perf_hooks.monitorEventLoopDelay([options])

• options <Object>
  • resolution <number> 采样率，以毫秒为单位。必须大于零。默认值： 10。
• 返回值：<IntervalHistogram>

此属性是 Node.js 的扩展。在 Web 浏览器中不可用。

【This property is an extension by Node.js. It is not available in Web browsers.】

创建一个 IntervalHistogram 对象，用于随时间采样并报告事件循环延迟。延迟将以纳秒为单位报告。

【Creates an IntervalHistogram object that samples and reports the event loop delay over time. The delays will be reported in nanoseconds.】

使用定时器检测事件循环的近似延迟之所以有效，是因为定时器的执行与 libuv 事件循环的生命周期紧密相关。也就是说，循环中的延迟会导致定时器执行的延迟，而这些延迟正是该 API 旨在检测的对象。

【Using a timer to detect approximate event loop delay works because the execution of timers is tied specifically to the lifecycle of the libuv event loop. That is, a delay in the loop will cause a delay in the execution of the timer, and those delays are specifically what this API is intended to detect.】

import { monitorEventLoopDelay } from 'node:perf_hooks';

const h = monitorEventLoopDelay({ resolution: 20 });
h.enable();
// Do something.
h.disable();
console.log(h.min);
console.log(h.max);
console.log(h.mean);
console.log(h.stddev);
console.log(h.percentiles);
console.log(h.percentile(50));
console.log(h.percentile(99));const { monitorEventLoopDelay } = require('node:perf_hooks');
const h = monitorEventLoopDelay({ resolution: 20 });
h.enable();
// Do something.
h.disable();
console.log(h.min);
console.log(h.max);
console.log(h.mean);
console.log(h.stddev);
console.log(h.percentiles);
console.log(h.percentile(50));
console.log(h.percentile(99));拷贝