class ActiveSupport::Notifications::Fanout

This class is thread safe. All methods are reentrant.
It just pushes events to all registered log subscribers.
This is a default queue implementation that ships with Notifications.

def finish(name, id, payload, listeners = listeners_for(name)) 

def finish(name, id, payload, listeners = listeners_for(name))
  listeners.each { |s| s.finish(name, id, payload) }
end

def initialize 

def initialize
  @subscribers = []
  @listeners_for = Concurrent::Map.new
  super
end

def listeners_for(name) 

def listeners_for(name)
  # this is correctly done double-checked locking (Concurrent::Map's lookups have volatile semantics)
  @listeners_for[name] || synchronize do
    # use synchronisation when accessing @subscribers
    @listeners_for[name] ||= @subscribers.select { |s| s.subscribed_to?(name) }
  end
end

def listening?(name) 

def listening?(name)
  listeners_for(name).any?
end

def publish(name, *args) 

def publish(name, *args)
  listeners_for(name).each { |s| s.publish(name, *args) }
end

def start(name, id, payload) 

def start(name, id, payload)
  listeners_for(name).each { |s| s.start(name, id, payload) }
end

def subscribe(pattern = nil, block = Proc.new) 

def subscribe(pattern = nil, block = Proc.new)
  subscriber = Subscribers.new pattern, block
  synchronize do
    @subscribers << subscriber
    @listeners_for.clear
  end
  subscriber
end

def unsubscribe(subscriber_or_name) 

def unsubscribe(subscriber_or_name)
  synchronize do
    case subscriber_or_name
    when String
      @subscribers.reject! { |s| s.matches?(subscriber_or_name) }
    else
      @subscribers.delete(subscriber_or_name)
    end
    @listeners_for.clear
  end
end

def wait

This is a sync queue, so there is no waiting. 
def wait
end