Re: What would make musl 1.2?

[Justin Cormack <justin@specialbusservice.com>]

On 13 February 2015 at 09:38, Anthony J. Bentley <anthony@cathet.us> wrote:
> Raphael Cohn writes:
>> Is there any possibility of adding in the ucontext.h functions? I know
>> they're deprecated, but they're still widely used - particularly by go for
>> goroutines, IIRC.
>
> It's worth mentioning that OpenBSD doesn't have ucontext, so given the
> size of its package repository (which also contains Go), ucontext can't
> be *that* widely used.

The plan9-derived Go compilers do not need the ucontext functions, it
is gccgo that does, which is needed for less common architectures but
generally not used much elsewhere as it seems to have compatibility
issues.

I do not think it is used much elsewhere but there are those of us who
use them and there is no nice substitute.

I had been planning to implement it for Musl but I am a bit unsure.
The users of it really do not want any syscalls (because the point of
green threads is speed) but there seemed to be a view that the Posix
version should preserve signal masks, although this was not clear to
me from the spec if it was really required. Most/all implementations
do in fact make syscalls, so it is in fact unclear if they are that
useful, so was coming to the conclusion that a standalone library
would be better. I have not found one, so I may write one, if only so
there is a reference assembly implementation that people can just
reuse.

Musl should remove the prototypes while it is missing the functions
though, and we should decide whether to support them (I think the
previous decision was a weak yes).

Justin


Justin