Interface: DistributedSemaphore

Control access to shared resources with a semaphore.

Max count limits number of concurrent accesses allowed.

Example

Safely using a semaphore by always releasing

// Ensure you import LockPowers
import { LockPowers } from "@andi/powers";

// acquire one of the 5 leases to my-shared-lock
const semaphore = await LockPowers.createSemaphore("my-shared-lock", 5);
try {
    // may throw `LockAcquireTimeoutError`. To avoid errors, can also use `.tryAcquire()`
    await semaphore.acquire();
    // critical code with at most 5 concurrent processes
} finally {
    await semaphore.release();
}

Extends

DistributedMutex

Accessors

identifier

Get Signature

get identifier(): string;

Internal

identifier helpful for debugging

Returns

string

Inherited from

DistributedMutex.identifier

isAcquired

Get Signature

get isAcquired(): boolean;

Returns

boolean

Inherited from

DistributedMutex.isAcquired

key

Get Signature

get key(): string;

Returns

string

Inherited from

DistributedMutex.key

limit

Get Signature

get limit(): number;

Returns

number

Methods

acquire()

acquire(): Promise<void>;

Attempt to acquire lock.

Returns

Promise<void>

Throws

LockAcquireTimeoutError if lock is not acquired within the configured lockTimeout

Inherited from

DistributedMutex.acquire

release()

release(): Promise<void>;

Release lock.

Returns

Promise<void>

Inherited from

DistributedMutex.release

tryAcquire()

tryAcquire(): Promise<boolean>;

Method to acquire lock. Will not throw an error if acquireTimeout occurs.

Returns

Promise<boolean>

Inherited from

DistributedMutex.tryAcquire