some sort of examples 'how to use threads

gistfile1.txt

require 'thread'
require 'net/http'

urls = ["http://slonweb.ru", "https://github.com", "http://www.ruby-doc.org/core-2.0/Thread.html"]

threads = []
responses = []
responses_mutex = Mutex.new

urls.each do |url|
  threads << Thread.new(url) do |url|
    response = Net::HTTP.get_response URI.parse(url)
    responses_mutex.synchronize { responses << response }
  end
end

threads.each(&:join)

gistfile2.txt

$buffer = {}
$bufflock = Mutex.new

threads = (0..2).map do |i|
  Thread.new do
    puts "Starting Thread #{i}"
    3.times do
      puts "Thread #{i} got: #{$buffer[:foo].inspect}"
      $bufflock.synchronize{ $buffer[:foo] = ($buffer[:foo] || 1) * (i+1) }
      sleep rand
    end
    puts "Ending Thread #{i}"
  end
end
threads.each{ |t| t.join;  }

gistfile3.txt

threads = []
(1..5).each do |i|
  threads << Thread.new { Thread.current[:output] = `echo Hi from thread ##{i}` }
end
threads.each do |t|
  t.join
  puts t[:output]
end

gistfile4.txt

require 'net/http'

pages = %w( www.rubycentral.com
            www.awl.com
            www.pragmaticprogrammer.com
           )

threads = []

for page in pages
  threads << Thread.new(page) { |myPage|

    h = Net::HTTP.new(myPage, 80)
    puts "Fetching: #{myPage}"
    resp, data = h.get('/', nil )
    puts "Got #{myPage}:  #{resp.message}"
  }
end

threads.each { |aThread|  aThread.join }

https://blog.engineyard.com/2011/a-modern-guide-to-threads

http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_threads.html