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bcdd228f90
Add a sampling-based event loop delay monitor.
```js
const { monitorEventLoopDelay } = require('perf_hooks');
const h = monitorEventLoopDelay();
h.enable();
h.disable();
console.log(h.percentiles);
console.log(h.min);
console.log(h.max);
console.log(h.mean);
console.log(h.stddev);
console.log(h.percentile(50));
```
PR-URL: https://github.com/nodejs/node/pull/25378
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
100 lines
2.4 KiB
JavaScript
100 lines
2.4 KiB
JavaScript
'use strict';
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const common = require('../common');
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const assert = require('assert');
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const {
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monitorEventLoopDelay
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} = require('perf_hooks');
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{
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const histogram = monitorEventLoopDelay();
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assert(histogram);
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assert(histogram.enable());
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assert(!histogram.enable());
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histogram.reset();
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assert(histogram.disable());
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assert(!histogram.disable());
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}
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{
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[null, 'a', 1, false, Infinity].forEach((i) => {
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common.expectsError(
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() => monitorEventLoopDelay(i),
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{
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type: TypeError,
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code: 'ERR_INVALID_ARG_TYPE'
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}
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);
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});
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[null, 'a', false, {}, []].forEach((i) => {
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common.expectsError(
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() => monitorEventLoopDelay({ resolution: i }),
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{
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type: TypeError,
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code: 'ERR_INVALID_ARG_TYPE'
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}
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);
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});
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[-1, 0, Infinity].forEach((i) => {
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common.expectsError(
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() => monitorEventLoopDelay({ resolution: i }),
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{
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type: RangeError,
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code: 'ERR_INVALID_OPT_VALUE'
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}
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);
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});
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}
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{
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const histogram = monitorEventLoopDelay({ resolution: 1 });
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histogram.enable();
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let m = 5;
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function spinAWhile() {
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common.busyLoop(1000);
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if (--m > 0) {
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setTimeout(spinAWhile, common.platformTimeout(500));
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} else {
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histogram.disable();
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// The values are non-deterministic, so we just check that a value is
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// present, as opposed to a specific value.
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assert(histogram.min > 0);
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assert(histogram.max > 0);
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assert(histogram.stddev > 0);
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assert(histogram.mean > 0);
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assert(histogram.percentiles.size > 0);
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for (let n = 1; n < 100; n = n + 0.1) {
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assert(histogram.percentile(n) >= 0);
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}
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histogram.reset();
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assert.strictEqual(histogram.min, 9223372036854776000);
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assert.strictEqual(histogram.max, 0);
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assert(Number.isNaN(histogram.stddev));
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assert(Number.isNaN(histogram.mean));
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assert.strictEqual(histogram.percentiles.size, 1);
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['a', false, {}, []].forEach((i) => {
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common.expectsError(
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() => histogram.percentile(i),
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{
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type: TypeError,
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code: 'ERR_INVALID_ARG_TYPE'
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}
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);
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});
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[-1, 0, 101].forEach((i) => {
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common.expectsError(
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() => histogram.percentile(i),
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{
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type: RangeError,
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code: 'ERR_INVALID_ARG_VALUE'
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}
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);
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});
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}
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}
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spinAWhile();
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}
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