Re: [libvirt] Redesigning Libvirt: Adopting use of a safe language

Goroutines are basically a union of the thread + coroutine concepts. The Go runtime will create N OS level threads, where the default N currently matches the number of logical CPU cores you host has (but is tunable to other values). The application code just always creates Goroutines which are userspace threads just like coroutines. The Go runtime will dynamically switch goroutines at key points, and automatically pick suitable OS level threads to run them on to maximize concurrency. Most cleverly goroutines have a 2 KB default stack size, and runtime will dynamically grow the stack if that limit is reached.

So this avoids the problem of picking a suitable stack size, and avoids any danger of overruns. As a result it is possible for a process to create *1000's* of goroutines and have less overhead than if you tried todo the same thing in C with threads+coroutines manually.