From mboxrd@z Thu Jan  1 00:00:00 1970
From: Claude Code Review Bot <claude-review@example.com>
To: dri-devel-reviews@example.com
Subject: Claude review: rust: sync: lock: Add Lock::get_mut_pinned()
Date: Thu, 04 Jun 2026 16:11:03 +1000
Message-ID: <review-patch1-20260529173137.303717-2-lyude@redhat.com>
In-Reply-To: <20260529173137.303717-2-lyude@redhat.com>
References: <20260529173137.303717-1-lyude@redhat.com> <20260529173137.303717-2-lyude@redhat.com>
X-Mailer: Claude Code Patch Reviewer
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Patch Review

**Correctness: Good.** The implementation is sound.

The method provides `Pin<&mut T>` from `Pin<&mut Lock<T, B>>` without acqui=
ring the lock, which is safe because `&mut` guarantees exclusive access. Th=
is mirrors `std::sync::Mutex::get_mut()` from the Rust stdlib.

```rust
pub fn get_mut_pinned(self: Pin<&mut Self>) -> Pin<&mut T> {
    // SAFETY: We return a pinned T, ensuring we don't move T.
    unsafe { self.map_unchecked_mut(|data| data.data.get_mut()) }
}
```

The safety of `map_unchecked_mut` relies on the returned reference pointing=
 to structurally pinned data. Since `data: UnsafeCell<T>` is `#[pin]` in th=
e `Lock` struct definition (line 119 of `lock.rs`), this is correct.

**Minor issues:**

1. **Commit message says "These two functions"** but only one function (`ge=
t_mut_pinned`) is added. Likely a leftover from an earlier revision:

   > These two functions are inspired by the Rust stdlib equivalent

2. **`#[inline(always)]` is arguably too strong.** The method is trivial an=
d the compiler will almost certainly inline it without the hint. `#[inline]=
` would suffice and avoids forcing inlining in debug builds. Very minor nit.

3. The method is placed in the `impl<T: ?Sized, B: Backend> Lock<T, B>` blo=
ck, which is correct =E2=80=94 it works for unsized types and any backend.

---

---
Generated by Claude Code Patch Reviewer