Tomoyuki Chikanaga <nagachika00 / gmail.com> wrote:
> To cover this race condition, ubf_select() also call
> add_signal_thread_list() to register "signal thread list". Timer
> thread periodically send SIGVTALRM to threads in signal thread list.

Ah, I missed the second part of that earlier.  My concern raised in
[ruby-core:39643] is no more, thank you.