GARP/GVRP Question

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Hello Everybody,

I have been trying to understand the example code provided for GARP in
802.1d 1998 edition.

There are certain variables for which I am not able to understand their
significance as regard to the code implementation.
If someone has implemented/studied this kindly suggest if my
understanding is correct.

There is a variable in Garp.h file

unsigned last_gid_used;

and it has been used at numerous places in the code.

I am giving excerpts from the example implementation in the standard

e.g

(1)in Gid.c under gid_create_gid as follows -

my_port->last_transmitted = application->last_gid_used;
my_port->last_to_transmit = application->last_gid_used;

Here I am assume that they are trying to make sure that at the time
when GID instance is created for this port it should be in default,
i.e insure to this port/instance that there are transmissions pending


(2) It has been used in Destroy GID as well where I assume code is
going through the whole array of GID instances and seeing if the
instances which are registered and then destroying them

static void gid_destroy_gid(Gid *gid)
{
unsigned gid_index;
for (gid_index = 0; gid_index <= gid->application-
>last_gid_used; gid_index++)
{
if (gid_registered_here(gid, gid_index))
gid->application->leave_indication_fn(gid->application,
gid, gid_index);
}
sysfree(gid->machines);
sysfree(gid);
}

(3)
static void gid_leaveall(Gid *my_port)
{ /*
* only for shared media at present
*/
unsigned i;
Garp *application;
application = my_port->application;
for (i = 0; i <= application->last_gid_used; i++)
(void) gidtt_event(my_port, &my_port->machines[i], Gid_rcv_leaveempty);
}

I am having problems undestanding the code at this point because I was
assuming that last_gid_used is keeping track of the number og gid
instances created for the application

But above code is used for sending leaveall messages to all the state
machines of a port(Participant)
How come we are using last_gid_used?
Should not we use upper_limit of gid machines allowed per port

Kindly correct me my understanding??

Your help would be highly appreciated.

Thanks in advance.
Sincerely,
Jassy.