[linux-audio-dev] A "best" event delegation strategy?

Lukas Degener AFBLukas at gmx.de
Fri May 30 07:51:01 UTC 2003

Hi list,
Here is a propblem that is propably already solved in another context, 
so i would like to know some opinions on it:

I am trying to implement a (hopefully:-) ) simple general-purpose event 
delegation architecture.
The actual application will propably be something like a network of 
modules that can do arbitrary filtering, generation and manipulation of 
midi events in real time.

As propably different kinds of external event sources, like several midi 
ports, maybe joystick device and of course a gui, are involved, how 
would one efficiently organize the delegation of events passed between 
the modules, so that the everything is still thread-safe?

The three main ideas i can currently think of are:

A: don't do it at all, that is, everything is implemented as simple 
subject/observer patterns, so that the communication is a pure 
module-to-module thing.
    Mutexes et al, would have to be managed by each individual plugin.

B: use a global, mutexed event queue. This could be a priority queue for 
time-stamped events, or a simple FIFO.

C: use local queues. As above, but for each individual module.

Each of the above aproaches seems to have its advantages and 
disatvantages. E.g. if queues are used, this would as far as i an judge, 
make it easy to have feedback cycles.
OTOH this would propably introduce some overhead which aproach A 
wouldn't have. C would propably involve a single thread for each module, 
or a global "clock" thread that periodicaly calls an "process_queue" 
method on each module.

Is there a general "best" way to do this?

Kind regards,

More information about the Linux-audio-dev mailing list