fix clock

src/circuits/clock.rs

@@ -46,6 +46,9 @@ impl Clock {
 
     #[track_caller]
     fn schedule_next_update(frequency: f32, pwm: f32, state: &mut ClockState) -> Option<Duration> {
+        if frequency <= 0.0 {
+            return None;
+        }
         if pwm <= 0.0 || pwm >= 1.0 {
             return Some(Duration::ZERO);
         }
@@ -216,7 +219,7 @@ impl Clock {
 
 impl CircuitImpl for Clock {
     fn draw(&self, state_ctx: &CircuitStateContext, paint_ctx: &PaintContext) {
-        let enabled = state_ctx
+        let enabled = self.frequency > 0.0 && state_ctx
             .read_circuit_internal_state(|s: &ClockState| s.enabled || s.state)
             .unwrap_or_default();
         Clock::draw(self.pwm, enabled, paint_ctx, false);
@@ -362,7 +365,10 @@ impl CircuitPreviewImpl for Preview {
     }
 
     fn description(&self) -> DynStaticStr {
-        "TODO".into()
+        "Clock pulses its output with set frequency specified in its parameters.\n\
+         % of the time signal stays on during the clock cycle can be set with PWM Fill property.\n\
+         Control pin can be enabled to turn the clock on or off.\
+        ".into()
     }
 
     fn draw_preview(&self, props: &CircuitPropertyStore, ctx: &PaintContext, in_world: bool) {

src/state.rs

@@ -801,6 +801,14 @@ impl State {
 
     fn schedule_update(self: &Arc<Self>, task: UpdateTask) {
         let mut queue = self.queue.lock();
+
+        if queue.len() > 10_000_000 {
+            println!("warning! queue contains too many elements! draining...");
+            for _ in 0..1_000_000 {
+                queue.dequeue();
+            }
+        }
+
         queue.enqueue(task);
 
         #[cfg(not(feature = "single_thread"))]

src/ui/editor.rs

@@ -611,6 +611,7 @@ impl CircuitBoardEditor {
                 _ => (),
             }
 
+            let queue_len = self.board.state.queue_len();
             let states = self.board.board.states.states.read().iter().count();
             let frozen_states = self
                 .board
@@ -631,7 +632,7 @@ impl CircuitBoardEditor {
                 .filter(|s| !s.is_being_used())
                 .count();
 
-            let text = format!("This board has {states} state(s), {frozen_states} are frozen, {unused_states} will be removed");
+            let text = format!("This board has {states} state(s), {frozen_states} are frozen, {unused_states} will be removed\nCurrent queue length: {queue_len}");
 
             ui.monospace(text);
         }