WPT details: https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/web_tests/external/wpt/html/infrastructure/safe-passing-of-structured-data/shared-array-buffers/no-coop-coep.https.any.js https://github.com/tc39/test262/tree/master/test/built-ins/SharedArrayBuffer https://github.com/tc39/test262/tree/master/test/built-ins/Atomics
Adds the JavaScript type SharedArrayBuffer gated behind COOP/COEP. The concept of a SharedArrayBuffer is that a message to a worker, is posted but instead of copying the content of the array just a reference to it is shared. The Atomic API provides atomic loads and stores and Read/Modify/Write accesses to SharedArrayBuffers. The Atomic.wait provides the ability for a worker to wait for another worker to signal it, without having to spinlock.
Docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer