Modern Systems Programming with Scala Native

Introducing Concurrency with fork() and wait()

In a UNIX-like OS, processes are traditionally created with the system call fork(). fork() doesn’t create a process out of thin air; instead, it creates a copy of the process that calls it, which will have access to all of the calling process’s state and code. This is for a good reason: even if we’re going to call exec, we need some way to control the behavior of the new process before exec is called. fork() allows us to both create a new process and coordinate its behavior with the rest of our code.

Its signature is simple:

def fork():Int

fork() takes no arguments and returns an Int. Unlike every other function we’ve discussed, and probably unlike every function you’ve ever written, fork() returns ...