Explore socket.io API - 1

README.md

Usage

1. Open 2 terminal
2. On the first one install dependencies & run the experiment as follows

npm install socket.io
npm install socket.io-client

node experiment_socket.io.js

3. Note down the PID as printed on the console.
4. On the second terminal send SIGUSR1, SIGUSR2 & SIGINIT signal to the running node process

KILL -INT <PID>
KILL -USR1 <PID>
KILL -USR2 <PID>

P.S: substitute <PID> with the actual process id of the running node process.

experiment_socket.io.js

const { Server } = require("socket.io");

const serverIO = new Server();

serverIO.on("connection", (socket) => {
  console.log(`Client connected. socket-id: ${socket.id}`);
});

serverIO.on("disconnected", (reason) => {
  console.log(`Client disconnected. reason: ${reason}`);
});

serverIO.listen(4100);

const { io } = require("socket.io-client");

const socket = io("http://localhost:4100");

socket.on("connect", () => {
  console.log(`Server connected. socket-id: ${socket.id}`);
});

socket.on("disconnect", (reason) => {
  console.log(`Server disconnected. reason: ${reason}`);
});

socket.on("TEST_EVENT", function () {
  console.log("this = ", this);
});

process.on("SIGUSR1", (signal) => {
  console.log("Received signal:", signal);
  serverIO.close((err) => {
    if (err) {
      console.log(err);
    }
  });
});

process.on("SIGUSR2", (signal) => {
  console.log("Received signal:", signal);
  socket.close();
});

process.on("SIGINT", (signal) => {
  console.log("Received signal:", signal);
  serverIO.emit("TEST_EVENT", { id: Math.random() });
  return false;
});

console.log("PID:", process.pid, "PPID:", process.ppid);