From 4a7c5685c86d0349c98b2725ad01aa70ebcc3581 Mon Sep 17 00:00:00 2001
From: Matthew Draper <matthew@trebex.net>
Date: Thu, 6 Oct 2016 10:31:14 +1030
Subject: [PATCH] Close the IO from the read loop thread

IO#close and IO#read across threads don't get along so well:

After T1 enters #read and releases the GVL, T2 can call #close on the
IO, thereby both closing the fd and freeing the buffer while T1 is using
them.
---
 actioncable/lib/action_cable/connection/stream.rb            | 1 -
 actioncable/lib/action_cable/connection/stream_event_loop.rb | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/actioncable/lib/action_cable/connection/stream.rb b/actioncable/lib/action_cable/connection/stream.rb
index d66e1b4e41..e620b93845 100644
--- a/actioncable/lib/action_cable/connection/stream.rb
+++ b/actioncable/lib/action_cable/connection/stream.rb
@@ -106,7 +106,6 @@ module ActionCable
         def clean_rack_hijack
           return unless @rack_hijack_io
           @event_loop.detach(@rack_hijack_io, self)
-          @rack_hijack_io.close
           @rack_hijack_io = nil
         end
     end
diff --git a/actioncable/lib/action_cable/connection/stream_event_loop.rb b/actioncable/lib/action_cable/connection/stream_event_loop.rb
index eec24638b6..2d1af0ff9f 100644
--- a/actioncable/lib/action_cable/connection/stream_event_loop.rb
+++ b/actioncable/lib/action_cable/connection/stream_event_loop.rb
@@ -36,6 +36,7 @@ module ActionCable
         @todo << lambda do
           @nio.deregister io
           @map.delete io
+          io.close
         end
         wakeup
       end