// Blocking(Synchronous) IO example in PHP 
// Can handle only one request at a time
// (IO---CPU-)(IO--CPU--)(IO------CPU--)

<?php

echo 'Starting ...' . PHP_EOL;
echo 'Contents of file: ' . file_get_contents('file.txt') . PHP_EOL;
echo 'Executing the next job ...' . PHP_EOL;

// $ php example.php
// Starting ...
// Contents of file: This is the content of this file.
// Executing the next job ...


// Non-blocking IO example in NodeJS (Asynchronous)
// Handle multiple request at a time
// IO---  CPU
// IO--CPU
// IO------  CPU

var fs = require('fs');

console.log('Starting ...');
fs.readFile('file.txt', function(error, data) {
  console.log('Contents of file: ' + data);
});
console.log('Executing the next job ...');

// $ node example.js
// Starting ...
// Executing the next job ...
// Contents of file: This is the content of this file.