net/http/httptest: fix possible race on historyListener.history

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6845077

diff --git a/src/pkg/net/http/httptest/server.go b/src/pkg/net/http/httptest/server.go
index 0997a8a2321bf8efbb0f7813662139142a7ca87f..0ad05483a4cca75b06ee948081158d9ad8cad7a4 100644 (file)
--- a/src/pkg/net/http/httptest/server.go
+++ b/src/pkg/net/http/httptest/server.go
@@ -36,13 +36,16 @@ type Server struct {
 // accepted.
 type historyListener struct {
        net.Listener
-       history []net.Conn
+       sync.Mutex // protects history
+       history    []net.Conn
 }
 
 func (hs *historyListener) Accept() (c net.Conn, err error) {
        c, err = hs.Listener.Accept()
        if err == nil {
+               hs.Lock()
                hs.history = append(hs.history, c)
+               hs.Unlock()
        }
        return
 }
@@ -96,7 +99,7 @@ func (s *Server) Start() {
        if s.URL != "" {
                panic("Server already started")
        }
-       s.Listener = &historyListener{s.Listener, make([]net.Conn, 0)}
+       s.Listener = &historyListener{Listener: s.Listener}
        s.URL = "http://" + s.Listener.Addr().String()
        s.wrapHandler()
        go s.Config.Serve(s.Listener)
@@ -122,7 +125,7 @@ func (s *Server) StartTLS() {
        }
        tlsListener := tls.NewListener(s.Listener, s.TLS)
 
-       s.Listener = &historyListener{tlsListener, make([]net.Conn, 0)}
+       s.Listener = &historyListener{Listener: tlsListener}
        s.URL = "https://" + s.Listener.Addr().String()
        s.wrapHandler()
        go s.Config.Serve(s.Listener)
@@ -161,9 +164,11 @@ func (s *Server) CloseClientConnections() {
        if !ok {
                return
        }
+       hl.Lock()
        for _, conn := range hl.history {
                conn.Close()
        }
+       hl.Unlock()
 }
 
 // waitGroupHandler wraps a handler, incrementing and decrementing a