effect-concurrency-fibers

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

```ts

const results = yield* Effect.all(tasks, { concurrency: 10 })

```

```ts

const processed = yield* Effect.forEach(items, processItem, { concurrency: 5 })

```

```ts

const fiber = yield* Effect.fork(work)

const value = yield* Fiber.join(fiber)

yield* Fiber.interrupt(fiber)

```

```ts

const fastest = yield* Effect.race(slow, fast)

const withTimeout = yield* Effect.timeout(operation, "5 seconds")

```

• 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

• 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

• Errors & Retries: backoff + jitter for transient failures
• Streams & Pipelines: concurrent map over streams
• EffectPatterns inspiration: https://github.com/PaulJPhilp/EffectPatterns

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

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