synchronizing access to an object

synchronize_access_object.rb

# encoding: utf-8
 # frozen_string_literal: true

require 'thwait'

class Object
  def synchronize
    mutex.synchronize { yield self }
  end

  def mutex
    @mutex ||= Mutex.new
  end
end

list = []
thread_1 = Thread.new { list.synchronize { |l| sleep(1); 3.times { l.push "Thread 1" } } }
thread_2 = Thread.new { list.synchronize { |l| 3.times { l.push "Thread 2" } } }
thread_1.join
thread_2.join
p list # ["Thread 1", "Thread 1", "Thread 1", "Thread 2", "Thread 2", "Thread 2"]

list = []
thread_1 = Thread.new { sleep(3); 3.times { list.push "Thread 1" } }
thread_2 = Thread.new { 3.times { list.push "Thread 2" } }
thread_1.join
thread_2.join
p list # ["Thread 2", "Thread 2", "Thread 2", "Thread 1", "Thread 1", "Thread 1"]