CODEWITHSUNDEEP
rubyeventmachine
Sato
Sato

Reputation: 8582

eventmachine: how to be concurrency?

Here is my code, I use sleep to simulate a long running request

require 'eventmachine'


def test (i)
    puts "#{i} start to sleep..."
    sleep i
    puts "#{i} end..."
end

EventMachine.run do
    (1..3).each do |i|
        test i
    end
    Signal.trap("INT") do
        connection.close do
            EM.stop { exit }
        end
    end
end

It gives me :

1 start to sleep...
#### after 1 second
1 end...
2 start to sleep...
#### after 2 seconds
2 end...
3 start to sleep...
#### after 3 seconds
3 end...

I suppose to get:

#### immediately
1 start to sleep...
2 start to sleep...
3 start to sleep...
#### after 1 second
1 end...
#### after 1 second
2 end...
#### after 1 second
3 end...

What is wrong with my code?How to be concurrency? Or how can I do it?

Upvotes: 0

Views: 414

Answers (2)

Aleksei Matiushkin
Aleksei Matiushkin

Reputation: 120990

You likely want to use EventMachine#map method:

EM::Iterator.new(1..3).map(proc{ |num,iter|
  iter.return(test(num))
}, proc{ |results|
  p results
})

I didn’t test the code since I have no env here, but it should give you a tip. Hope it helps.

Upvotes: 0

MiGro
MiGro

Reputation: 1511

I think you mixed up concurrency with multithreading. Event machine is single threaded... Look at the examples how to simulate concurrency:
https://github.com/eventmachine/eventmachine/wiki/Code-Snippets

Upvotes: 1

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