AgentSkillsCN

effect-concurrency-fibers

并发与Effect.all、forEach并发、Fiber生命周期、竞争和超时。用于安全地并行化任务。

SKILL.md
--- frontmatter
name: effect-concurrency-fibers
description: Concurrency with Effect.all, forEach concurrency, Fiber lifecycle, race and timeouts. Use for parallelizing tasks safely.
allowed-tools: Read, Grep, Glob, Edit, Write, mcp__effect-docs__effect_docs_search

Concurrency & Fibers

When to use

  • •Parallelizing independent work safely with limits
  • •Coordinating background tasks and lifecycle
  • •Racing operations for latency control

Parallel Patterns

ts
const results = yield* Effect.all(tasks, { concurrency: 10 })
ts
const processed = yield* Effect.forEach(items, processItem, { concurrency: 5 })

Fiber Lifecycle

ts
const fiber = yield* Effect.fork(work)
const value = yield* Fiber.join(fiber)
yield* Fiber.interrupt(fiber)

Racing / Timeouts

ts
const fastest = yield* Effect.race(slow, fast)
const withTimeout = yield* Effect.timeout(operation, "5 seconds")

Guidance

  • •Limit concurrency to protect resources
  • •Use fork for background loops; always manage interruption
  • •Prefer Effect.all for independent operations
  • •Use Effect.forEach with concurrency for pools
  • •Combine with retries and timeouts for resilient parallelism

Pitfalls

  • •Unbounded concurrency can exhaust CPU/IO or hit rate limits
  • •Always interrupt background fibers on shutdown
  • •Don’t block inside fibers; keep work asynchronous/effectful

Cross-links

Local Source Reference

CRITICAL: Search local Effect source before implementing

The full Effect source code is available at docs/effect-source/. Always search the actual implementation before writing Effect code.

Key Source Files

  • •Effect: docs/effect-source/effect/src/Effect.ts
  • •Fiber: docs/effect-source/effect/src/Fiber.ts
  • •Duration: docs/effect-source/effect/src/Duration.ts

Example Searches

bash
# Find Effect.all and concurrency patterns
grep -F "Effect.all" docs/effect-source/effect/src/Effect.ts

# Find forEach with concurrency
grep -rF "forEach" docs/effect-source/effect/src/ | grep -F "concurrency"

# Study Fiber lifecycle operations
grep -F "export" docs/effect-source/effect/src/Fiber.ts | grep -E "fork|join|interrupt"

# Find race and timeout implementations
grep -F "race" docs/effect-source/effect/src/Effect.ts
grep -F "timeout" docs/effect-source/effect/src/Effect.ts

Workflow

  1. •Identify the concurrency API you need (e.g., Effect.all, fork)
  2. •Search docs/effect-source/effect/src/Effect.ts for the implementation
  3. •Study the types and concurrency options
  4. •Look at test files for usage examples
  5. •Write your code based on real implementations

Real source code > documentation > assumptions

References