A stackfull coroutine is brittle and doesn't compose as cleanly as stackless coroutines. As a default language primitive, the latter is almost always the robust

A stackfull coroutine is brittle and doesn't compose as cleanly as stackless coroutines. As a default language primitive, the latter is almost always the robust choice. Most devs should be using stackless coroutines for async unless they can articulate a technical justification for introducing the issues that stackfull coroutines bring with them. I've implemented several stackfull and stackless async engines from scratch. When I started out I had a naive bias toward stackfull but over time have come to appreciate that stackless is the correct model even if it seems more complicated to use. That said, I don't know why everyone uses runtimes like tokio for async. If performance is your objective then not designing and writing your own scheduler misses the point.