Slightly off topic, but I wanted to clear this up:
> The guy uses PHP and instead of built-in HTTPRequest he uses curl to make a request
HTTPRequest is not built-in to PHP. It is a PECL extension that is usually installed separately from PHP.
Curl is more built-in to PHP - it's a PHP compile-time flag, and it is distributed with PHP source.
So the best approach for the given problem (just send the request, fetch the response, without too much overhead) seems to be using something a bit lower level:
> It's impossible (or just not worth the trade-off) to make one piece of software (this time, kernel) fast for any use case imaginable.
We're not nearly at the theoretical limit of what /dev/urandom can provide.
The guy uses PHP and instead of built-in HTTPRequest he uses curl to make a request to "a bucketed key-value store built on PostgreSQL that speaks HTTP which uses Clojure and the Compojure web framework to provide a REST interface over HTTP." A bit of shooting the flies with cannons on every side?
On another side, if it can be proved that urandom has serious problems in reasonable use cases it should be checked what can be changed and how.