Concurrency primitives

One of the promises of Rust is to enable fearless concurrency. Quite naturally, Rust has support for writing concurrent code through a number of mechanisms. In this chapter, we will discuss a few of these. We have seen how the Rust compiler uses borrow checking to ensure correctness of programs at compile time. It turns out that those primitives are also useful in verifying correctness of concurrent code. Now, there are multiple ways of implementing threading in a language. The simplest possible way is to create a new OS thread for each thread created in the platform. This is often called 1:1 threading. On the other hand, a number of application threads can be mapped to one OS thread. This is called N:1 threading. While this approach is resource-light since we end up with fewer actual threads, there is a higher overhead of context switches. A middle ground...