#!/dmsp/reference/bin/ruby
STDOUT.sync = true
$VERBOSE=nil
require 'posixlock'
sec = 8
loopno = 0
loop do
  begin
    open('q/lock','r+') do |f| 
      puts 'locking...'
      #f.lockf File::F_LOCK, 0
      (locked=f.lockf(File::F_TLOCK, 0)) or sleep(1 + rand) until locked
      #locked = f.lockf(File::F_TLOCK, 0) until locked
      system "touch -B 3600 q/lock"
      puts 'locked'
      sleep(30)
    end
    puts 'un-locked'
    #sleep((2 * sec) + rand(42))
    #sleep(sec + rand(sec))
    sleep 300
  rescue => e
    p e
  end
  puts loopno
  loopno += 1
end