| Feature | Status | ETA | Owner |
| ASSERT when UI is delayed by more than 50ms | Core instrumentation landed
SDR: N || SIR: N |
2011-04-29 | dietrich |
Summary
Any time the user interface takes more than 50ms to respond to an action, it can appear sluggish to the user. To determine how often this happens, and what parts of our code are frequent offenders, we should add the ability to detect when the main-thread event loop is delayed by more than 50ms and log it as an ASSERT.
Release Requirements
- does not affect performance in production or beta builds
- can be logged to screen or file
- logging has been added to all primary user interface events
Next Steps
- Complete project definition (ETA: 2011/04/01, Complete)
- Work with UX to identify 15 primary UI events (ETA: 2011/04/01, google doc, Complete)
- Implement core instrumentation of event loop (bug 601268, Complete)
- Investigate options for correlation of event loop delays with high and low level code
- Identify top 10 code points causing event loop delays
Related Bugs & Dependencies
Tracking Bugs
- bug 651580 - main project tracking bug
Related Bugs
- bug 601268 - adds "canary in a coal mine" instrumentation to nsThread.cpp
- bug 606574 - adds ability to report information in Talos
- TBD - adds ability to dump JS function calls executed
- TBD - adds ability to hook into a profiler (eg Shark)
Related Documents
- no test plan needed
- no product marketing plan needed
Team
Anyone interested in this project is encouraged to jump in and get involved. The list here is to provide contact and ownership information:
- Development Lead: dietrich
- Infrastructure Lead: ted
Designs
No designs required
Goals/Use Cases
- provide insight to developers into what is causing the Firefox user interface to feel slow or unresponsive to users
- identify high impact areas for UI responsiveness work
Non-Goals
- provide information to end-users about what is causing Firefox to feel slow or unresponsive
- provide UI profiling
Other Documentation
Security
Security Contact: Curtis Koenig
- No security review necessarily for this feature