> What if our fibers invoke operating system primitives that block, or interfaces which indirectly do? The best fiber interfaces, like virtual threads in Java,

> What if our fibers invoke operating system primitives that block, or interfaces which indirectly do? The best fiber interfaces, like virtual threads in Java, intercept these blocking primitives and perform the yield there implicitly. This means that user code just doesn't need to worry about this at all and can block as they normally would.