doc: broken PerformanceObserver code sample
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The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
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louwers
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Nov 2, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: nodejs#54227
Reviewed-By: Chengzhong Wu <[email protected]>
aduh95
pushed a commit
that referenced
this pull request
Nov 5, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: #54227
Reviewed-By: Chengzhong Wu <[email protected]>
aduh95
pushed a commit
that referenced
this pull request
Nov 6, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: #54227
Reviewed-By: Chengzhong Wu <[email protected]>
tpoisseau
pushed a commit
to tpoisseau/node
that referenced
this pull request
Nov 21, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: nodejs#54227
Reviewed-By: Chengzhong Wu <[email protected]>
ruyadorno
pushed a commit
that referenced
this pull request
Nov 27, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: #54227
Reviewed-By: Chengzhong Wu <[email protected]>
ruyadorno
pushed a commit
that referenced
this pull request
Nov 27, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: #54227
Reviewed-By: Chengzhong Wu <[email protected]>
ruyadorno
pushed a commit
that referenced
this pull request
Nov 27, 2024
The code sample at the top of the "Performance measurements API"
section of the docs does not run.
The code in question:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
doSomeLongRunningProcess(() => {
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
});
```
If you replace `doSomeLongRunningProcess` with an IIFE with a sleep()
at the top of it, you get this:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
When you run this, you get the following output:
```sh
$ node performance-test.js
17.873416
node:internal/per_context/domexception:53
ErrorCaptureStackTrace(this);
^
DOMException [SyntaxError]: The "A" performance mark has not been set
at new DOMException (node:internal/per_context/domexception:53:5)
at __node_internal_ (node:internal/util:695:10)
at getMark (node:internal/perf/usertiming:65:11)
at calculateStartDuration (node:internal/perf/usertiming:202:13)
at measure (node:internal/perf/usertiming:220:7)
at Performance.measure (node:internal/perf/performance:135:12)
at /private/tmp/performance-test.js:14:15
Node.js v20.11.1
```
I believe it's due to the call to `performance.clearMarks();` in the
PerformanceObserver callback. If you remove that, it works as expected:
```js
const { PerformanceObserver, performance } = require('node:perf_hooks');
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
});
obs.observe({ type: 'measure' });
performance.measure('Start to Now');
performance.mark('A');
(async function doSomeLongRunningProcess() {
await new Promise(r => setTimeout(r, 5000));
performance.measure('A to Now', 'A');
performance.mark('B');
performance.measure('A to B', 'A', 'B');
})()
```
```sh
$ node performance-test.js
17.761083
5002.468417
```
PR-URL: #54227
Reviewed-By: Chengzhong Wu <[email protected]>
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The code sample at the top of the "Performance measurements API" section of the docs does not run.
The code in question:
If you replace
doSomeLongRunningProcesswith an IIFE with a sleep() at the top of it, you get this:When you run this, you get the following output:
$ node performance-test.js 17.873416 node:internal/per_context/domexception:53 ErrorCaptureStackTrace(this); ^ DOMException [SyntaxError]: The "A" performance mark has not been set at new DOMException (node:internal/per_context/domexception:53:5) at __node_internal_ (node:internal/util:695:10) at getMark (node:internal/perf/usertiming:65:11) at calculateStartDuration (node:internal/perf/usertiming:202:13) at measure (node:internal/perf/usertiming:220:7) at Performance.measure (node:internal/perf/performance:135:12) at /private/tmp/performance-test.js:14:15 Node.js v20.11.1I believe it's due to the call to
performance.clearMarks();in the PerformanceObserver callback. If you remove that, it works as expected: