How can the Singleton Pattern be implemented to be thread-safe in JavaScript?
let instance = null;
class ThreadSafeSingleton {
constructor() {
if (instance) {
return instance;
}
this.initialize();
instance = this;
Object.freeze(instance);
}
static getInstance() {
if (!instance) {
instance = new ThreadSafeSingleton();
}
return instance;
}
initialize() {
// Initialize singleton state
}
}
Since JavaScript runs in a single thread (except for Web Workers which have their own separate contexts), traditional thread-safety concerns don't apply to Singleton implementations. The JavaScript event loop and its non-blocking nature handle concurrent operations differently than multi-threaded environments. However, using Object.freeze() can prevent modifications to the singleton instance, adding an extra layer of immutability.