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