Split up metalistener, fix deadlock in accept routine, I think

handler.go

@@ -0,0 +1,68 @@
+package meta
+
+import (
+	"net"
+	"time"
+)
+
+// handleListener runs in a separate goroutine for each added listener
+// and forwards accepted connections to the connCh channel.
+func (ml *MetaListener) handleListener(id string, listener net.Listener) {
+	defer func() {
+		log.Printf("Listener goroutine for %s exiting", id)
+		ml.listenerWg.Done()
+	}()
+
+	for {
+		// First check if the MetaListener is closed
+		select {
+		case <-ml.closeCh:
+			log.Printf("MetaListener closed, stopping %s listener", id)
+			return
+		default:
+		}
+
+		// Set a deadline for Accept to prevent blocking indefinitely
+		if deadline, ok := listener.(interface{ SetDeadline(time.Time) error }); ok {
+			deadline.SetDeadline(time.Now().Add(1 * time.Second))
+		}
+
+		conn, err := listener.Accept()
+		if err != nil {
+			// Check if this is a timeout error (which we expect due to our deadline)
+			if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
+				continue
+			}
+
+			// Check if this is any other temporary error
+			if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
+				log.Printf("Temporary error in %s listener: %v, retrying in 100ms", id, err)
+				time.Sleep(100 * time.Millisecond)
+				continue
+			}
+
+			log.Printf("Permanent error in %s listener: %v, stopping", id, err)
+			ml.mu.Lock()
+			delete(ml.listeners, id)
+			ml.mu.Unlock()
+			return
+		}
+
+		// If we reach here, we have a valid connection
+		log.Printf("Listener %s accepted connection from %s", id, conn.RemoteAddr())
+
+		// Try to forward the connection, but don't block indefinitely
+		select {
+		case ml.connCh <- ConnResult{Conn: conn, src: id}:
+			log.Printf("Connection from %s successfully forwarded via %s", conn.RemoteAddr(), id)
+		case <-ml.closeCh:
+			log.Printf("MetaListener closing while forwarding connection, closing connection")
+			conn.Close()
+			return
+		case <-time.After(5 * time.Second):
+			// If we can't forward within 5 seconds, something is seriously wrong
+			log.Printf("WARNING: Connection forwarding timed out, closing connection from %s", conn.RemoteAddr())
+			conn.Close()
+		}
+	}
+}