*Intent to Ship: Add JavaScript timer wake up alignment for unimportant cross-origin frames*
Contact emails zheda.c...@intel.com, fdo...@chromium.org Specification https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html Summary Align wake ups of JavaScript timers for unimportant cross-origin frames. Currently, DOM timers <32ms are all opt-out from AlignWakeUps [1] due to performance concerns. This is very conservative and actually some unimportant frames are eligible to use JS timer alignment. WebKit uses the policy to align DOM timer of non-interacted cross origin frames to 30ms. This feature adds JavaScript timer wake up alignment for unimportant frames on foreground pages. Unimportant frames means they are cross origin, visible but have non-large proportion of page’s visible area, and have no user interaction. The alignment interval is 32ms. [1] https://chromium-review.googlesource.com/c/chromium/src/+/4589092 Blink component Blink>PerformanceAPIs>Timers <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EPerformanceAPIs%3ETimers> TAG review None TAG review status Not applicable Risks Interoperability and Compatibility "Other vendors already have interoperable implementation" Safari has a similar intervention. DOM timers of non-interacted cross origin frames are aligned to 30ms. In Firefox, all DOM timers (both same-origin and cross-origin) in foreground pages would be aligned to 16ms. "A mature specification in the relevant standards body" This intervention is spec-compliant. The spec mentions "the SetTimeout/SetInterval API does not guarantee that timers will run exactly on schedule. Delays due to CPU load, other tasks, etc, are to be expected. ". The wait length of time is implementation-defined, "which is intended to allow user agents to pad timeouts as needed to optimize the power usage of the device. " https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html "A shared test suite for that specification" It isn't clear what should be tested specifically for this intervention since the spec allows waiting for an "implementation-defined" length. *Gecko*: Shipped/Shipping In Firefox, all DOM timers of frames (both same origin and cross origin) are aligned to 16ms *WebKit*: Shipped/Shipping In Safari, DOM timers of non-interacted cross origin frames are aligned to 30ms after reaching max nesting level (>=5) *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 Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)? Yes Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> ? Yes This intervention doesn't require changes to the spec. Timers are already covered by Web Platform Tests. Flag name on chrome://flags None Finch feature name ThrottleUnimportantFrameTimers Requires code in //chrome? False Tracking bug https://issues.chromium.org/issues/40942028 Launch bug https://issues.chromium.org/issues/40942028 Estimated milestones Shipping on desktop 123 DevTrial on desktop 121 Shipping on Android 123 DevTrial on Android 121 Anticipated spec changes Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way). None Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5106220399853568 Links to previous Intent discussions This intent message was generated by Chrome Platform Status <https://chromestatus.com/>. On Friday, March 15, 2024 at 6:24:06 AM UTC+8 mike...@chromium.org wrote: The privacy and security teams review all intents, so requesting reviews and answering the relevant questionnaires is the best path forward. Looking forward to the new I2S - thanks! On 3/14/24 11:22 AM, Zheda Chen wrote: More details are updated in ChromeStatus, including interoperability and compatibility risks, Safari/Firefox views, web platform tests. It compares the behaviors across different browser vendors. https://chromestatus.com/feature/5106220399853568 Will send the updated "intent to ship" to this thread later if it looks good. AFAIK, I don't see potential privacy/security issues, so can i set "security review status" and "privacy review status" to "not applicable"? Please let us know if you have any concerns. On Wednesday, March 13, 2024 at 10:00:35 AM UTC+8 dom...@chromium.org wrote: Can you fill out the interoperability and compatibility risks section here? I don't think standards position requests are necessary, but saying how this behavior might break existing sites that assume Chromium's current behavior, and how this new behavior compares to WebKit and Gecko, would be helpful. Also, can you request the privacy/security/enterprise/debuggability/testing gates on Chrome Status? On Tue, Mar 12, 2024 at 10:12 PM Zheda Chen <zheda...@intel.com> wrote: Okay I update the process stage in Chrome Platform Status, and paste the newly-generated Intent above. Please take a look. https://chromestatus.com/feature/5106220399853568 -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/fef3fef7-e01a-4c97-927d-4c1095cba2cdn%40chromium.org.
