no-spurious-wakeup-on-exchange.js

Enable keyboard shortcuts

// |reftest| skip async -- Atomics.waitAsync is not supported

// Copyright (C) 2020 Rick Waldron. All rights reserved.

// This code is governed by the BSD license found in the LICENSE file.

/*---

esid: sec-atomics.waitasync

description: >

  Waiter does not spuriously notify on index which is subject to exchange operation

info: |

  AddWaiter ( WL, waiterRecord )

  5. Append waiterRecord as the last element of WL.[[Waiters]]

  6. If waiterRecord.[[Timeout]] is finite, then in parallel,

    a. Wait waiterRecord.[[Timeout]] milliseconds.

    b. Perform TriggerTimeout(WL, waiterRecord).

  TriggerTimeout( WL, waiterRecord )

  3. If waiterRecord is in WL.[[Waiters]], then

    a. Set waiterRecord.[[Result]] to "timed-out".

    b. Perform RemoveWaiter(WL, waiterRecord).

    c. Perform NotifyWaiter(WL, waiterRecord).

  4. Perform LeaveCriticalSection(WL).

flags: [async]

includes: [atomicsHelper.js]

features: [Atomics.waitAsync, SharedArrayBuffer, TypedArray, Atomics, BigInt, arrow-function, async-functions]

---*/

assert.sameValue(typeof Atomics.waitAsync, 'function', 'The value of `typeof Atomics.waitAsync` is "function"');

const RUNNING = 1;

const TIMEOUT = $262.agent.timeouts.small;

const i64a = new BigInt64Array(new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 4));

$262.agent.start(`

  $262.agent.receiveBroadcast(async (sab) => {

    const i64a = new BigInt64Array(sab);

    Atomics.add(i64a, ${RUNNING}, 1n);

    const before = $262.agent.monotonicNow();

    const unpark = await Atomics.waitAsync(i64a, 0, 0n, ${TIMEOUT}).value;

    const duration = $262.agent.monotonicNow() - before;

    $262.agent.report(duration);

    $262.agent.report(unpark);

    $262.agent.leaving();

});

`);

$262.agent.safeBroadcastAsync(i64a, RUNNING, 1n).then(async agentCount => {

  assert.sameValue(agentCount, 1n, 'The value of `agentCount` is 1n');

  Atomics.exchange(i64a, 0, 1n);

  const lapse = await $262.agent.getReportAsync();

  assert(lapse >= TIMEOUT, 'The result of evaluating `(lapse >= TIMEOUT)` is true');

  const result = await $262.agent.getReportAsync();

  assert.sameValue(result, 'timed-out', 'The value of `result` is "timed-out"');

  assert.sameValue(

    Atomics.notify(i64a, 0),

0,

    'Atomics.notify(new BigInt64Array(new SharedArrayBuffer(BigInt64Array.BYTES_PER_ELEMENT * 4)), 0) must return 0'

);

}).then($DONE, $DONE);