Re: [Qemu-devel] [PATCH v7 06/42] Add wrapper for setting blocking status on a QEMUFile

[Dr. David Alan Gilbert]

* Juan Quintela (address@hidden) wrote:
> "Dr. David Alan Gilbert (git)" <address@hidden> wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> >
> > Add a wrapper to change the blocking status on a QEMUFile
> > rather than having to use qemu_set_block(qemu_get_fd(f));
> > it seems best to avoid exposing the fd since not all QEMUFile's
> > really have one.  With this wrapper we could move the implementation
> > down to be different on different transports.
> >
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> > Reviewed-by: Amit Shah <address@hidden>
> 
> Reviewed-by: Juan Quintela <address@hidden>
> 
> Can we improve naming?
> 
> > ---
> >  include/migration/qemu-file.h |  1 +
> >  migration/qemu-file.c         | 15 +++++++++++++++
> >  2 files changed, 16 insertions(+)
> >
> > diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
> > index 29a9d69..d43c835 100644
> > --- a/include/migration/qemu-file.h
> > +++ b/include/migration/qemu-file.h
> > @@ -193,6 +193,7 @@ int qemu_file_get_error(QEMUFile *f);
> >  void qemu_file_set_error(QEMUFile *f, int ret);
> >  int qemu_file_shutdown(QEMUFile *f);
> >  void qemu_fflush(QEMUFile *f);
> > +void qemu_file_change_blocking(QEMUFile *f, bool block);
> >  
> >  static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
> >  {
> > diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> > index c111a6b..c746129 100644
> > --- a/migration/qemu-file.c
> > +++ b/migration/qemu-file.c
> > @@ -651,3 +651,18 @@ size_t qemu_get_counted_string(QEMUFile *f, char 
> > buf[256])
> >  
> >      return res == len ? res : 0;
> >  }
> > +
> > +/*
> > + * Change the blocking state of the QEMUFile.
> > + * Note: On some transports the OS only keeps a single blocking state for
> > + *       both directions, and thus changing the blocking on the main
> > + *       QEMUFile can also affect the return path.
> > + */
> > +void qemu_file_change_blocking(QEMUFile *f, bool block)
> 
> qemu_file_set_blocking?
> 
> It don't change the blocking, it just do whatever block says?
> 
> > +{
> > +    if (block) {
> > +        qemu_set_block(qemu_get_fd(f));
> > +    } else {
> > +        qemu_set_nonblock(qemu_get_fd(f));
> > +    }
> > +}

I worry about having a:
   qemu_file_set_blocking
and a 
   qemu_set_block

it sounds a bit similar when one always 'sets' (i.e. turns on)
and the other either turns on or off.

Dave
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK