webrick/server.rb: stop immediately

* lib/webrick/server.rb (WEBrick::GenericServer#start): flush
  shutdown pipe.
* lib/webrick/server.rb (WEBrick::GenericServer#stop): request the
  server to stop immediately by sending data via shutdown pipe.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51231 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 22 insertions, 11 deletions

diff --git a/lib/webrick/server.rb b/lib/webrick/server.rb
index 5ada88ac73..1d87cdae70 100644
--- a/lib/webrick/server.rb
+++ b/lib/webrick/server.rb
@@ -172,8 +172,13 @@ module WEBrick
         begin
           while @status == :Running
             begin
-              if svrs = IO.select([shutdown_pipe[0], *@listeners], nil, nil, 2.0)
-                if svrs[0].include? shutdown_pipe[0]
+              sp = shutdown_pipe[0]
+              if svrs = IO.select([sp, *@listeners], nil, nil, 2.0)
+                if svrs[0].include? sp
+                  # swallow shutdown pipe
+                  buf = String.new
+                  nil while String ===
+                            sp.read_nonblock([sp.nread, 8].max, buf, exception: false)
                   break
                 end
                 svrs[0].each{|svr|
@@ -221,6 +226,8 @@ module WEBrick
       if @status == :Running
         @status = :Shutdown
       end
+
+      alarm_shutdown_pipe {|f| f.write_nonblock("\0")}
     end
 
     ##
@@ -230,15 +237,7 @@ module WEBrick
     def shutdown
       stop
 
-      shutdown_pipe = @shutdown_pipe # another thread may modify @shutdown_pipe.
-      if shutdown_pipe
-        if !shutdown_pipe[1].closed?
-          begin
-            shutdown_pipe[1].close
-          rescue IOError # closed by another thread.
-          end
-        end
-      end
+      alarm_shutdown_pipe {|f| f.close}
     end
 
     ##
@@ -343,6 +342,18 @@ module WEBrick
       }
     end
 
+    def alarm_shutdown_pipe
+      _, pipe = @shutdown_pipe # another thread may modify @shutdown_pipe.
+      if pipe
+        if !pipe.closed?
+          begin
+            yield pipe
+          rescue IOError # closed by another thread.
+          end
+        end
+      end
+    end
+
     def cleanup_listener
       @listeners.each{|s|
         if @logger.debug?