fix(controller): cancel nfc poll when selecting other future

Author: DASPRiD

Cargo.lock

@@ -23,7 +23,6 @@ nfc1 = "0.4.0"
 serde_json = "1.0.85"
 wpactrl = "0.5.1"
 tokio-rustls = "0.23.4"
-webpki = "0.22.0"
 webpki-roots = "0.22.5"
 tokio-io-timeout = "1.2.0"
 thiserror = "1.0.37"

Cargo.toml

@@ -11,20 +11,19 @@ use crate::nfc::reader::{NfcReader, Uid};
 pub enum NfcCommand {
     Poll {
         responder: oneshot::Sender<Uid>,
+        cancel_rx: oneshot::Receiver<()>,
     },
     Read {
         uid: Uid,
         responder: oneshot::Sender<Option<String>>,
     },
     Release {
         responder: oneshot::Sender<()>,
+        cancel_rx: oneshot::Receiver<()>,
     },
 }
 
-pub fn start_nfc_listener(
-    mut nfc_rx: mpsc::Receiver<NfcCommand>,
-    mut cancel_rx: oneshot::Receiver<()>,
-) {
+pub fn start_nfc_listener(mut nfc_rx: mpsc::Receiver<NfcCommand>) {
     thread::spawn(move || {
         let mut context = nfc1::Context::new().unwrap();
         let device = context.open().unwrap();
@@ -34,7 +33,10 @@ pub fn start_nfc_listener(
             use NfcCommand::*;
 
             match command {
-                Poll { responder } => {
+                Poll {
+                    responder,
+                    mut cancel_rx,
+                } => {
                     let uid = loop {
                         if cancel_rx.try_recv() != Err(TryRecvError::Empty) {
                             return;
@@ -57,7 +59,10 @@ pub fn start_nfc_listener(
                         _ => responder.send(None).unwrap(),
                     }
                 }
-                Release { responder } => {
+                Release {
+                    responder,
+                    mut cancel_rx,
+                } => {
                     loop {
                         if cancel_rx.try_recv() != Err(TryRecvError::Empty) {
                             return;

src/client.rs

@@ -66,7 +66,12 @@ impl Controller {
             self.set_idle_led().await?;
 
             let (uid_tx, uid_rx) = oneshot::channel();
-            nfc.send(NfcCommand::Poll { responder: uid_tx }).await?;
+            let (_cancel_tx, cancel_rx) = oneshot::channel::<()>();
+            nfc.send(NfcCommand::Poll {
+                responder: uid_tx,
+                cancel_rx,
+            })
+            .await?;
 
             tokio::select! {
                 result = uid_rx => {
@@ -249,8 +254,10 @@ impl Controller {
 
     async fn wait_for_release(&self, nfc: &mpsc::Sender<NfcCommand>) -> Result<()> {
         let (released_tx, released_rx) = oneshot::channel();
+        let (_cancel_tx, cancel_rx) = oneshot::channel::<()>();
         nfc.send(NfcCommand::Release {
             responder: released_tx,
+            cancel_rx,
         })
         .await?;
         released_rx.await?;
@@ -266,7 +273,12 @@ impl Controller {
         self.led.send(LedState::Blink { color: MAGENTA }).await?;
 
         let (uid_tx, uid_rx) = oneshot::channel();
-        nfc.send(NfcCommand::Poll { responder: uid_tx }).await?;
+        let (_cancel_tx, cancel_rx) = oneshot::channel::<()>();
+        nfc.send(NfcCommand::Poll {
+            responder: uid_tx,
+            cancel_rx,
+        })
+        .await?;
         let uid = uid_rx.await?;
 
         if !config_uids.contains(&uid) {
@@ -290,9 +302,7 @@ impl Controller {
 impl IntoSubsystem<Error> for Controller {
     async fn run(mut self, subsys: SubsystemHandle) -> Result<()> {
         let (nfc_tx, nfc_rx) = mpsc::channel(1);
-        let (_cancel_nfc_tx, cancel_nfc_rx) = oneshot::channel::<()>();
-
-        start_nfc_listener(nfc_rx, cancel_nfc_rx);
+        start_nfc_listener(nfc_rx);
 
         tokio::select! {
             _ = subsys.on_shutdown_requested() => {