Fix Token...

crossbeam-channel/src/channel.rs

@@ -1514,7 +1514,7 @@ pub(crate) unsafe fn write<T>(s: &Sender<T>, token: &mut Token, msg: T) -> Resul
     unsafe {
         match &s.flavor {
             SenderFlavor::Array(chan) => chan.write(token, msg),
-            SenderFlavor::List(chan) => chan.write(token, msg),
+            SenderFlavor::List(chan) => chan.write(&mut token.list, msg),
             SenderFlavor::Zero(chan) => chan.write(token, msg),
         }
     }
@@ -1525,7 +1525,7 @@ pub(crate) unsafe fn read<T>(r: &Receiver<T>, token: &mut Token) -> Result<T, ()
     unsafe {
         match &r.flavor {
             ReceiverFlavor::Array(chan) => chan.read(token),
-            ReceiverFlavor::List(chan) => chan.read(token),
+            ReceiverFlavor::List(chan) => chan.read(&mut token.list),
             ReceiverFlavor::Zero(chan) => chan.read(token),
             ReceiverFlavor::At(chan) => {
                 mem::transmute_copy::<Result<Instant, ()>, Result<T, ()>>(&chan.read(token))

crossbeam-channel/src/flavors/list.rs

@@ -203,7 +203,7 @@ impl<T> Channel<T> {
     }
 
     /// Attempts to reserve a slot for sending a message.
-    fn start_send(&self, token: &mut Token) {
+    fn start_send(&self, token: &mut ListToken) {
         let backoff = Backoff::new();
         let mut next_block = ptr::null_mut::<Block<T>>();
 
@@ -215,7 +215,7 @@ impl<T> Channel<T> {
 
             // Check if the channel is disconnected.
             if tail & MARK_BIT != 0 {
-                token.list.block = ptr::null();
+                token.block = ptr::null();
                 break;
             }
 
@@ -266,8 +266,8 @@ impl<T> Channel<T> {
                         (*block).next.store(n, Ordering::Release);
                     }
 
-                    token.list.block = block as *const u8;
-                    token.list.offset = offset;
+                    token.block = block as *const u8;
+                    token.offset = offset;
                     break;
                 },
                 Err(_) => {
@@ -282,15 +282,15 @@ impl<T> Channel<T> {
     }
 
     /// Writes a message into the channel.
-    pub(crate) unsafe fn write(&self, token: &mut Token, msg: T) -> Result<(), T> {
+    pub(crate) unsafe fn write(&self, token: &mut ListToken, msg: T) -> Result<(), T> {
         // If there is no slot, the channel is disconnected.
-        if token.list.block.is_null() {
+        if token.block.is_null() {
             return Err(msg);
         }
 
         // Write the message into the slot.
-        let block = token.list.block.cast::<Block<T>>();
-        let offset = token.list.offset;
+        let block = token.block.cast::<Block<T>>();
+        let offset = token.offset;
         let slot = unsafe { (*block).get_slot_unchecked(offset) };
         unsafe { slot.msg.get().write(msg) }
         slot.state.fetch_or(WRITE, Ordering::Release);
@@ -301,7 +301,7 @@ impl<T> Channel<T> {
     }
 
     /// Attempts to reserve a slot for receiving a message.
-    fn start_recv(&self, token: &mut Token) -> bool {
+    fn start_recv(&self, token: &mut ListToken) -> bool {
         let backoff = Backoff::new();
         let mut head;
         let mut block;
@@ -330,7 +330,7 @@ impl<T> Channel<T> {
                     // If the channel is disconnected...
                     if tail & MARK_BIT != 0 {
                         // ...then receive an error.
-                        token.list.block = ptr::null();
+                        token.block = ptr::null();
                         return true;
                     } else {
                         // Otherwise, the receive operation is not ready.
@@ -371,8 +371,8 @@ impl<T> Channel<T> {
                         self.head.index.store(next_index, Ordering::Release);
                     }
 
-                    token.list.block = block as *const u8;
-                    token.list.offset = offset;
+                    token.block = block as *const u8;
+                    token.offset = offset;
                     return true;
                 },
                 Err(_) => {
@@ -383,15 +383,15 @@ impl<T> Channel<T> {
     }
 
     /// Reads a message from the channel.
-    pub(crate) unsafe fn read(&self, token: &mut Token) -> Result<T, ()> {
-        if token.list.block.is_null() {
+    pub(crate) unsafe fn read(&self, token: &mut ListToken) -> Result<T, ()> {
+        if token.block.is_null() {
             // The channel is disconnected.
             return Err(());
         }
 
         // Read the message.
-        let block = token.list.block as *mut Block<T>;
-        let offset = token.list.offset;
+        let block = token.block as *mut Block<T>;
+        let offset = token.offset;
         let slot = unsafe { (*block).get_slot_unchecked(offset) };
         slot.wait_write();
         let msg = unsafe { slot.msg.get().read() };
@@ -423,8 +423,7 @@ impl<T> Channel<T> {
         msg: T,
         _deadline: Option<Instant>,
     ) -> Result<(), SendTimeoutError<T>> {
-        let token = MaybeUninit::uninit();
-        let token = &mut unsafe { token.assume_init() };
+        let token = &mut ListToken::default();
 
         self.start_send(token);
         unsafe {
@@ -435,8 +434,7 @@ impl<T> Channel<T> {
 
     /// Attempts to receive a message without blocking.
     pub(crate) fn try_recv(&self) -> Result<T, TryRecvError> {
-        let token = MaybeUninit::uninit();
-        let token = &mut unsafe { token.assume_init() };
+        let token = &mut ListToken::default();
 
         if self.start_recv(token) {
             unsafe { self.read(token).map_err(|_| TryRecvError::Disconnected) }
@@ -701,7 +699,7 @@ pub(crate) struct Sender<'a, T>(&'a Channel<T>);
 
 impl<T> SelectHandle for Receiver<'_, T> {
     fn try_select(&self, token: &mut Token) -> bool {
-        self.0.start_recv(token)
+        self.0.start_recv(&mut token.list)
     }
 
     fn deadline(&self) -> Option<Instant> {
@@ -737,7 +735,7 @@ impl<T> SelectHandle for Receiver<'_, T> {
 
 impl<T> SelectHandle for Sender<'_, T> {
     fn try_select(&self, token: &mut Token) -> bool {
-        self.0.start_send(token);
+        self.0.start_send(&mut token.list);
         true
     }