lib/listen/event/loop.rb
# frozen_string_literal: true
require 'thread'
require 'timeout'
require 'listen/event/processor'
require 'listen/thread'
require 'listen/error'
module Listen
module Event
class Loop
include Listen::FSM
Error = ::Listen::Error
NotStarted = ::Listen::Error::NotStarted # for backward compatibility
start_state :pre_start
state :pre_start
state :starting
state :started
state :stopped
def initialize(config)
@config = config
@wait_thread = nil
@reasons = ::Queue.new
initialize_fsm
end
def wakeup_on_event
if started? && @wait_thread&.alive?
_wakeup(:event)
end
end
def started?
state == :started
end
MAX_STARTUP_SECONDS = 5.0
# @raises Error::NotStarted if background thread hasn't started in MAX_STARTUP_SECONDS
def start
# TODO: use a Fiber instead?
return unless state == :pre_start
transition! :starting
@wait_thread = Listen::Thread.new("wait_thread") do
_process_changes
end
Listen.logger.debug("Waiting for processing to start...")
wait_for_state(:started, timeout: MAX_STARTUP_SECONDS) or
raise Error::NotStarted, "thread didn't start in #{MAX_STARTUP_SECONDS} seconds (in state: #{state.inspect})"
Listen.logger.debug('Processing started.')
end
def pause
# TODO: works?
# fail NotImplementedError
end
def stop
transition! :stopped
@wait_thread&.join
@wait_thread = nil
end
def stopped?
state == :stopped
end
private
def _process_changes
processor = Event::Processor.new(@config, @reasons)
transition! :started
processor.loop_for(@config.min_delay_between_events)
end
def _wakeup(reason)
@reasons << reason
@wait_thread.wakeup
end
end
end
end