[AGENT++] Handling result of missing object?

[dominik.vogt at external.thalesgroup.com]

On Tue, Jan 25, 2011 at 10:00:34PM +0100, Jochen Katz wrote:
>    Am 25.01.2011 08:30, schrieb dominik.vogt at external.thalesgroup.com:
>    > On Tue, Jan 25, 2011 at 07:35:26AM +0100, Dominik Vogt wrote:
>    >>    For the records:  With the patch, Vb::get_value() returns
>    >>    SNMP_CLASS_INVALID, so it's not necessary to add an additional
>    >>    get_syntax() or get_exception_status().
>    >
>    > *rolleyes*  I should have tested that instead of just reading the
>    > source code.  get_value() does *not* return ...INVALID.  However,
>    > I think it should.  This can be done by calling get_syntax()
>    > indirectly through Vb::get_syntax() instead of directly through
>    > SnmpSyntax->get_syntax().  See attached patch.
> 
>    >     if (iv_vb_value &&
>    >         iv_vb_value->valid() &&
>    > -       (iv_vb_value->get_syntax() == sNMP_SYNTAX_INT32 ))
>    > +       (get_syntax() == sNMP_SYNTAX_INT32 ))
> 
>    Like you, reading the source code, I don't see any possibility for
>    get_value() returning anything different than INVALID after the
>    exception status has been set, as iv_vb_value is freed and set to 0. So
>    my guess would be, that something with the rebuild after the change to
>    vb.h failed.

Note that *iv_vb_value is of type *SnmpSyntax* and does not know
anything about the exception status of the *Vb* where it is
stored.  iv_vb_value->get_syntax() always returns
sNMP_SYNTAX_INT32 because that is its syntax type.  On the other
hand, Vb::get_value() does roughly the same but looks at the
exception_status before calling iv_vb_value->get_syntax().

Ciao

Dominik ^_^  ^_^

-- 

Dominik Vogt