03 - synchronizing access to an object.rb

O Reilly Ruby Cookbook source code

require 'thread'
class Object
  def synchronize
    mutex.synchronize { yield self }
  end

  def mutex
    @mutex ||= Mutex.new
  end
end
#---
list = []
Thread.new { list.synchronize { |l| sleep(5); 3.times { l.push "Thread 1" } } }
Thread.new { list.synchronize { |l| 3.times { l.push "Thread 2" } } }
sleep(6)
list
# => ["Thread 1", "Thread 1", "Thread 1", "Thread 2", "Thread 2", "Thread 2"]
#---
list = []
Thread.new { list.synchronize { |l| sleep(5); 3.times { l.push "Thread 1" } } }
Thread.new { 3.times { list.push "Thread 2" } }
sleep(6)
list
# => ["Thread 2", "Thread 2", "Thread 2", "Thread 1", "Thread 1", "Thread 1"]
#---
require 'aspectr'
require 'thread'

class Synchronized < AspectR::Aspect
  def lock(method_sym, object, return_value, *args)
    object.mutex.lock
  end

  def unlock(method_sym, object, return_value, *args)
    object.mutex.unlock
  end
end
#---
array = %w{do re mi fa so la ti}
Synchronized.new.wrap(array, :lock, :unlock, :push, :pop, :each)
#---
Thread.new { array.each { |x| puts x } }
Thread.new do
  puts 'Destroying the array.'
  array.pop until array.empty?
  puts 'Destroyed!'
end
# do
# re
# mi 
# fa
# so
# la
# ti
# Destroying the array.
# Destroyed!
#---