Pause event loop during modal dialogs

Misc

When using alert(), confirm() or onbeforeunload, Chromium's old behavior was to block JS waiting for the result, but allows all declarative animations to continue. This change is to make all main-thread tasks (such as <marquee> and CSS 2d animations) also pause during this interval.

Comments

Chrome’s old behavior was implemented with a nested message loop on the Blink main thread. Any code that might ever run on a nested message loop must be robust to reentrancy and reordering, otherwise there will be stability and security bugs.

Demo

http://jsfiddle.net/sfc75sg6/10/

Specification

Established standard

Status in Chromium

Blink components: Blink

Enabled by default (launch bug) in:

Chrome for desktop release 52
Chrome for Android release 52
Android WebView release 52
Opera release 39
Opera for Android release 39

Consensus & Standardization

Firefox: No public signals
Edge: No public signals
Safari: Shipped
Web Developers: No signals

Owners

Last updated on 2017-06-14