*context are unfortunately quite slow as they require a system call to update the signal mask. The sigaltstack trick popularized by Pth is probably still more portable and faster.<p>BTW makecontext and friend were made obsolete by posix for a technicality: makecontext signature isn&#x27;t expressible any longer in a strictly conforming C99 applications, although in practice it will work with any C compiler.<p>Ironically this happened around the same time that coroutines started becoming popular again.