Run results for: onIdle 1000

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
CancelCallback	150.2 Ops/sec
IfNotCallback	1158.4 Ops/sec

Script Preparation code:

    function onceIdle1(func = Boolean, group = func) {
        window.cancelIdleCallback(group.idleCallback);
        group.idleCallback = window.requestIdleCallback(func);
    }

    function onceIdle2(func = Boolean, group = func) {
        if (!group.idleCallback) {
            group.idleCallback = window.requestIdleCallback(() => {
                group.idleCallback = false;
                func();
            });
        }
    }

    function noop() {
        console.log(new Date().toISOString());
    }

Tests:

CancelCallback
for(i = 0; i < 1000; i++) {onceIdle1(noop);}
IfNotCallback
for(j = 0; j < 1000; j++) {onceIdle2(noop);}

Run results for: onIdle 1000

Testing if window.cancelIdleCallback is fast or slow

CancelCallback

IfNotCallback