Fibers and green threads
Note!
This is an example of M:N threading. Many tasks can run concurrently on one OS thread. Fibers and green threads are often referred to as stackful coroutines.
The name “green threads” originally stems from an early implementation of an M:N threading model used in Java and has since been associated with different implementations of M:N threading. You will encounter different variations of this term, such as “green processes” (used in Erlang), which are different from the ones we discuss here. You’ll also see some that define green threads more broadly than we do here.
The way we define green threads in this book makes them synonymous with fibers, so both terms refer to the same thing going forward.
The implementation of fibers and green threads implies that there is a runtime with a scheduler that’s responsible for scheduling what task (M) gets time to run on the OS thread (N). There are many more tasks...
