Gilles Chanteperdrix wrote: > Philippe Gerum wrote: > > Gilles Chanteperdrix wrote: > > > The two syscalls defined in the posix skin now moved to the sys skin, > they are > > > used in user-space by include/asm-generic/bits/bind.h and the new header > > > include/asm-generic/bits/current.h. The global and process-specific > shared heaps > > > are now part of this patch. > > > > > > > Is there any reason why the nucleus should not implement a full-fledged "RT > > futex" support, instead of a toolbox to build them? I'm concerned by skins > > reinventing their own wheel uselessly to get to the same point at the end > of the > > day; e.g. cb_lock ops seem to me fairly generic when it comes to handling > > futexes, so I would move them upstream one level more. > > > > In that respect, talking about "semaphore heaps" at nucleus level looks a > bit of > > a misnomer: if we mostly bring a service to map non-cacheable memory to > > user-space, then we don't actually provide semaphore support. > > If I understand correctly, a futex is, in xenomai terms, a way to > associate a user-space address, with an xnsynch object.
I would specialize it more actually so that it really resembles the vanilla futex support, i.e. a basic object implementing the required operations to provide mutually exclusive access, working on a pinned memory area shared between kernel and userland. AFAICS, the current patchset implements the pinned memory support in the nucleus, but not the operations, which remain a per-skin issue. I feel this > would complicate things: currently, the way I implemented user-space > mutexes for the posix skin kept the old association between the > user-space mutex, and its kernel-space companion, also used by > kernel-space operations. > My concern boils down to: how much of the POSIX implementation, beyond the cb_lock stuff, would have to be duplicated to get the same support ported to, say the VxWorks semM services? -- Philippe. _______________________________________________ Xenomai-core mailing list Xenomaifirstname.lastname@example.org https://mail.gna.org/listinfo/xenomai-core