Benchmark: onIdle() - MeasureThat.net

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
onceIdle1(noop)
IfNotCallback
onceIdle2(noop)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
CancelCallback
IfNotCallback

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36

Browser/OS: Chrome 93 on Windows

View result in a separate tab

Test name	Executions per second
CancelCallback	346394.1 Ops/sec
IfNotCallback	4717708.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down what is being tested on the provided JSON.

**Benchmark Definition**

The benchmark tests the performance of two different approaches to canceling idle callbacks in JavaScript:

1. `onceIdle1(func = Boolean, group = func)`: This function cancels the previous idle callback and then sets up a new one with the provided `func`. The `group.idleCallback` is only set once, when the function is first called.
2. `onceIdle2(func = Boolean, group = func)`: This function checks if an idle callback has already been set for the `group` object. If not, it sets up a new idle callback with the provided `func`. However, in this implementation, the previous idle callback is not actually canceled, but rather replaced with a new one that does nothing (i.e., it just returns).

**Options Compared**

The two approaches are compared in terms of their performance:

* `onceIdle1`: This approach cancels the previous idle callback and sets up a new one, which may result in better performance.
* `onceIdle2`: This approach checks if an idle callback has already been set for the group object, but does not actually cancel the previous one. This may lead to worse performance due to the overhead of checking the existence of the idle callback.

**Pros and Cons**

Pros of `onceIdle1`:

* Canceling the previous idle callback can improve performance by reducing the overhead of maintaining multiple idle callbacks.
* This approach ensures that only one idle callback is active at a time, which may be beneficial for certain use cases.

Cons of `onceIdle1`:

* Setting up a new idle callback every time this function is called may lead to increased memory usage and potential performance issues if the number of concurrent idle callbacks increases.

Pros of `onceIdle2`:

* This approach eliminates the need to cancel the previous idle callback, which can simplify code and reduce overhead.
* However, it does not actually cancel the previous idle callback, which may lead to increased memory usage and potential performance issues.

Cons of `onceIdle2`:

* The existence check for the idle callback can introduce additional overhead, potentially leading to worse performance.

**Library**

There is no explicit library mentioned in the benchmark definition or test cases. However, the use of `window.requestIdleCallback()` suggests that the implementation relies on the Web API for handling idle callbacks.

**Special JS Features/Syntax**

This benchmark does not explicitly use any special JavaScript features or syntax beyond what is already available in modern browsers.

**Other Considerations**

When using these approaches in a real-world application, it's essential to consider factors such as:

* Memory usage: How many idle callbacks can be maintained simultaneously without causing memory issues?
* Performance overhead: What are the performance implications of canceling and setting up new idle callbacks versus checking for the existence of an existing callback?

**Alternatives**

Other alternatives to these approaches might include:

* Using a different library or framework that provides optimized idle callback management.
* Implementing a custom solution using worker threads or other concurrency mechanisms.
* Optimizing the application's overall architecture to reduce the need for idle callbacks.

It's worth noting that these alternatives may not provide better performance or be more suitable for specific use cases, and should be evaluated on a case-by-case basis.

Related benchmarks:

onIdle() (version: 0)

Testing if window.cancelIdleCallback is fast or slow

Comparing performance of: CancelCallback vs IfNotCallback

Created: 3 years ago by: Guest

Jump to the latest result

CancelCallback

IfNotCallback

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):