Class: God::EventHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/god/event_handler.rb

Constant Summary collapse

@@actions = 
{}
@@handler = 
nil
@@loaded = 
false

Class Method Summary collapse

Class Method Details

.call(pid, event, extra_data = {}) ⇒ Object 



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# File 'lib/god/event_handler.rb', line 50

def self.call(pid, event, extra_data = {})
  @@actions[pid][event].call(extra_data) if watching_pid?(pid) && @@actions[pid][event]
end

.deregister(pid, event) ⇒ Object 



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# File 'lib/god/event_handler.rb', line 41

def self.deregister(pid, event)
  return unless watching_pid?(pid)

  running = ::Process.kill(0, pid.to_i) rescue false
  @@actions[pid].delete(event)
  @@handler.register_process(pid, @@actions[pid].keys) if running
  @@actions.delete(pid) if @@actions[pid].empty?
end

.event_system ⇒ Object 



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# File 'lib/god/event_handler.rb', line 13

def self.event_system
  @@handler::EVENT_SYSTEM
end

.load ⇒ Object 



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# File 'lib/god/event_handler.rb', line 17

def self.load
  case RUBY_PLATFORM
  when /darwin/i, /bsd/i
    require 'god/event_handlers/kqueue_handler'
    @@handler = KQueueHandler
  when /linux/i
    require 'god/event_handlers/netlink_handler'
    @@handler = NetlinkHandler
  else
    raise NotImplementedError, 'Platform not supported for EventHandler'
  end
  @@loaded = true
rescue Exception
  require 'god/event_handlers/dummy_handler'
  @@handler = DummyHandler
  @@loaded = false
end

.loaded? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/god/event_handler.rb', line 9

def self.loaded?
  @@loaded
end

.operational? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/god/event_handler.rb', line 77

def self.operational?
  com = [false]

  Thread.new do
    pid = fork do
      loop { sleep(1) }
    end

    register(pid, :proc_exit) do
      com[0] = true
    end

    ::Process.kill('KILL', pid)
    ::Process.waitpid(pid)

    sleep(0.1)

    deregister(pid, :proc_exit) rescue nil
  rescue => e
    puts e.message
    puts e.backtrace.join("\n")
  end.join

  sleep(0.1)

  com.first
end

.register(pid, event, &block) ⇒ Object 



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# File 'lib/god/event_handler.rb', line 35

def self.register(pid, event, &block)
  @@actions[pid] ||= {}
  @@actions[pid][event] = block
  @@handler.register_process(pid, @@actions[pid].keys)
end

.start ⇒ Object 



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# File 'lib/god/event_handler.rb', line 58

def self.start
  @@thread = Thread.new do
    loop do
      @@handler.handle_events
    rescue Exception => e
      message = format("Unhandled exception (%{class}): %{message}\n%{backtrace}",
                       class: e.class, message: e.message, backtrace: e.backtrace.join("\n"))
      applog(nil, :fatal, message)
    end
  end

  # do a real test to make sure events are working properly
  @@loaded = operational?
end

.stop ⇒ Object 



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# File 'lib/god/event_handler.rb', line 73

def self.stop
  @@thread&.kill
end

.watching_pid?(pid) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/god/event_handler.rb', line 54

def self.watching_pid?(pid)
  @@actions[pid]
end