diff --git a/client_windows.go b/client_windows.go
index 33e0566ff..d9cbbde4b 100644
--- a/client_windows.go
+++ b/client_windows.go
@@ -205,7 +205,7 @@ func (cli *Client) EnrollContext(nc net.Conn, ctx interface{}) (gc Conn, err err
 		c := newUDPConn(cli.el, nil, nc.LocalAddr(), nc.RemoteAddr())
 		c.SetContext(ctx)
 		c.rawConn = nc
-		cli.el.ch <- &openConn{c: c, isDatagram: true, cb: func() { close(connOpened) }}
+		cli.el.ch <- &openConn{c: c, cb: func() { close(connOpened) }}
 		go func(uc net.Conn, el *eventloop) {
 			var buffer [0x10000]byte
 			for {
diff --git a/connection_windows.go b/connection_windows.go
index e46498f9d..efdfc22c9 100644
--- a/connection_windows.go
+++ b/connection_windows.go
@@ -45,7 +45,6 @@ type udpConn struct {
 type openConn struct {
 	c          *conn
 	cb         func()
-	isDatagram bool
 }
 
 type conn struct {
diff --git a/eventloop_unix.go b/eventloop_unix.go
index 617cf9162..97475302c 100644
--- a/eventloop_unix.go
+++ b/eventloop_unix.go
@@ -226,28 +226,13 @@ loop:
 	return nil
 }
 
-func (el *eventloop) close(c *conn, err error) (rerr error) {
-	if addr := c.localAddr; addr != nil && strings.HasPrefix(c.localAddr.Network(), "udp") {
-		rerr = el.poller.Delete(c.fd)
-		if _, ok := el.listeners[c.fd]; !ok {
-			rerr = unix.Close(c.fd)
-			el.connections.delConn(c)
-		}
-		if el.eventHandler.OnClose(c, err) == Shutdown {
-			return errorx.ErrEngineShutdown
-		}
-		c.release()
-		return
-	}
-
+func (el *eventloop) close(c *conn, err error) error {
 	if !c.opened || el.connections.getConn(c.fd) == nil {
-		return // ignore stale connections
+		return nil // ignore stale connections
 	}
 
 	el.connections.delConn(c)
-	if el.eventHandler.OnClose(c, err) == Shutdown {
-		rerr = errorx.ErrEngineShutdown
-	}
+	action := el.eventHandler.OnClose(c, err)
 
 	// Send residual data in buffer back to the remote before actually closing the connection.
 	for !c.outboundBuffer.IsEmpty() {
@@ -262,8 +247,10 @@ func (el *eventloop) close(c *conn, err error) (rerr error) {
 		}
 	}
 
-	err0, err1 := el.poller.Delete(c.fd), unix.Close(c.fd)
+	c.release()
+
 	var errStr strings.Builder
+	err0, err1 := el.poller.Delete(c.fd), unix.Close(c.fd)
 	if err0 != nil {
 		err0 = fmt.Errorf("failed to delete fd=%d from poller in event-loop(%d): %v",
 			c.fd, el.idx, os.NewSyscallError("delete", err0))
@@ -276,16 +263,10 @@ func (el *eventloop) close(c *conn, err error) (rerr error) {
 		errStr.WriteString(err1.Error())
 	}
 	if errStr.Len() > 0 {
-		if rerr != nil {
-			el.getLogger().Errorf(strings.TrimSuffix(errStr.String(), " | "))
-		} else {
-			rerr = errors.New(strings.TrimSuffix(errStr.String(), " | "))
-		}
+		return errors.New(strings.TrimSuffix(errStr.String(), " | "))
 	}
 
-	c.release()
-
-	return
+	return el.handleAction(c, action)
 }
 
 func (el *eventloop) wake(c *conn) error {
@@ -333,19 +314,6 @@ func (el *eventloop) ticker(ctx context.Context) {
 	}
 }
 
-func (el *eventloop) handleAction(c *conn, action Action) error {
-	switch action {
-	case None:
-		return nil
-	case Close:
-		return el.close(c, nil)
-	case Shutdown:
-		return errorx.ErrEngineShutdown
-	default:
-		return nil
-	}
-}
-
 func (el *eventloop) readUDP(fd int, _ netpoll.IOEvent, _ netpoll.IOFlags) error {
 	n, sa, err := unix.Recvfrom(fd, el.buffer, 0)
 	if err != nil {
@@ -372,6 +340,19 @@ func (el *eventloop) readUDP(fd int, _ netpoll.IOEvent, _ netpoll.IOFlags) error
 	return nil
 }
 
+func (el *eventloop) handleAction(c *conn, action Action) error {
+	switch action {
+	case None:
+		return nil
+	case Close:
+		return el.close(c, nil)
+	case Shutdown:
+		return errorx.ErrEngineShutdown
+	default:
+		return nil
+	}
+}
+
 /*
 func (el *eventloop) execCmd(itf interface{}) (err error) {
 	cmd := itf.(*asyncCmd)
diff --git a/eventloop_windows.go b/eventloop_windows.go
index ea0f87377..565f3ef30 100644
--- a/eventloop_windows.go
+++ b/eventloop_windows.go
@@ -18,8 +18,8 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"runtime"
-	"strings"
 	"sync/atomic"
 	"time"
 
@@ -97,10 +97,8 @@ func (el *eventloop) open(oc *openConn) error {
 	}
 
 	c := oc.c
-	if !oc.isDatagram {
-		el.connections[c] = struct{}{}
-		el.incConn(1)
-	}
+	el.connections[c] = struct{}{}
+	el.incConn(1)
 
 	out, action := el.eventHandler.OnOpen(c)
 	if out != nil {
@@ -188,28 +186,18 @@ func (el *eventloop) wake(c *conn) error {
 }
 
 func (el *eventloop) close(c *conn, err error) error {
-	if addr := c.localAddr; addr != nil && strings.HasPrefix(addr.Network(), "udp") {
-		action := el.eventHandler.OnClose(c, err)
-		if c.rawConn != nil {
-			if err := c.rawConn.Close(); err != nil {
-				el.getLogger().Errorf("failed to close connection(%s), error:%v", c.remoteAddr.String(), err)
-			}
-		}
-		c.release()
-		return el.handleAction(c, action)
-	}
-
-	if _, ok := el.connections[c]; !ok {
+	if _, ok := el.connections[c]; c.rawConn == nil || !ok {
 		return nil // ignore stale wakes.
 	}
 
 	delete(el.connections, c)
 	el.incConn(-1)
 	action := el.eventHandler.OnClose(c, err)
-	if err := c.rawConn.Close(); err != nil {
-		el.getLogger().Errorf("failed to close connection(%s), error:%v", c.remoteAddr.String(), err)
-	}
+	err = c.rawConn.Close()
 	c.release()
+	if err != nil {
+		return fmt.Errorf("failed to close connection=%s in event-loop(%d): %v", c.remoteAddr, el.idx, err)
+	}
 
 	return el.handleAction(c, action)
 }