Issue #16160 has been updated by Earlopain (Earlopain _). Status changed from Open to Closed Attached PR is merged ---------------------------------------- Misc #16160: Lazy init thread local storage https://bugs.ruby-lang.org/issues/16160#change-118561 * Author: methodmissing (Lourens Naudé) * Status: Closed ---------------------------------------- References PR https://github.com/ruby/ruby/pull/2295 ### Why? The `local_storage` member of execution context is lazy initialized and drives the `Thread#[]` and `Thread#[]=` APIs, which are Fiber local and not Thread local storage. I think the same lazy init pattern should be applied to the APIs below as well - reduces one `Hash` alloc per thread created that does not use thread locals. ### Lazy allocates thread local storage for the following APIs * `Thread#thread_variable_get` - early returns `nil` on locals Hash not initialised * `Thread#thread_variable_set` - forces allocation of the locals Hash if not initilalised * `Thread#thread_variables` - early returns the empty array AND saves on Hash iteration if locals Hash not initialised * `Thread#thread_variable?` - early returns `false` on locals Hash not initialised ### Other notes * Moved initial implementation from `internal.h` to `thread.c` local to call sites. * Preferred `defs/id.def` for the `locals` ID (seeing this pattern used more often, but not sure if that is preferred to inline `rb_intern` yet. Either way there's quite a few different conventions around IDs in the codebase at the moment and happy to help converging to a standard instead. * Maybe a flag is overkill and `NIL_P` on `locals` ivar could also work ... Thoughts? -- https://bugs.ruby-lang.org/