Class Semaphore

A semaphore that limits the number of concurrent operations. Used to prevent connection pool exhaustion by limiting concurrent database operations to the pool size.

Constructors

constructor

Methods

acquire dispose getAvailablePermits getMaxPermits getMetrics getWaitingCount isDisposed on once release withPermit

Constructors

constructor

Methods

acquire

  • acquire(options?): Promise<void>

  • Acquire a permit. If no permits are available, waits until one becomes available.

    Parameters

    • Optionaloptions: {
          signal?: AbortSignal;
          timeout?: number;
      }
      • Optionalsignal?: AbortSignal
      • Optionaltimeout?: number

    Returns Promise<void>

dispose

  • dispose(): void

  • Dispose the semaphore, rejecting all waiting operations and preventing new ones.

    Returns void

getAvailablePermits

  • getAvailablePermits(): number

  • Get current number of available permits (for debugging)

    Returns number

getMaxPermits

getMetrics

  • getMetrics(): {
        availablePermits: number;
        disposed: boolean;
        maxPermits: number;
        utilization: number;
        waitingCount: number;
    }

  • Get metrics about the current state of the semaphore

    Returns {
        availablePermits: number;
        disposed: boolean;
        maxPermits: number;
        utilization: number;
        waitingCount: number;
    }

    • availablePermits: number
    • disposed: boolean
    • maxPermits: number
    • utilization: number
    • waitingCount: number

getWaitingCount

isDisposed

on

  • on(type, handler): (() => void)

  • Parameters

    • type:
          | "queued"
          | "acquired"
          | "released"
          | "timeout"
          | "aborted"
          | "disposed"
    • handler: ((event: SemaphoreEvent) => any)
        • (event): any

        • Parameters

          • event: SemaphoreEvent

          Returns any

    Returns (() => void)

      • (): void

      • Returns void

once

  • once(type, handler): (() => void)

  • Parameters

    • type:
          | "queued"
          | "acquired"
          | "released"
          | "timeout"
          | "aborted"
          | "disposed"
    • handler: ((event: SemaphoreEvent) => any)
        • (event): any

        • Parameters

          • event: SemaphoreEvent

          Returns any

    Returns (() => void)

      • (): void

      • Returns void

release

withPermit

  • withPermit<T>(fn, options?): Promise<T>

  • Execute a function with a permit, automatically releasing it afterwards.

    Type Parameters

    • T

    Parameters

    • fn: (() => Promise<T>)
        • (): Promise<T>

        • Returns Promise<T>

    • Optionaloptions: {
          signal?: AbortSignal;
          timeout?: number;
      }
      • Optionalsignal?: AbortSignal
      • Optionaltimeout?: number

    Returns Promise<T>

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