em-synchrony using http.get and iterators causing can't yield in root Fiber error

Question

A very simple case where I get the root Fiber error.

require 'em-synchrony'
require 'em-synchrony/em-http'

urls = %w{http://www.google.com http://www.google.com http://www.google.com http://www.google.com http://www.google.com http://www.google.com}
EM.synchrony do

  EM::Synchrony::Iterator.new(urls, 2).each(
      proc { |url, iter|

        EM::HttpRequest.new(url).get
        iter.next
      }
  )
end

I can use async here, but not a sync http request.

To me it seems too complicated. I would not call `run_em_normalization` recursively because I am not sure what happens when you attempt to start EM loop from inside an existing EM loop (that is what `EM.synchrony` is - an event loop with some fibers code added). — akonsu, Jun 25 '13 at 15:28

score 2 · Accepted Answer · answered Jun 25 '13 at 17:12

Looks like if I'm going to use the sync get request I should be using FiberIterator.

require 'em-synchrony'
require 'em-synchrony/em-http'
require "em-synchrony/fiber_iterator"

urls = %w{http://www.google.com http://www.google.com http://www.google.com http://www.google.com http://www.google.com http://www.google.com}
EM.synchrony do


  EM::Synchrony::FiberIterator.new(urls, 2).each(
      proc { |url|

        EM::HttpRequest.new(url).get

      }
  )
end

yeap, FiberIterator is what you need – fl00r Jun 26 '13 at 21:49 — fl00r, Jun 26 '13 at 21:49

em-synchrony using http.get and iterators causing can't yield in root Fiber error

1 Answers1