Benchmark: await delay vs setTimeout

Script Preparation code:

const delayA = time => new Promise(res=>setTimeout(res,time));
const delayT = (func, wait) => {
    var args = slice.call(arguments, 2);
    return setTimeout(function(){
      return func.apply(null, args);
    }, wait);
  };
var test = function(){
  return;
}

Tests:

delayA
(async function(){ await delayA(0); test(); return; })();
delayT
(async function(){ await delayT(test,0); return; })();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
delayA
delayT

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 and explain what's being tested, compared, and considered.

**Benchmark Overview**

The benchmark compares two approaches to introduce a delay in asynchronous code execution: `await delayA` and `delayT`. Both functions are designed to create promises that can be used with `async/await` syntax.

**Options Compared**

The two options being compared are:

1. **`await delayA`**: This approach uses the `new Promise` constructor to create a promise that resolves after a specified time using `setTimeout`. The `delayA` function returns this promise, which is then awaited in the test code.
2. **`delayT`**: This approach also creates a promise that resolves after a specified time, but it's implemented differently. It uses `setTimeout` to schedule a callback function that executes the provided function (`test`) with the original arguments.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **`await delayA`**:
	* Pros: Simple, easy to understand, and well-documented in modern JavaScript.
	* Cons: Can lead to performance issues if used extensively due to its synchronous nature (i.e., it blocks the execution of the code until the promise resolves).
2. **`delayT`**:
	* Pros: More efficient than `await delayA`, as it avoids blocking the execution of the code, making it suitable for concurrent and parallel execution.
	* Cons: Less straightforward to understand and use compared to `await delayA`.

**Library**

In this benchmark, neither `delayA` nor `delayT` uses a specific library. However, `slice.call` is used in `delayT`, which is a part of the ECMAScript standard (section 8.5). This function returns an array-like object from an array or other iterable.

**Special JavaScript Features**

No special JavaScript features or syntax are being tested in this benchmark.

**Benchmark Preparation Code**

The provided preparation code defines two functions: `delayA` and `delayT`. These functions create promises that can be used with `async/await` syntax. The test code simply calls these functions with a delay of 0 milliseconds, followed by the `test` function, which is an empty function.

**Latest Benchmark Result**

The benchmark result shows two test runs for each option:

1. **`delayT`**: 74023.59375 executions per second
2. **`delayA`**: 73338.375 executions per second

This suggests that `delayT` outperforms `delayA` in terms of execution speed.

**Alternatives**

If you're interested in alternative approaches to introduce delays in asynchronous code execution, consider:

1. **Using Web Workers**: You can create a separate worker thread and communicate with the main thread using messages or shared variables.
2. **Utilizing async/await with `performance.now()`**: Instead of using promises, you can use `performance.now()` to get the current timestamp and calculate the delay.
3. **Implementing your own timing functions**: You can create a custom timing function that schedules callbacks at specific intervals.

Keep in mind that these alternatives might not be as efficient or straightforward as using promises with `await` syntax, but they offer different design choices and trade-offs.

Related benchmarks:

await delay vs setTimeout (version: 0)

Comparing performance of: delayA vs delayT

Created: 8 years ago by: Guest

Jump to the latest result

delayA

delayT

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):