class Rake::ThreadPool

def start_thread # :nodoc:
  @threads_mon.synchronize do
    next unless @threads.count < @max_active_threads
    t = Thread.new do
      begin
        while @threads.count <= @max_active_threads && !@queue.empty? do
          # Even though we just asked if the queue was empty, it
          # still could have had an item which by this statement
          # is now gone. For this reason we pass true to Queue#deq
          # because we will sleep indefinitely if it is empty.
          block = @queue.deq(true)
          stat :item_dequeued, item_id: block.object_id
          block.call
        end
      rescue ThreadError # this means the queue is empty
      ensure
        @threads_mon.synchronize do
          @threads.delete Thread.current
          stat :thread_deleted, deleted_thread: Thread.current.object_id, thread_count: @threads.count
          @join_cond.broadcast if @threads.empty?
        end
      end
    end
    @threads << t
    stat :thread_created, new_thread: t.object_id, thread_count: @threads.count
    @total_threads_in_play = @threads.count if @threads.count > @total_threads_in_play
  end
end