Don't re-arm timerfd each epoll_wait #264
Merged
Conversation
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
|
I need to write a few tests but the idea is the same as: |
normanmaurer
force-pushed
the
timerfd_rearm
branch
2 times, most recently
from
0205ccd to
7ae80fe
Compare
normanmaurer
force-pushed
the
timerfd_rearm
branch
from
7ae80fe to
0b2ab4d
Compare
|
Test added PTAL |
Lukasa
approved these changes
Apr 3, 2018
Lukasa
requested changes
Apr 3, 2018
Sources/NIO/Selector.swift
Outdated
| // expensive. | ||
| let next = DispatchTime.now().uptimeNanoseconds + UInt64(timeAmount.nanoseconds) | ||
| if next < earliestTimer { | ||
| earliestTimer = next |
There was a problem hiding this comment.
Actually, please use explicit self's on earliestTimer`. It'll help make this a lot clearer.
Motivation: When calling Selector.whenReady(...) and using a SelectorStrategy.blockUntil(...) we may end up re-arm the timerfd each time even if the wakeup time did not change. This is expensive and can be avoided in most situations. Modifications: Keep track of the earliest scheduled timer and only schedule a new one if it would fire sooner. Result: Less overhead when using epoll and timers.
normanmaurer
force-pushed
the
timerfd_rearm
branch
from
0b2ab4d to
0c7c131
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Motivation:
When calling Selector.whenReady(...) and using a SelectorStrategy.blockUntil(...) we may end up re-arm the timerfd each time even if the wakeup time did not change.
This is expensive and can be avoided in most situations.
Modifications:
Keep track of the earliest scheduled timer and only schedule a new one if it would fire sooner.
Result:
Less overhead when using epoll and timers.