Uh oh!
There was an error while loading. Please reload this page.
events: optimize condition for optimal scenario - #20452
Closed
apapirovski wants to merge 2 commits into
Closed
Conversation
Instead of always checking whether we've already warned about a possible EventEmitter memory leak, first run the rest of the code as accessing random properties on an Array is expensive.
apapirovski
commented
May 1, 2018
ContributorAuthor
mscdex
commented
May 1, 2018
Contributor
Can you share benchmark results? |
apapirovski
commented
May 1, 2018
ContributorAuthor
@mscdex I'm not claiming it's huge or anything but it's like 1.5-2% with 100 runs. IMO it's a pretty sensible change. The code inside the |
jasnell
approved these changes
May 1, 2018
lpinca
approved these changes
May 2, 2018
bnoordhuis
approved these changes
May 2, 2018
| process.emitWarning(w); | ||
| } | ||
| m = $getMaxListeners(target); | ||
| if (m && m > 0 && existing.length > m && !existing.warned) { |
Member
There was a problem hiding this comment.
If you have time and inclination to test: does reducing m && m > 0 to m > 0 make a difference?
ContributorAuthor
There was a problem hiding this comment.
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.
apapirovski
commented
May 2, 2018
ContributorAuthor
CI after the change proposed by @bnoordhuis: https://ci.nodejs.org/job/node-test-pull-request/14621/ |
BridgeAR
approved these changes
May 2, 2018
cjihrig
approved these changes
May 2, 2018
tniessen
approved these changes
May 2, 2018
trivikr
approved these changes
May 3, 2018
apapirovski
commented
May 3, 2018
ContributorAuthor
Landed in fe87945 |
apapirovski added a commit
that referenced
this pull request
May 3, 2018
Instead of always checking whether we've already warned about a possible EventEmitter memory leak, first run the rest of the code as accessing random properties on an Array is expensive. In addition, remove an unnecessary truthy check. PR-URL: #20452 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
MylesBorins pushed a commit
that referenced
this pull request
May 4, 2018
Instead of always checking whether we've already warned about a possible EventEmitter memory leak, first run the rest of the code as accessing random properties on an Array is expensive. In addition, remove an unnecessary truthy check. PR-URL: #20452 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Merged
MylesBorins pushed a commit
that referenced
this pull request
May 8, 2018
Instead of always checking whether we've already warned about a possible EventEmitter memory leak, first run the rest of the code as accessing random properties on an Array is expensive. In addition, remove an unnecessary truthy check. PR-URL: #20452 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment
9 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Instead of always checking whether we've already warned about a possible EventEmitter memory leak, first run the rest of the code as accessing custom properties on an Array is decently slow.
I believe it makes more sense to optimize for well written user-code than code that is already attaching too many listeners and getting this warning, without having set a higher number of maxListeners.
I've also adjusted the benchmark to be a bit more representative as there's too much noise with the current iteration count.
Checklist
make -j4 test(UNIX), orvcbuild test(Windows) passes