JavaScript · Senior · Question 56 of 75

What must a page do to use `SharedArrayBuffer`?

✓Correct answer: Be cross-origin isolated by sending COOP same-origin and COEP require-corp (or credentialless) headers
2Request a permission from the user
3Nothing; it is always available

Explanation

After Spectre, shared memory and high-resolution timers were restricted. Isolation can break third-party embeds that don't send CORP/CORS headers.

Further reading

MDN: SharedArrayBuffer ↗

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