Re: [LAD] jack client autoconnection (fwd) - Linux-audio-dev

4 Feb 2008

Jonatan Liljedahl:
...

 Thanks for clearing up. But I'm pretty sure your idea is too
 simple. We also need a way to create ports which are not
 autoconnected.

 The ideal way, if we follow this thread of thinking, would
 be to add another type of jack_port_register function, which
 does not autoconnect:

 jack_port_register_no_autoconnect(client,...);

 However, this new API will break a lot of current programs
 which are using the old jack_port_register function instead.
 Infact I don't think there is any (sane) way to make your
 proposal work without creating lots of mess with ports
 in old programs who are autoconnecting when it shouldn't. 
 I think my proposal with a JackPortAutoConnect bit in JackPortFlags is
 sane, it would not break old applications; they would continue to
 function exactly as they are now. but updated code can get rid of their
 own autoconnection and use this autoconnect bit in the flags to
 jack_port_register() instead.

Yes, as long as JackPortAutoConnect is false by default, that's 
definietely a sane solution. Its basically the same kind of
proposal I made, just using a flag to jack_port_register
instead of a new function.

But there is one problem with it:

jack_client_t *client=...
jack_port_t
   *out_port[0]=jack_port_register(client,...JackPortAutoConnect);
jack_port_t
   *out_port[1]=jack_port_register(client,...JackPortAutoConnect);

<something happens>

jack_port_t
   *new_out_port[0]=jack_port_register(client,...JackPortAutoConnect);
jack_port_t
   *new_out_port[1]=jack_port_register(client,...JackPortAutoConnect);

The problem is that new_out_port[0] and new_out_port[1] will
connect to physical port number 2 and 3 instead of 0 and 1.

How do you fix this problem without adding a new function to jacklib?