ChatGPT – What is a simple way for creating asynchronous PHP?

Posted by on Dec 24 2022, in php

The following is recent conversation I had with ChatGPT. I was pretty amazed at the response.

Question: What is a simple way to make PHP asynchronous? For example, I’d like to call 3 eternal json files, in a non blocking fashion. How can this be done in an explicit and easy to understand way?

Answer: There are a few options for making PHP code asynchronous. One option is to use the pcntl_fork function, which creates a child process that can run concurrently with the parent process. Here’s an example of how you might use pcntl_fork to call three external JSON files asynchronously:

<?php
// Function to retrieve a JSON file from a URL
function retrieveJson($url) {
// Use file_get_contents to retrieve the JSON data
$jsonData = file_get_contents($url);
// Decode the JSON data into an associative array
$data = json_decode($jsonData, true);
// Return the data
return $data;
}

// Array of URLs to retrieve
$urls = array(
‘http://example.com/file1.json’,
‘http://example.com/file2.json’,
‘http://example.com/file3.json’
);

// Loop through the URLs
foreach ($urls as $url) {
// Create a child process for each URL
$pid = pcntl_fork();
if ($pid == –1) {
// Error creating child process
exit();
} elseif ($pid == 0) {
// Child process
$data = retrieveJson($url);
// Do something with the data
// …
exit();
}
}

// Wait for all child processes to finish
while (pcntl_waitpid(0, $status) != –1) {
// Do nothing
}

 

This code will create a child process for each URL, and each child process will retrieve the corresponding JSON file and do something with the data. The parent process will wait for all child processes to finish before exiting.

Another option for making PHP code asynchronous is to use a library like ReactPHP or Amp, which provide asyncronous programming primitives such as promises and event loops. These libraries can be used to build more complex asyncronous applications, but may have a steeper learning curve than the pcntl_fork function.

Question: Which version of php did pcntl_fork first app

Answer: The pcntl_fork function was introduced in PHP version 4.0. It is part of the Process Control (PCNTL) extension, which provides functions for creating and manipulating child processes.

To use the pcntl_fork function, you will need to have the PCNTL extension installed and enabled in your PHP environment. You can check if the PCNTL extension is installed by calling the phpinfo function, or by using the php -m command to list installed PHP extensions.

If the PCNTL extension is not installed, you can install it by compiling PHP with the –enable-pcntl flag, or by installing the php-pcntl package if you are using a package manager like yum or apt.

Note that the PCNTL extension is not available on Windows platforms. If you need to use the pcntl_fork function on Windows, you can use the Winsock extension or a third-party library like pcntl-win32 instead.