Monitor

        # Monitor < Object

(from ruby core)
---
Use the Monitor class when you want to have a lock object for blocks
with mutual exclusion.

    require 'monitor'

    lock = Monitor.new
    lock.synchronize do
      # exclusive access
    end

---
# Instance methods:

    enter
    exit
    mon_check_owner
    mon_enter
    mon_exit
    mon_locked?
    mon_owned?
    mon_synchronize
    mon_try_enter
    new_cond
    synchronize
    try_enter
    try_mon_enter
    wait_for_cond