fix and test Rack hijack support

Rack hijacking may close the socket before it yields control back to our
epoll event loop.  So it's not safe to attempt to use the socket (or
even get the .fileno) with :delete/EPOLL_CTL_DEL.

So change :delete to :ignore, and only decrement the FD counter to allow
yahns to do graceful shutdown.  This means we'll potentially waste ~200
bytes of kernel memory due to epoll overhead until the FD is closed by
the app hijacking.

I'm not sure how Rack servers handle graceful shutdown when
hijacking, but maybe they just retrap SIGQUIT...

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/yahns/http_response.rb b/lib/yahns/http_response.rb
index b6228e5..3ee4e21 100644
--- a/lib/yahns/http_response.rb
+++ b/lib/yahns/http_response.rb
@@ -52,8 +52,8 @@ module Yahns::HttpResponse # :nodoc:
     case rv # trysendfile return value
     when nil
       case alive
-      when :delete
-        @state = :delete
+      when :ignore
+        @state = :ignore
       when true, false
         http_response_done(alive)
       end
@@ -140,7 +140,7 @@ module Yahns::HttpResponse # :nodoc:
 
     if hijack
       hijack.call(self)
-      return :delete # trigger EPOLL_CTL_DEL
+      return :ignore
     end
 
     if body.respond_to?(:to_path)