Fix: lots of various fixes

src/engine/audio.rs

@@ -443,8 +443,11 @@ pub fn build_stream(
             &stream_config,
             move |data: &mut [f32], _| {
                 if !rt_set {
-                    super::realtime::set_realtime_priority();
+                    let ok = super::realtime::set_realtime_priority();
                     rt_set = true;
+                    if !ok {
+                        super::realtime::warn_no_rt("audio");
+                    }
                 }
 
                 let buffer_samples = data.len() / channels;

src/engine/dispatcher.rs

@@ -6,7 +6,7 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use super::link::LinkState;
-use super::realtime::{precise_sleep_us, set_realtime_priority};
+use super::realtime::{precise_sleep_us, set_realtime_priority, warn_no_rt};
 use super::sequencer::MidiCommand;
 use super::timing::SyncTime;
 
@@ -55,10 +55,8 @@ pub fn dispatcher_loop(
     link: Arc<LinkState>,
 ) {
     let has_rt = set_realtime_priority();
-
-    #[cfg(target_os = "linux")]
     if !has_rt {
-        eprintln!("[cagire] Warning: Could not set realtime priority for dispatcher thread.");
+        warn_no_rt("dispatcher");
     }
 
     let mut queue: BinaryHeap<TimedMidiCommand> = BinaryHeap::with_capacity(256);

src/engine/realtime.rs

@@ -148,6 +148,17 @@ pub fn set_realtime_priority() -> bool {
     false
 }
 
+#[cfg(target_os = "linux")]
+pub fn warn_no_rt(thread_name: &str) {
+    eprintln!(
+        "[cagire] Warning: No realtime priority for {thread_name} thread. \
+         Add user to 'audio' group and configure rtprio limits."
+    );
+}
+
+#[cfg(not(target_os = "linux"))]
+pub fn warn_no_rt(_thread_name: &str) {}
+
 /// High-precision sleep using clock_nanosleep on Linux.
 /// Uses monotonic clock for jitter-free sleeping.
 #[cfg(target_os = "linux")]

src/engine/sequencer.rs

@@ -1007,6 +1007,7 @@ impl SequencerState {
                                 speed: speed_mult,
                                 fill,
                                 nudge_secs,
+                                sr,
                                 cc_access: self.cc_access.as_deref(),
                                 speed_key,
                                 mouse_x,
@@ -1128,6 +1129,7 @@ impl SequencerState {
                     speed: speed_mult,
                     fill,
                     nudge_secs,
+                    sr,
                     cc_access: self.cc_access.as_deref(),
                     speed_key: "",
                     mouse_x,
@@ -1266,13 +1268,16 @@ fn sequencer_loop(
 ) {
     use std::sync::atomic::Ordering;
 
-    set_realtime_priority();
+    let has_rt = set_realtime_priority();
+    if !has_rt {
+        super::realtime::warn_no_rt("sequencer");
+    }
 
     let rng: Rng = Arc::new(Mutex::new(StdRng::seed_from_u64(0)));
     let mut seq_state = SequencerState::new(variables, dict, rng, cc_access);
 
-    // Lookahead window: ~20ms expressed in beats, recomputed each tick
-    const LOOKAHEAD_SECS: f64 = 0.02;
+    // Lookahead window: 20ms normally, 40ms on Linux without RT to compensate for jitter
+    let lookahead_secs: f64 = if cfg!(target_os = "linux") && !has_rt { 0.04 } else { 0.02 };
     // Wake cadence: how long to sleep between scheduling passes
     const WAKE_INTERVAL: std::time::Duration = std::time::Duration::from_millis(3);
 
@@ -1302,7 +1307,7 @@ fn sequencer_loop(
         let tempo = state.tempo();
 
         let lookahead_beats = if tempo > 0.0 {
-            LOOKAHEAD_SECS * tempo / 60.0
+            lookahead_secs * tempo / 60.0
         } else {
             0.0
         };