Intent to Prototype: Delayed Messages Timing API

[Chromestatus]

Contact emails

jo...@chromium.org, joon...@microsoft.com

Explainer

https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/DelayedMessages/explainer.md

Specification

None

Summary

Web applications frequently use the postMessage API for communication across different execution contexts, such as between windows, iframes, and web workers. However, message delays often occur when messages are queued but not processed promptly. These delays can degrade the user experience by making applications feel unresponsive. While developers can detect that a delay happened, identifying the specific cause—whether it's a busy thread, a congested message queue, or serialization/deserialization overhead—is challenging with current tools. The Delayed Messages API will provide developers with end-to-end timing metrics and details on blocking tasks, allowing them to pinpoint the root causes of these delays and improve application performance.

Blink component

Blink>PerformanceAPIs

Motivation

The web needs the Delayed Messages API because web applications frequently use postMessage, but the resulting message delays can significantly degrade user experience. While developers can currently detect these delays, they lack the tools to accurately diagnose their root cause. Delays can stem from a variety of sources, including a receiver's thread being busy with long tasks, congestion in the message queue, or serialization/deserialization overhead. Manually measuring these internal timings with existing tools is often imprecise and cumbersome. A dedicated API is therefore necessary to precisely measure and attribute these specific sources of delay. Without it, web developers face considerable challenges in identifying and resolving these critical performance issues, leading to a poorer experience for end-users.

Initial public proposal

https://docs.google.com/document/d/1x9bJlXXsR8ZrHMsZHl0o9IYuGUgrPjX1APGSfFZqUWQ/edit?usp=sharing

Search tags

postMessage

TAG review

None

TAG review status

Pending

Risks

Interoperability and Compatibility

None

Gecko: No signal

WebKit: No signal

Web developers: No signals

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

None

Debuggability

None

Is this feature fully tested by web-platform-tests?

No

Flag name on about://flags

None

Finch feature name

None

Non-finch justification

None

Requires code in //chrome?

False

Tracking bug

https://issues.chromium.org/u/1/issues/437952019

Estimated milestones

No milestones specified

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5096283303968768?gate=5095798207545344

This intent message was generated by Chrome Platform Status.