Possible to fix race conditions

bunny_shutdown_fix.diff

diff --git a/lib/bunny/channel.rb b/lib/bunny/channel.rb
index 236f41c..4a500da 100644
--- a/lib/bunny/channel.rb
+++ b/lib/bunny/channel.rb
@@ -230,9 +230,9 @@ module Bunny
     # {Bunny::Queue}, {Bunny::Exchange} and {Bunny::Consumer} instances.
     # @api public
     def close
+      @work_pool.shutdown
       @connection.close_channel(self)
       @status = :closed
-      @work_pool.shutdown
       maybe_kill_consumer_work_pool!
     end
 
diff --git a/lib/bunny/consumer_work_pool.rb b/lib/bunny/consumer_work_pool.rb
index fe84404..49ba0ab 100644
--- a/lib/bunny/consumer_work_pool.rb
+++ b/lib/bunny/consumer_work_pool.rb
@@ -58,6 +58,9 @@ module Bunny
           throw :terminate
         end
       end
+      while busy?
+        sleep 0.1
+      end
     end
 
     def join(timeout = nil)