Jack2 calls back from a notification thread and the callback (PortManager::connect_callback())
could end up holding the final reference on 1 or more ports. The ports would then be
unregistered as we leave the callback scope, which is illegal (no server calls from
a notification thread)
If the script doesn't provide a dsp_ioconfig() function, or if it does
not return a table of tables, provide an empty table of table as
default, which means a single configuration with default values.
Demote configurations if they have mismatched midi in or out with the
same mechanism as for audio, but with lower coefficients so that
mismatched midi has less influence than mismatched audio in selecting
the best configuration.
POLICY CHANGE.
Just refuse configurations without any output at all, and let the
remaining logic take care of selecting configurations with no audio
output if they make sense and there are no better configurations.
POLICY CHANGE: configurations with no output might now be considered
even if they have audio inputs (e.g. a pure pitch detector without audio
passthrough), whereas they were skipped before.
Instead of uniformly demote configurations with a non-matching audio
input count (using a penalty offset of 1000), also grade the
impreciseness of the configuration so that those with the nearest input
count are preferred. As for outputs, give a slightly higher handicap to
configuration with too many inputs with regard to the actual audio
inputs that can be fed to the plugin.
POLICY CHANGE: when only imprecise configurations are found the actually
selected one can be different (better) than before this commit.
Just make the code responsible for possible_in > 0 also handle
possible_in == 0 since it nearly does the same thing.
The only difference is that the possible_in == 0 case didn't check at
all for audio_in, essentially acting as if possible_in was audio_in.
There is thus a small POLICY CHANGE, but the selected configuration will
stay the same unless a better matching configuration is available.
Still no policy change, since when a configuration is chosen that would
have belonged to the second pass, then its penalty will be increased by
1000 and it will be selected only as last recourse.
This doesn't change the policy since configurations are given an
additional 1000 penalty if audio_in != possible_in, and will thus be
trumped by any "precise" configuration (unless the latter has 1000
excess or missing outputs which should be less than likely).
Instead of setting \imprecise at the end of the loop if a configuration
was found (which clobbered valuable information, see dae2406187), set it
each time a new configuration is chosen.
In the second loop that tries harder, resetting \imprecise also avoids a
previous "imprecise->set(AUDIO, 0)" to last even if another
configuration is chosen later.
Last but not least, it will enable correctly setting the midi input
count hoped for by the configuration.
Merge the cases in == -1 and in == -2 since those are both wildcards,
almost symmetric in the AU spec, and handled completely symmetrically by
the code here considering it accepts invalid or unspecified demands.
Also merge the cases in > 0 and in < -2 since they are handled exactly
the same as far as outputs are concerned.
That code modifies \imprecise if it is not NULL, but
- if a configuration is found, \imprecise will be set to in, clobbering
the tentative changes done here;
- if a configuration is not found, a last-resort loop will be run that
will set the same member of \imprecise, also clobbering our changes.
Remove it since it does nothing that is looked at before being
forgotten. A way to get the intended outcome will be introduced later.
...to later enable that condition truthiness to depend on the
loop iteration. The goal here is to prepare for the upcoming rewrite,
without introducing any policy change for now.
There is no behavior change because if all loop iterations are skipped,
then \found will be false, and with \imprecise being null the last
attempt will be skipped and we will return false.
Instead of doing an initial loop for detection of exact matches, then
letting the following loop set \audio_out yet ignore its value, merge
the two loops but give exact matches a negative penalty so that the
\audio_out value they set won't change afterwards.
No policy change.
