[crossposting since this is of general interest]
On Nov 12, 2008 at 00:30, Klaus Darilion klaus.mailinglists@pernau.at wrote:
Hi Miklos!
This sounds great. Can you make a sample function which uses the new feature?
We are thinking of doing a dns_prefetch module using this. The sip-router.cfg will look like:
route{ ... dns_prefetch("uri", ROUTE_DNS_OK); # end of script }
route[ROUTE_DNS_OK]{ if (dns_error){ ... } # continue normal processing # the uri was resolved and is in the dns cache ... t_relay() ... }
However don't expect something quickly as everybody is quite busy and we would still need to write a dns resolver process pool (time consuming).
Note that this is not the "final" async. solution since it's not transparent for the script writer (scripts would have to be written in a special way), works only with tm and it's also a little inefficient for dns usage. In the long term we will have completely transparent async. support for dns and maybe db lookups (though it's controversial if we really need it for normal db lookups). This will take much longer and will require among other things reviewing all the global variable use (most of the global variables will either need to be registered or allocated in some known special place). If Miklos doesn't beat me to it, I'll probably start working on it only after the core merging is complete.
Can this also be used for DNS lookups and TCP/TLS connection setup?
Yes for DNS (see above) and in general for any route-level async processing involving tm (e.g. lookup some part of the message in a slow DB and execute automatically another route when the DB responds).
It cannot be used for TCP/TLS, but it's not needed anyway. In ser TCP connection setup and TCP send is already asynchronous, at least if you have tcp_buf_write=yes in ser.cfg (I agree it's not a very well chosen name :-)). TLS does not support it yet, so if you use TLS you should not set this option (that's why it's not yet the default). TLS support for it requires non-trivial changes in the tcp core and it will probably come after the merge (it's started already but far from finished). (BTW: most of the core new options documentation in ser can be found in NEWS)
Andrei
Further, also for Kamailio cooperation better documentation would be needed. Thus, instead of writing long CVS commit messages I think it would be better to write the text into the module documentation, and then copy/paste it into the CVS commit.
regards Klaus
Miklos Tirpak wrote:
tirpi 2008/11/10 13:47:03 CET
SER CVS Repository
Modified files: modules/tm t_cancel.c t_fwd.c t_reply.c t_reply.h tm.c tm_load.c tm_load.h Added files: modules/tm t_suspend.c t_suspend.h Log: t_suspend() and t_continue() functions are introduced.
These fuctions can be used by other modules to implement asynchronous actions: t_suspend() saves the transaction, returns its identifiers, and t_continue() continues the SIP request processing. (The transaction processing does not continue from the same point in the script, a separate route block defined by the parameter of t_continue() is executed instead. The reply lock is held during the route block execution.) FR timer is ticking while the transaction is suspended, and the transaction's failure route is executed if t_continue() is not called in time.
Missing: msg lumps are saved by t_suspend() and are not updated by the subsequent t_relay(). This means that the modifications made between them are lost.
Revision Changes Path 1.32 +7 -2 sip_router/modules/tm/t_cancel.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_cancel... 1.107 +8 -2 sip_router/modules/tm/t_fwd.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_fwd.c.... 1.162 +4 -4 sip_router/modules/tm/t_reply.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_reply.... 1.31 +7 -1 sip_router/modules/tm/t_reply.h http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_reply.... 1.1 +154 -0 sip_router/modules/tm/t_suspend.c (new) http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_suspen... 1.1 +42 -0 sip_router/modules/tm/t_suspend.h (new) http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_suspen... 1.177 +3 -1 sip_router/modules/tm/tm.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/tm.c.dif... 1.31 +11 -1 sip_router/modules/tm/tm_load.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/tm_load.... 1.31 +4 -1 sip_router/modules/tm/tm_load.h http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/tm_load.... _______________________________________________ Serdev mailing list Serdev@lists.iptel.org http://lists.iptel.org/mailman/listinfo/serdev
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