Re: [Minios-devel] [UNIKRAFT/LWIP PATCH] sockets.c: Add ppoll() function

[Stefan Teodorescu <stefanl.teodorescu@xxxxxxxxx>]

Apparently, as this function is non-standard, there are multiple
implementations (and, thus, multiple explanations in man pages) and
blocking indefinitely is okay.

Reviewed-by: Stefan Teodorescu <stefanl.teodorescu@xxxxxxxxx>

On Mon, Nov 25, 2019 at 3:48 PM Stefan Teodorescu
<stefanl.teodorescu@xxxxxxxxx> wrote:
>
> Looks good to me, as this is the same code as described in the man
> page of ppoll. I have a mention that, below this code, it is stated
> that:
>
>        The above code segment is described as nearly equivalent
> because whereas a negative timeout value for poll()
>        is  interpreted  as  an  infinite  timeout,  a  negative  value
> expressed in *tmo_p results in an error from
>        ppoll().
>
> I believe this case should also be treated, right? The man page says
> below that the function should return -1 in that case and set errno to
>
>        EINVAL (ppoll()) The timeout value expressed in *ip is invalid
> (negative).
>
> Stefan
>
> On Mon, Nov 25, 2019 at 9:47 AM Costin Lupu <costin.lupu@xxxxxxxxx> wrote:
> >
> > This ppoll() implementation is adapted from its man page.
> >
> > Signed-off-by: Costin Lupu <costin.lupu@xxxxxxxxx>
> > ---
> >  Config.uk |  6 ++++++
> >  sockets.c | 26 ++++++++++++++++++++++++++
> >  2 files changed, 32 insertions(+)
> >
> > diff --git a/Config.uk b/Config.uk
> > index 8f501fc..debf0c7 100644
> > --- a/Config.uk
> > +++ b/Config.uk
> > @@ -170,6 +170,12 @@ if LWIP_SOCKET
> >                         lwip's select() implementation supports only 
> > sockets. This
> >                         configuration option makes it possible to use other 
> > file descriptor
> >                         types as well, even though they are not supported 
> > by lwip.
> > +
> > +       config LWIP_SOCKET_PPOLL
> > +               bool "Enable ppoll()"
> > +               default y
> > +               help
> > +                       Enable ppoll() implementation.
> >  endif
> >
> >  menuconfig LWIP_DEBUG
> > diff --git a/sockets.c b/sockets.c
> > index c2cf57f..5b499af 100644
> > --- a/sockets.c
> > +++ b/sockets.c
> > @@ -34,7 +34,11 @@
> >   */
> >
> >  /* network stub calls */
> > +#include <uk/config.h>
> >  #include <sys/time.h>
> > +#if CONFIG_LWIP_SOCKET_PPOLL
> > +#include <signal.h>
> > +#endif
> >  #include <vfscore/dentry.h>
> >  #include <vfscore/file.h>
> >  #include <vfscore/fs.h>
> > @@ -473,6 +477,28 @@ EXIT:
> >         return ret;
> >  }
> >
> > +#if CONFIG_LWIP_SOCKET_PPOLL
> > +#if CONFIG_LIBPTHREAD_EMBEDDED
> > +#define __sigmask   pthread_sigmask
> > +#else
> > +#define __sigmask   sigprocmask
> > +#endif
> > +int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *tmo_p,
> > +               const sigset_t *sigmask)
> > +{
> > +       sigset_t origmask;
> > +       int timeout, rc;
> > +
> > +       timeout = (tmo_p == NULL) ? -1 :
> > +               (tmo_p->tv_sec * 1000 + tmo_p->tv_nsec / 1000000);
> > +       __sigmask(SIG_SETMASK, sigmask, &origmask);
> > +       rc = poll(fds, nfds, timeout);
> > +       __sigmask(SIG_SETMASK, &origmask, NULL);
> > +
> > +       return rc;
> > +}
> > +#endif /* CONFIG_LWIP_SOCKET_PPOLL */
> > +
> >  int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
> >                 struct timeval *timeout)
> >  {
> > --
> > 2.20.1
> >

_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel