Module: TestLab::Support::Parallel

Included in:
TestLab
Defined in:
lib/testlab/support/parallel.rb

Instance Method Summary collapse

Instance Method Details

#before_fork(pid) ⇒ Object

Our before fork hook; we should reset our SSH connections before forking, they will automatically re-establish after forking.



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# File 'lib/testlab/support/parallel.rb', line 13

def before_fork(pid)
  defined?(nodes) and nodes.each do |node|
    node.ssh_shutdown!
  end
end

#do_parallel_actions(klass, objects, action, reverse = false, &block) ⇒ Boolean

Perform actions against a collection of objects in parallel.

Returns:

  • (Boolean) —

    True if successful.



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# File 'lib/testlab/support/parallel.rb', line 9

def do_parallel_actions(klass, objects, action, reverse=false, &block)

  # Our before fork hook; we should reset our SSH connections before
  # forking, they will automatically re-establish after forking.
  def before_fork(pid)
    defined?(nodes) and nodes.each do |node|
      node.ssh_shutdown!
    end
  end

  # Clear the screen and move the cursor to x:0, y:0 using ANSI escape
  # codes
  #
  # @return [Boolean] Returns True if successful.
  def reset_screen
    self.ui.stdout.puts(ZTK::ANSI.reset)
    self.ui.stdout.puts(ZTK::ANSI.goto(0, 0))

    true
  end

  klass_name = klass.to_s.split('::').last
  command    = ZTK::Command.new(:silence => true, :ignore_exit_status => true)
  parallel   = ZTK::Parallel.new(:ui => self.ui, :raise_exceptions => false)
  parallel.config do |config|
    config.before_fork = method(:before_fork)
  end

  priority_groups = klass.priority_groups
  (reverse == true) and priority_groups.reverse!

  priority_groups.each do |priority_group|

    selected_objects = objects.select{ |c| c.priority == priority_group }
    if selected_objects.count == 1
      object = selected_objects.first

      block.call(object, action, klass)
    else
      selected_objects.each do |object|
        parallel.process do
          $0 = "TestLab #{klass_name.capitalize} #{action.to_s.capitalize}: #{object.id.inspect}"

          # Redirect all standard I/O to /dev/null
          self.ui.stdout.reopen("/dev/null", "a")
          self.ui.stderr.reopen("/dev/null", "a")
          self.ui.stdin.reopen("/dev/null")

          # Redirect logging to an object specific log file
          log_filename = "/tmp/testlab.log.#{object.id.to_s.downcase}"
          File.exists?(log_filename) && FileUtils.rm_f(log_filename)
          self.ui.logger = ZTK::Logger.new(log_filename)

          block.call(object, action, klass)
        end
      end

      while (parallel.count > 0) do
        message = format_message("Parallel #{action.to_s.capitalize} Running:".yellow)

        reset_screen
        self.ui.stdout.puts(message)
        self.ui.stdout.puts("-" * message.uncolor.length)
        self.ui.stdout.print(command.exec(%(ps u --pid #{parallel.pids.join(' ')} 2>/dev/null)).output)

        sleep(1)

        # Attempt to reap processes faster, otherwise we'll only reap one
        # per second if we're lucky.
        for x in 1..(parallel.count) do
          parallel.wait(Process::WNOHANG)
        end
      end

      reset_screen
    end
  end

  exception_count = parallel.results.count{ |result| (Exception === result) }
  if (exception_count > 0)
    message = "Encountered #{exception_count} exceptions during parallel operations! (See logs for details)"
    self.ui.logger.fatal { message }
    raise TestLabError, message
  end

  true
end

#reset_screen ⇒ Boolean

Clear the screen and move the cursor to x:0, y:0 using ANSI escape codes

Returns:

  • (Boolean) —

    Returns True if successful.



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# File 'lib/testlab/support/parallel.rb', line 23

def reset_screen
  self.ui.stdout.puts(ZTK::ANSI.reset)
  self.ui.stdout.puts(ZTK::ANSI.goto(0, 0))

  true
end