diff --git a/lib/puma/client.rb b/lib/puma/client.rb
index 96c2f796..4ad819f8 100644
--- a/lib/puma/client.rb
+++ b/lib/puma/client.rb
@@ -222,6 +222,14 @@ module Puma
       end
     end # IS_JRUBY
 
+    def finish
+      return true if @ready
+      until try_to_finish
+        IO.select([@to_io], nil, nil)
+      end
+      true
+    end
+
     def read_body
       # Read an odd sized chunk so we can read even sized ones
       # after this
diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index fe616bc7..1354e3fb 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -27,6 +27,7 @@ module Puma
       @options[:after_worker_boot] ||= []
       @options[:worker_timeout] ||= DefaultWorkerTimeout
       @options[:worker_shutdown_timeout] ||= DefaultWorkerShutdownTimeout
+      @options[:queue_requests] ||= true
     end
 
     attr_reader :options
@@ -402,6 +403,23 @@ module Puma
       def worker_shutdown_timeout(timeout)
         @options[:worker_shutdown_timeout] = timeout
       end
+
+      # When set to true (the default), workers accept all requests
+      # and queue them before passing them to the handlers.
+      # When set to false, each worker process accepts exactly as
+      # many requests as it is configured to simultaneously handle.
+      #
+      # Queueing requests generally improves performance. In some
+      # cases, such as a single threaded application, it may be
+      # better to ensure requests get balanced across workers.
+      #
+      # Note that setting this to false disables HTTP keepalive and
+      # slow clients will occupy a handler thread while the request
+      # is being sent. A reverse proxy, such as nginx, can handle
+      # slow clients and queue requests before they reach puma.
+      def queue_requests(answer=true)
+        @options[:queue_requests] = answer
+      end
     end
   end
 end
diff --git a/lib/puma/server.rb b/lib/puma/server.rb
index a99daf6c..69b1b2b8 100644
--- a/lib/puma/server.rb
+++ b/lib/puma/server.rb
@@ -241,7 +241,12 @@ module Puma
         process_now = false
 
         begin
-          process_now = client.eagerly_finish
+          if @options[:queue_requests]
+            process_now = client.eagerly_finish
+          else
+            client.finish
+            process_now = true
+          end
         rescue HttpParserError => e
           client.write_400
           client.close
@@ -261,9 +266,10 @@ module Puma
 
       @thread_pool.clean_thread_locals = @options[:clean_thread_locals]
 
-      @reactor = Reactor.new self, @thread_pool
-
-      @reactor.run_in_thread
+      if @options[:queue_requests]
+        @reactor = Reactor.new self, @thread_pool
+        @reactor.run_in_thread
+      end
 
       if @auto_trim_time
         @thread_pool.auto_trim!(@auto_trim_time)
@@ -296,6 +302,7 @@ module Puma
                   if io = sock.accept_nonblock
                     client = Client.new io, @binder.env(sock)
                     pool << client
+                    pool.wait_until_not_full unless @options[:queue_requests]
                   end
                 rescue SystemCallError
                 end
@@ -312,9 +319,10 @@ module Puma
         @events.fire :state, @status
 
         graceful_shutdown if @status == :stop || @status == :restart
-        @reactor.clear! if @status == :restart
-
-        @reactor.shutdown
+        if @options[:queue_requests]
+          @reactor.clear! if @status == :restart
+          @reactor.shutdown
+        end
       rescue Exception => e
         STDERR.puts "Exception handling servers: #{e.message} (#{e.class})"
         STDERR.puts e.backtrace
@@ -367,6 +375,7 @@ module Puma
             close_socket = false
             return
           when true
+            return unless @options[:queue_requests]
             buffer.reset
 
             unless client.reset(@status == :run)
diff --git a/lib/puma/thread_pool.rb b/lib/puma/thread_pool.rb
index 7ec36ff9..acca9276 100644
--- a/lib/puma/thread_pool.rb
+++ b/lib/puma/thread_pool.rb
@@ -12,7 +12,8 @@ module Puma
     # thread.
     #
     def initialize(min, max, *extra, &block)
-      @cond = ConditionVariable.new
+      @not_empty = ConditionVariable.new
+      @not_full = ConditionVariable.new
       @mutex = Mutex.new
 
       @todo = []
@@ -60,7 +61,8 @@ module Puma
         todo  = @todo
         block = @block
         mutex = @mutex
-        cond  = @cond
+        not_empty = @not_empty
+        not_full = @not_full
 
         extra = @extra.map { |i| i.new }
 
@@ -83,10 +85,11 @@ module Puma
               end
 
               @waiting += 1
-              cond.wait mutex
-              @waiting -= 1
+              not_full.signal
+              not_empty.wait mutex
             end
 
+            @waiting -= 1
             work = todo.shift if continue
           end
 
@@ -125,9 +128,18 @@ module Puma
 
         if @waiting < @todo.size and @spawned < @max
           spawn_thread
+          @waiting+=1
         end
 
-        @cond.signal
+        @not_empty.signal
+      end
+    end
+
+    def wait_until_not_full
+      @mutex.synchronize do
+        until @todo.size - @waiting < @max - @spawned or @shutdown
+          @not_full.wait @mutex
+        end
       end
     end
 
@@ -139,7 +151,7 @@ module Puma
       @mutex.synchronize do
         if (force or @waiting > 0) and @spawned - @trim_requested > @min
           @trim_requested += 1
-          @cond.signal
+          @not_empty.signal
         end
       end
     end
@@ -178,7 +190,8 @@ module Puma
     def shutdown
       @mutex.synchronize do
         @shutdown = true
-        @cond.broadcast
+        @not_empty.broadcast
+        @not_full.broadcast
 
         @auto_trim.stop if @auto_trim
       end