effect-io-ai

Package: effect
Module: TxSemaphore

TxSemaphore.acquireN

Acquires the specified number of permits from the semaphore.

When to use

Use to manually acquire multiple permits transactionally, waiting until all requested permits are available.

Details

If fewer than n permits are available, the transaction retries until enough permits are released.

Gotchas

Passing a non-positive n dies with a defect. Passing a value greater than the semaphore capacity can wait forever because the capacity is fixed.

Example (Acquiring multiple permits)

import { Console, Effect, TxSemaphore } from "effect"

const program = Effect.gen(function*() {
  const semaphore = yield* TxSemaphore.make(5)

  yield* Console.log("Acquiring 3 permits...")
  yield* TxSemaphore.acquireN(semaphore, 3)
  yield* Console.log("3 permits acquired")

  const available = yield* TxSemaphore.available(semaphore)
  yield* Console.log(`Available permits: ${available}`) // 2
})

See

• tryAcquireN for a non-blocking multi-permit attempt
• releaseN for returning multiple permits
• withPermits for automatic acquire and release around an effect

Signature

declare const acquireN: (self: TxSemaphore, n: number) => Effect.Effect<void>

Source

Since v2.0.0