wip: AudioEngine pt.2 (rewrite activation sanely)

crates/tek_sequencer/src/sequencer.rs

@@ -9,7 +9,7 @@ pub type PhraseChunk = [Vec<PhraseMessage>];
 /// Root level object for standalone `tek_sequencer`
 pub struct Sequencer<E: Engine> {
     /// JACK client handle (needs to not be dropped for standalone mode to work).
-    pub jack:         Option<Arc<JackClient>>,
+    pub jack:         Arc<RwLock<JackClient>>,
     /// Which view is focused
     pub focus_cursor: (usize, usize),
     /// Controls the JACK transport.
@@ -392,7 +392,7 @@ impl PartialEq for Phrase { fn eq (&self, other: &Self) -> bool { self.uuid == o
 impl Eq for Phrase {}
 impl PhrasePlayer {
     pub fn new (
-        jack:  &Arc<JackClient>,
+        jack:  &Arc<RwLock<JackClient>>,
         clock: &Arc<TransportTime>
     ) -> Self {
         Self {