effect-io-ai

Package: effect
Module: TxSemaphore

TxSemaphore.withPermit

Executes an effect with a single permit from the semaphore. The permit is automatically acquired before execution and released afterwards, even if the effect fails or is interrupted.

When to use

Use to run an effect while automatically acquiring and releasing one transactional permit.

Details

The permit acquisition and release operations use atomic semantics to ensure proper resource management with Effect’s scoped operations.

Example (Running an effect with a permit)

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

const program = Effect.gen(function*() {
  const semaphore = yield* TxSemaphore.make(2)

  // Execute database operation with automatic permit management
  const result = yield* TxSemaphore.withPermit(
    semaphore,
    Effect.gen(function*() {
      yield* Console.log("Permit acquired, accessing database...")
      yield* Effect.sleep("100 millis") // Simulate database work
      yield* Console.log("Database operation complete")
      return "query result"
    })
  )

  yield* Console.log(`Result: ${result}`)
  // Permit is automatically released here
})

See

• withPermits for automatically acquiring and releasing multiple permits
• withPermitScoped for acquiring one permit for the current scope
• acquire for manual single-permit acquisition

Signature

declare const withPermit: { (self: TxSemaphore): <A, E, R>(effect: Effect.Effect<A, E, R>) => Effect.Effect<A, E, R>; <A, E, R>(self: TxSemaphore, effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, R>; }

Source

Since v2.0.0