Re: [Xen-devel] [PATCH] libxl/libxl_qmp.c: Fix code style in qmp_next()

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Thu, Dec 22, 2016 at 10:47:35AM +0000, Wei Liu wrote:
> On Thu, Dec 22, 2016 at 05:53:07PM +0800, Zhang Chen wrote:
> > diff --git a/tools/libxl/libxl_qmp.c b/tools/libxl/libxl_qmp.c
> > index ad22ad4..123a6bf 100644
> > --- a/tools/libxl/libxl_qmp.c
> > +++ b/tools/libxl/libxl_qmp.c
> > @@ -427,79 +427,78 @@ static int qmp_next(libxl__gc *gc, libxl__qmp_handler 
> > *qmp)
> >      size_t incomplete_size = 0;
> >      int rc = 0;
> >  
> > -    do {
> > -        fd_set rfds;
> > -        int ret = 0;
> > -        struct timeval timeout = {
> > -            .tv_sec = qmp->timeout,
> > -            .tv_usec = 0,
> > -        };
> > +    fd_set rfds;
> > +    int ret = 0;
> > +    struct timeval timeout = {
> > +        .tv_sec = qmp->timeout,
> > +        .tv_usec = 0,
> > +    };
> >  
> > -        FD_ZERO(&rfds);
> > -        FD_SET(qmp->qmp_fd, &rfds);
> > +    FD_ZERO(&rfds);
> > +    FD_SET(qmp->qmp_fd, &rfds);
> >  
> > +    do {
> >          ret = select(qmp->qmp_fd + 1, &rfds, NULL, NULL, &timeout);
> > -        if (ret == 0) {
> > -            LOGD(ERROR, qmp->domid, "timeout");
> > -            return -1;
> > -        } else if (ret < 0) {
> > -            if (errno == EINTR)
> > -                continue;
> > -            LOGED(ERROR, qmp->domid, "Select error");
> > -            return -1;
> > -        }
> > +    } while (ret == -1 && errno == EINTR);
> >  
> 
> A side note.
> 
> Select may modify timeout, so I think we need to reset timeout at the
> beginning of the loop.
> 

rfds is also modified by select() and needs to be reset before calling
select again.

-- 
Anthony PERARD

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