Barrier

Kind: Class

Source: packages/core/helpers/barrier.ts

Part of: Core

A simple barrier to synchronize flow of multiple async operations.

Barrier synchronizes multiple asynchronous operations at a shared checkpoint. Call signal() when an operation reaches the barrier, and use wait() to pause until the required signals have been received; signalAndWait() performs both steps atomically for participating operations.

Methods

Diagram

mermaid
graph LR
  A[Async operation A] -->|signal / signalAndWait| B[Barrier]
  C[Async operation B] -->|signal / signalAndWait| B
  D[Async operation C] -->|signal / signalAndWait| B
  B -->|all participants signaled| E[Release waiting operations]

Usage

ts
import { Barrier } from '@your-package/core/helpers/barrier';

const barrier = new Barrier(2);

async function worker(name: string) {
  console.log(`${name} reached the checkpoint`);

  await barrier.signalAndWait();

  console.log(`${name} continues after the checkpoint`);
}

await Promise.all([
  worker('worker-a'),
  worker('worker-b'),
]);

AI Coding Instructions

• Create a Barrier with the number of async participants expected to reach the synchronization point.
• Prefer signalAndWait() when a participant should both register its arrival and wait for all other participants.
• Use signal() only for operations that should notify the barrier without blocking themselves.
• Ensure every expected participant signals the barrier; otherwise, calls to wait() can remain pending indefinitely.
• Use barriers for deterministic coordination between concurrent tasks, not as a replacement for error handling or cancellation logic.