使用PHP从REST API和RSS异步获取数据

I'm currently rewriting my iOS app in PHP and I need to fetch data from an API and an RSS feed asynchronously. The reason that I want it to be async is because of speed. Because I need to make something like 20 requests, on iOS it happens much quicker if I make several requests at the same time and then gather the data as the responses come back.

This is how I did it in iOS:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    // fetch data here
    // completion code here
});

How do I achieve this in PHP? Is it even possible? I googled this and I found only a way to fire off a GET/POST request, but without fetching any data.

Thanks!

Found this great library which allows parallel async http requests:

https://github.com/stil/curl-easy