Alef (arguably one of the antecedent of Go) had stackful couroutines/fibers yet it could have had such a seamless FFI to the standard C API/ABI. The plan9 libt

Alef (arguably one of the antecedent of Go) had stackful couroutines/fibers yet it could have had such a seamless FFI to the standard C API/ABI. The plan9 libthread (which reimplemented the Alef concurrency model for C) did have seamless use of the C API/ABI. The mechanism was that it had threads and coroutines, a function needing to make use of the C API in a seamless manner would simply run as a thread rather than a coroutine. It was then easy to share data as the CSP model (with channels) worked between both coroutines, threads, and coroutines within a thread. So if one wishes to use stackful coroutines, and still have that seamless compatibility, an approach mixing the Go and Alef approaches would seem necessary. i.e. the Go migrating coroutines as a default, but with the option to use Alef like thread bound coroutines when necessary.