fix: bugs

Author: jayantxie

connstate/conn.go

@@ -25,16 +25,24 @@ import (
 type ConnState uint32
 
 const (
+	// StateOK means the connection is normal.
 	StateOK ConnState = iota
+	// StateRemoteClosed means the remote side has closed the connection.
 	StateRemoteClosed
+	// StateClosed means the connection has been closed by local side.
 	StateClosed
 )
 
+// ConnStater is the interface to get the ConnState of a connection.
+// Must call Close to release it if you're going to close the connection.
 type ConnStater interface {
 	Close() error
 	State() ConnState
 }
 
+// ListenConnState returns a ConnStater for the given connection.
+// It's generally used for availability checks when obtaining connections from a connection pool.
+// Conn must be a syscall.Conn.
 func ListenConnState(conn net.Conn) (ConnStater, error) {
 	pollInitOnce.Do(createPoller)
 	sysConn, ok := conn.(syscall.Conn)

connstate/conn_test.go

@@ -0,0 +1,15 @@
+// Copyright 2025 CloudWeGo Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package connstate

connstate/poll.go

@@ -42,5 +42,8 @@ func createPoller() {
 	if err != nil {
 		panic(fmt.Sprintf("gopkg.connstate openpoll failed, err: %v", err))
 	}
-	go poll.wait()
+	go func() {
+		err := poll.wait()
+		fmt.Printf("gopkg.connstate epoll wait exit, err: %v\n", err)
+	}()
 }

connstate/poll_cache.go

@@ -27,7 +27,7 @@ type fdOperator struct {
 	index int32
 
 	fd   int
-	conn unsafe.Pointer // *connWithState
+	conn unsafe.Pointer // *connStater
 }
 
 var pollcache pollCache