From 7c31c2738c7d02e5a9ac6167c650cb8a5411321d Mon Sep 17 00:00:00 2001
From: normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 25 Aug 2018 02:32:15 +0000
Subject: [PATCH] drb: close graceful shutdown pipe before socket

Closing a listen socket while entering select(2) may
trigger IOError or even deadlock because another thread
may give the file descriptor to another file description;
meaning the kernel can wait on the wrong description.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64532 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/drb/drb.rb  | 1 +
 lib/drb/unix.rb | 1 +
 2 files changed, 2 insertions(+)

diff --git a/lib/drb/drb.rb b/lib/drb/drb.rb
index 36b2b1ade4..a20ee1f143 100644
--- a/lib/drb/drb.rb
+++ b/lib/drb/drb.rb
@@ -953,6 +953,7 @@ module DRb
     # returned by #open or by #accept, then it closes this particular
     # client-server session.
     def close
+      shutdown
       if @socket
         @socket.close
         @socket = nil
diff --git a/lib/drb/unix.rb b/lib/drb/unix.rb
index adc38ff591..7dcf2daaf8 100644
--- a/lib/drb/unix.rb
+++ b/lib/drb/unix.rb
@@ -95,6 +95,7 @@ module DRb
     public
     def close
       return unless @socket
+      shutdown # DRbProtocol#shutdown
       path = @socket.path if @server_mode
       @socket.close
       File.unlink(path) if @server_mode