Fix hanging consoles: Close other client sockets in spring application forks

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Next Release
 
+* Fix bug which makes rails consoles to hang at exit when multiple of them are open (#647)
+
 ## 2.1.1
 
 * Avoid -I rubylibdir with default-gem bundler

lib/spring/application.rb

@@ -12,6 +12,7 @@ def initialize(manager, original_env, spring_env = Env.new)
       @spring_env   = spring_env
       @mutex        = Mutex.new
       @waiting      = Set.new
+      @clients      = Set.new
       @preloaded    = false
       @state        = :initialized
       @interrupt    = IO.pipe
@@ -151,6 +152,8 @@ def serve(client)
       log "got client"
       manager.puts
 
+      @clients << client
+
       _stdout, stderr, _stdin = streams = 3.times.map { client.recv_io }
       [STDOUT, STDERR, STDIN].zip(streams).each { |a, b| a.reopen(b) }
 
@@ -167,6 +170,10 @@ def serve(client)
       end
 
       pid = fork {
+        # Make sure to close other clients otherwise their graceful termination
+        # will be impossible due to reference from this fork.
+        @clients.select { |c| c != client }.each(&:close)
+
         Process.setsid
         IGNORE_SIGNALS.each { |sig| trap(sig, "DEFAULT") }
         trap("TERM", "DEFAULT")