Locker v2

[corhere]

Breaking changes:

• The minimum Go version is go1.19
• Locker has been replaced with the generic MutexMap[T]
• The result parameter to (*MutexMap[T]).Unlock() has been dropped. Instead the application will crash with the same fatal run-time error as calling (sync.Mutex).Unlock() on an unlocked mutex.
• ErrNoSuchLock has been removed.
• New() has been removed. The zero value is valid.

Modernize the codebase by taking advantage of Go 1.18 generics and Go 1.19 atomics. Add an RWMutexMap for read-write locks. Add sync.Locker interface adapters for MutexMap and RWMutexMap.

[Copilot]

Pull Request Overview

This PR modernizes the locking API by removing legacy functions and error returns while leveraging Go 1.19 atomics and introducing an RWLocker with associated sync.Locker adapters. Key changes include removal of New() and ErrNoSuchLock, updating tests to use zero values, and refactoring the unlock functions for both Locker and RWLocker for consistency with standard library panic behavior.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
rwlocker_test.go	Tests for RWLocker functionality and concurrency management.
rwlocker.go	Implementation of RWLocker with atomic waiters and lock deletion logic.
locker_test.go	Tests updated to use zero value Locker instead of New().
locker.go	Refactored Locker implementation; removed error return from Unlock.
go.mod	Updates module name to v2 and bumps Go version to 1.19

[Copilot]

Pull Request Overview

This PR releases Locker v2 by removing legacy APIs (including New() and ErrNoSuchLock) and modernizing the code to use Go 1.19 atomics, while adding an RWLocker for read–write locks and sync.Locker adapters.

• Removed the old Locker implementation and its associated error and constructor functions.
• Introduced RWMutexMap and updated MutexMap to use atomic counters and a zero–value valid pattern.
• Updated go.mod and CI workflow to require Go 1.19 and use the latest GitHub Actions.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
rwmutexmap_test.go	Added tests for the new RWMutexMap locking behavior.
rwmutexmap.go	Implements the RWMutexMap using atomics with helper functions for locking/unlock.
mutexmap_test.go	Updated tests for MutexMap (removal of New() and atomic counter checks).
mutexmap.go	Implements MutexMap using atomics and sync.Pool for lock counter management.
locker.go	Removed legacy Locker code as part of breaking changes.
go.mod	Updated module path and Go version to 1.19.
.github/workflows/test.yml	Updated workflow settings to use new checkout and Go setup actions.

[corhere]

My RWMutex implementation is bugged. I'll submit it in a separate PR.