Fix websocket timer throttle blocking writes #670
Closed
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Outdated suggestions cannot be applied.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.
Note: the
engine.io.js
file is the generated output ofmake engine.io.js
, and should not be manually modified.The kind of change this PR does introduce
Current behaviour
An immediate setTimeout is used to unblock the WebSocket write. Unfortunately, this setTimeout can be throttled by browsers when the tab is backgrounded. This can lead to missed pong responses to server pings which leads to disconnects.
New behaviour
Move the unblocking code block into a then handler of an immediate Promise.resolve. The then handler does not suffer from Timer throttling and will ensure the code gets executed asynchronously without unintended delay.
Other information (e.g. related issues)
#649 (comment)