simplify hue locking with local cell rather than global atomic

src/main.rs

@@ -1,7 +1,6 @@
-use std::cell::RefCell;
+use std::cell::{Cell, RefCell};
 use std::convert::Infallible;
 use std::process;
-use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
@@ -23,7 +22,6 @@ const CHANNEL_VEC_SIZE: usize = 32;
 thread_local! {
   static AUDIO_CHILD: RefCell<Option<process::Child>> = RefCell::new(None);
 }
-static HUE_LOCKED: AtomicBool = AtomicBool::new(false);
 
 #[tokio::main(basic_scheduler)]
 async fn main() {
@@ -38,18 +36,18 @@ async fn main() {
   pin.set_async_interrupt(Trigger::FallingEdge, move |level| button_pressed(level, &clients))
      .expect("set interrupt");
 
-  let reqwest = reqwest::Client::new();
+  let reqwest = &reqwest::Client::new();
   let (tx, rx) = mpsc::channel(1);
   events_clients.lock().unwrap().push(tx);
-  let pushes = rx.for_each_concurrent(2, |()| async {
+  let hue_busy = &Cell::new(false);
+  let pushes = rx.for_each_concurrent(2, |()| async move {
     if !audio_busy() {
       play_chime()
     } else { debug!("doorbell still ringing, not playing new chime"); }
 
-    let locked = HUE_LOCKED.compare_and_swap(false, true, Ordering::Acquire);
-    if !locked {
-      flash_patio(&reqwest).await;
-      HUE_LOCKED.store(false, Ordering::Release);
+    if !hue_busy.replace(true) {
+      flash_porch(&reqwest).await;
+      hue_busy.set(false);
     } else { debug!("hue already in use, not scheduling new flashing"); }
   });
 
@@ -139,7 +137,7 @@ async fn hue_base(reqwest: &reqwest::Client, body: &'static str, delay_millis: u
   delay_for(Duration::from_millis(delay_millis)).await;
 }
 
-async fn flash_patio(reqwest: &reqwest::Client) {
+async fn flash_porch(reqwest: &reqwest::Client) {
   hue_base(reqwest,
            r#"{"transitiontime":0,"on":true,"bri":254,"sat":254}"#,  // activate/resaturate
            250).await;