Merge #30

30: Implement OnceLock r=bertptrs a=bertptrs

1.70 brought `OnceLock`. This needs a new wrapper and should replace all usage of `lazy_static!`, as well as the current internal implementation of OnceLock.

Co-authored-by: Bert Peters <bert@bertptrs.nl>

.github/workflows/ci.yml

@@ -15,6 +15,7 @@ jobs:
     strategy:
       matrix:
         rust:
+          - "1.70" # minimum stable rust version
           - stable
           - beta
           - nightly

CHANGELOG.md

@@ -6,6 +6,22 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Added
+
+- The minimum supported Rust version is now defined as 1.70. Previously it was undefined.
+- Wrappers for `std::sync` primitives can now be `const` constructed.
+- Add support for `std::sync::OnceLock`
+
+### Breaking
+
+- Update [`parking_lot`][parking_lot] dependency to `0.12`.
+- Restructured the crate to reduce typename verbosity. For details, see: #25.
+
+### Fixed
+
+- Enforce that all internal mutex guards are `!Send`. They already should be according to other
+  reasons, but this adds extra security through the type system.
+
 ## [0.2.1] - 2022-05-23
 
 ### Added

Cargo.toml

@@ -10,6 +10,7 @@ keywords = ["mutex", "rwlock", "once", "thread"]
 description = "Ensure deadlock-free mutexes by allocating in order, or else."
 readme = "README.md"
 repository = "https://github.com/bertptrs/tracing-mutex"
+rust-version = "1.70"
 
 [package.metadata.docs.rs]
 # Build docs for all features so the documentation is more complete
@@ -18,9 +19,8 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [dependencies]
-lazy_static = "1"
 lock_api = { version = "0.4", optional = true }
-parking_lot = { version = "0.11", optional = true }
+parking_lot = { version = "0.12", optional = true }
 
 [dev-dependencies]
 criterion = "0.3"

README.md

@@ -23,10 +23,12 @@ tree out of it, and panics if your dependencies would create a cycle. It provide
 existing synchronization primitives with an identical API, and should be a drop-in replacement.
 
 Inspired by [this blogpost][whileydave], which references a similar behaviour implemented by
-[Abseil][abseil-mutex] for their mutexes.
+[Abseil][abseil-mutex] for their mutexes. [This article goes into more depth on the exact
+implementation.][article]
 
 [whileydave]: https://whileydave.com/2020/12/19/dynamic-cycle-detection-for-lock-ordering/
 [abseil-mutex]: https://abseil.io/docs/cpp/guides/synchronization
+[article]: https://bertptrs.nl/2022/06/23/deadlock-free-mutexes-and-directed-acyclic-graphs.html
 
 ## Usage
 
@@ -42,9 +44,9 @@ Replacements for the synchronization primitives in `std::sync` can be found in t
 Support for other synchronization primitives is planned.
 
 ```rust
-use tracing_mutex::stdsync::TracingMutex;
+use tracing_mutex::stdsync::Mutex;
 
-let some_mutex = TracingMutex::new(42);
+let some_mutex = Mutex::new(42);
 *some_mutex.lock().unwrap() += 1;
 println!("{:?}", some_mutex);
 ```
@@ -59,6 +61,9 @@ performance penalty in your production environment, this library also offers deb
 when debug assertions are enabled, and to `Mutex` when they are not. Similar helper types are
 available for other synchronization primitives.
 
+The minimum supported Rust version is 1.70. Increasing this is not considered a breaking change, but
+will be avoided within semver-compatible releases if possible.
+
 ### Features
 
 - Dependency-tracking wrappers for all locking primitives

benches/mutex.rs

@@ -7,7 +7,7 @@ use criterion::BenchmarkId;
 use criterion::Criterion;
 use criterion::Throughput;
 use rand::prelude::*;
-use tracing_mutex::stdsync::TracingMutex;
+use tracing_mutex::stdsync::tracing::Mutex as TracingMutex;
 
 const SAMPLE_SIZES: [usize; 5] = [10, 30, 100, 300, 1000];
 

bors.toml

@@ -1,4 +1,5 @@
 status = [
+    'Rust project (1.70)',
     'Rust project (stable)',
     'Rust project (beta)',
     'Documentation build',

src/lib.rs

@@ -41,26 +41,23 @@
 //!
 //! These operations have been reasonably optimized, but the performance penalty may yet be too much
 //! for production use. In those cases, it may be beneficial to instead use debug-only versions
-//! (such as [`stdsync::DebugMutex`]) which evaluate to a tracing mutex when debug assertions are
+//! (such as [`stdsync::Mutex`]) which evaluate to a tracing mutex when debug assertions are
 //! enabled, and to the underlying mutex when they're not.
 //!
 //! [paper]: https://whileydave.com/publications/pk07_jea/
 #![cfg_attr(docsrs, feature(doc_cfg))]
 use std::cell::RefCell;
-use std::cell::UnsafeCell;
 use std::fmt;
 use std::marker::PhantomData;
-use std::mem::MaybeUninit;
 use std::ops::Deref;
 use std::ops::DerefMut;
-use std::ptr;
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering;
 use std::sync::Mutex;
-use std::sync::Once;
+use std::sync::MutexGuard;
+use std::sync::OnceLock;
 use std::sync::PoisonError;
 
-use lazy_static::lazy_static;
 #[cfg(feature = "lockapi")]
 #[cfg_attr(docsrs, doc(cfg(feature = "lockapi")))]
 pub use lock_api;
@@ -79,11 +76,6 @@ pub mod lockapi;
 pub mod parkinglot;
 pub mod stdsync;
 
-/// Counter for Mutex IDs. Atomic avoids the need for locking.
-///
-/// Should be part of the `MutexID` impl but static items are not yet a thing.
-static ID_SEQUENCE: AtomicUsize = AtomicUsize::new(0);
-
 thread_local! {
     /// Stack to track which locks are held
     ///
@@ -92,10 +84,6 @@ thread_local! {
     static HELD_LOCKS: RefCell<Vec<usize>> = RefCell::new(Vec::new());
 }
 
-lazy_static! {
-    static ref DEPENDENCY_GRAPH: Mutex<DiGraph<usize>> = Default::default();
-}
-
 /// Dedicated ID type for Mutexes
 ///
 /// # Unstable
@@ -114,6 +102,9 @@ impl MutexId {
     /// This function may panic when there are no more mutex IDs available. The number of mutex ids
     /// is `usize::MAX - 1` which should be plenty for most practical applications.
     pub fn new() -> Self {
+        // Counter for Mutex IDs. Atomic avoids the need for locking.
+        static ID_SEQUENCE: AtomicUsize = AtomicUsize::new(0);
+
         ID_SEQUENCE
             .fetch_update(Ordering::SeqCst, Ordering::SeqCst, |id| id.checked_add(1))
             .map(Self)
@@ -134,7 +125,10 @@ impl MutexId {
     /// This method panics if the new dependency would introduce a cycle.
     pub fn get_borrowed(&self) -> BorrowedMutex {
         self.mark_held();
-        BorrowedMutex(self)
+        BorrowedMutex {
+            id: self,
+            _not_send: PhantomData,
+        }
     }
 
     /// Mark this lock as held for the purposes of dependency tracking.
@@ -204,17 +198,13 @@ impl Drop for MutexId {
 ///
 /// This type can be largely replaced once std::lazy gets stabilized.
 struct LazyMutexId {
-    inner: UnsafeCell<MaybeUninit<MutexId>>,
+    inner: OnceLock<MutexId>,
-    setter: Once,
-    _marker: PhantomData<MutexId>,
 }
 
 impl LazyMutexId {
     pub const fn new() -> Self {
         Self {
-            inner: UnsafeCell::new(MaybeUninit::uninit()),
+            inner: OnceLock::new(),
-            setter: Once::new(),
-            _marker: PhantomData,
         }
     }
 }
@@ -231,51 +221,30 @@ impl Default for LazyMutexId {
     }
 }
 
-/// Safety: the UnsafeCell is guaranteed to only be accessed mutably from a `Once`.
-unsafe impl Sync for LazyMutexId {}
-
 impl Deref for LazyMutexId {
     type Target = MutexId;
 
     fn deref(&self) -> &Self::Target {
-        self.setter.call_once(|| {
+        self.inner.get_or_init(MutexId::new)
-            // Safety: this function is only called once, so only one mutable reference should exist
-            // at a time.
-            unsafe {
-                *self.inner.get() = MaybeUninit::new(MutexId::new());
-            }
-        });
-
-        // Safety: after the above Once runs, there are no longer any mutable references, so we can
-        // hand this out safely.
-        //
-        // Explanation of this monstrosity:
-        //
-        // - Get a pointer to the data from the UnsafeCell
-        // - Dereference that to get a reference to the underlying MaybeUninit
-        // - Use as_ptr on MaybeUninit to get a pointer to the initialized MutexID
-        // - Dereference the pointer to turn in into a reference as intended.
-        //
-        // This should get slightly nicer once `maybe_uninit_extra` is stabilized.
-        unsafe { &*((*self.inner.get()).as_ptr()) }
-    }
-}
-
-impl Drop for LazyMutexId {
-    fn drop(&mut self) {
-        if self.setter.is_completed() {
-            // We have a valid mutex ID and need to drop it
-
-            // Safety: we know that this pointer is valid because the initializer has successfully run.
-            let mutex_id = unsafe { ptr::read((*self.inner.get()).as_ptr()) };
-
-            drop(mutex_id);
-        }
     }
 }
 
+/// Borrowed mutex ID
+///
+/// This type should be used as part of a mutex guard wrapper. It can be acquired through
+/// [`MutexId::get_borrowed`] and will automatically mark the mutex as not borrowed when it is
+/// dropped.
+///
+/// This type intentionally is [`!Send`](std::marker::Send) because the ownership tracking is based
+/// on a thread-local stack which doesn't work if a guard gets released in a different thread from
+/// where they're acquired.
 #[derive(Debug)]
-struct BorrowedMutex<'a>(&'a MutexId);
+struct BorrowedMutex<'a> {
+    /// Reference to the mutex we're borrowing from
+    id: &'a MutexId,
+    /// This value serves no purpose but to make the type [`!Send`](std::marker::Send)
+    _not_send: PhantomData<MutexGuard<'static, ()>>,
+}
 
 /// Drop a lock held by the current thread.
 ///
@@ -286,13 +255,16 @@ struct BorrowedMutex<'a>(&'a MutexId);
 impl<'a> Drop for BorrowedMutex<'a> {
     fn drop(&mut self) {
         // Safety: the only way to get a BorrowedMutex is by locking the mutex.
-        unsafe { self.0.mark_released() };
+        unsafe { self.id.mark_released() };
     }
 }
 
 /// Get a reference to the current dependency graph
 fn get_dependency_graph() -> impl DerefMut<Target = DiGraph<usize>> {
+    static DEPENDENCY_GRAPH: OnceLock<Mutex<DiGraph<usize>>> = OnceLock::new();
+
     DEPENDENCY_GRAPH
+        .get_or_init(Default::default)
         .lock()
         .unwrap_or_else(PoisonError::into_inner)
 }

src/parkinglot.rs

@@ -1,19 +1,20 @@
 //! Wrapper types and type aliases for tracing [`parking_lot`] mutexes.
 //!
 //! This module provides type aliases that use the [`lockapi`][crate::lockapi] module to provide
-//! tracing variants of the `parking_lot` primitives. Each of the `TracingX` type aliases wraps an
+//! tracing variants of the `parking_lot` primitives. The [`tracing`] module contains type aliases
-//! `X` in the `parkint_lot` api with dependency tracking, and a `DebugX` will refer to a `TracingX`
+//! that use dependency tracking, while the main `parking_lot` primitives are reexported as [`raw`].
-//! when  `debug_assertions` are enabled and to `X` when they're not. This can be used to aid
+//!
-//! debugging in development while enjoying maximum performance in production.
+//! This main module imports from [`tracing`] when `debug_assertions` are enabled, and from [`raw`]
+//! when they're not. Note that primitives for which no tracing wrapper exists are not imported into
+//! the main module.
 //!
 //! # Usage
 //!
 //! ```
 //! # use std::sync::Arc;
 //! # use std::thread;
-//! # use lock_api::Mutex;
+//! use tracing_mutex::parkinglot::Mutex;
-//! # use tracing_mutex::parkinglot::TracingMutex;
+//! let mutex = Arc::new(Mutex::new(0));
-//! let mutex = Arc::new(TracingMutex::new(0));
 //!
 //! let handles: Vec<_> = (0..10).map(|_| {
 //!    let mutex = Arc::clone(&mutex);
@@ -37,141 +38,89 @@
 //! In addition, the mutex guards returned by the tracing wrappers are `!Send`, regardless of
 //! whether `parking_lot` is configured to have `Send` mutex guards. This is a limitation of the
 //! current bookkeeping system.
-use parking_lot::Once;
-use parking_lot::OnceState;
 
-use crate::lockapi::TracingWrapper;
+pub use parking_lot as raw;
-use crate::LazyMutexId;
 
-macro_rules! debug_variant {
+#[cfg(debug_assertions)]
-    ($debug_name:ident, $tracing_name:ident, $normal_name:ty) => {
+pub use tracing::{
-        type $tracing_name = TracingWrapper<$normal_name>;
+    FairMutex, FairMutexGuard, MappedFairMutexGuard, MappedMutexGuard, MappedReentrantMutexGuard,
+    MappedRwLockReadGuard, MappedRwLockWriteGuard, Mutex, MutexGuard, Once, OnceState,
+    ReentrantMutex, ReentrantMutexGuard, RwLock, RwLockReadGuard, RwLockUpgradableReadGuard,
+    RwLockWriteGuard,
+};
 
-        #[cfg(debug_assertions)]
+#[cfg(not(debug_assertions))]
-        type $debug_name = TracingWrapper<$normal_name>;
+pub use parking_lot::{
-        #[cfg(not(debug_assertions))]
+    FairMutex, FairMutexGuard, MappedFairMutexGuard, MappedMutexGuard, MappedReentrantMutexGuard,
-        type $debug_name = $normal_name;
+    MappedRwLockReadGuard, MappedRwLockWriteGuard, Mutex, MutexGuard, Once, OnceState,
-    };
+    ReentrantMutex, ReentrantMutexGuard, RwLock, RwLockReadGuard, RwLockUpgradableReadGuard,
-}
+    RwLockWriteGuard,
+};
 
-debug_variant!(
+/// Dependency tracing wrappers for [`parking_lot`].
-    DebugRawFairMutex,
+pub mod tracing {
-    TracingRawFairMutex,
+    pub use parking_lot::OnceState;
-    parking_lot::RawFairMutex
-);
-debug_variant!(DebugRawMutex, TracingRawMutex, parking_lot::RawMutex);
-debug_variant!(DebugRawRwLock, TracingRawRwLock, parking_lot::RawRwLock);
 
-/// Dependency tracking fair mutex. See: [`parking_lot::FairMutex`].
+    use crate::lockapi::TracingWrapper;
-pub type TracingFairMutex<T> = lock_api::Mutex<TracingRawFairMutex, T>;
+    use crate::LazyMutexId;
-/// Mutex guard for [`TracingFairMutex`].
-pub type TracingFairMutexGuard<'a, T> = lock_api::MutexGuard<'a, TracingRawFairMutex, T>;
-/// RAII guard for `TracingFairMutexGuard::map`.
-pub type TracingMappedFairMutexGuard<'a, T> =
-    lock_api::MappedMutexGuard<'a, TracingRawFairMutex, T>;
-/// Debug-only dependency tracking fair mutex.
-///
-/// If debug assertions are enabled this resolves to [`TracingFairMutex`] and to
-/// [`parking_lot::FairMutex`] otherwise.
-pub type DebugFairMutex<T> = lock_api::Mutex<DebugRawFairMutex, T>;
-/// Mutex guard for [`DebugFairMutex`].
-pub type DebugFairMutexGuard<'a, T> = lock_api::MutexGuard<'a, DebugRawFairMutex, T>;
-/// RAII guard for `DebugFairMutexGuard::map`.
-pub type DebugMappedFairMutexGuard<'a, T> = lock_api::MappedMutexGuard<'a, DebugRawFairMutex, T>;
 
-/// Dependency tracking mutex. See: [`parking_lot::Mutex`].
+    type RawFairMutex = TracingWrapper<parking_lot::RawFairMutex>;
-pub type TracingMutex<T> = lock_api::Mutex<TracingRawMutex, T>;
+    type RawMutex = TracingWrapper<parking_lot::RawMutex>;
-/// Mutex guard for [`TracingMutex`].
+    type RawRwLock = TracingWrapper<parking_lot::RawRwLock>;
-pub type TracingMutexGuard<'a, T> = lock_api::MutexGuard<'a, TracingRawMutex, T>;
-/// RAII guard for `TracingMutexGuard::map`.
-pub type TracingMappedMutexGuard<'a, T> = lock_api::MappedMutexGuard<'a, TracingRawMutex, T>;
-/// Debug-only dependency tracking mutex.
-///
-/// If debug assertions are enabled this resolves to [`TracingMutex`] and to [`parking_lot::Mutex`]
-/// otherwise.
-pub type DebugMutex<T> = lock_api::Mutex<DebugRawMutex, T>;
-/// Mutex guard for [`DebugMutex`].
-pub type DebugMutexGuard<'a, T> = lock_api::MutexGuard<'a, DebugRawMutex, T>;
-/// RAII guard for `TracingMutexGuard::map`.
-pub type DebugMappedMutexGuard<'a, T> = lock_api::MappedMutexGuard<'a, DebugRawMutex, T>;
 
-/// Dependency tracking reentrant mutex. See: [`parking_lot::ReentrantMutex`].
+    /// Dependency tracking fair mutex. See: [`parking_lot::FairMutex`].
-///
+    pub type FairMutex<T> = lock_api::Mutex<RawFairMutex, T>;
-/// **Note:** due to the way dependencies are tracked, this mutex can only be acquired directly
+    /// Mutex guard for [`FairMutex`].
-/// after itself. Acquiring any other mutex in between introduces a dependency cycle, and will
+    pub type FairMutexGuard<'a, T> = lock_api::MutexGuard<'a, RawFairMutex, T>;
-/// therefore be rejected.
+    /// RAII guard for [`FairMutexGuard::map`].
-pub type TracingReentrantMutex<T> =
+    pub type MappedFairMutexGuard<'a, T> = lock_api::MappedMutexGuard<'a, RawFairMutex, T>;
-    lock_api::ReentrantMutex<TracingWrapper<parking_lot::RawMutex>, parking_lot::RawThreadId, T>;
-/// Mutex guard for [`TracingReentrantMutex`].
-pub type TracingReentrantMutexGuard<'a, T> = lock_api::ReentrantMutexGuard<
-    'a,
-    TracingWrapper<parking_lot::RawMutex>,
-    parking_lot::RawThreadId,
-    T,
->;
-/// RAII guard for `TracingReentrantMutexGuard::map`.
-pub type TracingMappedReentrantMutexGuard<'a, T> =
-    lock_api::MappedReentrantMutexGuard<'a, TracingRawMutex, parking_lot::RawThreadId, T>;
 
-/// Debug-only dependency tracking reentrant mutex.
+    /// Dependency tracking mutex. See: [`parking_lot::Mutex`].
-///
+    pub type Mutex<T> = lock_api::Mutex<RawMutex, T>;
-/// If debug assertions are enabled this resolves to [`TracingReentrantMutex`] and to
+    /// Mutex guard for [`Mutex`].
-/// [`parking_lot::ReentrantMutex`] otherwise.
+    pub type MutexGuard<'a, T> = lock_api::MutexGuard<'a, RawMutex, T>;
-pub type DebugReentrantMutex<T> =
+    /// RAII guard for [`MutexGuard::map`].
-    lock_api::ReentrantMutex<DebugRawMutex, parking_lot::RawThreadId, T>;
+    pub type MappedMutexGuard<'a, T> = lock_api::MappedMutexGuard<'a, RawMutex, T>;
-/// Mutex guard for [`DebugReentrantMutex`].
-pub type DebugReentrantMutexGuard<'a, T> =
-    lock_api::ReentrantMutexGuard<'a, DebugRawMutex, parking_lot::RawThreadId, T>;
-/// RAII guard for `DebugReentrantMutexGuard::map`.
-pub type DebugMappedReentrantMutexGuard<'a, T> =
-    lock_api::MappedReentrantMutexGuard<'a, DebugRawMutex, parking_lot::RawThreadId, T>;
 
-/// Dependency tracking RwLock. See: [`parking_lot::RwLock`].
+    /// Dependency tracking reentrant mutex. See: [`parking_lot::ReentrantMutex`].
-pub type TracingRwLock<T> = lock_api::RwLock<TracingRawRwLock, T>;
+    ///
-/// Read guard for [`TracingRwLock`].
+    /// **Note:** due to the way dependencies are tracked, this mutex can only be acquired directly
-pub type TracingRwLockReadGuard<'a, T> = lock_api::RwLockReadGuard<'a, TracingRawRwLock, T>;
+    /// after itself. Acquiring any other mutex in between introduces a dependency cycle, and will
-/// Upgradable Read guard for [`TracingRwLock`].
+    /// therefore be rejected.
-pub type TracingRwLockUpgradableReadGuard<'a, T> =
+    pub type ReentrantMutex<T> = lock_api::ReentrantMutex<RawMutex, parking_lot::RawThreadId, T>;
-    lock_api::RwLockUpgradableReadGuard<'a, TracingRawRwLock, T>;
+    /// Mutex guard for [`ReentrantMutex`].
-/// Write guard for [`TracingRwLock`].
+    pub type ReentrantMutexGuard<'a, T> =
-pub type TracingRwLockWriteGuard<'a, T> = lock_api::RwLockWriteGuard<'a, TracingRawRwLock, T>;
+        lock_api::ReentrantMutexGuard<'a, RawMutex, parking_lot::RawThreadId, T>;
-/// RAII guard for `TracingRwLockReadGuard::map`.
+    /// RAII guard for `ReentrantMutexGuard::map`.
-pub type TracingMappedRwLockReadGuard<'a, T> =
+    pub type MappedReentrantMutexGuard<'a, T> =
-    lock_api::MappedRwLockReadGuard<'a, TracingRawRwLock, T>;
+        lock_api::MappedReentrantMutexGuard<'a, RawMutex, parking_lot::RawThreadId, T>;
-/// RAII guard for `TracingRwLockWriteGuard::map`.
-pub type TracingMappedRwLockWriteGuard<'a, T> =
-    lock_api::MappedRwLockWriteGuard<'a, TracingRawRwLock, T>;
 
-/// Debug-only dependency tracking RwLock.
+    /// Dependency tracking RwLock. See: [`parking_lot::RwLock`].
-///
+    pub type RwLock<T> = lock_api::RwLock<RawRwLock, T>;
-/// If debug assertions are enabled this resolved to [`TracingRwLock`] and to
+    /// Read guard for [`RwLock`].
-/// [`parking_lot::RwLock`] otherwise.
+    pub type RwLockReadGuard<'a, T> = lock_api::RwLockReadGuard<'a, RawRwLock, T>;
-pub type DebugRwLock<T> = lock_api::RwLock<DebugRawRwLock, T>;
+    /// Upgradable Read guard for [`RwLock`].
-/// Read guard for [`TracingRwLock`].
+    pub type RwLockUpgradableReadGuard<'a, T> =
-pub type DebugRwLockReadGuard<'a, T> = lock_api::RwLockReadGuard<'a, DebugRawRwLock, T>;
+        lock_api::RwLockUpgradableReadGuard<'a, RawRwLock, T>;
-/// Upgradable Read guard for [`TracingRwLock`].
+    /// Write guard for [`RwLock`].
-pub type DebugRwLockUpgradableReadGuard<'a, T> =
+    pub type RwLockWriteGuard<'a, T> = lock_api::RwLockWriteGuard<'a, RawRwLock, T>;
-    lock_api::RwLockUpgradableReadGuard<'a, DebugRawRwLock, T>;
+    /// RAII guard for `RwLockReadGuard::map`.
-/// Write guard for [`TracingRwLock`].
+    pub type MappedRwLockReadGuard<'a, T> = lock_api::MappedRwLockReadGuard<'a, RawRwLock, T>;
-pub type DebugRwLockWriteGuard<'a, T> = lock_api::RwLockWriteGuard<'a, DebugRawRwLock, T>;
+    /// RAII guard for `RwLockWriteGuard::map`.
-/// RAII guard for `DebugRwLockReadGuard::map`.
+    pub type MappedRwLockWriteGuard<'a, T> = lock_api::MappedRwLockWriteGuard<'a, RawRwLock, T>;
-pub type DebugMappedRwLockReadGuard<'a, T> = lock_api::MappedRwLockReadGuard<'a, DebugRawRwLock, T>;
-/// RAII guard for `DebugRwLockWriteGuard::map`.
-pub type DebugMappedRwLockWriteGuard<'a, T> =
-    lock_api::MappedRwLockWriteGuard<'a, DebugRawRwLock, T>;
 
-/// A dependency-tracking wrapper for [`parking_lot::Once`].
+    /// A dependency-tracking wrapper for [`parking_lot::Once`].
-#[derive(Debug, Default)]
+    #[derive(Debug, Default)]
-pub struct TracingOnce {
+    pub struct Once {
-    inner: Once,
+        inner: parking_lot::Once,
         id: LazyMutexId,
-}
+    }
 
-impl TracingOnce {
+    impl Once {
-    /// Create a new `TracingOnce` value.
+        /// Create a new `Once` value.
         pub const fn new() -> Self {
             Self {
-            inner: Once::new(),
+                inner: parking_lot::Once::new(),
                 id: LazyMutexId::new(),
             }
         }
@@ -181,8 +130,7 @@ impl TracingOnce {
             self.inner.state()
         }
 
-    ///
+        /// This call is considered as "locking this `Once`" and it participates in dependency
-    /// This call is considered as "locking this `TracingOnce`" and it participates in dependency
         /// tracking as such.
         ///
         /// # Panics
@@ -196,32 +144,24 @@ impl TracingOnce {
 
         /// Performs the given initialization routine once and only once.
         ///
-    /// This method is identical to [`TracingOnce::call_once`] except it ignores poisoning.
+        /// This method is identical to [`Once::call_once`] except it ignores poisoning.
         pub fn call_once_force(&self, f: impl FnOnce(OnceState)) {
             let _borrow = self.id.get_borrowed();
             self.inner.call_once_force(f);
         }
+    }
 }
 
-/// Debug-only `Once`.
-///
-/// If debug assertions are enabled this resolves to [`TracingOnce`] and to [`parking_lot::Once`]
-/// otherwise.
-#[cfg(debug_assertions)]
-pub type DebugOnce = TracingOnce;
-#[cfg(not(debug_assertions))]
-pub type DebugOnce = Once;
-
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;
     use std::thread;
 
-    use super::*;
+    use super::tracing;
 
     #[test]
     fn test_mutex_usage() {
-        let mutex = Arc::new(TracingMutex::new(()));
+        let mutex = Arc::new(tracing::Mutex::new(()));
         let local_lock = mutex.lock();
         drop(local_lock);
 
@@ -236,9 +176,9 @@ mod tests {
     #[should_panic]
     fn test_mutex_conflict() {
         let mutexes = [
-            TracingMutex::new(()),
+            tracing::Mutex::new(()),
-            TracingMutex::new(()),
+            tracing::Mutex::new(()),
-            TracingMutex::new(()),
+            tracing::Mutex::new(()),
         ];
 
         for i in 0..3 {
@@ -249,7 +189,7 @@ mod tests {
 
     #[test]
     fn test_rwlock_usage() {
-        let lock = Arc::new(TracingRwLock::new(()));
+        let lock = Arc::new(tracing::RwLock::new(()));
         let lock2 = Arc::clone(&lock);
 
         let _read_lock = lock.read();
@@ -264,19 +204,19 @@ mod tests {
 
     #[test]
     fn test_rwlock_upgradable_read_usage() {
-        let lock = TracingRwLock::new(());
+        let lock = tracing::RwLock::new(());
 
         // Should be able to acquire an upgradable read lock.
-        let upgradable_guard: TracingRwLockUpgradableReadGuard<'_, _> = lock.upgradable_read();
+        let upgradable_guard: tracing::RwLockUpgradableReadGuard<'_, _> = lock.upgradable_read();
 
         // Should be able to upgrade the guard.
-        let _write_guard: TracingRwLockWriteGuard<'_, _> =
+        let _write_guard: tracing::RwLockWriteGuard<'_, _> =
-            TracingRwLockUpgradableReadGuard::upgrade(upgradable_guard);
+            tracing::RwLockUpgradableReadGuard::upgrade(upgradable_guard);
     }
 
     #[test]
     fn test_once_usage() {
-        let once = Arc::new(TracingOnce::new());
+        let once = Arc::new(tracing::Once::new());
         let once_clone = once.clone();
 
         assert!(!once_clone.state().done());

src/stdsync.rs

@@ -1,130 +1,86 @@
 //! Tracing mutex wrappers for locks found in `std::sync`.
 //!
 //! This module provides wrappers for `std::sync` primitives with exactly the same API and
-//! functionality as their counterparts, with the exception that their acquisition order is
+//! functionality as their counterparts, with the exception that their acquisition order is tracked.
-//! tracked.
+//!
+//! Dedicated wrappers that provide the dependency tracing can be found in the [`tracing`] module.
+//! The original primitives are available from [`std::sync`], imported as [`raw`] for convenience.
+//!
+//! If debug assertions are enabled, this module imports the primitives from [`tracing`], otherwise
+//! it will import from [`raw`].
 //!
 //! ```rust
-//! # use tracing_mutex::stdsync::TracingMutex;
+//! # use tracing_mutex::stdsync::tracing::Mutex;
-//! # use tracing_mutex::stdsync::TracingRwLock;
+//! # use tracing_mutex::stdsync::tracing::RwLock;
-//! let mutex = TracingMutex::new(());
+//! let mutex = Mutex::new(());
 //! mutex.lock().unwrap();
 //!
-//! let rwlock = TracingRwLock::new(());
+//! let rwlock = RwLock::new(());
 //! rwlock.read().unwrap();
 //! ```
-use std::fmt;
+pub use std::sync as raw;
-use std::ops::Deref;
-use std::ops::DerefMut;
-use std::sync::Condvar;
-use std::sync::LockResult;
-use std::sync::Mutex;
-use std::sync::MutexGuard;
-use std::sync::Once;
-use std::sync::OnceState;
-use std::sync::PoisonError;
-use std::sync::RwLock;
-use std::sync::RwLockReadGuard;
-use std::sync::RwLockWriteGuard;
-use std::sync::TryLockError;
-use std::sync::TryLockResult;
-use std::sync::WaitTimeoutResult;
-use std::time::Duration;
 
-use crate::BorrowedMutex;
-use crate::LazyMutexId;
-use crate::MutexId;
-
-/// Debug-only tracing `Mutex`.
-///
-/// Type alias that resolves to [`TracingMutex`] when debug assertions are enabled and to
-/// [`std::sync::Mutex`] when they're not. Use this if you want to have the benefits of cycle
-/// detection in development but do not want to pay the performance penalty in release.
-#[cfg(debug_assertions)]
-pub type DebugMutex<T> = TracingMutex<T>;
 #[cfg(not(debug_assertions))]
-pub type DebugMutex<T> = Mutex<T>;
+pub use std::sync::{
+    Condvar, Mutex, MutexGuard, Once, OnceLock, RwLock, RwLockReadGuard, RwLockWriteGuard,
+};
 
-/// Mutex guard for [`DebugMutex`].
 #[cfg(debug_assertions)]
-pub type DebugMutexGuard<'a, T> = TracingMutexGuard<'a, T>;
+pub use tracing::{
-#[cfg(not(debug_assertions))]
+    Condvar, Mutex, MutexGuard, Once, OnceLock, RwLock, RwLockReadGuard, RwLockWriteGuard,
-pub type DebugMutexGuard<'a, T> = MutexGuard<'a, T>;
+};
 
-/// Debug-only `Condvar`
+/// Dependency tracing versions of [`std::sync`].
-///
+pub mod tracing {
-/// Type alias that accepts the mutex guard emitted from [`DebugMutex`].
+    use std::fmt;
-#[cfg(debug_assertions)]
+    use std::ops::Deref;
-pub type DebugCondvar = TracingCondvar;
+    use std::ops::DerefMut;
-#[cfg(not(debug_assertions))]
+    use std::sync;
-pub type DebugCondvar = Condvar;
+    use std::sync::LockResult;
+    use std::sync::OnceState;
+    use std::sync::PoisonError;
+    use std::sync::TryLockError;
+    use std::sync::TryLockResult;
+    use std::sync::WaitTimeoutResult;
+    use std::time::Duration;
 
-/// Debug-only tracing `RwLock`.
+    use crate::BorrowedMutex;
-///
+    use crate::LazyMutexId;
-/// Type alias that resolves to [`TracingRwLock`] when debug assertions are enabled and to
-/// [`std::sync::RwLock`] when they're not. Use this if you want to have the benefits of cycle
-/// detection in development but do not want to pay the performance penalty in release.
-#[cfg(debug_assertions)]
-pub type DebugRwLock<T> = TracingRwLock<T>;
-#[cfg(not(debug_assertions))]
-pub type DebugRwLock<T> = RwLock<T>;
 
-/// Read guard for [`DebugRwLock`].
+    /// Wrapper for [`std::sync::Mutex`].
-#[cfg(debug_assertions)]
+    ///
-pub type DebugReadGuard<'a, T> = TracingReadGuard<'a, T>;
+    /// Refer to the [crate-level][`crate`] documentation for the differences between this struct and
-#[cfg(not(debug_assertions))]
+    /// the one it wraps.
-pub type DebugReadGuard<'a, T> = RwLockReadGuard<'a, T>;
+    #[derive(Debug, Default)]
+    pub struct Mutex<T> {
+        inner: sync::Mutex<T>,
+        id: LazyMutexId,
+    }
 
-/// Write guard for [`DebugRwLock`].
+    /// Wrapper for [`std::sync::MutexGuard`].
-#[cfg(debug_assertions)]
+    ///
-pub type DebugWriteGuard<'a, T> = TracingWriteGuard<'a, T>;
+    /// Refer to the [crate-level][`crate`] documentation for the differences between this struct and
-#[cfg(not(debug_assertions))]
+    /// the one it wraps.
-pub type DebugWriteGuard<'a, T> = RwLockWriteGuard<'a, T>;
+    #[derive(Debug)]
-
+    pub struct MutexGuard<'a, T> {
-/// Debug-only tracing `Once`.
+        inner: sync::MutexGuard<'a, T>,
-///
-/// Type alias that resolves to [`TracingOnce`] when debug assertions are enabled and to
-/// [`std::sync::Once`] when they're not. Use this if you want to have the benefits of cycle
-/// detection in development but do not want to pay the performance penalty in release.
-#[cfg(debug_assertions)]
-pub type DebugOnce = TracingOnce;
-#[cfg(not(debug_assertions))]
-pub type DebugOnce = Once;
-
-/// Wrapper for [`std::sync::Mutex`].
-///
-/// Refer to the [crate-level][`crate`] documentaiton for the differences between this struct and
-/// the one it wraps.
-#[derive(Debug, Default)]
-pub struct TracingMutex<T> {
-    inner: Mutex<T>,
-    id: MutexId,
-}
-
-/// Wrapper for [`std::sync::MutexGuard`].
-///
-/// Refer to the [crate-level][`crate`] documentaiton for the differences between this struct and
-/// the one it wraps.
-#[derive(Debug)]
-pub struct TracingMutexGuard<'a, T> {
-    inner: MutexGuard<'a, T>,
         _mutex: BorrowedMutex<'a>,
-}
+    }
 
-fn map_lockresult<T, I, F>(result: LockResult<I>, mapper: F) -> LockResult<T>
+    fn map_lockresult<T, I, F>(result: LockResult<I>, mapper: F) -> LockResult<T>
-where
+    where
         F: FnOnce(I) -> T,
-{
+    {
         match result {
             Ok(inner) => Ok(mapper(inner)),
             Err(poisoned) => Err(PoisonError::new(mapper(poisoned.into_inner()))),
         }
-}
+    }
 
-fn map_trylockresult<T, I, F>(result: TryLockResult<I>, mapper: F) -> TryLockResult<T>
+    fn map_trylockresult<T, I, F>(result: TryLockResult<I>, mapper: F) -> TryLockResult<T>
-where
+    where
         F: FnOnce(I) -> T,
-{
+    {
         match result {
             Ok(inner) => Ok(mapper(inner)),
             Err(TryLockError::WouldBlock) => Err(TryLockError::WouldBlock),
@@ -132,14 +88,14 @@ where
                 Err(PoisonError::new(mapper(poisoned.into_inner())).into())
             }
         }
-}
+    }
 
-impl<T> TracingMutex<T> {
+    impl<T> Mutex<T> {
         /// Create a new tracing mutex with the provided value.
-    pub fn new(t: T) -> Self {
+        pub const fn new(t: T) -> Self {
             Self {
-            inner: Mutex::new(t),
+                inner: sync::Mutex::new(t),
-            id: MutexId::new(),
+                id: LazyMutexId::new(),
             }
         }
 
@@ -150,11 +106,11 @@ impl<T> TracingMutex<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn lock(&self) -> LockResult<TracingMutexGuard<T>> {
+        pub fn lock(&self) -> LockResult<MutexGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.lock();
 
-        let mapper = |guard| TracingMutexGuard {
+            let mapper = |guard| MutexGuard {
                 _mutex: mutex,
                 inner: guard,
             };
@@ -169,11 +125,11 @@ impl<T> TracingMutex<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn try_lock(&self) -> TryLockResult<TracingMutexGuard<T>> {
+        pub fn try_lock(&self) -> TryLockResult<MutexGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.try_lock();
 
-        let mapper = |guard| TracingMutexGuard {
+            let mapper = |guard| MutexGuard {
                 _mutex: mutex,
                 inner: guard,
             };
@@ -197,137 +153,132 @@ impl<T> TracingMutex<T> {
         pub fn into_inner(self) -> LockResult<T> {
             self.inner.into_inner()
         }
-}
+    }
 
-impl<T> From<T> for TracingMutex<T> {
+    impl<T> From<T> for Mutex<T> {
         fn from(t: T) -> Self {
             Self::new(t)
         }
-}
+    }
 
-impl<'a, T> Deref for TracingMutexGuard<'a, T> {
+    impl<'a, T> Deref for MutexGuard<'a, T> {
         type Target = T;
 
         fn deref(&self) -> &Self::Target {
             &self.inner
         }
-}
+    }
 
-impl<'a, T> DerefMut for TracingMutexGuard<'a, T> {
+    impl<'a, T> DerefMut for MutexGuard<'a, T> {
         fn deref_mut(&mut self) -> &mut Self::Target {
             &mut self.inner
         }
-}
+    }
 
-impl<'a, T: fmt::Display> fmt::Display for TracingMutexGuard<'a, T> {
+    impl<'a, T: fmt::Display> fmt::Display for MutexGuard<'a, T> {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             self.inner.fmt(f)
         }
-}
+    }
 
-/// Wrapper around [`std::sync::Condvar`].
+    /// Wrapper around [`std::sync::Condvar`].
-///
+    ///
-/// Allows `TracingMutexGuard` to be used with a `Condvar`. Unlike other structs in this module,
+    /// Allows `TracingMutexGuard` to be used with a `Condvar`. Unlike other structs in this module,
-/// this wrapper does not add any additional dependency tracking or other overhead on top of the
+    /// this wrapper does not add any additional dependency tracking or other overhead on top of the
-/// primitive it wraps. All dependency tracking happens through the mutexes itself.
+    /// primitive it wraps. All dependency tracking happens through the mutexes itself.
-///
+    ///
-/// # Panics
+    /// # Panics
-///
+    ///
-/// This struct does not add any panics over the base implementation of `Condvar`, but panics due to
+    /// This struct does not add any panics over the base implementation of `Condvar`, but panics due to
-/// dependency tracking may poison associated mutexes.
+    /// dependency tracking may poison associated mutexes.
-///
+    ///
-/// # Examples
+    /// # Examples
-///
+    ///
-/// ```
+    /// ```
-/// use std::sync::Arc;
+    /// use std::sync::Arc;
-/// use std::thread;
+    /// use std::thread;
-///
+    ///
-/// use tracing_mutex::stdsync::{TracingCondvar, TracingMutex};
+    /// use tracing_mutex::stdsync::tracing::{Condvar, Mutex};
-///
+    ///
-/// let pair = Arc::new((TracingMutex::new(false), TracingCondvar::new()));
+    /// let pair = Arc::new((Mutex::new(false), Condvar::new()));
-/// let pair2 = Arc::clone(&pair);
+    /// let pair2 = Arc::clone(&pair);
-///
+    ///
-/// // Spawn a thread that will unlock the condvar
+    /// // Spawn a thread that will unlock the condvar
-/// thread::spawn(move || {
+    /// thread::spawn(move || {
-///     let (lock, condvar) = &*pair2;
+    ///     let (lock, condvar) = &*pair2;
-///     *lock.lock().unwrap() = true;
+    ///     *lock.lock().unwrap() = true;
-///     condvar.notify_one();
+    ///     condvar.notify_one();
-/// });
+    /// });
-///
+    ///
-/// // Wait until the thread unlocks the condvar
+    /// // Wait until the thread unlocks the condvar
-/// let (lock, condvar) = &*pair;
+    /// let (lock, condvar) = &*pair;
-/// let guard = lock.lock().unwrap();
+    /// let guard = lock.lock().unwrap();
-/// let guard = condvar.wait_while(guard, |started| !*started).unwrap();
+    /// let guard = condvar.wait_while(guard, |started| !*started).unwrap();
-///
+    ///
-/// // Guard should read true now
+    /// // Guard should read true now
-/// assert!(*guard);
+    /// assert!(*guard);
-/// ```
+    /// ```
-#[derive(Debug, Default)]
+    #[derive(Debug, Default)]
-pub struct TracingCondvar(Condvar);
+    pub struct Condvar(sync::Condvar);
 
-impl TracingCondvar {
+    impl Condvar {
         /// Creates a new condition variable which is ready to be waited on and notified.
-    pub fn new() -> Self {
+        pub const fn new() -> Self {
-        Default::default()
+            Self(sync::Condvar::new())
         }
 
         /// Wrapper for [`std::sync::Condvar::wait`].
-    pub fn wait<'a, T>(
+        pub fn wait<'a, T>(&self, guard: MutexGuard<'a, T>) -> LockResult<MutexGuard<'a, T>> {
-        &self,
+            let MutexGuard { _mutex, inner } = guard;
-        guard: TracingMutexGuard<'a, T>,
-    ) -> LockResult<TracingMutexGuard<'a, T>> {
-        let TracingMutexGuard { _mutex, inner } = guard;
 
-        map_lockresult(self.0.wait(inner), |inner| TracingMutexGuard {
+            map_lockresult(self.0.wait(inner), |inner| MutexGuard { _mutex, inner })
-            _mutex,
-            inner,
-        })
         }
 
         /// Wrapper for [`std::sync::Condvar::wait_while`].
         pub fn wait_while<'a, T, F>(
             &self,
-        guard: TracingMutexGuard<'a, T>,
+            guard: MutexGuard<'a, T>,
             condition: F,
-    ) -> LockResult<TracingMutexGuard<'a, T>>
+        ) -> LockResult<MutexGuard<'a, T>>
         where
             F: FnMut(&mut T) -> bool,
         {
-        let TracingMutexGuard { _mutex, inner } = guard;
+            let MutexGuard { _mutex, inner } = guard;
 
-        map_lockresult(self.0.wait_while(inner, condition), |inner| {
+            map_lockresult(self.0.wait_while(inner, condition), |inner| MutexGuard {
-            TracingMutexGuard { _mutex, inner }
+                _mutex,
+                inner,
             })
         }
 
         /// Wrapper for [`std::sync::Condvar::wait_timeout`].
         pub fn wait_timeout<'a, T>(
             &self,
-        guard: TracingMutexGuard<'a, T>,
+            guard: MutexGuard<'a, T>,
             dur: Duration,
-    ) -> LockResult<(TracingMutexGuard<'a, T>, WaitTimeoutResult)> {
+        ) -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)> {
-        let TracingMutexGuard { _mutex, inner } = guard;
+            let MutexGuard { _mutex, inner } = guard;
 
             map_lockresult(self.0.wait_timeout(inner, dur), |(inner, result)| {
-            (TracingMutexGuard { _mutex, inner }, result)
+                (MutexGuard { _mutex, inner }, result)
             })
         }
 
         /// Wrapper for [`std::sync::Condvar::wait_timeout_while`].
         pub fn wait_timeout_while<'a, T, F>(
             &self,
-        guard: TracingMutexGuard<'a, T>,
+            guard: MutexGuard<'a, T>,
             dur: Duration,
             condition: F,
-    ) -> LockResult<(TracingMutexGuard<'a, T>, WaitTimeoutResult)>
+        ) -> LockResult<(MutexGuard<'a, T>, WaitTimeoutResult)>
         where
             F: FnMut(&mut T) -> bool,
         {
-        let TracingMutexGuard { _mutex, inner } = guard;
+            let MutexGuard { _mutex, inner } = guard;
 
             map_lockresult(
                 self.0.wait_timeout_while(inner, dur, condition),
-            |(inner, result)| (TracingMutexGuard { _mutex, inner }, result),
+                |(inner, result)| (MutexGuard { _mutex, inner }, result),
             )
         }
 
@@ -340,34 +291,34 @@ impl TracingCondvar {
         pub fn notify_all(&self) {
             self.0.notify_all();
         }
-}
+    }
 
-/// Wrapper for [`std::sync::RwLock`].
+    /// Wrapper for [`std::sync::RwLock`].
-#[derive(Debug, Default)]
+    #[derive(Debug, Default)]
-pub struct TracingRwLock<T> {
+    pub struct RwLock<T> {
-    inner: RwLock<T>,
+        inner: sync::RwLock<T>,
-    id: MutexId,
+        id: LazyMutexId,
-}
+    }
 
-/// Hybrid wrapper for both [`std::sync::RwLockReadGuard`] and [`std::sync::RwLockWriteGuard`].
+    /// Hybrid wrapper for both [`std::sync::RwLockReadGuard`] and [`std::sync::RwLockWriteGuard`].
-///
+    ///
-/// Please refer to [`TracingReadGuard`] and [`TracingWriteGuard`] for usable types.
+    /// Please refer to [`RwLockReadGuard`] and [`RwLockWriteGuard`] for usable types.
-#[derive(Debug)]
+    #[derive(Debug)]
-pub struct TracingRwLockGuard<'a, L> {
+    pub struct TracingRwLockGuard<'a, L> {
         inner: L,
         _mutex: BorrowedMutex<'a>,
-}
+    }
 
-/// Wrapper around [`std::sync::RwLockReadGuard`].
+    /// Wrapper around [`std::sync::RwLockReadGuard`].
-pub type TracingReadGuard<'a, T> = TracingRwLockGuard<'a, RwLockReadGuard<'a, T>>;
+    pub type RwLockReadGuard<'a, T> = TracingRwLockGuard<'a, sync::RwLockReadGuard<'a, T>>;
-/// Wrapper around [`std::sync::RwLockWriteGuard`].
+    /// Wrapper around [`std::sync::RwLockWriteGuard`].
-pub type TracingWriteGuard<'a, T> = TracingRwLockGuard<'a, RwLockWriteGuard<'a, T>>;
+    pub type RwLockWriteGuard<'a, T> = TracingRwLockGuard<'a, sync::RwLockWriteGuard<'a, T>>;
 
-impl<T> TracingRwLock<T> {
+    impl<T> RwLock<T> {
-    pub fn new(t: T) -> Self {
+        pub const fn new(t: T) -> Self {
             Self {
-            inner: RwLock::new(t),
+                inner: sync::RwLock::new(t),
-            id: MutexId::new(),
+                id: LazyMutexId::new(),
             }
         }
 
@@ -378,7 +329,7 @@ impl<T> TracingRwLock<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn read(&self) -> LockResult<TracingReadGuard<T>> {
+        pub fn read(&self) -> LockResult<RwLockReadGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.read();
 
@@ -395,7 +346,7 @@ impl<T> TracingRwLock<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn write(&self) -> LockResult<TracingWriteGuard<T>> {
+        pub fn write(&self) -> LockResult<RwLockWriteGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.write();
 
@@ -412,7 +363,7 @@ impl<T> TracingRwLock<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn try_read(&self) -> TryLockResult<TracingReadGuard<T>> {
+        pub fn try_read(&self) -> TryLockResult<RwLockReadGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.try_read();
 
@@ -429,7 +380,7 @@ impl<T> TracingRwLock<T> {
         /// This method participates in lock dependency tracking. If acquiring this lock introduces a
         /// dependency cycle, this method will panic.
         #[track_caller]
-    pub fn try_write(&self) -> TryLockResult<TracingWriteGuard<T>> {
+        pub fn try_write(&self) -> TryLockResult<RwLockWriteGuard<T>> {
             let mutex = self.id.get_borrowed();
             let result = self.inner.try_write();
 
@@ -450,49 +401,49 @@ impl<T> TracingRwLock<T> {
         pub fn into_inner(self) -> LockResult<T> {
             self.inner.into_inner()
         }
-}
+    }
 
-impl<T> From<T> for TracingRwLock<T> {
+    impl<T> From<T> for RwLock<T> {
         fn from(t: T) -> Self {
             Self::new(t)
         }
-}
+    }
 
-impl<'a, L, T> Deref for TracingRwLockGuard<'a, L>
+    impl<'a, L, T> Deref for TracingRwLockGuard<'a, L>
-where
+    where
         L: Deref<Target = T>,
-{
+    {
         type Target = T;
 
         fn deref(&self) -> &Self::Target {
             self.inner.deref()
         }
-}
+    }
 
-impl<'a, T, L> DerefMut for TracingRwLockGuard<'a, L>
+    impl<'a, T, L> DerefMut for TracingRwLockGuard<'a, L>
-where
+    where
         L: Deref<Target = T> + DerefMut,
-{
+    {
         fn deref_mut(&mut self) -> &mut Self::Target {
             self.inner.deref_mut()
         }
-}
+    }
 
-/// Wrapper around [`std::sync::Once`].
+    /// Wrapper around [`std::sync::Once`].
-///
+    ///
-/// Refer to the [crate-level][`crate`] documentaiton for the differences between this struct and
+    /// Refer to the [crate-level][`crate`] documentaiton for the differences between this struct
-/// the one it wraps.
+    /// and the one it wraps.
-#[derive(Debug)]
+    #[derive(Debug)]
-pub struct TracingOnce {
+    pub struct Once {
-    inner: Once,
+        inner: sync::Once,
         mutex_id: LazyMutexId,
-}
+    }
 
-impl TracingOnce {
+    impl Once {
         /// Create a new `Once` value.
         pub const fn new() -> Self {
             Self {
-            inner: Once::new(),
+                inner: sync::Once::new(),
                 mutex_id: LazyMutexId::new(),
             }
         }
@@ -511,7 +462,7 @@ impl TracingOnce {
             self.inner.call_once(f);
         }
 
-    /// Performs the same operation as [`call_once`][TracingOnce::call_once] except it ignores
+        /// Performs the same operation as [`call_once`][Once::call_once] except it ignores
         /// poisoning.
         ///
         /// # Panics
@@ -530,10 +481,146 @@ impl TracingOnce {
         pub fn is_completed(&self) -> bool {
             self.inner.is_completed()
         }
-}
+    }
 
-#[cfg(test)]
+    /// Wrapper for [`std::sync::OnceLock`]
-mod tests {
+    ///
+    /// The exact locking behaviour of [`std::sync::OnceLock`] is currently undefined, but may
+    /// deadlock in the event of reentrant initialization attempts. This wrapper participates in
+    /// cycle detection as normal and will therefore panic in the event of reentrancy.
+    ///
+    /// Most of this primitive's methods do not involve locking and as such are simply passed
+    /// through to the inner implementation.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tracing_mutex::stdsync::tracing::OnceLock;
+    ///
+    /// static LOCK: OnceLock<i32> = OnceLock::new();
+    /// assert!(LOCK.get().is_none());
+    ///
+    /// std::thread::spawn(|| {
+    ///    let value: &i32 = LOCK.get_or_init(|| 42);
+    ///    assert_eq!(value, &42);
+    /// }).join().unwrap();
+    ///
+    /// let value: Option<&i32> = LOCK.get();
+    /// assert_eq!(value, Some(&42));
+    /// ```
+    #[derive(Debug)]
+    pub struct OnceLock<T> {
+        id: LazyMutexId,
+        inner: sync::OnceLock<T>,
+    }
+
+    // N.B. this impl inlines everything that directly calls the inner implementation as there
+    // should be 0 overhead to doing so.
+    impl<T> OnceLock<T> {
+        /// Creates a new empty cell
+        pub const fn new() -> Self {
+            Self {
+                id: LazyMutexId::new(),
+                inner: sync::OnceLock::new(),
+            }
+        }
+
+        /// Gets a reference to the underlying value.
+        ///
+        /// This method does not attempt to lock and therefore does not participate in cycle
+        /// detection.
+        #[inline]
+        pub fn get(&self) -> Option<&T> {
+            self.inner.get()
+        }
+
+        /// Gets a mutable reference to the underlying value.
+        ///
+        /// This method does not attempt to lock and therefore does not participate in cycle
+        /// detection.
+        #[inline]
+        pub fn get_mut(&mut self) -> Option<&mut T> {
+            self.inner.get_mut()
+        }
+
+        /// Sets the contents of this cell to the underlying value
+        ///
+        /// As this method may block until initialization is complete, it participates in cycle
+        /// detection.
+        pub fn set(&self, value: T) -> Result<(), T> {
+            let _guard = self.id.get_borrowed();
+
+            self.inner.set(value)
+        }
+
+        /// Gets the contents of the cell, initializing it with `f` if the cell was empty.
+        ///
+        /// This method participates in cycle detection. Reentrancy is considered a cycle.
+        pub fn get_or_init<F>(&self, f: F) -> &T
+        where
+            F: FnOnce() -> T,
+        {
+            let _guard = self.id.get_borrowed();
+            self.inner.get_or_init(f)
+        }
+
+        /// Takes the value out of this `OnceLock`, moving it back to an uninitialized state.
+        ///
+        /// This method does not attempt to lock and therefore does not participate in cycle
+        /// detection.
+        #[inline]
+        pub fn take(&mut self) -> Option<T> {
+            self.inner.take()
+        }
+
+        /// Consumes the `OnceLock`, returning the wrapped value. Returns None if the cell was
+        /// empty.
+        ///
+        /// This method does not attempt to lock and therefore does not participate in cycle
+        /// detection.
+        #[inline]
+        pub fn into_inner(mut self) -> Option<T> {
+            self.take()
+        }
+    }
+
+    impl<T> Default for OnceLock<T> {
+        #[inline]
+        fn default() -> Self {
+            Self::new()
+        }
+    }
+
+    impl<T: PartialEq> PartialEq for OnceLock<T> {
+        #[inline]
+        fn eq(&self, other: &Self) -> bool {
+            self.inner == other.inner
+        }
+    }
+
+    impl<T: Eq> Eq for OnceLock<T> {}
+
+    impl<T: Clone> Clone for OnceLock<T> {
+        fn clone(&self) -> Self {
+            Self {
+                id: LazyMutexId::new(),
+                inner: self.inner.clone(),
+            }
+        }
+    }
+
+    impl<T> From<T> for OnceLock<T> {
+        #[inline]
+        fn from(value: T) -> Self {
+            Self {
+                id: LazyMutexId::new(),
+                inner: sync::OnceLock::from(value),
+            }
+        }
+    }
+
+    #[cfg(test)]
+    mod tests {
         use std::sync::Arc;
         use std::thread;
 
@@ -541,7 +628,7 @@ mod tests {
 
         #[test]
         fn test_mutex_usage() {
-        let mutex = Arc::new(TracingMutex::new(0));
+            let mutex = Arc::new(Mutex::new(0));
 
             assert_eq!(*mutex.lock().unwrap(), 0);
             *mutex.lock().unwrap() = 1;
@@ -563,7 +650,7 @@ mod tests {
 
         #[test]
         fn test_rwlock_usage() {
-        let rwlock = Arc::new(TracingRwLock::new(0));
+            let rwlock = Arc::new(RwLock::new(0));
 
             assert_eq!(*rwlock.read().unwrap(), 0);
             assert_eq!(*rwlock.write().unwrap(), 0);
@@ -590,7 +677,7 @@ mod tests {
 
         #[test]
         fn test_once_usage() {
-        let once = Arc::new(TracingOnce::new());
+            let once = Arc::new(Once::new());
             let once_clone = once.clone();
 
             assert!(!once.is_completed());
@@ -611,8 +698,8 @@ mod tests {
         #[test]
         #[should_panic(expected = "Mutex order graph should not have cycles")]
         fn test_detect_cycle() {
-        let a = TracingMutex::new(());
+            let a = Mutex::new(());
-        let b = TracingMutex::new(());
+            let b = Mutex::new(());
 
             let hold_a = a.lock().unwrap();
             let _ = b.lock();
@@ -622,4 +709,5 @@ mod tests {
             let _hold_b = b.lock().unwrap();
             let _ = a.lock();
         }
+    }
 }