Add `Lock` to std

Description

abstract class Lock[F[_]] {
  def shared: Resource[F, Unit]
  def exclusive: Resource[F, Unit]
}

Contributor guide

Tech stack

scala

Domain

backend

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-3 hours

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

active

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

cats effectResourceScala concurrency

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

45

Research direction

Review the referenced PR discussion (#3480) for context on the design. The implementation would involve creating a new abstract class Lock[F[ ]] with shared and exclusive methods returning Resource[F, Unit]. Consider existing concurrency primitives in cats effect for guidance. Ensure proper handling of cancellation and resource safety.