What's the correct way of doing recurrent timers?

[dblock]

I am looking for the equivalent of every in Celluloid. It was suggested to loop and task.sleep, however it doesn't behave the same way.

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "1: #{i}"
      task.sleep 3
    end
  end

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "2: #{i}"
      task.sleep 3
    end
  end

1: 0
1: 1
1: 2
2: 0
2: 1
2: 2

that said, it works if both reactor runs are inside of a reactor

::Async::Reactor.run do
  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "1: #{i}"
      task.sleep 3
    end
  end

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "2: #{i}"
      task.sleep 3
    end
  end
end

1: 0
2: 0
1: 1
2: 1
1: 2
2: 2

Is the latter the correct way?

Maybe implementing a higher level timers API could be valuable? It would ensure to start a "parent" reactor, always behave like the second version, and have predictable (eg. not bail out on error) error behavior?

I also see

async/lib/async/reactor.rb

Line 84 in 6b9b34e

def_delegators :@timers, :every, :after

.

require 'async'

i = 0
j = 0

reactor = Async::Reactor.new

reactor.run do |task|
  reactor.every 3 do
    puts "1: #{i}"
    i += 1
  end

  reactor.every 3 do
    puts "2: #{j}"
    j += 1
  end
end

Works as expected. Does nothing without reactor.run. Maybe it just needs documentation and/or being wrapped and error out if not running under a reactor?

[ioquatix]

If you run it like this:

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "1: #{i}"
      task.sleep 3
    end
  end

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "2: #{i}"
      task.sleep 3
    end
  end

You are running two sequential reactors and there is no interaction between the two.

::Async::Reactor.run do
  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "1: #{i}"
      task.sleep 3
    end
  end

  ::Async::Reactor.run do |task|
    3.times do |i|
      puts "2: #{i}"
      task.sleep 3
    end
  end
end

is the correct way.

reactor.run do |task|
  reactor.every 3 do
    puts "1: #{i}"
    i += 1
  end

  reactor.every 3 do
    puts "2: #{j}"
    j += 1
  end
end

This way is risky because it doesn't run in a task context. You should probably avoid it.