[LAD] Keeping "guardians" and "rebels" on the same boat

Hi all, I would be happy to get some reactions of this proposal that tries to keep the "guardians" and the "rebels" on the same boat. The pdf file for this proposal is : http://www.grame.fr/~letz/jackcontrol2.pdf. Compared to latest Fons proposal, this proposal basically combine the "control daemon" and the "jackd" server in a *unique* extended jackd (with control API IPC) (see 5). It also tries to minimize the number of shared libraries in the system, although we may decide to break-up the code in separated libraries if this is really needed (see 3). Concerning Torben proposal to have "control plug-ins" be part of the server, I agree with Fons here: this would be quite limited and more complex: a new interface would have to be defined, "who" is loading those plug-ins in the server... and so on. Let me explain it again: The first "big" conceptual change compared to the current SVN state is this new "control IPC" scheme. That is the so called control API can be used on client side also. The other point is this concept of "multi- config share state" (see 3). 1) Server side: - libjackserver.so contains: server code + C control API + "new" IPC control API (server side) + C Jack API + IPC Jack API (server side) - jackd executable is linked with libjackserver.so (nothing new here) - backends (ALSA, dummy...) are linked with libjackserver.so (nothing new here) - a "standalone" client (that wants to embed the server in it's process) is linked with libjackserver.so and directly uses the C control API to control/start the server and C Jack API to be a client (nothing new here). 2) Client side: - libjack.so contains : "new" IPC control API (client side) + IPC Jack API (client side) + config API (TO BE DEFINED) - clients are linked to libjack.so (nothing new here) - new control front-end (jackdbus, jackOSC...) are linked to libjack.so: they control the server using the IPC control API (client side), they can be regular clients using IPC Jack API (client side) to deal with connections management and so on... - a "default" centralized state for the server is always kept in ~/ jackdrc. When a client wants to auto-start, this "default" state is used. (this is important to keep in mind) - libjack may have to start the "jackd" executable using the fork+exec way, or the "jackd" process is an "always running + relaunch" process (this has to be more defined later on...) - Qjakctl stays as a regular client, it can still start the "jackd" process as usual. It can keep its own way of keeping multiple configurations as it does now. - more sophisticated control front-end (jackdbus, jackOSC...) are now regular clients. They can use the IPC control API (client side) for more sophisticated control of the server. As regular clients, they access the API to control connections... and so on. The important thing is that those clients are *obliged* to deal with this "default" centralized state. 3) Centralized multi-settings share state - the idea is to provide a way to *share* multiple server configurations in a unique place for all control applications. This is part the D-Bus proposal in some sense. WE HAVE TO DECIDE IF WE WANT THIS FEATURE BE PART OF JACK OR NOT (this can be coded as part of libjack.so or in a separated library called "libjackconfig.so" is we need to share this code between the sever and client side). - If we don't share a unique state, then any control application (jackdbus or any other in the future) will have the choice to use any format (XML...) but then obviously we loose the fact that all control applications would always see the same settings. 4) General: - a single jack2 package is needed. It contains the "jackd" daemon/ server as before. - "jackdbus" is now conceptually separated from the Jack source code. It only uses jack.h + control.h + config.h (??) and is linked to libjack.so as any regular client. It can be distributed separately as a more sophisticated control front-end available, or be available in the jack2 package. 5) Points of discussion: - this model is somewhat simplified compared to the latest Fons proposal (a daemon process + [possibly] several separated jackd servers). The point is that separated processes for control daemon and jackd servers would need another mechanism for "control daemon" <===> jackd server communications (that is: the control daemon launches the jackd server, but then has to control it while it is running, possibly get some info from it (notifications.. etc..)). If we stay with a unique "extended jackd" (with control API IPC), then things are a lot simpler. We can consider that having a single running jackd server is a common case and having several running jackd server a "corner case". It we decide that several running jackd servers is really necessary, then the "extended jackd" can still handle the situation if we accept to have several jackd servers running in a same process. Otherwise a more complex model for "completely separated control daemon and several jackd servers" has to be defined. - multi-config stare state: is this part of Jack or not? - if multi-config share state is part of Jack, then a new API to handle that has to be defined - when proposing new things, please keep in mind that jack2 is now multi-platform... don't be too Linux focused. Comments welcome! Stéphane