Class: MemoryMutex

Package: @litert/concurrentImport path: @litert/concurrentSource: packages/partials/concurrent/src/Classes/MemoryMutex.ts

A lightweight in-memory mutex. Multiple instances can share the same lock by calling share() — each shared instance gets a unique lock identifier and competes for access without accidentally releasing a lock held by another instance.

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Constructor

new MemoryMutex(opts?: IMemoryMutexOptions)

See IMemoryMutexOptions.

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Properties

Property	Type	Description
reentrant	boolean (readonly)	Whether the mutex allows the same instance to re-acquire an already held lock

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Methods

lock()

lock(): boolean

Attempts to acquire the lock.

• If the mutex is unlocked, acquires it and returns true.
• If the mutex is held by this same instance and reentrant is true, returns true.
• If the mutex is held by another instance (or by this instance when reentrant is false), returns false.

Returns: boolean — true if the lock was acquired.

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unlock()

unlock(): boolean

Releases the lock if it is held by this instance.

Returns: boolean — true if successfully released.

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isLocked()

isLocked(): boolean

Returns true if the mutex is currently locked by any instance.

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share()

share(): MemoryMutex

Returns a new MemoryMutex instance that shares the same underlying lock state. The new instance has its own unique lock identifier, so it can compete for the same lock without conflicting with the original.

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run(fn)

run<T extends IFunction>(fn: T): ReturnType<T>

Acquires the lock, calls fn, then releases the lock.

Throws: E_LOCK_FAILED if the lock cannot be acquired.

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wrap(fn)

wrap<T extends IFunction>(fn: T): T

Returns a wrapper function that acquires the lock before each call and releases it after.

Throws: E_LOCK_FAILED on each call if the lock cannot be acquired.

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Example

import { MemoryMutex } from '@litert/concurrent';

const mutex = new MemoryMutex();

if (mutex.lock()) {
    try {
        doExclusiveWork();
    } finally {
        mutex.unlock();
    }
} else {
    console.log('Could not acquire lock');
}

// Using run() for automatic lock management
mutex.run(() => {
    doExclusiveWork();
});

// Sharing the lock across two instances
const mutexA = new MemoryMutex();
const mutexB = mutexA.share();

mutexA.lock();     // true
mutexB.lock();     // false — same underlying lock, different ID
mutexA.unlock();
mutexB.lock();     // true now