I have code (I use https://github.com/fiorix/go-smpp):
// -----------------------------------------------
// handleConnection new clients.
// -----------------------------------------------
func (_srv *ServerSmpp) handleConnection(_cfg *ConfigSmpp, c *conn) {
defer c.Close()
if err := _srv.auth(_cfg, c); err != nil {
if err != io.EOF {
log.Printf("smpp_server: server auth failed: %s\n", err)
}
return
}
notify := make(chan error)
go func() {
for {
pb, err := c.Read()
if err != nil {
notify <- err
return
}
err = _srv.Handler(_srv.RemoteProvider, c, pb)
if err != nil {
fmt.Printf("%s\n", err)
notify <- err
return
}
}
}()
for {
select {
case err:= <-notify:
if io.EOF == err {
fmt.Printf("Smpp server (read): %s\n", err)
return
}
case <-time.After(time.Second * 10):
fmt.Printf("Client disconnected by timeout.\n")
return
}
}
}
Code for invoked handleConnection:
func (_srv *ServerSmpp) Serve(_cfg *ConfigSmpp) {
for {
client, err := _srv.NetListener.Accept()
if err != nil {
break
}
c := newConn(client)
go _srv.handleConnection(_cfg, c)
}
}
When this code work, the server disconnects all clients by timeout 10 sec, but how I can disconnect the client when it's doesn't work 10 sec?
Your client object seems to be a net.Conn,
choose a way to call client.SetReadDeadline() with the appropriate time.Time value before blocking on client.Read() :
c.client.SetDeadline( time.Now().Add(10 * time.Second )
pb, err := c.Read() { ...
Related
I want to continuously feed the websocket via grpc stream(server stream).
I need to terminate the stream when the websocket connection down. But I couldn’t find any way out, unfortunately. I tried to use chan, but it didn't go the way I wanted.
if anyone has any ideas, I’d love to hear them. Thank you.
SERVER:
done := make(chan bool)
go func() {
for {
response, err := req.RequestToServiceWithTrace()
if err != nil {
fmt.Println("Error getting")
}
if err := srv.Send(response); err != nil {
log.Printf("send error %v", err)
done <- true
}
log.Printf("finishing request number : %d", 1)
time.Sleep(1 * time.Second)
}
}()
<-done
CLIENT:
wsupgrader.CheckOrigin = func(r *http.Request) bool { return true }
connWebSocket, err := wsupgrader.Upgrade(w, r, nil)
if err != nil {
fmt.Printf("Failed to set websocket upgrade: %s", err.Error())
return
}
var stream trace.StreamService_GetResponseTimeClient
for {
done := make(chan bool)
t, msg, errWebsocket := connWebSocket.ReadMessage()
if errWebsocket != nil {
fmt.Println(errWebsocket.Error(), "ssssssssssss")
done <- true
}
stream = sada(msg)
fmt.Println("vvvvvvvvv")
go func() {
for {
select {
case _, ok := <-done:
if ok {
fmt.Println("ssscccsssccscscscscscss")
return
} else {
fmt.Println("Channel closed!")
}
default:
resp, err := stream.Recv()
if err != nil {
return
}
log.Printf("Resp received: %s", resp)
jsonBytes, _ := protojson.Marshal(resp)
connWebSocket.WriteMessage(t, jsonBytes)
time.Sleep(1 * time.Second)
}
}
}()
}
I have this API that scans for drivers' locations and send them via web-socket every 1 second. The issue is that the loop cannot be escaped when client disconnects. It seems it is alive for ever. I am using Gin with nhooyr websocket library.
var GetDriverLocations = func(c *gin.Context) {
wsoptions := websocket.AcceptOptions{InsecureSkipVerify: true}
wsconn, err := websocket.Accept(c.Writer, c.Request, &wsoptions)
if err != nil {
return
}
defer wsconn.Close(websocket.StatusInternalError, "the sky is falling")
driverLocation := &models.DriverLocation{}
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case <-ticker.C:
case <-c.Request.Context().Done():
fmt.Println("done") //this never gets printed
return
}
coords, err := driverLocation.GetDrivers()
if err != nil {
break
}
err = wsjson.Write(c.Request.Context(), wsconn, &coords)
if websocket.CloseStatus(err) == websocket.StatusNormalClosure {
break
}
if err != nil {
break
}
}
fmt.Println("conn ended") //this never gets printed
}
I also tried this loop but also has the same issue:
for range ticker.C{
coords, err := driverLocation.GetDrivers()
if err != nil {
break
}
err = wsjson.Write(c.Request.Context(), wsconn, &coords)
if websocket.CloseStatus(err) == websocket.StatusNormalClosure {
break
}
if err != nil {
break
}
}
Because the network connection is hijacked from the net/http server by the nhooyr websocket library, the context c.Request.Context() is not canceled until handler returns.
Call CloseRead to get a context that's canceled when the connection is closed. Use that context in the loop.
var GetDriverLocations = func(c *gin.Context) {
wsoptions := websocket.AcceptOptions{InsecureSkipVerify: true}
wsconn, err := websocket.Accept(c.Writer, c.Request, &wsoptions)
if err != nil {
return
}
defer wsconn.Close(websocket.StatusInternalError, "")
ctx := wsconn.CloseRead(c.Request.Context())
driverLocation := &models.DriverLocation{}
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case <-ticker.C:
case <-ctx.Done():
return
}
coords, err := driverLocation.GetDrivers()
if err != nil {
break
}
err = wsjson.Write(c.Request.Context(), wsconn, &coords)
if err != nil {
break
}
}
}
Almost the same amount of time (point in time as redigo error log: write: connection reset by peer?), redis error log:
Client id=45183 addr=127.0.0.1:40420 fd=39 name= age=39706 idle=46 flags=N db=0 sub=8 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=16114 oll=528 omem=8545237 events=rw cmd=ping scheduled to be closed ASAP for overcoming of output buffer limits.
go error log
write tcp 127.0.0.1:40806->127.0.0.1:6379: write: connection reset by peer
Before that, the Go program didn't receive the subscription message for about 7 minutes. I presume it was a cache overflow caused by messages not being consumed.
The Redis client-output-buffer-limit is the default configuration.
The linux fd and connection count are normal, and I can't find of a reason for the unconsumable.
Here is my code:
server.go
func WaitFroMsg(ctx context.Context, pool *redis.Pool, onMessage func(channel string, data []byte) error, channel ...string) (err error) {
conn := pool.Get()
psc := redis.PubSubConn{Conn: conn}
if err := psc.Subscribe(redis.Args{}.AddFlat(channel)...); err != nil {
return err
}
done := make(chan error, 1)
go func() {
for {
switch n := psc.Receive().(type) {
case error:
done <- fmt.Errorf("redis pubsub receive err: %v", n)
return
case redis.Message:
if err = onMessage(n.Channel, n.Data); err != nil {
done <- err
return
}
case redis.Subscription:
if n.Count == 0 {
fmt.Println("all channels are unsubscribed", channel)
done <- nil
return
}
}
}
}()
const healthCheck = time.Minute
ticker := time.NewTicker(healthCheck)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if err = psc.Ping(""); err != nil {
fmt.Println("healthCheck ", err, channel)
return err
}
case err := <-done:
return err
case <-ctx.Done():
if err := psc.Unsubscribe(); err != nil {
return fmt.Errorf("redis unsubscribe failed: %v", err)
}
return nil
}
}
}
pool.go
func NewPool(addr string, db int) *redis.Pool {
return &redis.Pool{
MaxIdle: 3,
IdleTimeout: 240 * time.Second,
Dial: func() (redis.Conn, error) {
c, err := redis.Dial("tcp", addr)
if err != nil {
return nil, err
}
if _, err = c.Do("SELECT", db); err != nil {
c.Close()
return nil, err
}
return c, nil
},
TestOnBorrow: func(c redis.Conn, t time.Time) error {
if time.Since(t) < time.Minute {
return nil
}
_, err := c.Do("PING")
fmt.Println("PING error", err)
return err
},
}
}
I use high-level structures to create a ws server.
func wsHandler(w http.ResponseWriter, r *http.Request) {
re := regexp.MustCompile(`^\/ws\/([0-9a-zA-Z]+)\/*`)
match := re.FindStringSubmatch(r.URL.Path)
if len(match) != 2 {
http.NotFound(w, r)
return
}
conn, _, _, err := ws.UpgradeHTTP(r, w)
if err != nil {
log.Printf("gobwas/ws: %s", err)
}
go func() {
defer conn.Close()
channels.Lock()
channels.Channels[match[1]] = append(channels.Channels[match[1]], &conn)
channels.Unlock()
for {
msg, op, err := wsutil.ReadClientData(conn)
if err != nil {
if err != io.EOF {
log.Printf("gobwas/ws/wsutil: %s", err)
}
break
}
if len(msg) > 0 {
go sendMessage(&conn, op, match[1], msg)
}
}
deleteConn(&conn, match[1])
}()
}
Then, when I implement a graceful disconnection, then with the usual conn.Close (), the connection simply breaks outside the protocol. I use the following code to close:
func onShutdown() {
channels.RLock()
for _, channel := range channels.Channels {
for _, conn := range channel {
if err := ws.WriteFrame(*conn, ws.NewCloseFrame(ws.NewCloseFrameBody(ws.StatusNormalClosure, "Server shutdown"))); err != nil {
fmt.Println(err)
}
(*conn).Close()
}
}
channels.RUnlock()
}
And even if I wait for a response from the client and then close the connection, then anyway, the client fixes the disconnection. (The client is the browser and JS WebSocket).
Sample JS code:
var socket = new WebSocket(`${location.protocol === "https:" ? "wss:" : "ws:"}//${window.location.host}/ws/valid`);
socket.onclose = function (event) {
if (event.wasClean) {
console.log('Clean');
} else {
console.log('disconnect');
}
console.log('Code: ' + event.code + ' reason: ' + event.reason);
};
OS: windows/7/8/8.1/10 32bit
I have one question. How to create a service that would work like autorun?
Most applications install themselves in autorun through the registry or through C:\Users\Anon\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup. But there are those that are installing through the services, or rather as a service.
I have a code:
package main
import (
"fmt"
"strings"
"time"
"syscall"
"golang.org/x/sys/windows/svc"
"golang.org/x/sys/windows/svc/mgr"
"golang.org/x/sys/windows/svc/debug"
"log"
"os"
"path/filepath"
"golang.org/x/sys/windows/svc/eventlog"
)
var elog debug.Log
type myservice struct{}
func (m *myservice) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (ssec bool, errno uint32) {
const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown | svc.AcceptPauseAndContinue
changes <- svc.Status{State: svc.StartPending}
fasttick := time.Tick(500 * time.Millisecond)
slowtick := time.Tick(2 * time.Second)
tick := fasttick
changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
elog.Info(1, strings.Join(args, "-"))
loop:
for {
select {
case <-tick:
beep()
elog.Info(1, "beep")
case c := <-r:
switch c.Cmd {
case svc.Interrogate:
changes <- c.CurrentStatus
// Testing deadlock from https://code.google.com/p/winsvc/issues/detail?id=4
time.Sleep(100 * time.Millisecond)
changes <- c.CurrentStatus
case svc.Stop, svc.Shutdown:
break loop
case svc.Pause:
changes <- svc.Status{State: svc.Paused, Accepts: cmdsAccepted}
tick = slowtick
case svc.Continue:
changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
tick = fasttick
default:
elog.Error(1, fmt.Sprintf("unexpected control request #%d", c))
}
}
}
changes <- svc.Status{State: svc.StopPending}
return
}
func runService(name string, isDebug bool) {
var err error
if isDebug {
elog = debug.New(name)
} else {
elog, err = eventlog.Open(name)
if err != nil {
return
}
}
defer elog.Close()
elog.Info(1, fmt.Sprintf("starting %s service", name))
run := svc.Run
if isDebug {
run = debug.Run
}
err = run(name, &myservice{})
if err != nil {
elog.Error(1, fmt.Sprintf("%s service failed: %v", name, err))
return
}
elog.Info(1, fmt.Sprintf("%s service stopped", name))
}
func startService(name string) error {
m, err := mgr.Connect()
if err != nil {
return err
}
defer m.Disconnect()
s, err := m.OpenService(name)
if err != nil {
return fmt.Errorf("could not access service: %v", err)
}
defer s.Close()
err = s.Start("is", "auto-started")
if err != nil {
return fmt.Errorf("could not start service: %v", err)
}
return nil
}
func controlService(name string, c svc.Cmd, to svc.State) error {
m, err := mgr.Connect()
if err != nil {
return err
}
defer m.Disconnect()
s, err := m.OpenService(name)
if err != nil {
return fmt.Errorf("could not access service: %v", err)
}
defer s.Close()
status, err := s.Control(c)
if err != nil {
return fmt.Errorf("could not send control=%d: %v", c, err)
}
timeout := time.Now().Add(10 * time.Second)
for status.State != to {
if timeout.Before(time.Now()) {
return fmt.Errorf("timeout waiting for service to go to state=%d", to)
}
time.Sleep(300 * time.Millisecond)
status, err = s.Query()
if err != nil {
return fmt.Errorf("could not retrieve service status: %v", err)
}
}
return nil
}
func main() {
const svcName = "Best Service"
isIntSess, err := svc.IsAnInteractiveSession()
if err != nil {
log.Fatalf("failed to determine if we are running in an interactive session: %v", err)
}
if !isIntSess {
runService(svcName, false)
return
}
/*err = controlService(svcName, svc.Stop, svc.Stopped)
err = removeService(svcName)*/
err = installService(svcName, "Best Service")
runService(svcName, true)
if err != nil {
log.Fatalf("failed to %s: %v", svcName, err)
}
return
}
func exePath() (string, error) {
prog := os.Args[0]
p, err := filepath.Abs(prog)
if err != nil {
return "", err
}
fi, err := os.Stat(p)
if err == nil {
if !fi.Mode().IsDir() {
return p, nil
}
err = fmt.Errorf("%s is directory", p)
}
if filepath.Ext(p) == "" {
p += ".exe"
fi, err := os.Stat(p)
if err == nil {
if !fi.Mode().IsDir() {
return p, nil
}
err = fmt.Errorf("%s is directory", p)
}
}
return "", err
}
func installService(name, desc string) error {
exepath, err := exePath()
if err != nil {
return err
}
m, err := mgr.Connect()
if err != nil {
return err
}
defer m.Disconnect()
s, err := m.OpenService(name)
if err == nil {
s.Close()
return fmt.Errorf("service %s already exists", name)
}
s, err = m.CreateService(name, exepath, mgr.Config{DisplayName: desc, Description: "BB service"}, "is", "auto-started")
if err != nil {
return err
}
defer s.Close()
err = eventlog.InstallAsEventCreate(name, eventlog.Error|eventlog.Warning|eventlog.Info)
if err != nil {
s.Delete()
return fmt.Errorf("SetupEventLogSource() failed: %s", err)
}
return nil
}
func removeService(name string) error {
m, err := mgr.Connect()
if err != nil {
return err
}
defer m.Disconnect()
s, err := m.OpenService(name)
if err != nil {
return fmt.Errorf("service %s is not installed", name)
}
defer s.Close()
err = s.Delete()
if err != nil {
return err
}
err = eventlog.Remove(name)
if err != nil {
return fmt.Errorf("RemoveEventLogSource() failed: %s", err)
}
return nil
}
var (
beepFunc = syscall.MustLoadDLL("user32.dll").MustFindProc("MessageBeep")
)
func beep() {
beepFunc.Call(0xffffffff)
}
Application is installed and every time I exit the application the service stops. I need that even after restarting the PC the service worked and the application started. How can I do it?
maybe it's not actual but during the creation of the service you should extend and pass Config
mgr.Config{DisplayName: desc, StartType: mgr.StartAutomatic}
like here:
s, err = m.CreateService(name, exepath, mgr.Config{DisplayName: desc, StartType: mgr.StartAutomatic}, "is", "auto-started")
if err != nil {
return err
}
Here you can find all necessary constants and functions:
https://github.com/golang/sys/blob/master/windows/svc/mgr/config.go
On Windows 10 go to Task Scheduler > Task Scheduler Library > Create Basic Task > Trigger: when the computer starts > Action: Start a program.
When running the task, use the following user account: SYSTEM.
There is a package in the standard library that does this:
https://godoc.org/golang.org/x/sys/windows/svc
example: https://github.com/golang/sys/tree/master/windows/svc/example