gistfile1.txt

#!/usr/bin/ruby

# Horridly hacked together by David Smalley (david@davidsmalley.com) with bits pulled from the
# Rspec spec_server script, and the acts_as_ferret ferret_start/ferret_stop scripts
# 11/01/2007

require File.expand_path(File.dirname(__FILE__) + '/../config/boot')
require RAILS_ROOT + '/config/environment'
require 'async_observer/worker'

  ################################################################################
  # methods for becoming a daemon on Unix-like operating systems
module UnixDaemon

  ################################################################################
  def platform_daemon (&block)
    safefork do
      write_pid_file
      trap("TERM") { exit(0) }
      sess_id = Process.setsid
      STDIN.reopen("/dev/null")
      STDOUT.reopen("#{RAILS_ROOT}/log/async-worker.out", "a")
      STDERR.reopen(STDOUT)
      block.call
    end
  end

  ################################################################################
  # stop the daemon, nicely at first, and then forcefully if necessary
  def stop
    pid = read_pid_file
    if pid
      $stdout.puts("stopping async-worker...")
      Process.kill("TERM", pid)
      30.times { Process.kill(0, pid); sleep(0.5) }
      $stdout.puts("using kill -9 #{pid}")
      Process.kill(9, pid)
    else
      $stdout.puts("didn't find an async-worker...") 
    end
  rescue Errno::ESRCH => e
    $stdout.puts("process #{pid} has stopped")
  ensure
    File.unlink("#{RAILS_ROOT}/log/async-worker.pid") if File.exist?("#{RAILS_ROOT}/log/async-worker.pid")
  end

  ################################################################################
  def safefork (&block)
    @fork_tries ||= 0
    fork(&block)
  rescue Errno::EWOULDBLOCK
    raise if @fork_tries >= 20
    @fork_tries += 1
    sleep 5
    retry
  end

  #################################################################################
  # create the PID file and install an at_exit handler
  def write_pid_file
    open("#{RAILS_ROOT}/log/async-worker.pid", "w") {|f| f << Process.pid << "\n"}
    at_exit { File.unlink("#{RAILS_ROOT}/log/async-worker.pid") if read_pid_file == Process.pid }
  end

  #################################################################################
  def read_pid_file
    File.read("#{RAILS_ROOT}/log/async-worker.pid").to_i if File.exist?("#{RAILS_ROOT}/log/async-worker.pid")
  end

end
include UnixDaemon

case ARGV[0]
when "start"
  UnixDaemon.platform_daemon do
    begin
      AsyncObserver::Worker.new(binding).run()
    rescue
      $stderr.puts "Error starting Async worker: #{$!}"
      $stderr.puts $!.backtrace
      exit(1)
    end
  end
when "stop"
  UnixDaemon.stop
end