Benchmark: the cost of eventListeners

Script Preparation code:

var audio = document.createElement("audio");

function andAOne(e){ 
  e.count = (e.count|| 0) +1; 
}

function stop501(e){ 
  e.count === 501 && e.stopPropagationImmediately();
}

Tests:

running async 1000 event listeners
for (var i = 0; i <1000; i++) audio.addEventListener("ratechange",andAOne.bind({})); audio.playbackRate = 2;
running async 501 event listeners
for (var i = 0; i <1000; i++) audio.addEventListener("ratechange",andAOne.bind({})); audio.addEventListener("ratechange",stop501); audio.playbackRate = 2;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
running async 1000 event listeners
running async 501 event listeners

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Definition**

The benchmark measures the cost of calling an event listener in JavaScript. The script preparation code creates an `audio` element, defines two functions: `andAOne` and `stop501`, and sets up a playback rate for the audio. The HTML preparation code is empty, which suggests that the benchmark only runs in the browser's context and doesn't rely on any specific HTML structure.

**Test Cases**

There are two test cases:

1. **Running async 1000 event listeners**: This test case adds an event listener to the `audio` element 1000 times, using the `andAOne` function as the listener, and sets the playback rate to 2. The goal is to measure the cost of creating and executing this many event listeners asynchronously.
2. **Running async 501 event listeners**: This test case adds an event listener to the `audio` element 501 times, using a combination of both `andAOne` and `stop501` functions as listeners, and also sets the playback rate to 2. The goal is to measure the cost of creating and executing these many event listeners asynchronously.

**Options Compared**

The benchmark compares two approaches:

1. **Single listener**: Using only one event listener (in this case, `andAOne`) for all 1000 or 501 additions.
2. **Dual listeners**: Using both `andAOne` and `stop501` as event listeners for all 1000 or 501 additions.

**Pros and Cons**

* **Single listener**: This approach is simpler to implement and may have fewer overheads, but it might not accurately represent real-world scenarios where multiple event listeners are used.
* **Dual listeners**: Using both functions as event listeners can provide a more accurate representation of real-world usage patterns. However, this approach introduces additional overhead due to the need to handle both events.

**Libraries and Special JS Features**

There is no explicit mention of any libraries or special JavaScript features being used in these benchmark definitions. The script preparation code only uses standard JavaScript constructs such as `document.createElement`, functions, and event listeners.

**Other Considerations**

To get a more accurate representation of the cost of event listeners, it's essential to consider factors like:

* Browser version and platform
* Device type (e.g., desktop vs. mobile)
* Network conditions
* Other background activities that might interfere with benchmark results

In addition to these considerations, running multiple iterations of each test case can help increase the accuracy of the benchmark results.

**Alternatives**

Some alternative approaches to measuring the cost of event listeners include:

1. **Manual execution**: Manually executing each event listener 1000 or 501 times to get an accurate count.
2. **Profiling tools**: Using profiling tools like Chrome DevTools or Firefox Developer Edition to analyze the benchmark results and identify performance bottlenecks.
3. **Benchmarking frameworks**: Utilizing specialized benchmarking frameworks like Benchmark.js or jsperf to run the benchmarks in a controlled environment.

These alternatives can provide more accurate and detailed insights into the cost of event listeners, but they may require additional setup and expertise.

Related benchmarks:

the cost of eventListeners (version: 0)

meassuring the cost of just calling an event listener.

Comparing performance of: running async 1000 event listeners vs running async 501 event listeners

Created: 5 years ago by: Guest

Jump to the latest result

running async 1000 event listeners

running async 501 event listeners

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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