In Chapter 5, we covered one of the most popular ways of modeling concurrency in a programming language: fibers/green threads. Fibers/green threads are an example of stackful coroutines. The other
I want to round off this chapter by pointing out some of the advantages and disadvantages of this approach, which we went through in Chapter 2, since we now have
These are hex numbers indicating the offset from the memory pointer to which we want to read/write. I wrote down the base 10 numbers as comments, so as you can
There are a few functions we’ve referred to that are really important for our Runtime to actually work. Fortunately, all but one of them are extremely simple to understand. We’ll
Note I promised to point out where we close the impl Runtime block, and we do that after the spawn function. The upcoming functions are “free” functions that don’t belong
We need to explain the new concepts we introduced here. The assembly calls the function switch (the function is tagged with #[no_mangle] so we can call it by name). The
yield is a reserved word in Rust, so we can’t name our function that. If that was not the case, it would be my preferred name for it over the
Note The registers we save in our ThreadContext struct are the registers that are marked as callee saved in Figure 5.1. We need to save these since the ABI states
If you remember when we talked about the operating system ABI and calling conventions earlier, you probably remember that each architecture and OS have different requirements. This is especially important
Before we start, I want to make sure you understand that the code we write is quite unsafe and is not a “best practice” when writing Rust. I want to