Bug #20459: Ractor.select() deadlock?

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin20]
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[esad (Esad Hajdarevic)]

When I run this script

echo = Ractor.new { Ractor.receive }
Thread.new { puts Ractor.select(echo).inspect }
sleep 0.1
echo.send "test"

the script never terminates. If I change thread body to

Thread.new { puts echo.take.inspect }

or introduce a small delay before #select like:

Thread.new { sleep 1; puts Ractor.select(echo).inspect }

then it works/terminates.

[luke-gru (Luke Gruber)]

I just took a look at this and it's related to this ticket: https://redmine.ruby-lang.org/issues/20168. The linked pull request that fixes that issue also fixes this one.