Merge #31

31: Update CI dependencies r=bertptrs a=bertptrs

actions-rs uses deprecated features, move to dtolney for the toolchain and just use regular run commands for everything else

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

.github/workflows/ci.yml

@@ -2,48 +2,50 @@ on:
   push:
     branches:
       - master
+      - staging
+      - trying
   pull_request:
 
 name: Continuous integration
 
 jobs:
-  ci:
+  tests:
     name: Rust project
     runs-on: ubuntu-latest
     strategy:
       matrix:
         rust:
+          - "1.70" # minimum stable rust version
           - stable
           - beta
           - nightly
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@v1
         with:
-          profile: minimal
           toolchain: ${{ matrix.rust }}
-          override: true
           components: rustfmt, clippy
 
-      - uses: actions-rs/cargo@v1
+      - run: cargo build --all-features --all-targets
-        with:
+      - run: cargo test --all-features
-          command: build
+      - run: cargo fmt --all -- --check
-          # --all-targets ensures that we also build the benchmarks and tests already.
+      - run: cargo clippy --all-features --all-targets -- -D warnings
-          args: --all-features --all-targets
 
-      - uses: actions-rs/cargo@v1
+  docs:
-        with:
+    name: Documentation build
-          command: test
+    runs-on: ubuntu-latest
-          args: --all-features
 
-      - uses: actions-rs/cargo@v1
+    steps:
-        with:
+      - uses: actions/checkout@v3
-          command: fmt
-          args: --all -- --check
 
-      - uses: actions-rs/cargo@v1
+      - uses: dtolnay/rust-toolchain@v1
         with:
-          command: clippy
+          toolchain: nightly
-          args: --all-features --all-targets -- -D warnings
+
+      - name: Build documentation
+        env:
+          # Build the docs like docs.rs builds it
+          RUSTDOCFLAGS: --cfg docsrs
+        run: cargo doc --all-features

CHANGELOG.md

@@ -6,7 +6,35 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
-## [0.2.0]
+### 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
+
+- Build [docs.rs] documentation with all features enabled for completeness.
+- Add support for `std::sync::Condvar`
+
+### Fixed
+
+- The `parkinglot` module is now correctly enabled by the `parkinglot` feature rather than the
+  `lockapi` feature.
+
+## [0.2.0] - 2022-05-07
 
 ### Added
 - Generic support for wrapping mutexes that implement the traits provided by the
@@ -55,11 +83,13 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 Initial release.
 
-[Unreleased]: https://github.com/bertptrs/tracing-mutex/compare/v0.2.0...HEAD
+[Unreleased]: https://github.com/bertptrs/tracing-mutex/compare/v0.2.1...HEAD
+[0.2.1]: https://github.com/bertptrs/tracing-mutex/compare/v0.2.0...v0.2.1
 [0.2.0]: https://github.com/bertptrs/tracing-mutex/compare/v0.1.2...v0.2.0
 [0.1.2]: https://github.com/bertptrs/tracing-mutex/compare/v0.1.1...v0.1.2
 [0.1.1]: https://github.com/bertptrs/tracing-mutex/compare/v0.1.0...v0.1.1
 [0.1.0]: https://github.com/bertptrs/tracing-mutex/releases/tag/v0.1.0
 
+[docs.rs]: https://docs.rs/tracing-mutex/latest/tracing_mutex/
 [lock_api]: https://docs.rs/lock_api/
 [parking_lot]: https://docs.rs/parking_lot/

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tracing-mutex"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["Bert Peters <bert@bertptrs.nl>"]
 edition = "2021"
 license = "MIT OR Apache-2.0"
@@ -10,14 +10,20 @@ 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
+all-features = true
+# Set custom cfg so we can enable docs.rs magic
+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"
+criterion = "0.5"
 rand = "0.8"
 
 [[bench]]

LICENSE-APACHE

@@ -186,7 +186,7 @@ APPENDIX: How to apply the Apache License to your work.
    same "printed page" as the copyright notice for easier
    identification within third-party archives.
 
-Copyright [yyyy] [name of copyright owner]
+Copyright 2022 Bert Peters
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

LICENSE-MIT

@@ -1,4 +1,4 @@
-Copyright © 2021 Bert Peters
+Copyright © 2022 Bert Peters
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
 associated documentation files (the “Software”), to deal in the Software without restriction,

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
 
@@ -34,7 +36,7 @@ Add this dependency to your `Cargo.lock` file like any other:
 
 ```toml
 [dependencies]
-tracing-mutex = "0.1"
+tracing-mutex = "0.2"
 ```
 
 Then use the locks provided by this library instead of the ones you would use otherwise.
@@ -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);
 ```
@@ -59,12 +61,26 @@ 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
+- Optional opt-out for release mode code
+- Support for primitives from:
+  - `std::sync`
+  - `parking_lot`
+  - Any library that implements the `lock_api` traits
+
 ## Future improvements
 
 - Improve performance in lock tracing
 - Optional logging to make debugging easier
 - Better and configurable error handling when detecting cyclic dependencies
-- Support for other locking libraries, such as `parking_lot`
+- Support for other locking libraries
+- Support for async locking libraries
+- Support for `Send` mutex guards
 
 **Note:** `parking_lot` has already began work on its own deadlock detection mechanism, which works
 in a different way. Both can be complimentary.

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

@@ -0,0 +1,6 @@
+status = [
+    'Rust project (1.70)',
+    'Rust project (stable)',
+    'Rust project (beta)',
+    'Documentation build',
+]

src/lib.rs

@@ -41,44 +41,41 @@
 //!
 //! 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;
 #[cfg(feature = "parkinglot")]
+#[cfg_attr(docsrs, doc(cfg(feature = "parkinglot")))]
 pub use parking_lot;
 
 use crate::graph::DiGraph;
 
 mod graph;
 #[cfg(feature = "lockapi")]
+#[cfg_attr(docsrs, doc(cfg(feature = "lockapi")))]
 pub mod lockapi;
-#[cfg(feature = "lockapi")]
+#[cfg(feature = "parkinglot")]
+#[cfg_attr(docsrs, doc(cfg(feature = "parkinglot")))]
 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
     ///
@@ -87,10 +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
@@ -109,6 +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)
@@ -129,7 +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.
@@ -199,17 +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,
         }
     }
 }
@@ -226,51 +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.
 ///
@@ -281,13 +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);
@@ -37,191 +38,130 @@
 //! 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,
+        id: LazyMutexId,
-}
+    }
 
-impl TracingOnce {
+    impl Once {
-    /// Create a new `TracingOnce` value.
+        /// Create a new `Once` value.
-    pub const fn new() -> Self {
+        pub const fn new() -> Self {
-        Self {
+            Self {
-            inner: Once::new(),
+                inner: parking_lot::Once::new(),
-            id: LazyMutexId::new(),
+                id: LazyMutexId::new(),
+            }
+        }
+
+        /// Returns the current state of this `Once`.
+        pub fn state(&self) -> OnceState {
+            self.inner.state()
+        }
+
+        /// This call is considered as "locking this `Once`" and it participates in dependency
+        /// tracking as such.
+        ///
+        /// # Panics
+        ///
+        /// This method will panic if `f` panics, poisoning this `Once`. In addition, this function
+        /// panics when the lock acquisition order is determined to be inconsistent.
+        pub fn call_once(&self, f: impl FnOnce()) {
+            let _borrow = self.id.get_borrowed();
+            self.inner.call_once(f);
+        }
+
+        /// Performs the given initialization routine once and only once.
+        ///
+        /// 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);
         }
     }
-
-    /// Returns the current state of this `Once`.
-    pub fn state(&self) -> OnceState {
-        self.inner.state()
-    }
-
-    ///
-    /// This call is considered as "locking this `TracingOnce`" and it participates in dependency
-    /// tracking as such.
-    ///
-    /// # Panics
-    ///
-    /// This method will panic if `f` panics, poisoning this `Once`. In addition, this function
-    /// panics when the lock acquisition order is determined to be inconsistent.
-    pub fn call_once(&self, f: impl FnOnce()) {
-        let _borrow = self.id.get_borrowed();
-        self.inner.call_once(f);
-    }
-
-    /// Performs the given initialization routeine once and only once.
-    ///
-    /// This method is identical to [`TracingOnce::call_once`] except it ignores poisining.
-    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());