[ruby-core:119124] [Ruby master Bug#20723] `IO#close` is broken on Ruby 3.3+ when using the Fiber scheduler.

11 Sep 2024


      Issue #20723 has been reported by ioquatix (Samuel Williams).

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Bug #20723: `IO#close` is broken on Ruby 3.3+ when using the Fiber scheduler.
https://bugs.ruby-lang.org/issues/20723

* Author: ioquatix (Samuel Williams)
* Status: Open
* Assignee: kjtsanaktsidis (KJ Tsanaktsidis)
* Backport: 3.3: REQUIRED
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The following program seems to work okay on Ruby 3.2 but hangs on Ruby 3.3:

```ruby
#!/usr/bin/env ruby

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'async'
end

require 'socket'

def close_while_reading(io)
  thread = Thread.new do
    Thread.current.report_on_exception = false
    io.wait_readable
  end
  
  # Wait until the thread is blocked on read:
  Thread.pass until thread.status == "sleep"
  
  Async do
    io.close
  end
  
  thread.join
end

begin
  client, server = Socket.pair(:UNIX, :STREAM)
  close_while_reading(client)
rescue => error
  $stderr.puts error.full_message
end
```


-- 
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