RxPHP and pthreads
A good question is how is all this about pthreads related to RxPHP and to Rx in general.
In PHP, we're typically not used to work with asynchronous tasks and if we do, the implementation details are well hidden from us. This is for example the case with event loops and RxPHP, where we don't need to care what's going on inside RxPHP classes under the hood.
In the next chapter, we'd like to achieve the same state where we'll have a general purpose Observable or an operator that runs tasks in parallel using pthreads. Since working with asynchronous code in RxPHP is easy, pthreads is a perfect candidate that could add very interesting functionality which can be easily reused anywhere.
