[scheduler] Post to MessageChannel instead of window #14234
Merged
Conversation
This file contains 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
Scheduler needs to schedule a task that fires after paint. To do this, it currently posts a message event to `window`. This happens on every frame until the queue is empty. An unfortunate consequence is that every other message event handler also gets called on every frame; even if they exit immediately, this adds up to significant per-frame overhead. Instead, we'll create a MessageChannel and post to that, with a fallback to the old behavior if MessageChannel does not exist.
sophiebits
approved these changes
Nov 14, 2018
acdlite
force-pushed
the
messagechannel
branch
from
1736f33
to
9126e21
Compare
|
React: size: 🔺+0.9%, gzip: 🔺+0.9% Details of bundled changes.Comparing: d7fd679...9126e21 react
scheduler
Generated by 🚫 dangerJS |
sebmarkbage
reviewed
Nov 14, 2018
| @@ -533,13 +533,14 @@ if (typeof window !== 'undefined' && window._schedMock) { | |||
| }; | |||
|
|
|||
| // We use the postMessage trick to defer idle work until after the repaint. | |||
| var port = null; | |||
| var messageKey = | |||
There was a problem hiding this comment.
The overhead of this is no longer necessary in this mechanism since it's a unique channel.
| } else { | ||
| // Otherwise post a message to the window. This isn't ideal because message | ||
| // handlers will fire on every frame until the queue is empty, including | ||
| // some browser extensions. |
There was a problem hiding this comment.
Do we need this fallback? IE9? Do we even support that anyway?
There was a problem hiding this comment.
Idk, for some reason I thought FB did but I guess we don't any longer
|
Maybe just fallback to |
jetoneza
pushed a commit
to jetoneza/react
that referenced
this pull request
Jan 23, 2019
Scheduler needs to schedule a task that fires after paint. To do this, it currently posts a message event to `window`. This happens on every frame until the queue is empty. An unfortunate consequence is that every other message event handler also gets called on every frame; even if they exit immediately, this adds up to significant per-frame overhead. Instead, we'll create a MessageChannel and post to that, with a fallback to the old behavior if MessageChannel does not exist.
n8schloss
pushed a commit
to n8schloss/react
that referenced
this pull request
Jan 31, 2019
Scheduler needs to schedule a task that fires after paint. To do this, it currently posts a message event to `window`. This happens on every frame until the queue is empty. An unfortunate consequence is that every other message event handler also gets called on every frame; even if they exit immediately, this adds up to significant per-frame overhead. Instead, we'll create a MessageChannel and post to that, with a fallback to the old behavior if MessageChannel does not exist.
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.
Scheduler needs to schedule a task that fires after paint. To do this, it currently posts a message event to
window. This happens on every frame until the queue is empty. An unfortunate consequence is that every other message event handler also gets called on every frame; even if they exit immediately, this adds up to significant per-frame overhead.Instead, we'll create a MessageChannel and post to that, with a fallback to the old behavior if MessageChannel does not exist.