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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /long-animation-frame/tentative/loaf-blocking-duration.html - WPT Dashboard Interop Dashboard
<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Long Animation Frame Timing: basic</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/utils.js"></script>
<body>
<h1>Long Animation Frame: blocking duration</h1>
<div id="log"></div>
<script>
function loaf_blocking_duration_test(run, label) {
const OVERHEAD_EPSILON = 5;
const BLOCKING_THRESHOLD = 50;
promise_test(async t => {
let found = false;
for (let i = 0; i < 10 && !found; ++i) {
const longtask_promise = new Promise(resolve => new PerformanceObserver(
(entries, observer) => {
resolve(entries.getEntries());
observer.disconnect();
}).observe({entryTypes: ["longtask"]}));
const [longtask_entries, loaf_entry] = await Promise.all(
[longtask_promise, expect_long_frame(run, t)]);
const overlapping = longtask_entries.filter(longtask =>
(longtask.startTime >= loaf_entry.startTime &&
longtask.startTime < (loaf_entry.startTime + loaf_entry.duration) &&
(!loaf_entry.renderStart ||
(longtask.startTime < loaf_entry.renderStart - OVERHEAD_EPSILON))));
const longest_index = overlapping.reduce(
(max, cur, i) => cur > overlapping[max] ? i : max, 0);
let expected_blocking_duration = 0;
overlapping.forEach(({duration}, i) => {
if (i === longest_index && loaf_entry.renderStart)
duration += loaf_entry.startTime + loaf_entry.duration -
loaf_entry.renderStart;
expected_blocking_duration += Math.max(0, duration - BLOCKING_THRESHOLD);
});
if (!overlapping.length && loaf_entry.renderStart) {
expected_blocking_duration =
Math.max(0,
loaf_entry.startTime + loaf_entry.duration - loaf_entry.renderStart -
BLOCKING_THRESHOLD);
}
if (Math.abs(loaf_entry.blockingDuration - expected_blocking_duration) <
OVERHEAD_EPSILON) {
found = true;
}
}
assert_true(found);
}, `LoAF blockingDuration should be equivalent to long tasks: ${label}`);
}
loaf_blocking_duration_test(t => t.step_timeout(busy_wait), "Non-rendering");
loaf_blocking_duration_test(t => t.step_timeout(() => {
busy_wait();
requestAnimationFrame(busy_wait);
}), "Rendering");
</script>
</body>