Re: [libvirt] [PATCH] introduce VIR_CLOSE to be used rather than close()
On 10/15/2010 11:32 AM, Eric Blake wrote:
> +int virClose(int *fdptr);
Needs an ATTRIBUTE_NONNULL(1). I'm also debating whether it needs
ATTRIBUTE_RETURN_CHECK; normally, close() fails in very few situations,
and in cleanup paths, you tend to already have another error more
important so you can ignore the secondary close() failures. So I'm
probably 80-20 against adding ATTRIBUTE_RETURN_CHECK.
> +
> +# define VIR_CLOSE(FD) \
> + virClose(&(FD))
Thinking about it a bit more, what if we provide two variants?
int virClose(int *fdptr, bool preserve_errno)
{
int saved_errno;
int rc;
if (*fdptr >= 0) {
if (preserve_errno)
saved_errno = errno;
rc = close(*fdptr);
*fdptr = -1;
if (preserve_errno)
errno = saved_errno;
} else
rc = 0;
return rc;
}
int virClose(int *fdptr) ATTRIBUTE_RETURN_CHECK;
/* For use on normal paths; caller must check return value, and failure
sets errno per close(). */
#define VIR_CLOSE(FD) virClose(&(FD),false);
/* For use on cleanup paths; errno is unaffected by close, and no return
value to worry about. */
#define VIR_FORCE_CLOSE(FD) ignore_value(virClose(&(FD),true))
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org