Source code
Revision control
Copy as Markdown
Other Tools
Test Info:
- This WPT test may be referenced by the following Test IDs:
- /performance-timeline/multiple-buffered-flag-observers.any.html - WPT Dashboard Interop Dashboard
- /performance-timeline/multiple-buffered-flag-observers.any.worker.html - WPT Dashboard Interop Dashboard
promise_test(() => {
// The first promise waits for one buffered flag observer to receive 3 entries.
const promise1 = new Promise(resolve1 => {
let numObserved1 = 0;
new PerformanceObserver((entryList, obs) => {
// This buffered flag observer is constructed after a regular observer detects a mark.
new PerformanceObserver(list => {
numObserved1 += list.getEntries().length;
if (numObserved1 == 3)
resolve1();
}).observe({type: 'mark', buffered: true});
obs.disconnect();
}).observe({entryTypes: ['mark']});
performance.mark('foo');
});
// The second promise waits for another buffered flag observer to receive 3 entries.
const promise2 = new Promise(resolve2 => {
step_timeout(() => {
let numObserved2 = 0;
// This buffered flag observer is constructed after a delay of 100ms.
new PerformanceObserver(list => {
numObserved2 += list.getEntries().length;
if (numObserved2 == 3)
resolve2();
}).observe({type: 'mark', buffered: true});
}, 100);
performance.mark('bar');
});
performance.mark('meow');
// Pass if and only if both buffered observers received all 3 mark entries.
return Promise.all([promise1, promise2]);
}, 'Multiple PerformanceObservers with buffered flag see all entries');