Class: RJR::EMAdapter

Inherits:
Object show all
Defined in:
lib/rjr/util/em_adapter.rb

Overview

EventMachine adapater interface, ties reactor lifecycle to an instance of this class.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ EMAdapter

EMAdapter initializer



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# File 'lib/rjr/util/em_adapter.rb', line 17

def initialize
  @em_lock = Mutex.new

  EventMachine.error_handler { |e|
    puts "EventMachine raised critical error #{e} #{e.backtrace}"
    # TODO dispatch to registered event handlers
  }
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_id, *args, &bl) ⇒ Object

Delegates everything else directly to eventmachine

(eg schedule, add_timer, add_periodic_timer,
    reactor_running?, stop_event_loop, etc)



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# File 'lib/rjr/util/em_adapter.rb', line 67

def method_missing(method_id, *args, &bl)
  @em_lock.synchronize{
    EventMachine.send method_id, *args, &bl
  }
end

Instance Attribute Details

#reactor_thread ⇒ Object

Run reactor in its own interally managed thread



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# File 'lib/rjr/util/em_adapter.rb', line 14

def reactor_thread
  @reactor_thread
end

Instance Method Details

#halt ⇒ Object

Halt the reactor if running

Returns:

  • self



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# File 'lib/rjr/util/em_adapter.rb', line 50

def halt
  self.stop_event_loop if self.reactor_running?
  self
end

#join ⇒ Object

Block until reactor thread is terminated

Returns:

  • self



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# File 'lib/rjr/util/em_adapter.rb', line 58

def join
  th = @em_lock.synchronize{ @reactor_thread }
  th.join unless th.nil?
  self
end

#start ⇒ Object

Start the eventmachine reactor thread if not running



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# File 'lib/rjr/util/em_adapter.rb', line 27

def start
  @em_lock.synchronize{
    # TODO on event of the process ending this thread will be
    # shutdown before a local finalizer can be run,
    # would be good to gracefully shut this down / wait for completion
    @reactor_thread  = Thread.new {
      begin
        EventMachine.run
      rescue Exception => e
        # TODO option to autorestart the reactor on errors ?
        puts "Critical exception #{e}\n#{e.backtrace.join("\n")}"
      ensure
        @em_lock.synchronize { @reactor_thread = nil }
      end
    } unless @reactor_thread
  }
  sleep 0.01 until EventMachine.reactor_running? # XXX hack but needed
  self
end