Why kill a simple "ClientList.Remove(entry)" all connections from other clients ?
I have a very simple Go TCP Server that makes connectionhandling and loginhandling. After that if creates a Client and start a GO Routine with the TCP Client.
newClient := &Client{"", "", login.LoginToken, conn} go ClientReader(newClient) ClientList.PushBack(*newClient)
The Go routine read all incoming data. And when the Connection have a timeout or a networkchange ( the client get new IP ) it removes the Client from the clientlist.
but when it remove the client from the list .... all other client connections are dead ? in the loop it find the right client and remove it.
look at removeloop:
Routine:
func ClientReader(client *Client) {
buffer := make([]byte, 2048)
for {
bytesRead, error := client.Conn.Read(buffer)
if error != nil {
Log(error)
break
}
var m Message
err := json.Unmarshal([]byte(buffer[0:bytesRead]), &m)
if err != nil {
Log(err)
} else {
switch m.Cmd {
case "Message":
case "Ping":
Log("Ping from: ", client.Name, " on ", client.Conn.RemoteAddr())
client.Conn.SetDeadline(time.Now().Add(25 * time.Second))
pong := []byte(`{"PONG":"..."}` + "
")
client.Conn.Write(pong)
Log("PONG: " + time.Now().Format(time.RFC850))
Log("User Online: " + strconv.Itoa(ClientList.Len()))
Log("Goroutines: " + strconv.Itoa(runtime.NumGoroutine()))
default:
Log("Not supported Command: ", m.Cmd)
clienterror := []byte(`{"Err":"Command not supported"}` + "
")
client.Conn.Write(clienterror)
}
for i := 0; i < 2048; i++ {
buffer[i] = 0x00
}
}
}
RemoveLoop:
for entry := ClientList.Front(); entry != nil; entry = entry.Next() {
listclient := entry.Value.(Client)
if client.Conn.RemoteAddr() == listclient.Conn.RemoteAddr() {
ClientList.Remove(entry)
Log("## SEARCH: ", client.Name, client.Conn.RemoteAddr())
Log("## FOUND: ", listclient.Name,listclient.Conn.RemoteAddr())
Log("## REMOVED: ", entry.Value)
break RemoveLoop
}
}
Log("Exit Client Reader Routine ", client.Name, " on ", client.Conn.RemoteAddr())
}
Currently your code:
Please fix these things and start debugging again from there.
P.S. You might also want to change ClientReader to be a method of Client rather than a function?
Take a look at this version (http://play.golang.org/p/MDZlFSStiN):
func ClientReader(client *Client) {
buffer := new(bytes.Buffer)
for {
_, err := buffer.ReadFrom(client.Conn)
if err != nil {
log.Println(err)
break
}
var m Message
if err = json.Unmarshal(buffer.Bytes(), &m); err != nil {
log.Println(err)
} else {
switch m.Cmd {
case "Message":
case "Ping":
log.Printf("Ping from: %s on %s
", client.Name, client.Conn.RemoteAddr())
client.Conn.SetDeadline(time.Now().Add(25 * time.Second))
client.Conn.Write([]byte("{\"PONG\":\"...\"}
"))
log.Printf("PONG: %s
", time.Now().Format(time.RFC850))
clientListLock.RLock()
log.Printf("User Online: %s
", strconv.Itoa(len(clientList)))
clientListLock.RUnlock()
log.Printf("Goroutines: %s
", strconv.Itoa(runtime.NumGoroutine()))
default:
log.Printf("Not supported Command: %s
", m.Cmd)
client.Conn.Write([]byte("{\"Err\":\"Command not supported\"}
"))
}
buffer.Truncate(0)
}
}
clientListLock.Lock()
delete(clientList, client.Conn.RemoteAddr().String())
clientListLock.Unlock()
log.Printf("Exit Client Reader Routine %s on %s
", client.Name, client.Conn.RemoteAddr())
}
Thanks for your quick answer :) I have made your suggests ( The threadsafe clientList ) but my problem still exist.
After testing and some rewrite, i see a very crazy thing in the serverlog.
After the ServerStart it has 4 Goroutines .... is OK. ( Golang intern Routines ? )
Client 1 logged in ... and Goroutine 5 is started ....is OK ( the first ClientReader ) Client 2 logged in ... and Goroutine 6 is started ....is OK ( the second ClientReader )
Client 2 is a MobilePhone an i switch randomly between Mobile and WLAN.
The Server detect the ip-change from the Phone...is OK. The MobilePhone logged in with the the new IP adress and the server kills the old Connection after the ConnectionTimout ...is OK.
And than after 2-n pings from the MobilePhone the server increase the Goroutines from 6 to 7 and the Phone lost the Connection ?
The Goroutine is NOT the Clientreader ( it logs every START and EXIT ) And the Clientreader is the only Goroutine in my code.
What is GOLANG doing and why is there a Goroutine number 7 ?