Изучаю сетевое программирование в golang, нашел в каком-то блоге вот такой пример websocket чат-сервера. Как он работает - вполне понятно - тупо бродкастит сообщения от клиентов. Но почему после нескольких коннектов ядро прибивает процесс из-за OOM - не могу разобраться. Вроде все ресурсы освобождаются, каналы закрываются. Пробовал проанализировать кучу с помощью pprof - не могу поймать момент, когда происходит утечка. Как вообще отлаживаются подобные ошибки в go?
package main
import (
"encoding/json"
"fmt"
"net"
"net/http"
"github.com/gorilla/websocket"
uuid "github.com/satori/go.uuid"
)
//Client management
type ClientManager struct {
//The client map stores and manages all long connection clients, online is TRUE, and those who are not there are FALSE
clients map[*Client]bool
//Web side MESSAGE we use Broadcast to receive, and finally distribute it to all clients
broadcast chan []byte
//Newly created long connection client
register chan *Client
//Newly canceled long connection client
unregister chan *Client
}
//Client
type Client struct {
//User ID
id string
//Connected socket
socket *websocket.Conn
//Message
send chan []byte
}
//Will formatting Message into JSON
type Message struct {
//Message Struct
Sender string `json:"sender,omitempty"`
Recipient string `json:"recipient,omitempty"`
Content string `json:"content,omitempty"`
ServerIP string `json:"serverIp,omitempty"`
SenderIP string `json:"senderIp,omitempty"`
}
//Create a client manager
var manager = ClientManager{
broadcast: make(chan []byte),
register: make(chan *Client),
unregister: make(chan *Client),
clients: make(map[*Client]bool),
}
func (manager *ClientManager) start() {
for {
select {
//If there is a new connection access, pass the connection to conn through the channel
case conn := <-manager.register:
//Set the client connection to true
manager.clients[conn] = true
//Format the message of returning to the successful connection JSON
jsonMessage, _ := json.Marshal(&Message{Content: "/A new socket has connected. ", ServerIP: LocalIp(), SenderIP: conn.socket.RemoteAddr().String()})
//Call the client's send method and send messages
manager.send(jsonMessage, conn)
//If the connection is disconnected
case conn := <-manager.unregister:
//Determine the state of the connection, if it is true, turn off Send and delete the value of connecting client
if _, ok := manager.clients[conn]; ok {
close(conn.send)
delete(manager.clients, conn)
jsonMessage, _ := json.Marshal(&Message{Content: "/A socket has disconnected. ", ServerIP: LocalIp(), SenderIP: conn.socket.RemoteAddr().String()})
manager.send(jsonMessage, conn)
}
//broadcast
case message := <-manager.broadcast:
//Traversing the client that has been connected, send the message to them
for conn := range manager.clients {
select {
case conn.send <- message:
default:
close(conn.send)
delete(manager.clients, conn)
}
}
}
}
}
//Define the send method of client management
func (manager *ClientManager) send(message []byte, ignore *Client) {
for conn := range manager.clients {
//Send messages not to the shielded connection
if conn != ignore {
conn.send <- message
}
}
}
//Define the read method of the client structure
func (c *Client) read() {
defer func() {
manager.unregister <- c
_ = c.socket.Close()
}()
for {
//Read message
_, message, err := c.socket.ReadMessage()
//If there is an error message, cancel this connection and then close it
if err != nil {
manager.unregister <- c
_ = c.socket.Close()
break
}
//If there is no error message, put the information in Broadcast
jsonMessage, _ := json.Marshal(&Message{Sender: c.id, Content: string(message), ServerIP: LocalIp(), SenderIP: c.socket.RemoteAddr().String()})
manager.broadcast <- jsonMessage
}
}
func (c *Client) write() {
defer func() {
_ = c.socket.Close()
}()
for {
select {
//Read the message from send
case message, ok := <-c.send:
//If there is no message
if !ok {
_ = c.socket.WriteMessage(websocket.CloseMessage, []byte{})
return
}
//Write it if there is news and send it to the web side
_ = c.socket.WriteMessage(websocket.TextMessage, message)
}
}
}
func main() {
fmt.Println("Starting application...")
//Open a goroutine execution start program
go manager.start()
//Register the default route to /ws, and use the wsHandler method
http.HandleFunc("/ws", wsHandler)
http.HandleFunc("/health", healthHandler)
//Surveying the local 8011 port
fmt.Println("chat server start.....")
//Note that this must be 0.0.0.0 to deploy in the server to use
_ = http.ListenAndServe("0.0.0.0:8448", nil)
}
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024 * 1024 * 1024,
WriteBufferSize: 1024 * 1024 * 1024,
//Solving cross-domain problems
CheckOrigin: func(r *http.Request) bool {
return true
},
}
func wsHandler(res http.ResponseWriter, req *http.Request) {
//Upgrade the HTTP protocol to the websocket protocol
conn, err := upgrader.Upgrade(res, req, nil)
if err != nil {
http.NotFound(res, req)
return
}
//Every connection will open a new client, client.id generates through UUID to ensure that each time it is different
client := &Client{id: uuid.Must(uuid.NewV4(), nil).String(), socket: conn, send: make(chan []byte)}
//Register a new link
manager.register <- client
//Start the message to collect the news from the web side
go client.read()
//Start the corporation to return the message to the web side
go client.write()
}
func healthHandler(res http.ResponseWriter, _ *http.Request) {
_, _ = res.Write([]byte("ok"))
}
func LocalIp() string {
address, _ := net.InterfaceAddrs()
var ip = "localhost"
for _, address := range address {
if ipAddress, ok := address.(*net.IPNet); ok && !ipAddress.IP.IsLoopback() {
if ipAddress.IP.To4() != nil {
ip = ipAddress.IP.String()
}
}
}
return ip
}
