fix argument error when running on ruby 2.5.0

[tompng]

related to rails/rails#31517

With ruby 2.5.0 (macOS Sierra), NIO::Selector#select raises ArgumentError

% ruby -v
ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin16]

[1] pry(main)> require 'nio'
=> true
[2] pry(main)> NIO::Selector.new.select
ArgumentError: wrong number of arguments (given 4, expected 0)
from (pry):2:in `lock'
[3] pry(main)> NIO::Selector.new.select
ArgumentError: wrong number of arguments (given 1587058240, expected 0)
from (pry):3:in `lock'
[4] pry(main)> RUBY_VERSION
=> "2.5.0"
[5] pry(main)> NIO::Selector.new.backend
=> :select

Failing tests on ruby 2.5.0

Failures:

  1) NIO acceptables TCPServer behaves like an NIO acceptable selects for read readiness
     Failure/Error: waiting_monitor = selector.register(unacceptable_subject, :r)
     
     ArgumentError:
       wrong number of arguments (given 4, expected 0)
     Shared Example Group: "an NIO acceptable" called from ./spec/nio/acceptables_spec.rb:32
     # ./spec/nio/acceptables_spec.rb:10:in `lock'
     # ./spec/nio/acceptables_spec.rb:10:in `register'
     # ./spec/nio/acceptables_spec.rb:10:in `block (3 levels) in <top (required)>'

  2) NIO::Selector knows which IO objects are registered
     Failure/Error: subject.register(reader, :r)
     
     ArgumentError:
       wrong number of arguments (given 1472809792, expected 0)
     # ./spec/nio/selector_spec.rb:63:in `lock'
     # ./spec/nio/selector_spec.rb:63:in `register'
     # ./spec/nio/selector_spec.rb:63:in `block (2 levels) in <top (required)>'

  3) NIO::Selector closes
     Failure/Error: subject.close
     
     ArgumentError:
       wrong number of arguments (given 1472809808, expected 0)
     # ./spec/nio/selector_spec.rb:214:in `lock'
     # ./spec/nio/selector_spec.rb:214:in `close'
     # ./spec/nio/selector_spec.rb:214:in `block (2 levels) in <top (required)>'

...

Finished in 1.33 seconds (files took 0.66801 seconds to load)
103 examples, 54 failures, 2 pending

changed rb_funcall(recv, mid, 0, 0) to rb_funcall(recv, mid, 0)

[tarcieri]

Thanks. Perhaps try adding Ruby 2.5.0 to .travis.yml too so we can confirm in CI it's fixed? It looks like support for it was merged to rvm yesterday:

rvm/rvm#4265

[tompng]

Added 2.5.0

It seems like running tests on 2.5.0 without my rb_funcall patch passes on travis.
https://travis-ci.org/tompng/nio4r/builds/322038078

Maybe the ArgumentError problem occures in only specific OS.

[tarcieri]

Hmm, well as far as I can tell this is more correct, so I'll go ahead and merge it anyway