Ruby

If Ractor#close_incoming is called on a Ractor, any pending Ractor.receive call will raise Ractor::ClosedError. However, any pending Ractor.receive_if call will not; instead, it never returns.

r1 = Ractor.new do Ractor.receive rescue => e e end r1.close_incoming result = r1.take puts "**** taken: #{result}" # displays the Ractor::ClosedError r2 = Ractor.new do Ractor.receive_if { true } puts "**** never reaches here" rescue => e puts "**** never reaches here" e end r2.close_incoming puts "**** hangs here..." r2.take puts "**** never reaches here" 

This was tested against both 3.0.0 and 3.1.0 head, with the same result.

% ruby -v ruby 3.1.0dev (2021-02-09T13:22:37Z master e7a831de8e) [x86_64-darwin20] 

% ruby -v ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin20 

I have also tried including sleep statements to force the Ractor.receive_if to execute both before and after the Ractor#close_incoming call. The result is the same either way. receive_if hangs regardless of whether the incoming port is already closed when receive_if is invoked, or whether the port is closed while the receive_if is already blocking.