I wanted to make my own coroutine library (for amd64 Linux), so I did.
Yeah, it isn't the best but it was fun to make.
These coroutines are very similar to like Python's generators.
Note that this library only supports using coroutines in a single thread at a time, since IDK how to do thread_local in assembly.
co_handle_t co_allocate(intptr_t (*func)(intptr_t));: allocates the necessary resources for a coroutine that will run func and returns an opaque pointer handle type usable to await, query finished-ness, and free resources after completion. If the returned co_handle_t compares equal to 0/NULL/nullptr , then the argument was invalid or the resource allocation failed.
The function passed to co_allocate will not start executing until the coroutine is first co_awaited.
intptr_t co_await(co_handle_t handle, intptr_t arg): If the coroutine has not started execution, it will start execution with arg as its argument. If it has started execution (and has yielded) then co_yield will return arg and execution will continue from where the function yielded. co_await will return either when the coroutine returns (in which case the return value is the return value of the function) or calls co_yield (in which case the return value is the arg passed to co_yield). This function does not (currently) deal with invalid arguments.
intptr_t co_yield(intptr_t arg): This function should only be called in functions that will be used as coroutines. Calling this function outside of a coroutine is badTM. The caller's co_await will return arg from where it left off. This coroutine will continue from where it left off when it is next co_awaited. This function does not (currently) deal with invalid arguments or call conditions.
bool co_finished(co_handle_t handle): This function can be used to see if a coroutine has completed (returns true) or if it is still waiting to be co_awaited (returns false)
int co_free(co_handle_t handle): This function will release the resources that a completed coroutine was using. Return value of 0 indicates success, -1 indicates that the coroutine has not completed, -2 indicated that the handle does not refer to a valid coroutine.