zmq4: remove load-balanced writer

msgio.go

@@ -180,65 +180,6 @@ func (w *mwriter) write(ctx context.Context, msg Msg) error {
 	return err
 }
 
-type lbwriter struct {
-	ctx context.Context
-	c   chan Msg
-	sem *semaphore
-}
-
-func newLBWriter(ctx context.Context) *lbwriter {
-	const size = 10
-	return &lbwriter{
-		ctx: ctx,
-		c:   make(chan Msg, size),
-		sem: newSemaphore(),
-	}
-}
-
-func (lw *lbwriter) Close() error {
-	close(lw.c)
-	return nil
-}
-
-func (lw *lbwriter) addConn(w *Conn) {
-	lw.sem.enable()
-	go lw.listen(lw.ctx, w)
-}
-
-func (*lbwriter) rmConn(w *Conn) {}
-
-func (lw *lbwriter) write(ctx context.Context, msg Msg) error {
-	lw.sem.lock()
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case lw.c <- msg:
-		return nil
-	}
-}
-
-func (lw *lbwriter) listen(ctx context.Context, w *Conn) {
-	defer lw.rmConn(w)
-	defer w.Close()
-
-	for {
-		select {
-		case <-ctx.Done():
-			return
-		case msg, ok := <-lw.c:
-			if !ok {
-				return
-			}
-			err := w.SendMsg(msg)
-			if err != nil {
-				// try another msg writer
-				lw.c <- msg
-				break
-			}
-		}
-	}
-}
-
 type semaphore struct {
 	ready chan struct{}
 }
@@ -265,5 +206,4 @@ func (sem *semaphore) lock() {
 var (
 	_ rpool = (*qreader)(nil)
 	_ wpool = (*mwriter)(nil)
-	_ wpool = (*lbwriter)(nil)
 )