Bunny::Channel#close should throw immediately if the channel is already closed by the server

[carlhoerberg]

require 'bunny'

b = Bunny.new.start
ch1 = b.create_channel
ch1.queue("q1").subscribe(exclusive: true) {|d,h,p| }
ch2 = b.create_channel

begin
  ch2.queue("q1").subscribe(exclusive: true) {|d,h,p| }
rescue => e
  puts e.inspect
  ch2.close
end

Result:

#<Bunny::AccessRefused: ACCESS_REFUSED - queue 'q1' in vhost '/' in exclusive use>
W, [2017-11-06T15:49:06.381848 #62510]  WARN -- #<Bunny::Session:0x7fd2f2863748 guest@127.0.0.1:5672, vhost=/, addresses=[127.0.0.1:5672]>: Recovering from connection.close (CHANNEL_ERROR - expected 'channel.open')
W, [2017-11-06T15:49:06.382057 #62510]  WARN -- #<Bunny::Session:0x7fd2f2863748 guest@127.0.0.1:5672, vhost=/, addresses=[127.0.0.1:5672]>: Will recover from a network failure (no retry limit)...
/Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/concurrent/continuation_queue.rb:39:in `block in poll': Timeout::Error (Timeout::Error)
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/concurrent/continuation_queue.rb:30:in `synchronize'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/concurrent/continuation_queue.rb:30:in `poll'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/session.rb:1343:in `wait_on_continuations'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/session.rb:537:in `block in close_channel'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/2.4.0/monitor.rb:214:in `mon_synchronize'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/session.rb:533:in `close_channel'
        from /Users/carl/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bunny-2.7.1/lib/bunny/channel.rb:236:in `close'
        from bug.rb:12:in `rescue in <main>'
        from bug.rb:8:in `<main>'

shell returned 1

[michaelklishin]

This is a race condition we cannot avoid entirely. Server-sent channel.close does not arrive immediately.

[carlhoerberg]

I don't know, even adding sleep 1 between rescue and ch2.close raises the exception?

[michaelklishin]

Bunny::Channel#close doesn't throw early the way most other clients do.

[michaelklishin]

@carlhoerberg I'm curious to know if the solution I ended up with in 9df7cb0 makes sense to you. If so I'm happy to release a 2.8.0 very soon.

Thanks again for reporting the issues you encounter.

[carlhoerberg]

Super nice!

[michaelklishin]

Shipped in 2.8.0.