run bgrewriteaof without blocking redis

gistfile1.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'redis'

r = Redis.new(:timeout => 1)
append_fsync_val = r.config(:get, 'appendfsync').values.first

puts "Disabling appendfsync..."
r.config(:set, 'appendfsync', 'no')
begin
  puts "Running BGREWRITEAOF..."
  r.bgrewriteaof
  loop do
    begin
      break if r.info["bgrewriteaof_in_progress"] == "0"
      sleep 1
    rescue Errno::EAGAIN => e
      true
    end
  end
ensure
  puts "Enabling appendfsync..."
  r.config(:set, 'appendfsync', append_fsync_val)
end
puts "Done!"
exit 0