ksync/
lock_token.rs

1// Copyright 2026 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use core::marker::PhantomData;
6
7/// A token proving that a lock of lock class `Class` is currently held by the current thread.
8///
9/// This token acts as a static proof to permit type-safe borrow access to cell values guarded by
10/// this lock class (via `KCell`).
11pub struct LockToken<'a, Class> {
12    _marker: PhantomData<&'a Class>,
13    _phantom: PhantomData<*const ()>,
14}
15
16impl<'a, Class> LockToken<'a, Class> {
17    /// Creates a new proof token for the lock class `Class`.
18    ///
19    /// # Safety
20    ///
21    /// The caller must guarantee that the mutual exclusion lock associated with this lock class is
22    /// currently held by the current thread and that the lifetime `'a` is bounded to the duration
23    /// of the lock being held. Creating a token when the lock is not held, or letting the token
24    /// outlive the lock hold duration, can lead to concurrent mutation or data races, which is
25    /// undefined behavior.
26    #[inline]
27    pub unsafe fn new() -> Self {
28        Self { _marker: PhantomData, _phantom: PhantomData }
29    }
30}
ksync/lock_token.rs

ksync/
lock_token.rs
