[whatwg] Event loop processing model, and current time
https://html.spec.whatwg.org/multipage/webappapis.html#processing-model-9 says: 1. Let now be the value that would be returned by the Performance object's now() method 2. Let docs be the list of Document objects associated with the event loop in question… ... 4. For each fully active Document in docs, run the resize steps for that Document, passing in now as the timestamp ... This makes no sense, as performance.now() is per-document (it’s relative to the document start time), so passing the same value to all documents in the browsing context is bogus. What may be intended is to “freeze” the performance.now() time in all documents before processing those documents, but give each document its own performance.now() time. Simon
Re: [whatwg] Event loop processing model, and current time
On Mon, Feb 23, 2015 at 4:57 PM, Simon Fraser s...@me.com wrote: https://html.spec.whatwg.org/multipage/webappapis.html#processing-model-9 says: 1. Let now be the value that would be returned by the Performance object's now() method 2. Let docs be the list of Document objects associated with the event loop in question… ... 4. For each fully active Document in docs, run the resize steps for that Document, passing in now as the timestamp ... This makes no sense, as performance.now() is per-document (it’s relative to the document start time), so passing the same value to all documents in the browsing context is bogus. What may be intended is to “freeze” the performance.now() time in all documents before processing those documents, but give each document its own performance.now() time. That is the intent. The algorithm should grab a timestamp for each document at the same time (which is really just a matter of grabbing one timestamp and applying the correct offset for each document). - James
Re: [whatwg] Event loop processing model, and current time
On Feb 23, 2015, at 5:26 PM, James Robinson jam...@chromium.org wrote: On Mon, Feb 23, 2015 at 4:57 PM, Simon Fraser s...@me.com wrote: https://html.spec.whatwg.org/multipage/webappapis.html#processing-model-9 says: 1. Let now be the value that would be returned by the Performance object's now() method 2. Let docs be the list of Document objects associated with the event loop in question… ... 4. For each fully active Document in docs, run the resize steps for that Document, passing in now as the timestamp ... This makes no sense, as performance.now() is per-document (it’s relative to the document start time), so passing the same value to all documents in the browsing context is bogus. What may be intended is to “freeze” the performance.now() time in all documents before processing those documents, but give each document its own performance.now() time. That is the intent. The algorithm should grab a timestamp for each document at the same time (which is really just a matter of grabbing one timestamp and applying the correct offset for each document). In that case, step 1 should probably define a list of timestamps, not the value. Alternatively, now should be defined for each document. - R. Niwa
