Not processable interrupt queue for a thread after it's notified that FD is closed in some other thread.
In the bugfix for https://bugs.ruby-lang.org/issues/13076 has been introduced another bug, caused by a busy waiting in rb_notify_fd_close method, while the FD is being released. During this waiting, it pumps huge amounts of the ruby_error_stream_closed errors into thread's interrupt queue, which almost all stay there unprocessed. It can be up for several hundred of exceptions in the queue, depending on circumstances.
a =  t =  10.times do r,w = IO.pipe a << [r,w] t << Thread.new do while r.gets end rescue IOError # Interrupt queue is full and all IO is broken Thread.current.pending_interrupt? # Expected to be false, because it's already rescued IO.sysopen ("/dev/tty") # Expected not to throw an error. On each such call, it dequeues the next item from interrupt queue until there's none end end a.each do |r,w| w.puts "test" w.close r.close end t.each do |th| th.join end
Traceback (most recent call last): 1: from test2.rb:9:in `block (2 levels) in <main>' test2.rb:9:in `sysopen': stream closed in another thread (IOError)