class variables (@@foo) from non-main Ractors
  • Currently @foo is allowed to be read, but @@foo isn't allowed
  • Rails uses @@foo so I'd like to make them allowed

[jneen (Jeanine Adkisson)]

• [Bug #21870] Regexp: Warnings when using slightly overlapping \p{...} classes (jneen)
  • Warning spam on code that definitely isn't a mistake (/[\p{Word}\p{S}]/ and other overlapping properties)
  • Noted some possible ways forward in https://bugs.ruby-lang.org/issues/21870#note-20, including an easy path that I'm happy to take on
  • It looks like this was discussed in DevMeeting 2026-02-12 (https://github.com/ruby/dev-meeting-log/blob/master/2026/DevMeeting-2026-02-12.md, near the bottom), unclear if any decision was made
  • Could use some clarity on the best path forward, both short-term and long-term

[jpl-coconut (Jacob Lacouture)]

• [Bug #21685] Unnecessary context-switching, especially bad on multi-core machines. (jpl-coconut)
  • Ruby exhibits excessive context switching around fast syscalls, which compromises performance. Microbenchmarks (linked from issue and PR) show the impact in isolation.
  • A small (+68 LOC) PR fixes the issue. Microbenchmark results are included. Two production rails apps (shopify and github) see ~10% overall perf improvements with the fix, which seem likely to generalize to others.
  • How to move this forward?
  • How to better facilitate future contributions/discussions related to concurrency/perf, where tradeoffs my be more subtle.

[byroot (Jean Boussier)]

• [Feature #21861] C API: expose ruby_xfree_sized, ruby_xrealloc_sized, etc (byroot)
  • C23 added void free_sized(void *ptr, size_t old_size).
  • It has both speed and correctness benefits.
  • Several common allocators already support it, including latest glibc and the very popular jemalloc.
  • Maps well with ruby_sized_xfree used internally to provide the freed size to GC statistics.
  • I'd like to expose ruby_xfree_sized and ruby_xrealloc_sized to C extensions so they can make use of it too.
  • I'd also like to expose RB_FREE_SIZED, RB_FREE_SIZED_N and RB_REALLOC_SIZED_N macros for convenience.
• [Feature #21853] Make Embedded TypedData a public API (byroot)
  • RUBY_TYPED_EMBEDDABLE was introduced in 3.3 as private API which help reduce memory usage and sped up numerous core types.
  • I'd like to expose this capability to C extensions, so they can get the same benefits.
  • I think the API is currently fine, but we can make change before making it public if desired.
• [Feature #21852] New improved allocator function interface (byroot)
  • The current typedef VALUE (*rb_alloc_func_t)(VALUE klass); interface is too limited for Ractor and Embedded Typed Data
  • When duping or cloning some objects, the allocator do need to receive the source object to allocate in the correct size pool.
  • I propose to introduce typedef VALUE (*rb_copy_alloc_func_t)(VALUE klass, VALUE other);
  • I have a PR that does so without breaking backward compatibility: https://github.com/ruby/ruby/pull/15795
  • I believe @ko1 (Koichi Sasada) would like to introduce more change for Ractors.