check udp connection alive

change_log.md

@@ -14,6 +14,11 @@
 ## develop history ##
 ---
 
+- 2018/03/18
+    > improvement
+    * nerr -> netError
+    * check udp connection alive after connect()
+    
 - 2018/03/17
     > improvement
     * add end point type
@@ -284,7 +289,7 @@
     >
     > 4 reconstruct session output token string session.go:(Session)sessionToken
     >
-    > 5 use err instead of nerr in session.go:(Session)handlePackage:defer:OnError
+    > 5 use err instead of netError in session.go:(Session)handlePackage:defer:OnError
     >
     > 6 version: 0.2.07
 

client.go

@@ -22,6 +22,7 @@ import (
 )
 
 import (
+	"github.com/AlexStocks/goext/log"
 	"github.com/AlexStocks/goext/sync"
 	log "github.com/AlexStocks/log4go"
 	"github.com/gorilla/websocket"
@@ -31,6 +32,7 @@ const (
 	connInterval   = 3e9 // 3s
 	connectTimeout = 5e9
 	maxTimes       = 10
+	pingPacket     = "ping"
 )
 
 /////////////////////////////////////////
@@ -143,8 +145,11 @@ func (c *client) dialUDP() Session {
 		conn      *net.UDPConn
 		localAddr *net.UDPAddr
 		peerAddr  *net.UDPAddr
+		length    int
+		buf       []byte
 	)
 
+	buf = make([]byte, 128)
 	localAddr = &net.UDPAddr{IP: net.IPv4zero, Port: 0}
 	peerAddr, _ = net.ResolveUDPAddr("udp", c.addr)
 	for {
@@ -155,6 +160,23 @@ func (c *client) dialUDP() Session {
 		if err == nil && conn.LocalAddr().String() == conn.RemoteAddr().String() {
 			err = errSelfConnect
 		}
+
+		// check connection alive by write/read action
+		copy(buf, []byte(pingPacket))
+		conn.SetWriteDeadline(wheel.Now().Add(1e9))
+		if length, err = conn.Write(buf[:len(pingPacket)]); err != nil {
+			log.Warn("conn.Write(%s) = {length:%d, err:%s}", pingPacket, length, err)
+			continue
+		}
+		conn.SetReadDeadline(wheel.Now().Add(1e9))
+		length, err = conn.Read(buf)
+		if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
+			err = nil
+		}
+		if err != nil {
+			log.Info("conn{%#v}.Read() = err{%s}", conn, err)
+			continue
+		}
 		if err == nil {
 			return newUDPSession(conn, c.endPointType)
 		}

session.go

@@ -21,7 +21,6 @@ import (
 
 import (
 	"github.com/AlexStocks/goext/context"
-	"github.com/AlexStocks/goext/log"
 	"github.com/AlexStocks/goext/sync"
 	"github.com/AlexStocks/goext/time"
 	log "github.com/AlexStocks/log4go"
@@ -461,7 +460,7 @@ LOOP:
 		case inPkg = <-s.rQ:
 			// 这个条件分支通过(session)rQ排空确保(session)handlePackage gr不会阻塞在(session)rQ上
 			if flag {
-				gxlog.CInfo("%#v <-s.rQ", inPkg)
+				log.Debug("%#v <-s.rQ", inPkg)
 				s.listener.OnMessage(s, inPkg)
 				s.incReadPkgCount()
 			} else {
@@ -515,7 +514,6 @@ func (s *session) handlePackage() {
 		grNum = atomic.AddInt32(&(s.grNum), -1)
 		log.Info("%s, [session.handlePackage] gr will exit now, left gr num %d", s.sessionToken(), grNum)
 		s.stop()
-		// if s.errFlag {
 		if err != nil {
 			log.Error("%s, [session.handlePackage] error{%s}", s.sessionToken(), err)
 			s.listener.OnError(s, err)
@@ -544,7 +542,7 @@ func (s *session) handleTCPPackage() error {
 	var (
 		ok       bool
 		err      error
-		nerr   net.Error
+		netError net.Error
 		conn     *gettyTCPConn
 		exit     bool
 		bufLen   int
@@ -569,7 +567,7 @@ func (s *session) handleTCPPackage() error {
 			// s.conn.SetReadTimeout(time.Now().Add(s.rTimeout))
 			bufLen, err = conn.read(buf)
 			if err != nil {
-				if nerr, ok = err.(net.Error); ok && nerr.Timeout() {
+				if netError, ok = err.(net.Error); ok && netError.Timeout() {
 					break
 				}
 				log.Error("%s, [session.conn.read] = error{%s}", s.sessionToken(), err)
@@ -622,7 +620,7 @@ func (s *session) handleUDPPackage() error {
 	var (
 		ok       bool
 		err      error
-		nerr   net.Error
+		netError net.Error
 		conn     *gettyUDPConn
 		bufLen   int
 		buf      []byte
@@ -643,8 +641,8 @@ func (s *session) handleUDPPackage() error {
 		}
 
 		bufLen, addr, err = conn.read(buf)
-		gxlog.CInfo("conn.read() = bufLen:%d, addr:%#v, err:%s", bufLen, pkgLen, err)
-		if nerr, ok = err.(net.Error); ok && nerr.Timeout() {
+		log.Debug("conn.read() = bufLen:%d, addr:%#v, err:%s", bufLen, pkgLen, err)
+		if netError, ok = err.(net.Error); ok && netError.Timeout() {
 			continue
 		}
 		if err != nil {
@@ -653,7 +651,7 @@ func (s *session) handleUDPPackage() error {
 		}
 
 		pkg, pkgLen, err = s.reader.Read(s, buf[:bufLen])
-		gxlog.CInfo("s.reader.Read() = pkg:%#v, pkgLen:%d, err:%s", pkg, pkgLen, err)
+		log.Debug("s.reader.Read() = pkg:%#v, pkgLen:%d, err:%s", pkg, pkgLen, err)
 		if err == nil && s.maxMsgLen > 0 && bufLen > int(s.maxMsgLen) {
 			err = ErrMsgTooLong
 		}
@@ -673,7 +671,7 @@ func (s *session) handleWSPackage() error {
 	var (
 		ok           bool
 		err          error
-		nerr         net.Error
+		netError     net.Error
 		length       int
 		conn         *gettyWSConn
 		pkg          []byte
@@ -686,8 +684,7 @@ func (s *session) handleWSPackage() error {
 			break
 		}
 		pkg, err = conn.read()
-		if nerr, ok = err.(net.Error); ok && nerr.Timeout() {
-
+		if netError, ok = err.(net.Error); ok && netError.Timeout() {
 			continue
 		}
 		if err != nil {