sync.rb

  sync.rb - 2 phase lock with counter
      $Release Version: 1.0$
      $Revision: 11708 $
      $Date: 2007-02-12 17:01:19 -0600 (Mon, 12 Feb 2007) $
      by Keiju ISHITSUKA(keiju@ishitsuka.com)

—

 Sync_m, Synchronizer_m
 Usage:
  obj.extend(Sync_m)
  or
  class Foo
      include Sync_m
      :
  end

  Sync_m#sync_mode
  Sync_m#sync_locked?, locked?
  Sync_m#sync_shared?, shared?
  Sync_m#sync_exclusive?, sync_exclusive?
  Sync_m#sync_try_lock, try_lock
  Sync_m#sync_lock, lock
  Sync_m#sync_unlock, unlock

  Sync, Synchronicer:
      include Sync_m
  Usage:
  sync = Sync.new

  Sync#mode
  Sync#locked?
  Sync#shared?
  Sync#exclusive?
  Sync#try_lock(mode) -- mode = :EX, :SH, :UN
  Sync#lock(mode)     -- mode = :EX, :SH, :UN
  Sync#unlock
  Sync#synchronize(mode) {...}