Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

Added

Changed

Fixed

[0.9.8] - 2023-04-03

Fixed

• Unsoundness in Once::try_call_once caused by an Err(_) result

[0.9.7] - 2023-03-27

Fixed

• Relaxed accidentally restricted Send/Sync bounds for Mutex guards

[0.9.6] - 2023-03-13

Fixed

• Relaxed accidentally restricted Send/Sync bounds for RwLock guards

[0.9.5] - 2023-02-07

Added

• FairMutex, a new mutex implementation that reduces writer starvation.
• A MSRV policy: Rust 1.38 is currently required

Changed

• The crate's CI now has full MIRI integration, further improving the confidence you can have in the implementation.

Fixed

• Ensured that the crate's abstractions comply with stacked borrows rules.
• Unsoundness in the RwLock that could be triggered via a reader overflow
• Relaxed various Send/Sync bound requirements to make the crate more flexible

[0.9.4] - 2022-07-14

Fixed

• Fixed unsoundness in RwLock on reader overflow
• Relaxed Send/Sync bounds for SpinMutex and TicketMutex (doesn't affect Mutex itself)

[0.9.3] - 2022-04-17

Added

• Implemented Default for Once
• Once::try_call_once

Fixed

• Fixed bug that caused Once::call_once to incorrectly fail

[0.9.2] - 2021-07-09

Changed

• Improved Once performance by reducing the memory footprint of internal state to one byte

Fixed

• Improved performance of Once by relaxing ordering guarantees and removing redundant checks

[0.9.1] - 2021-06-21

Added

• Default type parameter on Once for better ergonomics

[0.9.0] - 2021-03-18

Changed

• Placed all major API features behind feature flags

Fixed

• A compilation bug with the lock_api feature

[0.8.0] - 2021-03-15

Added

• Once::get_unchecked
• RelaxStrategy trait with type parameter on all locks to support switching between relax strategies

Changed

• lock_api1 feature is now named lock_api

[0.7.1] - 2021-01-12

Fixed

• Prevented Once leaking the inner value upon drop

[0.7.0] - 2020-10-18

Added

• Once::initialized
• Once::get_mut
• Once::try_into_inner
• Once::poll
• RwLock, Mutex and Once now implement From<T>
• Lazy type for lazy initialization
• TicketMutex, an alternative mutex implementation
• std feature flag to enable thread yielding instead of spinning
• Mutex::is_locked/SpinMutex::is_locked/TicketMutex::is_locked
• Barrier

Changed

• Once::wait now spins even if initialization has not yet started
• Guard::leak is now an associated function instead of a method
• Improved the performance of SpinMutex by relaxing unnecessarily conservative ordering requirements

[0.6.0] - 2020-10-08

Added

• More dynamic Send/Sync bounds for lock guards
• lock_api compatibility
• Guard::leak methods
• RwLock::reader_count and RwLock::writer_count
• Display implementation for guard types

Changed

• Made Debug impls of lock guards just show the inner type like std