wait #

Available since 2.19.1

Deprecated since 2.57.0

Mutex is deprecated since 2.57.0: use withLock instead. Both take the same Redis key, so a Mutex and a withLock call on the same resource exclude each other, and call sites can be migrated one at a time.

withLock has no wait counterpart: have every node run the initialization under withLock, and skip it when it finds the work already done.

wait(options?: { attemptDelay?: number, timeout?: number }): Promise<boolean>

Waits for the resource to be unlocked, without locking it.

Arguments	Type	Description
`options`	object	Optional mutex override options (see below). Without it, the mutex settings apply. Before 2.60.0, the object was required: `wait()` without argument threw a `TypeError`

options #

The options object is used to override some mutex properties for this function. The following properties can be provided:

Option	Type	Description
`attemptDelay`	number	(default: `this.attemptDelay`) Delay in milliseconds between two checks of the resource
`timeout`	number	(default: `this.timeout`) Wait timeout, in milliseconds. If set to 0, the resource is checked once. If set to -1, the mutex waits for the resource to be free indefinitely

Returns #

Returns a promise, resolving to true if the resource was unlocked before the timeout, and false otherwise.

Usage #

Initializing a shared resource once, while the other nodes wait for it to be ready:

import { Mutex } from 'kuzzle';

async function initSharedStuff () {
  const mutex = new Mutex('initSharedStuff', { timeout: 0 });

  if (await mutex.lock()) {
    try {
      // Initialize shared stuff
    }
    finally {
      await mutex.unlock();
    }
  }
  else {
    // Wait for shared stuff to be initialized
    await mutex.wait({ timeout: -1 });
  }
}