Re: [Qemu-devel] Re: [PATCH 1/2] qemu-io: retry fgets() when errno is EINTR

[MORITA Kazutaka]

At Wed, 16 Jun 2010 13:04:47 +0200,
Kevin Wolf wrote:
> 
> Am 15.06.2010 19:53, schrieb MORITA Kazutaka:
> > posix-aio-compat sends a signal in aio operations, so we should
> > consider that fgets() could be interrupted here.
> > 
> > Signed-off-by: MORITA Kazutaka <address@hidden>
> > ---
> >  cmd.c |    3 +++
> >  1 files changed, 3 insertions(+), 0 deletions(-)
> > 
> > diff --git a/cmd.c b/cmd.c
> > index 2336334..460df92 100644
> > --- a/cmd.c
> > +++ b/cmd.c
> > @@ -272,7 +272,10 @@ fetchline(void)
> >             return NULL;
> >     printf("%s", get_prompt());
> >     fflush(stdout);
> > +again:
> >     if (!fgets(line, MAXREADLINESZ, stdin)) {
> > +           if (errno == EINTR)
> > +                   goto again;
> >             free(line);
> >             return NULL;
> >     }
> 
> This looks like a loop replaced by goto (and braces are missing). What
> about this instead?
> 
> do {
>     ret = fgets(...)
> } while (ret == NULL && errno == EINTR)
> 
> if (ret == NULL) {
>    fail
> }
> 

I agree.

However, it seems that my second patch have already solved the
problem.  We register this readline routines as an aio handler now, so
fgets() does not block and cannot return with EINTR.

This patch looks no longer needed, sorry.

Thanks,

Kazutaka