Issue #22274 has been updated by ioquatix (Samuel Williams).
Even on a frozen buffer, #locked updates lock_count with a non-atomic read-modify-write, so two Ractors calling #locked on the same buffer would cause a data race on it. It seems that freezing alone is not sufficient for sharing.
As per my design, a buffer that is frozen does not need to update or touch locked_count (in fact, only a buffer with locked_count == 0 can be frozen). Once frozen, all operations become safe, since the buffer cannot be resized, reallocated, freed, etc.
slice.set_string("x")
---------------------------------------- Feature #22274: Make `IO::Buffer` no longer experimental. https://bugs.ruby-lang.org/issues/22274#change-119126 * Author: ioquatix (Samuel Williams) * Status: Open * Assignee: ioquatix (Samuel Williams) ---------------------------------------- `IO::Buffer` was introduced in Ruby 3.1 by Feature #18020 as an experimental API. It provides an efficient buffer abstraction for fiber scheduler I/O, zero-copy operations, binary protocol implementations, and access from native extensions. Since then, the API has seen several Ruby releases of real-world use and substantial development. Ruby 4.1 now has cohesive semantics for buffer ownership and lifecycle, slicing, locking, string and file mappings, MemoryView integration, and single-transfer I/O operations. I propose making both the Ruby and public C interfaces of `IO::Buffer` non-experimental in Ruby 4.1. This would involve: * Removing the allocation-time experimental warning. * Removing the experimental status from the class documentation. * Removing `RB_IO_BUFFER_EXPERIMENTAL` from the public C header. * Removing warning suppression that is only required because `IO::Buffer` is experimental. * Updating NEWS to describe `IO::Buffer` as stable. `RUBY_IO_BUFFER_VERSION` would remain available for compile-time feature detection as the interface continues to evolve. Before stabilizing the interface, I would particularly appreciate feedback from JRuby and TruffleRuby maintainers. Related work: * Original proposal: https://bugs.ruby-lang.org/issues/18020 * CRuby implementation PR: https://github.com/ruby/ruby/pull/18486 * TruffleRuby implementation: https://github.com/truffleruby/truffleruby/pull/4248 * JRuby implementation: https://github.com/jruby/jruby/blob/master/core/src/main/java/org/jruby/Ruby... * JRuby file-mapping issue: https://github.com/jruby/jruby/issues/8714 -- https://bugs.ruby-lang.org/