# Non-Atomic Counter Increment Race Condition

> Detects concurrent counter increments and decrements without atomic operations or mutex protection.

- Skill: `zakirkun/non-atomic-counter-increment-race-condition` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add zakirkun/non-atomic-counter-increment-race-condition`
- Raw SKILL.md: https://api.skillmd.com/api/skills/zakirkun/non-atomic-counter-increment-race-condition/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: zakirkun (https://skillmd.com/u/zakirkun)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/zakirkun/non-atomic-counter-increment-race-condition

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# Non-Atomic Counter Race Condition

## Overview
Incrementing/decrementing shared counters (`count++`, `balance += amount`) without atomic operations creates race conditions where concurrent updates lose some increments, leading to incorrect values. This affects rate limiters, inventory counters, and financial balances.

## Remediation
- Go: Use `sync/atomic` package (`atomic.AddInt64()`)
- Java: Use `AtomicInteger`/`AtomicLong`
- JavaScript: Use a single event loop (Node.js) or worker locks
- C/C++: Use `std::atomic<int>` or `_Atomic int`