Comment by jart
5 years ago
So far the only platform where I've managed to get threads to work has been Windows. I came pretty close to getting clone() on Linux working a few days ago. Threads are so hard because no API was ever defined for them in original UNIX and BSD, so therefore each modern system today does them in a completely different way. Another blocker is that not all operating systems let us modify segment registers which is something that the Linux compiler assumes is available for TLS. So it'd be a miracle if it ended up being possible to make threads work portably. fork() on the other hand was easy to get working on all platforms. I love fork() and vfork().
As for GUIs I'm still open to merging raw x11 support. One tricky issue is that we'd need to define a new API that veneers framebuffers, and so far Cosmopolitan has mostly refrained from defining novel interfaces, since the focus has been twiddling with low level magic numbers in order to make the textbook interfaces we already have work everywhere!
Ah segregs is gonna be a pita indeed if it's all hard-wired to the compiler.
Considered making some way to add "portable" modules yet(generic APE code with plat-specific impls) to avoid adding stuff to the core? I know the default calling-conv is slightly different but maybe by smth like defining virtual ports? (ie "send" structs since alignment rules should be mostly the same?)
Threads are a PITA everywhere. On Linux the SYSCALL stuff complicates things because of all the register moves, the FUTEX stuff, and potential races with how threads are exited.