Merge branch 'fix-LiquidSFZ-race'

* Branch commit log:
  devices/liquidsfz/liquidsfz.cc: add TODO about unconditional event processing
	See also: #44 (comment)
  devices/liquidsfz/liquidsfz.cc: fix for LiquidSFZ race cond by Stefan Westerfeld, #44
	#44
	swesterfeld commented Jun 18, 2024:
	>
	> tim-janik commented Jun 18, 2024:
	> > all input events must always be processed in render
	>
	> I agree. At least the filename changes, midi events can safely be dropped while a file is being loaded.
	>
	> Your patch is not good, because it will introduce race conditions of both threads accessing the same data.
	> Since we cannot use locks due to RT constraints, I guess the real fix will be to use a lock-free queue to send events to the loader thread.
	> I'll look into it and come up with a real fix and submit a PR.
	> However, here is a quick fix that just avoids the initial load problem and is still safe as in it doesn't introduce race conditions

Signed-off-by: Tim Janik <[email protected]>

devices/liquidsfz/liquidsfz.cc

@@ -73,7 +73,7 @@ class LiquidSFZLoader
   {
     if (state_.load() == STATE_IDLE)
       {
-        if (want_sfz_ == have_sfz_ && want_sample_rate_ == have_sample_rate_)
+        if (want_sfz_ == have_sfz_ && (want_sample_rate_ == have_sample_rate_ || want_sfz_ == ""))
           return true;
       }
     state_.store (STATE_LOAD);
@@ -173,6 +173,8 @@ class LiquidSFZ : public AudioProcessor {
   void
   render (uint n_frames) override
   {
+    // TODO: rework the logic so midi_event_input(), and in particular MidiMessage::PARAM_VALUE are processed unconditionally
+    // See also: https://github.com/tim-janik/anklang/issues/44#issuecomment-2176839260
     if (loader_.idle())
       {
         if (synth_need_reset_)