diff --git a/lib/puma/queue_close.rb b/lib/puma/queue_close.rb
index a1d568ccfc..d9a94dc665 100644
--- a/lib/puma/queue_close.rb
+++ b/lib/puma/queue_close.rb
@@ -5,22 +5,22 @@ module Puma
   # Add a simple implementation for earlier Ruby versions.
   #
   module QueueClose
-    def initialize
-      @closed = false
-      super
-    end
     def close
+      num_waiting.times {push nil}
       @closed = true
     end
     def closed?
-      @closed
+      @closed ||= false
     end
     def push(object)
-      @closed ||= false
-      raise ClosedQueueError if @closed
+      raise ClosedQueueError if closed?
       super
     end
     alias << push
+    def pop(non_block=false)
+      return nil if !non_block && closed? && empty?
+      super
+    end
   end
   ::Queue.prepend QueueClose
 end
diff --git a/lib/puma/server.rb b/lib/puma/server.rb
index 1f1ffc2161..3912699cf6 100644
--- a/lib/puma/server.rb
+++ b/lib/puma/server.rb
@@ -311,6 +311,7 @@ def handle_servers
         sockets = [check] + @binder.ios
         pool = @thread_pool
         queue_requests = @queue_requests
+        drain = @options[:drain_on_shutdown] ? 0 : nil
 
         remote_addr_value = nil
         remote_addr_header = nil
@@ -322,9 +323,10 @@ def handle_servers
           remote_addr_header = @options[:remote_address_header]
         end
 
-        while @status == :run
+        while @status == :run || (drain && shutting_down?)
           begin
-            ios = IO.select sockets
+            ios = IO.select sockets, nil, nil, (shutting_down? ? 0 : nil)
+            break unless ios
             ios.first.each do |sock|
               if sock == check
                 break if handle_check
@@ -337,6 +339,7 @@ def handle_servers
                 rescue IO::WaitReadable
                   next
                 end
+                drain += 1 if shutting_down?
                 client = Client.new io, @binder.env(sock)
                 if remote_addr_value
                   client.peerip = remote_addr_value
@@ -351,6 +354,7 @@ def handle_servers
           end
         end
 
+        @events.debug "Drained #{drain} additional connections." if drain
         @events.fire :state, @status
 
         if queue_requests
@@ -553,28 +557,6 @@ def graceful_shutdown
         $stdout.syswrite "#{pid}: === End thread backtrace dump ===\n"
       end
 
-      if @options[:drain_on_shutdown]
-        count = 0
-
-        while true
-          ios = IO.select @binder.ios, nil, nil, 0
-          break unless ios
-
-          ios.first.each do |sock|
-            begin
-              if io = sock.accept_nonblock
-                count += 1
-                client = Client.new io, @binder.env(sock)
-                @thread_pool << client
-              end
-            rescue SystemCallError
-            end
-          end
-        end
-
-        @events.debug "Drained #{count} additional connections."
-      end
-
       if @status != :restart
         @binder.close
       end
diff --git a/test/test_puma_server.rb b/test/test_puma_server.rb
index 7ddcd1b50a..7ed629e4af 100644
--- a/test/test_puma_server.rb
+++ b/test/test_puma_server.rb
@@ -22,10 +22,9 @@ def teardown
     @ios.each { |io| io.close if io && !io.closed? }
   end
 
-  def server_run(app: @app, early_hints: false)
-    @server.app = app
+  def server_run(**options, &block)
+    @server = Puma::Server.new block || @app, @events, options
     @port = (@server.add_tcp_listener @host, 0).addr[1]
-    @server.early_hints = true if early_hints
     @server.run
     sleep 0.15 if Puma.jruby?
   end
@@ -54,7 +53,7 @@ def new_connection
   end
 
   def test_normalize_host_header_missing
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env["SERVER_NAME"], "\n", env["SERVER_PORT"]]]
     end
 
@@ -63,7 +62,7 @@ def test_normalize_host_header_missing
   end
 
   def test_normalize_host_header_hostname
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env["SERVER_NAME"], "\n", env["SERVER_PORT"]]]
     end
 
@@ -75,7 +74,7 @@ def test_normalize_host_header_hostname
   end
 
   def test_normalize_host_header_ipv4
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env["SERVER_NAME"], "\n", env["SERVER_PORT"]]]
     end
 
@@ -87,7 +86,7 @@ def test_normalize_host_header_ipv4
   end
 
   def test_normalize_host_header_ipv6
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env["SERVER_NAME"], "\n", env["SERVER_PORT"]]]
     end
 
@@ -104,7 +103,7 @@ def test_normalize_host_header_ipv6
   def test_proper_stringio_body
     data = nil
 
-    server_run app: ->(env) do
+    server_run do |env|
       data = env['rack.input'].read
       [200, {}, ["ok"]]
     end
@@ -123,7 +122,7 @@ def test_proper_stringio_body
 
   def test_puma_socket
     body = "HTTP/1.1 750 Upgraded to Awesome\r\nDone: Yep!\r\n"
-    server_run app: ->(env) do
+    server_run do |env|
       io = env['puma.socket']
       io.write body
       io.close
@@ -138,7 +137,7 @@ def test_puma_socket
   def test_very_large_return
     giant = "x" * 2056610
 
-    server_run app: ->(env) do
+    server_run do
       [200, {}, [giant]]
     end
 
@@ -179,7 +178,7 @@ def test_respect_x_forwarded_scheme
   end
 
   def test_default_server_port
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env['SERVER_PORT']]]
     end
 
@@ -194,7 +193,7 @@ def test_default_server_port
   end
 
   def test_default_server_port_respects_x_forwarded_proto
-    server_run app: ->(env) do
+    server_run do |env|
       [200, {}, [env['SERVER_PORT']]]
     end
 
@@ -210,7 +209,7 @@ def test_default_server_port_respects_x_forwarded_proto
   end
 
   def test_HEAD_has_no_body
-    server_run app: ->(env) { [200, {"Foo" => "Bar"}, ["hello"]] }
+    server_run { [200, {"Foo" => "Bar"}, ["hello"]] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -218,7 +217,7 @@ def test_HEAD_has_no_body
   end
 
   def test_GET_with_empty_body_has_sane_chunking
-    server_run app: ->(env) { [200, {}, [""]] }
+    server_run { [200, {}, [""]] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -226,7 +225,7 @@ def test_GET_with_empty_body_has_sane_chunking
   end
 
   def test_early_hints_works
-    server_run early_hints: true, app: ->(env) do
+    server_run(early_hints: true) do |env|
      env['rack.early_hints'].call("Link" => "</style.css>; rel=preload; as=style\n</script.js>; rel=preload")
      [200, { "X-Hello" => "World" }, ["Hello world!"]]
     end
@@ -250,15 +249,15 @@ def test_early_hints_works
 
   def test_early_hints_are_ignored_if_connection_lost
 
-    def @server.fast_write(*args)
-      raise Puma::ConnectionError
-    end
-
-    server_run early_hints: true, app: ->(env) do
+    server_run(early_hints: true) do |env|
       env['rack.early_hints'].call("Link" => "</script.js>; rel=preload")
       [200, { "X-Hello" => "World" }, ["Hello world!"]]
     end
 
+    def @server.fast_write(*args)
+      raise Puma::ConnectionError
+    end
+
     # This request will cause the server to try and send early hints
     _ = send_http "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -270,7 +269,7 @@ def @server.fast_write(*args)
   end
 
   def test_early_hints_is_off_by_default
-    server_run app: ->(env) do
+    server_run do |env|
      assert_nil env['rack.early_hints']
      [200, { "X-Hello" => "World" }, ["Hello world!"]]
     end
@@ -289,7 +288,7 @@ def test_early_hints_is_off_by_default
   end
 
   def test_GET_with_no_body_has_sane_chunking
-    server_run app: ->(env) { [200, {}, []] }
+    server_run { [200, {}, []] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -297,8 +296,7 @@ def test_GET_with_no_body_has_sane_chunking
   end
 
   def test_doesnt_print_backtrace_in_production
-    @server.leak_stack_on_error = false
-    server_run app: ->(env) { raise "don't leak me bro" }
+    server_run(environment: :production) { raise "don't leak me bro" }
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
 
@@ -319,9 +317,7 @@ def test_eof_on_connection_close_is_not_logged_as_an_error
 
   def test_force_shutdown_custom_error_message
     handler = lambda {|err, env, status| [500, {"Content-Type" => "application/json"}, ["{}\n"]]}
-    @server = Puma::Server.new @app, @events, {:lowlevel_error_handler => handler, :force_shutdown_after => 2}
-
-    server_run app: ->(env) do
+    server_run(lowlevel_error_handler: handler, force_shutdown_after: 2) do
       @server.stop
       sleep 5
     end
@@ -337,7 +333,7 @@ def test_lowlevel_error_message
     skip_if :windows
     @server = Puma::Server.new @app, @events, {:force_shutdown_after => 2}
 
-    server_run app: ->(env) do
+    server_run do
       require 'json'
 
       # will raise fatal: machine stack overflow in critical region
@@ -353,9 +349,7 @@ def test_lowlevel_error_message
   end
 
   def test_force_shutdown_error_default
-    @server = Puma::Server.new @app, @events, {:force_shutdown_after => 2}
-
-    server_run app: ->(env) do
+    server_run(force_shutdown_after: 2) do
       @server.stop
       sleep 5
     end
@@ -368,9 +362,7 @@ def test_force_shutdown_error_default
 
   def test_prints_custom_error
     re = lambda { |err| [302, {'Content-Type' => 'text', 'Location' => 'foo.html'}, ['302 found']] }
-    @server = Puma::Server.new @app, @events, {:lowlevel_error_handler => re}
-
-    server_run app: ->(env) { raise "don't leak me bro" }
+    server_run(lowlevel_error_handler: re) { raise "don't leak me bro" }
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
 
@@ -383,9 +375,7 @@ def test_leh_gets_env_as_well
       [302, {'Content-Type' => 'text', 'Location' => 'foo.html'}, ['302 found']]
     }
 
-    @server = Puma::Server.new @app, @events, {:lowlevel_error_handler => re}
-
-    server_run app: ->(env) { raise "don't leak me bro" }
+    server_run(lowlevel_error_handler: re) { raise "don't leak me bro" }
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
 
@@ -398,9 +388,7 @@ def test_leh_has_status
       [302, {'Content-Type' => 'text', 'Location' => 'foo.html'}, ['302 found']]
     }
 
-    @server = Puma::Server.new @app, @events, {:lowlevel_error_handler => re}
-
-    server_run app: ->(env) { raise "don't leak me bro" }
+    server_run(lowlevel_error_handler: re) { raise "don't leak me bro" }
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
 
@@ -408,7 +396,7 @@ def test_leh_has_status
   end
 
   def test_custom_http_codes_10
-    server_run app: ->(env) { [449, {}, [""]] }
+    server_run { [449, {}, [""]] }
 
     data = send_http_and_read "GET / HTTP/1.0\r\n\r\n"
 
@@ -416,7 +404,7 @@ def test_custom_http_codes_10
   end
 
   def test_custom_http_codes_11
-    server_run app: ->(env) { [449, {}, [""]] }
+    server_run { [449, {}, [""]] }
 
     data = send_http_and_read "GET / HTTP/1.1\r\nConnection: close\r\n\r\n"
 
@@ -424,7 +412,7 @@ def test_custom_http_codes_11
   end
 
   def test_HEAD_returns_content_headers
-    server_run app: ->(env) { [200, {"Content-Type" => "application/pdf",
+    server_run { [200, {"Content-Type" => "application/pdf",
                                      "Content-Length" => "4242"}, []] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
@@ -438,7 +426,7 @@ def test_status_hook_fires_when_server_changes_states
 
     @events.register(:state) { |s| states << s }
 
-    server_run app: ->(env) { [200, {}, [""]] }
+    server_run { [200, {}, [""]] }
 
     _ = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -449,9 +437,8 @@ def test_status_hook_fires_when_server_changes_states
     assert_equal [:booting, :running, :stop, :done], states
   end
 
-  def test_timeout_in_data_phase
-    @server.first_data_timeout = 1
-    server_run
+  def test_timeout_in_data_phase(**options)
+    server_run(first_data_timeout: 1, **options)
 
     sock = send_http "POST / HTTP/1.1\r\nHost: test.com\r\nContent-Type: text/plain\r\nContent-Length: 5\r\n\r\n"
 
@@ -463,8 +450,7 @@ def test_timeout_in_data_phase
   end
 
   def test_timeout_data_no_queue
-    @server = Puma::Server.new @app, @events, queue_requests: false
-    test_timeout_in_data_phase
+    test_timeout_in_data_phase(queue_requests: false)
   end
 
   # https://github.com/puma/puma/issues/2574
@@ -492,7 +478,7 @@ def test_no_timeout_after_data_received_no_queue
   end
 
   def test_http_11_keep_alive_with_body
-    server_run app: ->(env) { [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
+    server_run { [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
 
     sock = send_http "GET / HTTP/1.1\r\nConnection: Keep-Alive\r\n\r\n"
 
@@ -507,7 +493,7 @@ def test_http_11_keep_alive_with_body
   end
 
   def test_http_11_close_with_body
-    server_run app: ->(env) { [200, {"Content-Type" => "plain/text"}, ["hello"]] }
+    server_run { [200, {"Content-Type" => "plain/text"}, ["hello"]] }
 
     data = send_http_and_read "GET / HTTP/1.1\r\nConnection: close\r\n\r\n"
 
@@ -515,7 +501,7 @@ def test_http_11_close_with_body
   end
 
   def test_http_11_keep_alive_without_body
-    server_run app: ->(env) { [204, {}, []] }
+    server_run { [204, {}, []] }
 
     sock = send_http "GET / HTTP/1.1\r\nConnection: Keep-Alive\r\n\r\n"
 
@@ -525,7 +511,7 @@ def test_http_11_keep_alive_without_body
   end
 
   def test_http_11_close_without_body
-    server_run app: ->(env) { [204, {}, []] }
+    server_run { [204, {}, []] }
 
     sock = send_http "GET / HTTP/1.1\r\nConnection: close\r\n\r\n"
 
@@ -535,7 +521,7 @@ def test_http_11_close_without_body
   end
 
   def test_http_10_keep_alive_with_body
-    server_run app: ->(env) { [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
+    server_run { [200, {"Content-Type" => "plain/text"}, ["hello\n"]] }
 
     sock = send_http "GET / HTTP/1.0\r\nConnection: Keep-Alive\r\n\r\n"
 
@@ -548,7 +534,7 @@ def test_http_10_keep_alive_with_body
   end
 
   def test_http_10_close_with_body
-    server_run app: ->(env) { [200, {"Content-Type" => "plain/text"}, ["hello"]] }
+    server_run { [200, {"Content-Type" => "plain/text"}, ["hello"]] }
 
     data = send_http_and_read "GET / HTTP/1.0\r\nConnection: close\r\n\r\n"
 
@@ -558,7 +544,7 @@ def test_http_10_close_with_body
   def test_http_10_partial_hijack_with_content_length
     body_parts = ['abc', 'de']
 
-    server_run app: ->(env) do
+    server_run do
       hijack_lambda = proc do | io |
         io.write(body_parts[0])
         io.write(body_parts[1])
@@ -573,7 +559,7 @@ def test_http_10_partial_hijack_with_content_length
   end
 
   def test_http_10_keep_alive_without_body
-    server_run app: ->(env) { [204, {}, []] }
+    server_run { [204, {}, []] }
 
     sock = send_http "GET / HTTP/1.0\r\nConnection: Keep-Alive\r\n\r\n"
 
@@ -583,7 +569,7 @@ def test_http_10_keep_alive_without_body
   end
 
   def test_http_10_close_without_body
-    server_run app: ->(env) { [204, {}, []] }
+    server_run { [204, {}, []] }
 
     data = send_http_and_read "GET / HTTP/1.0\r\nConnection: close\r\n\r\n"
 
@@ -591,7 +577,7 @@ def test_http_10_close_without_body
   end
 
   def test_Expect_100
-    server_run app: ->(env) { [200, {}, [""]] }
+    server_run { [200, {}, [""]] }
 
     data = send_http_and_read "GET / HTTP/1.1\r\nConnection: close\r\nExpect: 100-continue\r\n\r\n"
 
@@ -601,7 +587,7 @@ def test_Expect_100
   def test_chunked_request
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -617,7 +603,7 @@ def test_chunked_request
   def test_large_chunked_request
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -647,7 +633,7 @@ def test_large_chunked_request
   def test_chunked_request_pause_before_value
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -668,7 +654,7 @@ def test_chunked_request_pause_before_value
   def test_chunked_request_pause_between_chunks
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -689,7 +675,7 @@ def test_chunked_request_pause_between_chunks
   def test_chunked_request_pause_mid_count
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -710,7 +696,7 @@ def test_chunked_request_pause_mid_count
   def test_chunked_request_pause_before_count_newline
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -731,7 +717,7 @@ def test_chunked_request_pause_before_count_newline
   def test_chunked_request_pause_mid_value
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -752,7 +738,7 @@ def test_chunked_request_pause_mid_value
   def test_chunked_request_pause_between_cr_lf_after_size_of_second_chunk
     body = nil
     content_length = nil
-    server_run app: ->(env)  {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -782,7 +768,7 @@ def test_chunked_request_pause_between_cr_lf_after_size_of_second_chunk
   def test_chunked_request_pause_between_closing_cr_lf
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -804,7 +790,7 @@ def test_chunked_request_pause_between_closing_cr_lf
   def test_chunked_request_pause_before_closing_cr_lf
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -826,7 +812,7 @@ def test_chunked_request_pause_before_closing_cr_lf
   def test_chunked_request_header_case
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -842,7 +828,7 @@ def test_chunked_request_header_case
   def test_chunked_keep_alive
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -862,7 +848,7 @@ def test_chunked_keep_alive
   def test_chunked_keep_alive_two_back_to_back
     body = nil
     content_length = nil
-    server_run app: ->(env) {
+    server_run { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       [200, {}, [""]]
@@ -903,8 +889,7 @@ def test_chunked_keep_alive_two_back_to_back_with_set_remote_address
     body = nil
     content_length = nil
     remote_addr =nil
-    @server = Puma::Server.new @app, @events, { remote_address: :header, remote_address_header: 'HTTP_X_FORWARDED_FOR'}
-    server_run app: ->(env) {
+    server_run(remote_address: :header, remote_address_header: 'HTTP_X_FORWARDED_FOR') { |env|
       body = env['rack.input'].read
       content_length = env['CONTENT_LENGTH']
       remote_addr = env['REMOTE_ADDR']
@@ -936,7 +921,7 @@ def test_chunked_encoding
     enc = Encoding::UTF_16LE
     str = "──иї_テスト──\n".encode enc
 
-    server_run app: ->(env) {
+    server_run {
       hdrs = {}
       hdrs['Content-Type'] = "text; charset=#{enc.to_s.downcase}"
 
@@ -958,7 +943,7 @@ def test_chunked_encoding
   end
 
   def test_empty_header_values
-    server_run app: ->(env) { [200, {"X-Empty-Header" => ""}, []] }
+    server_run { [200, {"X-Empty-Header" => ""}, []] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -967,7 +952,7 @@ def test_empty_header_values
 
   def test_request_body_wait
     request_body_wait = nil
-    server_run app: ->(env) {
+    server_run { |env|
       request_body_wait = env['puma.request_body_wait']
       [204, {}, []]
     }
@@ -985,7 +970,7 @@ def test_request_body_wait
 
   def test_request_body_wait_chunked
     request_body_wait = nil
-    server_run app: ->(env) {
+    server_run { |env|
       request_body_wait = env['puma.request_body_wait']
       [204, {}, []]
     }
@@ -1001,8 +986,8 @@ def test_request_body_wait_chunked
     assert_operator request_body_wait, :>=, 900
   end
 
-  def test_open_connection_wait
-    server_run app: ->(_) { [200, {}, ["Hello"]] }
+  def test_open_connection_wait(**options)
+    server_run(**options) { [200, {}, ["Hello"]] }
     s = send_http nil
     sleep 0.1
     s << "GET / HTTP/1.0\r\n\r\n"
@@ -1010,13 +995,12 @@ def test_open_connection_wait
   end
 
   def test_open_connection_wait_no_queue
-    @server = Puma::Server.new @app, @events, queue_requests: false
-    test_open_connection_wait
+    test_open_connection_wait(queue_requests: false)
   end
 
   # Rack may pass a newline in a header expecting us to split it.
   def test_newline_splits
-    server_run app: ->(_) { [200, {'X-header' => "first line\nsecond line"}, ["Hello"]] }
+    server_run { [200, {'X-header' => "first line\nsecond line"}, ["Hello"]] }
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -1024,7 +1008,7 @@ def test_newline_splits
   end
 
   def test_newline_splits_in_early_hint
-    server_run early_hints: true, app: ->(env) do
+    server_run(early_hints: true) do |env|
       env['rack.early_hints'].call({'X-header' => "first line\nsecond line"})
       [200, {}, ["Hello world!"]]
     end
@@ -1037,7 +1021,7 @@ def test_newline_splits_in_early_hint
   # To comply with the Rack spec, we have to split header field values
   # containing newlines into multiple headers.
   def assert_does_not_allow_http_injection(app, opts = {})
-    server_run(early_hints: opts[:early_hints], app: app)
+    server_run(early_hints: opts[:early_hints], &app)
 
     data = send_http_and_read "HEAD / HTTP/1.0\r\n\r\n"
 
@@ -1080,10 +1064,9 @@ def assert_does_not_allow_http_injection(app, opts = {})
 
   # Perform a server shutdown while requests are pending (one in app-server response, one still sending client request).
   def shutdown_requests(s1_complete: true, s1_response: nil, post: false, s2_response: nil, **options)
-    @server = Puma::Server.new @app, @events, options
     mutex = Mutex.new
     app_finished = ConditionVariable.new
-    server_run app: ->(env) {
+    server_run(**options) { |env|
       path = env['REQUEST_PATH']
       mutex.synchronize do
         app_finished.signal
@@ -1157,7 +1140,7 @@ def test_force_shutdown
   end
 
   def test_http11_connection_header_queue
-    server_run app: ->(_) { [200, {}, [""]] }
+    server_run { [200, {}, [""]] }
 
     sock = send_http "GET / HTTP/1.1\r\n\r\n"
     assert_equal ["HTTP/1.1 200 OK", "Content-Length: 0"], header(sock)
@@ -1169,7 +1152,7 @@ def test_http11_connection_header_queue
   end
 
   def test_http10_connection_header_queue
-    server_run app: ->(_) { [200, {}, [""]] }
+    server_run { [200, {}, [""]] }
 
     sock = send_http "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n"
     assert_equal ["HTTP/1.0 200 OK", "Connection: Keep-Alive", "Content-Length: 0"], header(sock)
@@ -1180,16 +1163,14 @@ def test_http10_connection_header_queue
   end
 
   def test_http11_connection_header_no_queue
-    @server = Puma::Server.new @app, @events, queue_requests: false
-    server_run app: ->(_) { [200, {}, [""]] }
+    server_run(queue_requests: false) { [200, {}, [""]] }
     sock = send_http "GET / HTTP/1.1\r\n\r\n"
     assert_equal ["HTTP/1.1 200 OK", "Connection: close", "Content-Length: 0"], header(sock)
     sock.close
   end
 
   def test_http10_connection_header_no_queue
-    @server = Puma::Server.new @app, @events, queue_requests: false
-    server_run app: ->(_) { [200, {}, [""]] }
+    server_run(queue_requests: false) { [200, {}, [""]] }
     sock = send_http "GET / HTTP/1.0\r\n\r\n"
     assert_equal ["HTTP/1.0 200 OK", "Content-Length: 0"], header(sock)
     sock.close
@@ -1233,9 +1214,7 @@ def test_client_quick_close_no_lowlevel_error_handler_call
       [500, {"Content-Type" => "application/json"}, ["{}\n"]]
     }
 
-    @server = Puma::Server.new @app, @events, {:lowlevel_error_handler => handler}
-
-    server_run app: ->(env) { [200, {}, ['Hello World']] }
+    server_run(lowlevel_error_handler: handler) { [200, {}, ['Hello World']] }
 
     # valid req & read, close
     sock = TCPSocket.new @host, @port
@@ -1303,4 +1282,34 @@ def test_custom_io_selector
 
     assert_equal selector.backend, backend
   end
+
+  def test_drain_on_shutdown(drain=true)
+    num_connections = 10
+
+    wait = Queue.new
+    server_run(drain_on_shutdown: drain, max_threads: 1) do
+      wait.pop
+      [200, {}, ["DONE"]]
+    end
+    connections = Array.new(num_connections) {send_http "GET / HTTP/1.0\r\n\r\n"}
+    @server.stop
+    wait.close
+    bad = 0
+    connections.each do |s|
+      begin
+        assert_match 'DONE', s.read
+      rescue Errno::ECONNRESET
+        bad += 1
+      end
+    end
+    if drain
+      assert_equal 0, bad
+    else
+      refute_equal 0, bad
+    end
+  end
+
+  def test_not_drain_on_shutdown
+    test_drain_on_shutdown false
+  end
 end