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Class: ActionCable::Connection::StreamEventLoop

Relationships & Source Files
Inherits: Object
Defined in: actioncable/lib/action_cable/connection/stream_event_loop.rb

Class Method Summary

Instance Method Summary

Constructor Details

.newStreamEventLoop

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 10

def initialize
  @nio = @executor = @thread = nil
  @map = {}
  @stopping = false
  @todo = Queue.new

  @spawn_mutex = Mutex.new
end

Instance Method Details

#attach(io, stream)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 30

def attach(io, stream)
  @todo << lambda do
    @map[io] = @nio.register(io, :r)
    @map[io].value = stream
  end
  wakeup
end

#detach(io, stream)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 38

def detach(io, stream)
  @todo << lambda do
    @nio.deregister io
    @map.delete io
    io.close
  end
  wakeup
end

#post(task = nil, &block)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 23

def post(task = nil, &block)
  task ||= block

  spawn
  @executor << task
end

#run (private)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 86

def run
  loop do
    if @stopping
      @nio.close
      break
    end

    until @todo.empty?
      @todo.pop(true).call
    end

    next unless monitors = @nio.select

    monitors.each do |monitor|
      io = monitor.io
      stream = monitor.value

      begin
        if monitor.writable?
          if stream.flush_write_buffer
            monitor.interests = :r
          end
          next unless monitor.readable?
        end

        incoming = io.read_nonblock(4096, exception: false)
        case incoming
        when :wait_readable
          next
        when nil
          stream.close
        else
          stream.receive incoming
        end
      rescue
        # We expect one of EOFError or Errno::ECONNRESET in normal operation (when the
        # client goes away). But if anything else goes wrong, this is still the best way
        # to handle it.
        begin
          stream.close
        rescue
          @nio.deregister io
          @map.delete io
        end
      end
    end
  end
end

#spawn (private)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 62

def spawn
  return if @thread && @thread.status

  @spawn_mutex.synchronize do
    return if @thread && @thread.status

    @nio ||= NIO::Selector.new

    @executor ||= Concurrent::ThreadPoolExecutor.new(
      min_threads: 1,
      max_threads: 10,
      max_queue: 0,
    )

    @thread = Thread.new { run }

    return true
  end
end

#stop

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 56

def stop
  @stopping = true
  wakeup if @nio
end

#timer(interval, &block)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 19

def timer(interval, &block)
  Concurrent::TimerTask.new(execution_interval: interval, &block).tap(&:execute)
end

#wakeup (private)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 82

def wakeup
  spawn || @nio.wakeup
end

#writes_pending(io)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/stream_event_loop.rb', line 47

def writes_pending(io)
  @todo << lambda do
    if monitor = @map[io]
      monitor.interests = :rw
    end
  end
  wakeup
end