Max concurrent connections for php's built in development server

Question

I have encountered a problem using php's built in webserver, in that it appears to only allow a single concurrent connection.

I discovered this when testing some concurrent ajax requests which all appeared to complete at the same time.

This isnt a big deal, as i can always fire up apache (which is how i came to above conclusion), but i have gotten used to running php directly from my IDE.

Is there any way to increase this, or is it a php limitation?

my example code that blocks with the inbuilt server but works fine on apache:

        $.ajax({
            type: "POST",
            url: slow.php,
            data: "",
            success: function(data){
                clearInterval(checkid);
                console.log('slow call finished');
            }
        });

        checkid = setInterval(function(){
            $.get('somefile.txt', function(data){
                console.log('quick call finished');
            });
        },1000);


        //slow.php
        sleep(10);
        echo 'all done';

Answer 1

Quoting from the manual:

PHP applications will stall if a request is blocked.

So yes, it's single threaded. Also, it's just an aid for development, in practice you'll seldom want to use it anyway as it doesn't support important external technologies like FallbackResource, mod_rewrite and .htaccess which are intertwined with most web projects.

Modern IDEs like PhpStorm support automatic deployment on save to local and remote testing webservers, which is far more practical in projects larger than a handful of files.