Multiple polls for 1 websocket client when using firefox as client #58

chubby1968 · 2019-12-11T15:40:50Z

Describe the bug
ESP32 is configured as server that accepts multiple clients. When connecting from firefox browser using server.poll(), two clients are registered (in most cases).

When this happens, no more code is executed. (It appears to be trapped in handshake part of server.accept() ).

To Reproduce
Using below code, connect to the esp32 board from firefox browser.

Library version 0.4.14
Board: ESP32-CAM
Firefox 71.0 (64-bit)

Expected behavior
Only 1 client is added to the list for each new connection (which is what happens in chrome).

Code

#include <WiFi.h>
#include <ArduinoWebsockets.h>
using namespace websockets;

const char *ssid = "xxxx";
const char *password = "xxxx";
const int maxClients = 4; // Accept up to 4 connections

WebsocketsServer server;
WebsocketsClient clients[maxClients];
int nClients = 0;

void setup()
{
  Serial.begin(115200);
  while (!Serial)
    ;

  // WIFI SETUP
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected, IP: ");
  Serial.println(WiFi.localIP());

  // WEBSOCKET: Open websocket on port 80
  server.listen(80);
  Serial.print("Is server live? ");
  Serial.println(server.available());
}

void loop()
{
  if (server.available())
  {
    // if there is a client that wants to connect
    if (server.poll() && nClients < maxClients)
    {
      //accept the connection and register callback
      Serial.print("Accepting a new client! Number of clients accepted: ");
      Serial.println(nClients + 1);
      WebsocketsClient client = server.accept();
      client.onMessage(onMessage);

      // store it for later use
      clients[nClients] = client;
      nClients++;
      delay(10);
    }

    // check for updates in all clients
    pollAllClients();

    delay(10);
  }
}

// this method goes thrugh every client and polls for new messages and events
void pollAllClients()
{
  for (int i = 0; i < nClients; i++)
  {
    clients[i].poll();
  }
}

// this callback is common for all clients, the client that sent that
// message is the one that gets the echo response
void onMessage(WebsocketsClient &client, WebsocketsMessage message)
{
  Serial.print("Got Message: ");
  Serial.print(message.data());
  Serial.println(", Sending Echo.");
  client.send("Echo: " + message.data());
}

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <meta http-equiv="X-UA-Compatible" content="ie=edge" />
        <link rel="stylesheet" href="../css/style.css" />
        <script src="../js/websocket.js" defer></script>
        <title>Websocket demo</title>
    </head>
    <body>
        <table>
            <thead>
                <th>Status</th>
                <th>Messages received</th>
            </thead>
            <tbody>
                <td id="status">Not connected</td>
                <td id="messages"></td>
            </tbody>
        </table>
        <form>
            <input type="button" id="msg_button" value="Send a msg" />
            <input type="text" placeholder="IP of server" name="IP" id="IP" value="" />
            <input type="button" id="IP_button" value="Configure IP" />
        </form>
    </body>
</html>

let messages = document.querySelector("#messages");
let status = document.querySelector("#status");
let ws;

document.querySelector("#IP_button").onclick = () => {
    
    if(typeof ws !== 'undefined'){
        ws.close();
    }
    ws = new WebSocket("ws://" + document.querySelector("#IP").value);
    status.innerHTML = "Websocket " + ws.readyState;

    ws.onopen = () => {
        status.innerHTML = "Websocket open";
        let i = 0;

        document.querySelector("#msg_button").onclick = () => {
            console.log("click");
            ws.send(i++);
        };

        ws.onmessage = event => {
            console.log(event);
            let txt = messages.innerHTML;
            messages.innerHTML = txt + "<br>" + event.data;
        };
    };

    ws.onclose = () => {
        status.innerHTML = "Websocket closed";
    };

    ws.onerror = event => {
        console.log(event);
        status.innerHTML = "Cannot connect to " + event.target.url;
    };
};

gilmaimon · 2019-12-17T19:18:54Z

Hi,

So, I was able to reproduce. The problem as far as I understand it has nothing to do with the library itself, it seems like esp32's WiFiServer impl claims that there is a client when there is not.
I will keep looking into it, meanwhile, you can check if the client that you got is connected by calling client.available. If it returns false, just skip that client.

Gil.

Cnets-io · 2022-03-18T16:55:21Z

Was there any solution to this? I am working with this otherwise great implementation, but looping even for 1 client does not seem to work. Always gets disconnected after the initial message was properly received (without me calling cloe() on the server)...

chubby1968 assigned gilmaimon Dec 11, 2019

gilmaimon added this to To do in Bugfixes via automation Dec 11, 2019

gilmaimon added the possible-bug Something isn't working, and I think it is a bug label Dec 11, 2019

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Multiple polls for 1 websocket client when using firefox as client #58

Multiple polls for 1 websocket client when using firefox as client #58

chubby1968 commented Dec 11, 2019

gilmaimon commented Dec 17, 2019 •

edited

Loading

Cnets-io commented Mar 18, 2022

Multiple polls for 1 websocket client when using firefox as client #58

Multiple polls for 1 websocket client when using firefox as client #58

Comments

chubby1968 commented Dec 11, 2019

gilmaimon commented Dec 17, 2019 • edited Loading

Cnets-io commented Mar 18, 2022

gilmaimon commented Dec 17, 2019 •

edited

Loading