Issue #20272 has been updated by luke-gru (Luke Gruber).
The messages in that case would be guaranteed to be received in order (first
"hello" then "world").
If you have 2 different ractors or 2 different threads both receiving messages from the
same ractor, then there is no guarantee of the order.
----------------------------------------
Misc #20272: Ambiguity around Ractor message sending FIFO semantics
https://bugs.ruby-lang.org/issues/20272#change-108137
* Author: forthoney (Seong-Heon Jung)
* Status: Open
----------------------------------------
The docs should explicitly state the semantics/properties of Ractor message, especially
when it comes to FIFO.
For example, assume I have two Ractors, Ractor A and Ractor B. Ractor A sends two messages
`"hello"` and `"world"` in this order to Ractor B.
If I call `Ractor.receive` on Ractor B, am I guaranteed to see `"hello"` and
then `"world"` or is it possible the messages are delivered out of order?
--
https://bugs.ruby-lang.org/