From 7b2b7c64cca7a0e8043c7c7c52b1f38c4d589246 Mon Sep 17 00:00:00 2001
From: Emil Fresk <emil.fresk@gmail.com>
Date: Thu, 15 Feb 2024 16:14:03 +0100
Subject: [PATCH] .

---
 rtic-sync/src/bit_channel.rs | 74 ++++++++++++++++++++++++------------
 1 file changed, 50 insertions(+), 24 deletions(-)

diff --git a/rtic-sync/src/bit_channel.rs b/rtic-sync/src/bit_channel.rs
index 703d351a64..bd436d1658 100644
--- a/rtic-sync/src/bit_channel.rs
+++ b/rtic-sync/src/bit_channel.rs
@@ -2,11 +2,9 @@
 
 use bitflags::{Bits, Flags};
 use core::sync::atomic::{AtomicU16, AtomicU8, Ordering};
+use portable_atomic::{AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicU32, AtomicU64};
 
-//
-// Bit channel
-//
-
+/// A channel for setting and clearing `bitflags` concurrently.
 pub struct BitChannel<T: Flags>
 where
     T: Flags,
@@ -20,44 +18,73 @@ where
     T: Flags,
     T::Bits: AtomicType,
 {
+    /// Create a new `bitflags` channel.
     pub const fn new() -> Self {
         BitChannel {
             atomic: T::Bits::ATOMIC_ZERO,
         }
     }
 
-    pub fn test(&self) {
-        T::Bits::fetch_and(&self.atomic, T::Bits::EMPTY, Ordering::Relaxed);
+    /// Set `bitflag`s.
+    #[inline]
+    pub fn send(&self, flags: T) {
+        T::Bits::fetch_or(&self.atomic, flags.bits(), Ordering::Relaxed);
+    }
+
+    /// Receive the current value of the `bitflags` and reset all flags.
+    #[inline]
+    pub fn recv(&self) -> T {
+        <T as Flags>::from_bits_retain(T::Bits::fetch_and(
+            &self.atomic,
+            T::Bits::EMPTY,
+            Ordering::Relaxed,
+        ))
     }
 }
 
+/// Generic atomic trait, allows for taking any `bitflags::Bits` as an atomic.
 pub trait AtomicType: Sized {
+    /// The underlying atomic, e.g. `AtomicU8`, `AtomicU16`.
     type Atomic: From<Self>;
-    
+
+    /// The definition of that atomic with value 0.
     const ATOMIC_ZERO: Self::Atomic;
 
+    /// The atomic's `fetch_and` implementation forwarded.
     fn fetch_and(a: &Self::Atomic, b: Self, order: Ordering) -> Self;
+
+    /// The atomic's `fetch_or` implementation forwarded.
+    fn fetch_or(a: &Self::Atomic, b: Self, order: Ordering) -> Self;
 }
 
-impl AtomicType for u16 {
-    type Atomic = AtomicU16;
-    
-    const ATOMIC_ZERO: Self::Atomic = AtomicU16::new(0);
+macro_rules! atomic_type_impl {
+    ($atomic:ty, $integer:ty) => {
+        impl AtomicType for $integer {
+            type Atomic = $atomic;
 
-    fn fetch_and(a: &Self::Atomic, b: Self, order: Ordering) -> Self {
-        a.fetch_and(b, order)
-    }
+            const ATOMIC_ZERO: Self::Atomic = <$atomic>::new(0);
+
+            #[inline(always)]
+            fn fetch_and(a: &Self::Atomic, b: Self, order: Ordering) -> Self {
+                a.fetch_and(b, order)
+            }
+
+            #[inline(always)]
+            fn fetch_or(a: &Self::Atomic, b: Self, order: Ordering) -> Self {
+                a.fetch_or(b, order)
+            }
+        }
+    };
 }
 
-impl AtomicType for u8 {
-    type Atomic = AtomicU8;
-
-    const ATOMIC_ZERO: Self::Atomic = AtomicU8::new(0);
-
-    fn fetch_and(a: &Self::Atomic, b: Self, order: Ordering) -> Self {
-        a.fetch_and(b, order)
-    }
-}
+atomic_type_impl!(AtomicU8, u8);
+atomic_type_impl!(AtomicU16, u16);
+atomic_type_impl!(AtomicU32, u32);
+atomic_type_impl!(AtomicU64, u64);
+atomic_type_impl!(AtomicI8, i8);
+atomic_type_impl!(AtomicI16, i16);
+atomic_type_impl!(AtomicI32, i32);
+atomic_type_impl!(AtomicI64, i64);
 
 // etc...
 
@@ -86,4 +113,3 @@ mod tests {
         let b = BitChannel::<FlagsU16>::new();
     }
 }
-