code review 70410044: net/http: proactively address potential race in Ser...

src/pkg/net/http/server.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // HTTP server.  See RFC 2616.
 
 package http
 
 import (
         "bufio"
@@ skipping 410 matching lines @@
 
 // Create new connection from rwc.
 func (srv *Server) newConn(rwc net.Conn) (c *conn, err error) {
         c = new(conn)
         c.remoteAddr = rwc.RemoteAddr().String()
         c.server = srv
         c.rwc = rwc
         if debugServerConnections {
                 c.rwc = newLoggingConn("server", c.rwc)
         }
-        c.setState(c.rwc, StateNew)
         c.sr = liveSwitchReader{r: c.rwc}
         c.lr = io.LimitReader(&c.sr, noLimit).(*io.LimitedReader)
         br := newBufioReader(c.lr)
         bw := newBufioWriterSize(c.rwc, 4<<10)
         c.buf = bufio.NewReadWriter(br, bw)
         return c, nil
 }
 
 var (
         bufioReaderPool   sync.Pool
@@ skipping 1273 matching lines @@
                                 time.Sleep(tempDelay)
                                 continue
                         }
                         return e
                 }
                 tempDelay = 0
                 c, err := srv.newConn(rw)
                 if err != nil {
                         continue
                 }
+                c.setState(c.rwc, StateNew) // before Serve can return
                 go c.serve()
         }
 }
 
 func (s *Server) doKeepAlives() bool {
         return atomic.LoadInt32(&s.disableKeepAlives) == 0
 }
 
 // SetKeepAlivesEnabled controls whether HTTP keep-alives are enabled.
 // By default, keep-alives are always enabled. Only very
@@ skipping 305 matching lines @@
         log.Printf("%s.Read(%d) = %d, %v", c.name, len(p), n, err)
         return
 }
 
 func (c *loggingConn) Close() (err error) {
         log.Printf("%s.Close() = ...", c.name)
         err = c.Conn.Close()
         log.Printf("%s.Close() = %v", c.name, err)
         return
 }