Posix threads can run in parallel on several cores, or with pre-emptive multitasking on onecore. However, many of the following words are the same as in the traditional cooperative multi-tasker.
In addition, there are words that allow you to make sure that only one
task at a time changes something, and for communicating between tasks.
These words are necessary for pre-emptive and multi-core
multi-tasking, because the cooperative-multitasking way of performing
transactions between calls to pause does not work in this
environment.