Примеры к статье «Ruby и многозадачность»

demo01.rb

# encoding: utf-8

puts 'begin'

th = Thread.new do
  (1..3).each { |i| puts i }
end

# sleep 0
puts '---'

th.join

puts 'end'

demo02.rb

# encoding: utf-8

th = Thread.new do
  puts 'started'
  Thread.stop
  puts 'continued'
  sleep 100
  puts 'finished'
end

sleep 0.1

puts 'wakeup'

th.wakeup

sleep 0

puts 'terminate'

th.terminate

th.join

demo03.rb

# encoding: utf-8

flag = true

5.times do
  Thread.new do
    puts 'true' if flag
    flag = false
  end
end

Thread.list.each do |th|
  if th != Thread.current
    th.join
  end
end

demo04.rb

# encoding: utf-8

flag = true

5.times do
  Thread.new do
    Thread.exclusive do
      puts 'true' if flag
      flag = false
    end
  end
end

Thread.list.each do |th|
  if th != Thread.current
    th.join
  end
end

demo05.rb

# encoding: utf-8

alpha = true
alpha_m = Mutex.new
beta = true
beta_m = Mutex.new

5.times do
  Thread.new do
    alpha_m.synchronize do
      puts 'alpha' if alpha
      alpha = false
    end
    beta_m.synchronize do
      puts 'beta' if beta
      beta = false
    end
  end
end

Thread.list.each do |th|
  if th != Thread.current
    th.join
  end
end

demo06.rb

# encoding: utf-8

th = Thread.new do
  sleep 0.1
  p Thread.current.thread_variable_get 'alpha'
end

th.thread_variable_set 'alpha', :alpha

th.join

demo07.rb

# encoding: utf-8

th = Thread.new do
  sleep 0.1
  p Thread.current['alpha']
end

th['alpha'] = :alpha

th.join

demo08.rb

# encoding: utf-8

f = Fiber.new do
  current = Time.new
  loop do
    last = current
    current = Time.new
    Fiber.yield [last, current]
  end
end

5.times do
  p f.resume
  sleep 1
end

demo09.rb

# encoding: utf-8

pid = fork do
  3.times do |i|
    sleep 0.01
    puts "Child [#{Process.pid}]: #{i}"
  end
end

3.times do |i|
  sleep 0.01
  puts "Parent [#{Process.pid}]: #{i}"
end

Process.waitpid pid

demo10.rb

# encoding: utf-8

child = fork do
  count = 0
  Signal.trap :USR1 do
    count += 1
    puts "Signal USR1: #{count}"
  end
  Signal.trap :TERM do
    puts 'Signal TERM'
    exit
  end
  sleep 1000
  puts 'Ooops!'
end

Signal.trap :CHLD do
  puts 'Child died.'
end

Process.kill :USR1, child
sleep 0.01
#Process.kill :USR2, child
Process.kill :USR1, child
Process.kill :TERM, child

Process.wait

demo11.rb

# encoding: utf-8

rd, wr = IO.pipe

child = fork do
  rd.close
  wr.write 'From Child'
  wr.close
end

wr.close
msg = rd.read
rd.close
p msg

Process.wait

demo12.rb

# encoding: utf-8

rd, wr = IO.pipe

child = spawn "echo 'External Child'",
    [ STDERR, STDOUT ] => wr

wr.close
msg = rd.read
rd.close
p msg

Process.wait