Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

events: optimize condition for optimal scenario #20452

Closed
wants to merge 2 commits into from
Closed

events: optimize condition for optimal scenario #20452

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
282749f
events: optimize condition for optimal scenario
apapirovski May 1, 2018
71a1aa1
fixup: simplify conditional further
apapirovski May 2, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion benchmark/events/ee-add-remove.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@
const common = require('../common.js');
const events = require('events');

const bench = common.createBenchmark(main, { n: [25e4] });
const bench = common.createBenchmark(main, { n: [1e6] });

function main({ n }) {
const ee = new events.EventEmitter();
Expand Down
30 changes: 14 additions & 16 deletions lib/events.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -235,22 +235,20 @@ function _addListener(target, type, listener, prepend) {
}

// Check for listener leak
if (!existing.warned) {
m = $getMaxListeners(target);
if (m && m > 0 && existing.length > m) {
existing.warned = true;
// No error code for this since it is a Warning
// eslint-disable-next-line no-restricted-syntax
const w = new Error('Possible EventEmitter memory leak detected. ' +
`${existing.length} ${String(type)} listeners ` +
'added. Use emitter.setMaxListeners() to ' +
'increase limit');
w.name = 'MaxListenersExceededWarning';
w.emitter = target;
w.type = type;
w.count = existing.length;
process.emitWarning(w);
}
m = $getMaxListeners(target);
if (m && m > 0 && existing.length > m && !existing.warned) {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If you have time and inclination to test: does reducing m && m > 0 to m > 0 make a difference?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not sure if it makes a difference yet but it seems a harmless change and simplifies the conditional further. I don't see why we shouldn't do it.

existing.warned = true;
// No error code for this since it is a Warning
// eslint-disable-next-line no-restricted-syntax
const w = new Error('Possible EventEmitter memory leak detected. ' +
`${existing.length} ${String(type)} listeners ` +
'added. Use emitter.setMaxListeners() to ' +
'increase limit');
w.name = 'MaxListenersExceededWarning';
w.emitter = target;
w.type = type;
w.count = existing.length;
process.emitWarning(w);
}
}

Expand Down