26 Jun
2003
26 Jun
'03
5:56 p.m.
On Jun 18, 2003 at 15:55, Younger Wang <wygmail(a)yeah.net> wrote:
I am trying to understand how tm module works.
I found in http://www.iptel.org/ser/doc/prerelease/x545.html--->Stateful
User Agent Server:
______________________________________________
t_newtran shields subsequent code from retransmissions. It returns success
and continues when a new request arrived. It exits current route block
immediately on receipt of a retransmissions.
-----------------------------------------------
I found in the README included in tm module:
_______________________________________________
Name: t_newtran
Params: 0
Desc: creates a new transaction, returns a negative value on
error; this is the only way a script can add a new transaction
in an atomic way; typically, it is used to deploy a UAS
-----------------------------------------------
I think the two explanations above are inconsistent. I am quite confused.
Take the scripts below for example:
_______________________________
if ( !t_newtran()) {
sl_reply_error();
break;
};
There are 3 possible outcomes of t_newtran:
- this is a new transaction => returns true
- this is a retransmission => in script it forces a break
(it does not return, it just stops script processing)
- some error occured (e.g. bad via ) => returns false
The actual module function (the C one, not the script one) will return 1
in the first case, 0 in the second (a module function returning 0 forces
a break/drop) and a value <0 in the third case (which is equivalent to
false in the script).
Andrei