sota-async-concurrencylisted

State-of-the-art rules for writing and auditing asynchronous and concurrent code across runtimes (Python asyncio, JS/Node, Go, Rust, JVM). Use when building anything with async/await, threads, processes, event loops, task groups, channels, or queues — and when auditing existing code for race conditions, deadlocks, leaked tasks, blocked event loops, missing cancellation, or backpressure failures. Not for latency/throughput profiling and optimization — use sota-performance. Trigger keywords: async, await, concurrency, parallelism, threads, race condition, deadlock, event loop, channels, queues, semaphore, mutex, cancellation, timeout, backpressure, task group, goroutine, tokio, asyncio.
martinholovsky/SOTA-skills · ★ 8 · AI & Automation · score 75

Install: claude install-skill martinholovsky/SOTA-skills

# SOTA Async & Concurrency ## Purpose Concurrency bugs are the most expensive class of defect: they pass tests, ship, and then corrupt data or hang production under load. This skill encodes the 2026 state of the art for concurrent design and the bug catalog auditors need to spot defects **by reading code**, without reproducing them. Concepts are cross-language; per-runtime notes are inlined where semantics genuinely differ (GIL, goroutine scheduling, tokio executors, Node's single loop). Two operating modes. Pick one explicitly before starting. ## BUILD mode When writing new concurrent code: 1. **Classify the workload first.** I/O-bound → async/event loop. CPU-bound → threads (if runtime has real parallelism) or processes. Mixed → async front-end + bounded worker pool. Read `rules/01` before choosing. 2. **Structured concurrency is the default.** Every task lives inside a scope (TaskGroup / nursery / errgroup / JoinSet) that joins or cancels it. Spawning a task with no owner is a design smell requiring written justification. 3. **Bound everything.** Every queue, channel, connection pool, in-flight request set, and spawn loop gets an explicit capacity. Unbounded = OOM with a delay timer. 4. **Every await gets a timeout policy** — a number, or a documented reason why it inherits one from an enclosing scope. 5. **Cancellation is a feature you build, not an exception you ignore.** Propagate context/AbortSignal/CancelledError; clean up in finally b