Concurrency issues can occur when using this framework for websocket transfers

[chenbaoding2818]

WARNING: DATA RACE
Read at 0x00c0004610f8 by goroutine 14:
github.com/gorilla/websocket.(*Conn).beginMessage()
/Users/vendor/github.com/gorilla/websocket/conn.go:472 +0x65
github.com/gorilla/websocket.(*Conn).WriteMessage()
/Users/vendor/github.com/gorilla/websocket/conn.go:757 +0xf9
github.com/apache/dubbo-getty.(*gettyWSConn).writePing()
/Users/vendor/github.com/apache/dubbo-getty/connection.go:627 +0x68
github.com/apache/dubbo-getty.heartbeat.func1()
/Users/vendor/github.com/apache/dubbo-getty/session.go:519 +0x6d
github.com/apache/dubbo-getty.heartbeat()
/Users/vendor/github.com/apache/dubbo-getty/session.go:533 +0x167
github.com/dubbogo/gost/time.(*TimerWheel).run()
/Users/vendor/github.com/dubbogo/gost/time/timer.go:281 +0x2b9
github.com/dubbogo/gost/time.NewTimerWheel.func1()
/Users/vendor/github.com/dubbogo/gost/time/timer.go:216 +0x4a4

Previous write at 0x00c0004610f8 by goroutine 7976:
github.com/gorilla/websocket.(*messageWriter).endMessage()
/Users/vendor/github.com/gorilla/websocket/conn.go:539 +0xcd
github.com/gorilla/websocket.(*messageWriter).flushFrame()
/Users/vendor/github.com/gorilla/websocket/conn.go:626 +0xb85
github.com/gorilla/websocket.(*Conn).WriteMessage()
/Users/vendor/github.com/gorilla/websocket/conn.go:763 +0x1d0
github.com/apache/dubbo-getty.(*gettyWSConn).send()
/Users/vendor/github.com/apache/dubbo-getty/connection.go:618 +0x117
github.com/apache/dubbo-getty.(*session).WritePkg()
/Users/vendor/github.com/apache/dubbo-getty/session.go:408 +0x3a7
server/common/net.(*Session).Write()

[chenbaoding2818]

当心跳与业务同时WriteMessage方法时，会导致c.writer存在竞态问题

[AlexStocks]

Will you submit a PR to solve this problem?

[FoghostCn]

it seems like heartbeat not obtain packetLock cause the problem

dubbo-getty/session.go

Lines 513 to 538 in 6a6e1d1

	func heartbeat(_ gxtime.TimerID, _ time.Time, arg interface{}) error {
	ss, _ := arg.(*session)
	if ss == nil || ss.IsClosed() {
	return ErrSessionClosed
	}
	f := func() {
	wsConn, wsFlag := ss.Connection.(*gettyWSConn)
	if wsFlag {
	err := wsConn.writePing()
	if err != nil {
	log.Warnf("wsConn.writePing() = error:%+v", perrors.WithStack(err))
	}
	}
	ss.listener.OnCron(ss)
	}
	// if enable task pool, run @f asynchronously.
	if taskPool := ss.EndPoint().GetTaskPool(); taskPool != nil {
	taskPool.AddTaskAlways(f)
	return nil
	}
	f()
	return nil
	}

[AlexStocks]

@chenbaoding2818 we have fixed this bug. Would you please check it by v1.4.12?