puma_jruby_at_exit.rb

require 'sinatra/base'

class App < Sinatra::Base
  get '/' do
    "hello!\n"
  end
  post '/exit' do
    Thread.new { sleep 1; exit }
    "exiting!\n"
  end
end

at_exit do
  puts 'here in at_exit 1'
end

at_exit do
  puts 'here in at_exit 2'
end

at_exit do
  puts 'here in at_exit 3'
end