diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a1acb9f91..4dd406206 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,7 +29,7 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v2
       - name: Run unit tests for utils
-        run: go test -v ./...
+        run: go test $(go list ./... | tail -n +2)
       - name: Run unit tests for server
         run: go test -v -coverprofile=coverage -covermode=count -timeout 60s
       - name: Upload code coverage report to Codecov
diff --git a/eventloop_unix.go b/eventloop_unix.go
index 81e5252ff..a0f74fce9 100644
--- a/eventloop_unix.go
+++ b/eventloop_unix.go
@@ -169,6 +169,10 @@ func (el *eventloop) loopRead(c *conn) error {
 }
 
 func (el *eventloop) loopWrite(c *conn) error {
+	if c.outboundBuffer.IsEmpty() {
+		return nil
+	}
+
 	el.eventHandler.PreWrite()
 
 	head, tail := c.outboundBuffer.LazyReadAll()
diff --git a/loop_bsd.go b/loop_bsd.go
index 84ca1d653..e3da3f1b1 100644
--- a/loop_bsd.go
+++ b/loop_bsd.go
@@ -24,26 +24,17 @@ package gnet
 
 import "github.com/panjf2000/gnet/internal/netpoll"
 
-func (el *eventloop) handleEvent(fd int, filter int16) error {
+func (el *eventloop) handleEvent(fd int, filter int16) (err error) {
 	if c, ok := el.connections[fd]; ok {
-		if filter == netpoll.EVFilterSock {
-			return el.loopCloseConn(c, nil)
+		switch filter {
+		case netpoll.EVFilterSock:
+			err = el.loopCloseConn(c, nil)
+		case netpoll.EVFilterWrite:
+			err = el.loopWrite(c)
+		case netpoll.EVFilterRead:
+			err = el.loopRead(c)
 		}
-
-		switch c.outboundBuffer.IsEmpty() {
-		// Don't change the ordering of processing EVFILT_WRITE | EVFILT_READ | EV_ERROR/EV_EOF unless you're 100%
-		// sure what you're doing!
-		// Re-ordering can easily introduce bugs and bad side-effects, as I found out painfully in the past.
-		case false:
-			if filter == netpoll.EVFilterWrite {
-				return el.loopWrite(c)
-			}
-		case true:
-			if filter == netpoll.EVFilterRead {
-				return el.loopRead(c)
-			}
-		}
-		return nil
+		return
 	}
 	return el.loopAccept(fd)
 }
diff --git a/loop_linux.go b/loop_linux.go
index 2d84bbc36..eeba2fc1a 100644
--- a/loop_linux.go
+++ b/loop_linux.go
@@ -24,19 +24,18 @@ import "github.com/panjf2000/gnet/internal/netpoll"
 
 func (el *eventloop) handleEvent(fd int, ev uint32) error {
 	if c, ok := el.connections[fd]; ok {
-		switch c.outboundBuffer.IsEmpty() {
 		// Don't change the ordering of processing EPOLLOUT | EPOLLRDHUP / EPOLLIN unless you're 100%
 		// sure what you're doing!
 		// Re-ordering can easily introduce bugs and bad side-effects, as I found out painfully in the past.
-		case false:
-			if ev&netpoll.OutEvents != 0 {
-				return el.loopWrite(c)
-			}
-		case true:
-			if ev&netpoll.InEvents != 0 {
-				return el.loopRead(c)
+		if ev&netpoll.OutEvents != 0 {
+			if err := el.loopWrite(c); err != nil {
+				return err
 			}
 		}
+
+		if ev&netpoll.InEvents != 0 {
+			return el.loopRead(c)
+		}
 		return nil
 	}
 	return el.loopAccept(fd)
diff --git a/reactor_bsd.go b/reactor_bsd.go
index 62f1853b6..c987af209 100644
--- a/reactor_bsd.go
+++ b/reactor_bsd.go
@@ -58,27 +58,18 @@ func (svr *server) activateSubReactor(el *eventloop, lockOSThread bool) {
 		go el.loopTicker()
 	}
 
-	err := el.poller.Polling(func(fd int, filter int16) error {
+	err := el.poller.Polling(func(fd int, filter int16) (err error) {
 		if c, ack := el.connections[fd]; ack {
-			if filter == netpoll.EVFilterSock {
-				return el.loopCloseConn(c, nil)
-			}
-
-			switch c.outboundBuffer.IsEmpty() {
-			// Don't change the ordering of processing EVFILT_WRITE | EVFILT_READ | EV_ERROR/EV_EOF unless you're 100%
-			// sure what you're doing!
-			// Re-ordering can easily introduce bugs and bad side-effects, as I found out painfully in the past.
-			case false:
-				if filter == netpoll.EVFilterWrite {
-					return el.loopWrite(c)
-				}
-			case true:
-				if filter == netpoll.EVFilterRead {
-					return el.loopRead(c)
-				}
+			switch filter {
+			case netpoll.EVFilterSock:
+				err = el.loopCloseConn(c, nil)
+			case netpoll.EVFilterWrite:
+				err = el.loopWrite(c)
+			case netpoll.EVFilterRead:
+				err = el.loopRead(c)
 			}
 		}
-		return nil
+		return
 	})
 	svr.logger.Infof("Event-loop(%d) is exiting normally on the signal error: %v", el.idx, err)
 }
diff --git a/reactor_linux.go b/reactor_linux.go
index 5c1a85ab0..f7fa5fa28 100644
--- a/reactor_linux.go
+++ b/reactor_linux.go
@@ -58,19 +58,18 @@ func (svr *server) activateSubReactor(el *eventloop, lockOSThread bool) {
 
 	err := el.poller.Polling(func(fd int, ev uint32) error {
 		if c, ack := el.connections[fd]; ack {
-			switch c.outboundBuffer.IsEmpty() {
 			// Don't change the ordering of processing EPOLLOUT | EPOLLRDHUP / EPOLLIN unless you're 100%
 			// sure what you're doing!
 			// Re-ordering can easily introduce bugs and bad side-effects, as I found out painfully in the past.
-			case false:
-				if ev&netpoll.OutEvents != 0 {
-					return el.loopWrite(c)
-				}
-			case true:
-				if ev&netpoll.InEvents != 0 {
-					return el.loopRead(c)
+			if ev&netpoll.OutEvents != 0 {
+				if err := el.loopWrite(c); err != nil {
+					return err
 				}
 			}
+
+			if ev&netpoll.InEvents != 0 {
+				return el.loopRead(c)
+			}
 		}
 		return nil
 	})