Source code
Revision control
Copy as Markdown
Other Tools
// |reftest| skip-if(!this.hasOwnProperty('Atomics')||!this.hasOwnProperty('SharedArrayBuffer')||(this.hasOwnProperty('getBuildConfiguration')&&getBuildConfiguration('arm64-simulator'))) -- Atomics,SharedArrayBuffer is not enabled unconditionally, ARM64 Simulator cannot emulate atomics
// Copyright (C) 2017 Mozilla Corporation. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-atomics.notify
description: >
Test that Atomics.notify notifies agents in the order they are waiting.
includes: [atomicsHelper.js]
features: [Atomics, SharedArrayBuffer, TypedArray]
---*/
const NUMAGENT = 3;
const WAIT_INDEX = 0; // Waiters on this will be woken
const SPIN = 1; // Worker i (zero-based) spins on location SPIN+i
const RUNNING = SPIN + NUMAGENT; // Accounting of live agents
const BUFFER_SIZE = RUNNING + 1;
// Create workers and start them all spinning. We set atomic slots to make
// them go into a wait, thus controlling the waiting order. Then we notify them
// one by one and observe the notification order.
for (var i = 0; i < NUMAGENT; i++) {
$262.agent.start(`
$262.agent.receiveBroadcast(function(sab) {
const i32a = new Int32Array(sab);
Atomics.add(i32a, ${RUNNING}, 1);
while (Atomics.load(i32a, ${SPIN + i}) === 0) {
/* nothing */
}
$262.agent.report(${i});
Atomics.wait(i32a, ${WAIT_INDEX}, 0);
$262.agent.report(${i});
$262.agent.leaving();
});
`);
}
const i32a = new Int32Array(
new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * BUFFER_SIZE)
);
$262.agent.safeBroadcast(i32a);
// Wait for agents to be running.
$262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
var waiterlist = [];
for (var i = 0; i < NUMAGENT; i++) {
assert.sameValue(
Atomics.store(i32a, SPIN + i, 1),
1,
`Atomics.store(i32a, SPIN + ${i}, 1) returns 1`
);
waiterlist.push($262.agent.getReport());
// Try to yield control to ensure the agent actually started to wait.
$262.agent.tryYield();
}
var notified = [];
for (var i = 0; i < NUMAGENT; i++) {
assert.sameValue(
Atomics.notify(i32a, WAIT_INDEX, 1),
1,
`Atomics.notify(i32a, WAIT_INDEX, 1) returns 1 (${i})`
);
notified.push($262.agent.getReport());
}
assert.sameValue(
notified.join(''),
waiterlist.join(''),
'notified.join(\'\') returns waiterlist.join(\'\')'
);
reportCompare(0, 0);