Intervention: Unblocking Scrolling for Unresponsive Main Threads

Identify cases where a user touch scroll is likely to be blocked on the main thread for a long time, and force the touch events to be uncancellable, allowing the scroll to occur on the compositor without blocking on main. This will replace the existing Touch Ack Timeout.

Comments

Other browsers don't implement this precise intervention, but we do see interventions meant to address the same issue. Safari: Safari has some odd behavior around touch event handlers cancellability when the main thread is busy, but it isn’t consistent. Edge: Edge appears to have something equivalent to the Touch Ack Timeout (verified experimentally on http://rbyers.github.io/touch-timeout.html) Firefox: The "APZ content response timeout" is equivalent to our Touch Ack Timeout.

Documentation

Status in Chromium

Blink>Input


Behind a flag (tracking bug)

Consensus & Standardization

  • No public signals
  • No public signals
  • No public signals
  • No signals

Owner

Last updated on 2017-06-14