Calling functions on test server must lock the thread loop, otherwise
the concurrency causes corruptiont in module-protocol-native and you get
bogus messages etc.
This allows registering arbitrary objects on the core's registry and
finding them later, without having to add API for each and every object.
I think this is useful enough to have it public, even though it's
probably not going to be used that much... The rationale here is to
allow registering custom component loaders without having to make them
subclass WpPlugin or to create custom API for registering component
loaders specifically.
Also, remove the wp_plugin_register() and wp_si_factory_register()
functions, since they are not going to be used much in the future.
The idea is to let the component loader do the registration under the
scenes, as the component is getting loaded.
Each component can optionally "provide" a feature, which is basically
a string that describes the feature (ex. "support.dbus"). If the
component loads successfully, the feature is marked as provided and
can be tested for its presence with wp_core_test_feature()
There is no reason to return the component object... all components
are supposed to be long-lived objects that are referenced by the
registry and there is API to find them. The caller is only interested
in the success or failure of the operation.
Do this in wp_core_load_component() and let the component loaders worry
only about creating the object.
Also run the main loop in tests while loading components, to ensure
that the async operation finishes before continuing execution. GTask
makes sure to make the operation async always, by emitting the callback
from an idle GSource.
Regarding the core parameter, the case used to be that WpComponentLoader
was a WpPlugin, so it had a reference to the core internally, but since
this is no longer a requirement, we need to pass this explicitly
This change completely refactors the way components are loaded in wireplumber:
- The module_init() function must return a GObject now. This object is either
a WpPlugin or a WpSiFactory in the current modules.
- When the component loader initializes a module, it automatically registers
the WpPlugin or WpSiFactory with their respective methods. There is no need
to register the WpPlugin or WpSiFactory in the module now.
- The wp_core_load_component() API has been refactored to be asynchronows. This
allows the component loader to automatically activate WpPlugin objects, and
therefore allows the application to directly get the WpPlugin without having
to find it. This simplifies a lot of things.
- The 'ifexists' and 'nofail' component flags now work even if the respective
WpPlugin could not be activated.
- The code that loads components in main.c has also been simplified a lot,
and the option to load dangling components has also been removed.
