Remove UI multi cam setup

src/input/gamecube/poll.rs

@@ -1,8 +1,6 @@
 use std::panic::{self, AssertUnwindSafe};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
-use std::thread::JoinHandle;
-use std::time::{Duration, Instant};
 
 use bevy::prelude::*;
 use gc_adapter_neo::{Controller, GcAdapter};
@@ -57,11 +55,10 @@ impl GcPortState {
 /// Shared, `Send + Sync` handle to the latest snapshot from the poll
 /// thread. Safe to store as an ordinary [`Resource`] (no `NonSend` needed)
 /// because the `GcAdapter` itself never leaves its thread.
-#[derive(Resource)]
+#[derive(Resource, Clone)]
 pub struct GcAdapterSnapshot {
     ports: Arc<Mutex<[GcPortState; 4]>>,
     shutdown: Arc<AtomicBool>,
-    poll_thread: Option<JoinHandle<()>>,
 }
 
 impl GcAdapterSnapshot {
@@ -72,36 +69,12 @@ impl GcAdapterSnapshot {
 
 impl Drop for GcAdapterSnapshot {
     fn drop(&mut self) {
-        self.shutdown.store(true, Ordering::Release);
+        // Only actually signals shutdown once the last clone (this resource
-
+        // is never cloned in practice, but be defensive) is dropped.
-        if let Some(poll_thread) = self.poll_thread.take() {
+        if Arc::strong_count(&self.shutdown) <= 1 {
-            if let Err(payload) = poll_thread.join() {
+            self.shutdown.store(true, Ordering::Relaxed);
-                error!(
-                    "GameCube Controller Adapter poll thread panicked during shutdown: {payload:?}"
-                );
         }
     }
-    }
-}
-
-const INITIAL_ERROR_BACKOFF: Duration = Duration::from_millis(1);
-const MAX_ERROR_BACKOFF: Duration = Duration::from_millis(100);
-
-fn next_error_backoff(backoff: Duration) -> Duration {
-    backoff.saturating_mul(2).min(MAX_ERROR_BACKOFF)
-}
-
-/// Wait for a retry while still allowing the owner to shut the poll thread down promptly.
-fn wait_for_retry(shutdown: &AtomicBool, delay: Duration) -> bool {
-    let deadline = Instant::now() + delay;
-    while !shutdown.load(Ordering::Acquire) {
-        let remaining = deadline.saturating_duration_since(Instant::now());
-        if remaining.is_zero() {
-            return true;
-        }
-        std::thread::sleep(remaining.min(Duration::from_millis(10)));
-    }
-    false
 }
 
 /// Connects to the first GameCube adapter found on the USB bus and starts
@@ -121,7 +94,7 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
 
     let thread_ports = ports.clone();
     let thread_shutdown = shutdown.clone();
-    let poll_thread = std::thread::Builder::new()
+    std::thread::Builder::new()
         .name("gc-adapter-poll".into())
         .spawn(move || {
             // Flush whatever the adapter had buffered before we started
@@ -134,27 +107,17 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
             let mut rate_window_start = std::time::Instant::now();
             #[cfg(debug_assertions)]
             let mut rate_window_count: u32 = 0;
-            let mut error_backoff = INITIAL_ERROR_BACKOFF;
 
-            while !thread_shutdown.load(Ordering::Acquire) {
+            while !thread_shutdown.load(Ordering::Relaxed) {
                 let result = panic::catch_unwind(AssertUnwindSafe(|| adapter.read_controllers()));
 
                 let controllers = match result {
-                    Ok(Ok(controllers)) => {
+                    Ok(Ok(controllers)) => controllers,
-                        error_backoff = INITIAL_ERROR_BACKOFF;
-                        controllers
-                    }
                     // Ignore this, for some reason we get a bunch of these when we start reading
                     Ok(Err(
                         gc_adapter_neo::AdapterError::Parse(_)
                         | gc_adapter_neo::AdapterError::ShortRead(_),
-                    )) => {
+                    )) => continue,
-                        if !wait_for_retry(&thread_shutdown, error_backoff) {
-                            break;
-                        }
-                        error_backoff = next_error_backoff(error_backoff);
-                        continue;
-                    }
                     Ok(Err(gc_adapter_neo::AdapterError::Usb(err))) => {
                         error!(
                             "GameCube Controller Adapter USB read failed ({err:?}); stopping \
@@ -197,32 +160,5 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
         })
         .expect("failed to spawn gc-adapter poll thread");
 
-    Ok(GcAdapterSnapshot {
+    Ok(GcAdapterSnapshot { ports, shutdown })
-        ports,
-        shutdown,
-        poll_thread: Some(poll_thread),
-    })
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn error_backoff_is_capped() {
-        let mut backoff = INITIAL_ERROR_BACKOFF;
-        for _ in 0..16 {
-            backoff = next_error_backoff(backoff);
-        }
-
-        assert_eq!(backoff, MAX_ERROR_BACKOFF);
-        assert_eq!(next_error_backoff(MAX_ERROR_BACKOFF), MAX_ERROR_BACKOFF);
-    }
-
-    #[test]
-    fn retry_wait_stops_when_shutdown_is_requested() {
-        let shutdown = AtomicBool::new(true);
-
-        assert!(!wait_for_retry(&shutdown, Duration::from_secs(1)));
-    }
 }