Forum: Mongrel Why Mongrel doesn't cancel connection on error?

Why Mongrel doesn't cancel connection on error?

Example: (Mongrel using Rack)

...
def call env
  begin
    p :start
    sleep 10
  ensure
    p :stop
  end
end
...

Open browser, go to localhost:8080, and immediatelly close the browser.
Output will be:

start
<waits for 10 sec>
end

Why it doesn't cancel/kill thread immediatelly?