From: Boqun Feng <boqun.feng@gmail.com>
To: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Cc: "Will Deacon" <will@kernel.org>,
"Waiman Long" <longman@redhat.com>,
linux-kernel@vger.kernel.org, "Boqun Feng" <boqun.feng@gmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Alice Ryhl" <aliceryhl@google.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Trevor Gross" <tmgross@umich.edu>,
rust-for-linux@vger.kernel.org (open list:RUST)
Subject: [PATCH locking 08/11] rust: sync: lock: Add an example for Guard::lock_ref()
Date: Fri, 7 Mar 2025 15:26:58 -0800 [thread overview]
Message-ID: <20250307232717.1759087-9-boqun.feng@gmail.com> (raw)
In-Reply-To: <20250307232717.1759087-1-boqun.feng@gmail.com>
To provide examples on usage of `Guard::lock_ref()` along with the unit
test, an "assert a lock is held by a guard" example is added.
[boqun: Apply feedback from Benno]
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250223072114.3715-1-boqun.feng@gmail.com
---
rust/kernel/sync/lock.rs | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index 8e7e6d5f61e4..f53e87d04cd2 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -201,6 +201,30 @@ unsafe impl<T: Sync + ?Sized, B: Backend> Sync for Guard<'_, T, B> {}
impl<'a, T: ?Sized, B: Backend> Guard<'a, T, B> {
/// Returns the lock that this guard originates from.
+ ///
+ /// # Examples
+ ///
+ /// The following example shows how to use [`Guard::lock_ref()`] to assert the corresponding
+ /// lock is held.
+ ///
+ /// ```
+ /// # use kernel::{new_spinlock, stack_pin_init, sync::lock::{Backend, Guard, Lock}};
+ ///
+ /// fn assert_held<T, B: Backend>(guard: &Guard<'_, T, B>, lock: &Lock<T, B>) {
+ /// // Address-equal means the same lock.
+ /// assert!(core::ptr::eq(guard.lock_ref(), lock));
+ /// }
+ ///
+ /// // Creates a new lock on the stack.
+ /// stack_pin_init!{
+ /// let l = new_spinlock!(42)
+ /// }
+ ///
+ /// let g = l.lock();
+ ///
+ /// // `g` originates from `l`.
+ /// assert_held(&g, &l);
+ /// ```
pub fn lock_ref(&self) -> &'a Lock<T, B> {
self.lock
}
--
2.47.1
next prev parent reply other threads:[~2025-03-07 23:29 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-26 4:12 [GIT PULL] LOCKDEP and Rust locking changes for v6.15 Boqun Feng
2025-02-28 18:57 ` Boqun Feng
2025-03-03 16:52 ` Waiman Long
2025-03-03 18:42 ` Peter Zijlstra
2025-03-07 23:26 ` [PATCH locking 00/11] " Boqun Feng
2025-03-07 23:26 ` [PATCH locking 01/11] locking/rtmutex: Use struct keyword in kernel-doc comment Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] locking/rtmutex: Use the 'struct' " tip-bot2 for Randy Dunlap
2025-03-07 23:26 ` [PATCH locking 02/11] locking/semaphore: Use wake_q to wake up processes outside lock critical section Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 03/11] locking/lock_events: Add locking events for rtmutex slow paths Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 04/11] locking/lock_events: Add locking events for lockdep Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 05/11] locking/lockdep: Disable KASAN instrumentation of lockdep.c Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 06/11] locking/lockdep: Add kasan_check_byte() check in lock_acquire() Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 07/11] rust: sync: Add accessor for the lock behind a given guard Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Alice Ryhl
2025-03-07 23:26 ` Boqun Feng [this message]
2025-03-08 0:08 ` [tip: locking/core] rust: sync: lock: Add an example for Guard:: Lock_ref() tip-bot2 for Boqun Feng
2025-03-07 23:26 ` [PATCH locking 09/11] rust: sync: condvar: Add wait_interruptible_freezable() Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Alice Ryhl
2025-03-07 23:27 ` [PATCH locking 10/11] rust: lockdep: Remove support for dynamically allocated LockClassKeys Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Mitchell Levy
2025-03-07 23:27 ` [PATCH locking 11/11] rust: lockdep: Use Pin for all LockClassKey usages Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Mitchell Levy
2025-03-08 0:01 ` [PATCH locking 00/11] LOCKDEP and Rust locking changes for v6.15 Ingo Molnar
2025-03-08 0:04 ` Boqun Feng
2025-03-08 0:11 ` Ingo Molnar
2025-03-08 0:11 ` Boqun Feng
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