Adds a test to capture #1835

test/test_puma_server_ssl.rb

@@ -34,8 +34,8 @@ class TestPumaServerSSL < Minitest::Test
 
   def setup
     return if DISABLE_SSL
-    port = UniquePort.call
-    host = "127.0.0.1"
+    @port = port = UniquePort.call
+    @host = host = "127.0.0.1"
 
     app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
 
@@ -80,6 +80,23 @@ def test_url_scheme_for_https
     assert_equal "https", body
   end
 
+  def test_request_wont_block_thread
+    # Open a connection and give enough data to trigger a read, then wait
+    socket = TCPSocket.new @host, @port
+    socket.write "x"
+    sleep 1
+
+    # Capture the amount of threads being used after connecting and being idle
+    thread_pool = @server.instance_variable_get(:@thread_pool)
+    busy_threads = thread_pool.spawned - thread_pool.waiting
+
+    socket.close
+
+    # The thread pool should be empty since the request would block on read
+    # and our request should have been moved to the reactor.
+    assert busy_threads.zero?, "Our connection is monopolizing a thread"
+  end
+
   def test_very_large_return
     giant = "x" * 2056610