How to find origin of current running threads

threads.rb

require 'objspace'
ObjectSpace.trace_object_allocations_start

def all_child_threads
  Thread.list - [Thread.current]
end

trap(:INFO) {
  puts "#" * 90
  all_child_threads.each do |t|
    p ObjectSpace.allocation_sourcefile(t) => ObjectSpace.allocation_sourceline(t)
  end
  puts "#" * 90
}

Thread.new do
  loop do
    puts 'thread 1'
    sleep(1)
  end
end


Thread.new do
  loop do
    puts 'thread 2'
    sleep(1)
  end
end

all_child_threads.each(&:join)