threads with static vars

threads.rb

       #!/usr/bin/env ruby

### singleton
class Prime
    @@start = 2
    @@inst = nil
    private_class_method :new

    def initialize *args, **kwargs
       kwargs.each {
        |k,v|

        instance_variable_set "@#{k}", v
       }
    end

    def is_prime? val
        flag = true
        while ( @@start < val )
            if ( val % @@start == 0 )
                flag = false
                break
            end
            @@start+=1
        end
        p "start is " + @@start.to_s + "\n"
        flag
    end

    def self.get_instance params={}
        if ( @@inst.nil? )
            @@inst = new(params)
        end
        return @@inst
    end

end

### instantiate
class Prime1
    #@@start = 2
    attr_accessor :start

    def initialize *args, **kwargs
       kwargs.each {
        |k,v|

        instance_variable_set "@#{k}", v
       }
       @start = 2
    end

    def is_prime? val
        flag = true
        #while ( @@start < val )
        #p "start - #{@@start} - val - #{val}\n"
        #    if ( val % @@start == 0 )
        #        p "NOT "
        #        flag = false
        #        break
        #    end
        #    @@start+=1
        #end
        while ( @start < val )
            if ( val % @start == 0 )
                flag = false
                break
            end
            @start+=1
        end
        flag
    end

end

class MyInt < Numeric
    attr_accessor :prime, :num

    def initialize *args, **kwargs
       super()
       kwargs.each {
        |k,v|

        instance_variable_set "@#{k}", v
       }

       @prime = !args[0].nil? ? Prime1.new : Prime.get_instance()
       p @prime
    end

    def check
        self.prime.is_prime?(self.num)
    end
end

## main
[ nil, 10 ].each {
    |args|
    pths = [*1..10].shuffle.map{
        |i|
        MyInt.new(args, num: i)
    }.map {
        |i|
        Thread.new {
            p i.num.to_s +  ( i.check ? " is prime " : " is not prime" )
            sleep 1
        }
    }

    pths.map(&:join)
}