Newly availableHighly specialized. Only use it in low-level concurrency code where spinning is already a deliberate design choice.
Language core Newly available

Atomics.pause()

Atomics.pause() gives engines a hint during spin-wait loops. It can help tune busy-wait behavior in advanced shared-memory coordination code.

AtomicsConcurrencyPerformance

Overview

Atomics.pause() gives engines a hint during spin-wait loops. It can help tune busy-wait behavior in advanced shared-memory coordination code.

Browser support

Feature Desktop Mobile
Chrome
Edge
Firefox
Safari
Chrome Android
Safari iOS
javascript.builtins.Atomics.pause
133
133
137
18.4
133
18.4
1+Supported (version) Not supported ※Has note Sub-feature descriptions sourced from MDN Web Docs (CC BY-SA 2.5)

Syntax

JAVASCRIPT 
// Atomics.pause() example
// See MDN Web Docs for details

Live demo

Check Atomics.pause support

Detect whether Atomics.pause is available in the current runtime.

JavaScript
Output
Press the Run button

Call Atomics.pause safely

Invoke Atomics.pause only when the API exists.

JavaScript
Output
Press the Run button

Use a guarded spin helper

Build a tiny helper that prefers Atomics.pause during a retry loop.

JavaScript
Output
Press the Run button

Use cases

  • Spin-wait tuning

    Improve busy loops that coordinate threads over shared memory in latency-sensitive code.

  • Lock-free experiments

    Use it in carefully profiled concurrency primitives where tiny timing behavior matters.

Cautions

  • Most application code should not use spin waits at all; message passing and higher-level coordination are usually safer.
  • Performance hints need profiling because they are not guaranteed to help every workload.

Accessibility

  • This feature has no direct accessibility behavior, but poor concurrency decisions can still damage responsiveness.
  • Only low-level performance code with a measured need should reach for this API.

Related links

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