Do you want concurrency?

If you need concurrency, it's best to add declare(ticks=1) at the top of your code. Example:

<?php

declare(ticks=1);

use vennv\vapm\CoroutineGen;

function execute(string $name)
{
    for ($i = 0; true; $i++) {
        echo "$name $i\n";
        yield CoroutineGen::delay(100);
    }
}

CoroutineGen::runNonBlocking(
    execute("First Statement ")
);

iterator_to_array(execute("Second Statement "));