Re: [libvirt] [PATCH 2/3] virutil: introduce helper to set memory limits
On Thu, Mar 05, 2015 at 10:11:50AM +0100, Peter Krempa wrote:
On Wed, Mar 04, 2015 at 17:17:06 +0100, Pavel Hrdina wrote:
> Using this macro will ensure that the value stored in domain def will
> never be greater than VIR_DOMAIN_MEMORY_PARAM_UNLIMITED.
>
> Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com>
> ---
> src/util/virutil.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/src/util/virutil.h b/src/util/virutil.h
> index d1173c1..003eee6 100644
> --- a/src/util/virutil.h
> +++ b/src/util/virutil.h
> @@ -98,6 +98,10 @@ const char *virEnumToString(const char *const*types,
> const char *name ## TypeToString(int type); \
> int name ## TypeFromString(const char*type);
>
> +# define VIR_SET_MEMORY_LIMIT(limit, value) \
> + limit = (value) < VIR_DOMAIN_MEMORY_PARAM_UNLIMITED ? (value) : \
> + VIR_DOMAIN_MEMORY_PARAM_UNLIMITED
You should document that @value cannot have side effects as it's
evaluated twice.
Also why don't you make an inline function that returns the truncated
value?
I was not sure whether to use MACRO or function, but as there is a one usage
where the value would be evaluated twice, I'll change it to function.
Additionally as suggested in next patch, I'll also create a function called
virMemoryLimitIsSet because that code is repeated a lot.
Pavel
Peter