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function ok(a, msg) {
dump("OK: " + !!a + " => " + a + ": " + msg + "\n");
postMessage({ type: "status", status: !!a, msg: a + ": " + msg });
}
function workerTestDone() {
postMessage({ type: "finish" });
}
ok(self.performance, "Performance object should exist.");
ok(
typeof self.performance.now == "function",
"Performance object should have a 'now' method."
);
var n = self.performance.now(),
d = Date.now();
ok(n >= 0, "The value of now() should be equal to or greater than 0.");
ok(
self.performance.now() >= n,
"The value of now() should monotonically increase."
);
// Spin on setTimeout() until performance.now() increases. Due to recent
// security developments, the hr-time working group has not yet reached
// consensus on what the recommend minimum clock resolution should be:
// Since setTimeout might return too early/late, our goal is for
// performance.now() to increase before a 2 ms deadline rather than specific
// number of setTimeout(N) invocations.
setTimeout(checkAfterTimeout, 1);
var checks = 0;
function checkAfterTimeout() {
checks++;
var d2 = Date.now();
var n2 = self.performance.now();
// Spin on setTimeout() until performance.now() increases. Abort the test
// if it runs for more than 2 ms or 50 timeouts.
let elapsedTime = d2 - d;
let elapsedPerf = n2 - n;
if (elapsedPerf == 0 && elapsedTime < 2 && checks < 50) {
setTimeout(checkAfterTimeout, 1);
return;
}
// can't assert that elapsedPerf >= 1 ms because this worker test runs with
// "privacy.reduceTimerPrecision" == false so performance.now() is not
// limited to 1 ms resolution.
ok(
elapsedPerf > 0,
`Loose - the value of now() should increase after 2ms. ` +
`delta now(): ${elapsedPerf} ms`
);
// If we need more than 1 iteration, then either performance.now() resolution
// is shorter than 1 ms or setTimeout() is returning too early.
ok(
checks == 1,
`Strict - the value of now() should increase after one setTimeout. ` +
`iters: ${checks}, dt: ${elapsedTime}, now(): ${n2}`
);
workerTestDone();
}