Class: Ups

Inherits:

SomeSingletonClass

• Object
• SomeSingletonClass
• Ups

Defined in:

lib/singleton.rb

Constant Summary

Constants included from Singleton

Singleton::FirstInstanceCall

Class Method Summary

• .__sleep ⇒ Object
• ._instantiate? ⇒ Boolean
• .instantiate_all ⇒ Object
• .new ⇒ Object

Instance Method Summary

• #initialize ⇒ Ups constructor

  A new instance of Ups.

Methods included from Singleton

__init__, #_dump, #clone, #dup

Constructor Details

#initialize ⇒ Ups

Returns a new instance of Ups.

# File 'lib/singleton.rb', line 215

def initialize
  self.class.__sleep
  puts "initialize called by thread ##{Thread.current[:i]}"
end

Class Method Details

.__sleep ⇒ Object

# File 'lib/singleton.rb', line 233

def __sleep
  sleep(rand(0.08))
end

._instantiate? ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/singleton.rb', line 222

def _instantiate?
  @enter.push Thread.current[:i]
  while false.equal?(@__instance__)
    Thread.critical = false
    sleep 0.08
    Thread.critical = true
  end
  @leave.push Thread.current[:i]
  @__instance__
end

.instantiate_all ⇒ Object

# File 'lib/singleton.rb', line 249

def instantiate_all
  @enter = []
  @leave = []
  1.upto(9) {|i|
    Thread.new {
      begin
        Thread.current[:i] = i
        __sleep
        instance
      rescue RuntimeError => mes
        puts mes
      end
    }
  }
  puts "Before there were #{num_of_instances(self)}"
  sleep 3
  puts "Now there is #{num_of_instances(self)}"
  puts "#{@enter.join '; '} was the order of threads entering the waiting loop"
  puts "#{@leave.join '; '} was the order of threads leaving the waiting loop"
end

.new ⇒ Object

# File 'lib/singleton.rb', line 237

def new
  begin
    __sleep
    raise  "boom - thread ##{Thread.current[:i]} failed to create instance"
  ensure
    # simple flip-flop
    class << self
      remove_method :new
    end
  end
end