fix: Don't close the listener when closing the server

When calling gluon.Serve(ctx, net.Listener), we take in a listener.
We shouldn't close this when closing gluon as we don't own this listener.
The surrounding caller who calls gluon.Serve(...) should be responsible for
closing it, to avoid double-close errors.

benchmarks/gluon_bench/imap_benchmarks/server/local.go

@@ -25,7 +25,11 @@ func (l *LocalServer) Address() net.Addr {
 }
 
 func (l *LocalServer) Close(ctx context.Context) error {
-	return l.server.Close(ctx)
+	if err := l.server.Close(ctx); err != nil {
+		return err
+	}
+
+	return l.listener.Close()
 }
 
 type LocalServerBuilder struct{}

demo/demo.go

@@ -77,6 +77,10 @@ func main() {
 	for err := range server.GetErrorCh() {
 		logrus.WithError(err).Error("Error while serving")
 	}
+
+	if err := listener.Close(); err != nil {
+		logrus.WithError(err).Error("Failed to close listener")
+	}
 }
 
 func addUser(ctx context.Context, server *gluon.Server, addresses []string, password string) error {

server.go

@@ -160,10 +160,7 @@ func (s *Server) Serve(ctx context.Context, l net.Listener) error {
 			Addr: l.Addr(),
 		})
 
-		connCh := newConnCh(l)
-		defer l.Close()
-
-		s.serve(ctx, connCh)
+		s.serve(ctx, newConnCh(l))
 	})
 
 	return nil
@@ -231,7 +228,6 @@ func (s *Server) GetUserDataPath(userID string) (string, error) {
 }
 
 // Close closes the server.
-// It firstly closes all TCP listeners then closes the backend.
 func (s *Server) Close(ctx context.Context) error {
 	ctx = reporter.NewContextWithReporter(ctx, s.reporter)
 

tests/server_test.go

@@ -213,6 +213,7 @@ func runServer(tb testing.TB, options *serverOptions, tests func(session *testSe
 	// Expect the server to shut down successfully when closed.
 	require.NoError(tb, server.Close(ctx))
 	require.NoError(tb, <-server.GetErrorCh())
+	require.NoError(tb, listener.Close())
 }
 
 // runServerWithPaths initializes and starts the mailserver.