google/leveldb

Make background thread stoppable

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#863 opened on Dec 18, 2020

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enhancementhelp wanted

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Description

Hi,

Current version of LevelDB has detached background thread that can't be stopped and each environment calls std::abort() in destructor. This behavior prevents using of LevelDB in plugin dlls that can be started and stopped when main application still runs.

I think it is better to allow background thread to finish tasks in queue and then exit, when environment is being destroyed. That will make database loadable and unloadable.

Contributor guide

Research direction
Examine the background thread implementation in LevelDB, specifically how the thread is created and detached, and how the environment destructor calls abort. Understand the task queue and propose a mechanism to join or stop the thread gracefully on destruction.
Tech stack
cpp
Domain
backenddatabase
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.
1-2 days
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
C++ThreadingLevelDB internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35