src/sync/Spinlock.rs

@@ -0,0 +1,57 @@
+use core::arch::asm;
+use core::sync::atomic::{AtomicBool, Ordering};
+use core::cell::UnsafeCell;
+
+pub struct Spinlock<T> {
+    locked: AtomicBool,
+    data: UnsafeCell<T>,
+}
+
+unsafe impl<T: Send> Sync for Spinlock<T> {}
+
+impl<T> Spinlock<T> {
+    pub const fn new(data: T) -> Self {
+        Self {
+            locked: AtomicBool::new(false),
+            data: UnsafeCell::new(data),
+        }
+    }
+
+    pub fn lock(&self) -> SpinlockGuard<T> {
+        while let Err(_) = self.locked.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
+            while self.locked.load(Ordering::Relaxed) {
+                // Spin until the lock is released
+                unsafe { asm!("pause") };
+            }
+        }
+    
+        SpinlockGuard {
+            spinlock: &self,
+        }
+    }
+    
+}
+
+pub struct SpinlockGuard<'a, T> {
+    spinlock: &'a Spinlock<T>,
+}
+
+impl<'a, T> core::ops::Deref for SpinlockGuard<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        unsafe { &*self.spinlock.data.get() }
+    }
+}
+
+impl<'a, T> core::ops::DerefMut for SpinlockGuard<'a, T> {
+    fn deref_mut(&mut self) -> &mut T {
+        unsafe { &mut *self.spinlock.data.get() }
+    }
+}
+
+impl<'a, T> Drop for SpinlockGuard<'a, T> {
+    fn drop(&mut self) {
+        self.spinlock.locked.store(false, Ordering::Release);
+    }
+}