Google is looking to improve page responsiveness in its Chrome browser by introducing a Long Task API that will enable Web apps and their developers to figure out the elements behind the delay and provide a fix accordingly. With the help of Long Task API, the performance issues on the browser can be specifically tied to particular components of the page and can then be fixed for improving the response time or unresponsiveness in some cases.
The Long Task API essentially helps in identification of the Long Tasks (i.e. processes whose execution time is longer than 50 milliseconds). "The major culprit behind these responsiveness issues is main thread contention, which in turn is caused by 'long tasks'. Long tasks monopolise the UI thread for extended periods of time and block other critical tasks from being executed - for instance reacting to input," the search giant said in the Google Group for Blink Dev (Chromium).
The long tasks often tie up the main thread and prevent users from interacting with the page even though the page is rendered visually, a post on code repository site GitHub says. The post mentions that poorly-designed content from third-parties has been found to be a frequent culprit behind long tasks.
As the user interactions such as taps or clicks are queued behind the long tasks, it can result in an unpleasant user experience. The Long Task API now holds "Intent to ship" status in Chromium and can therefore be expected to come with future browser updates, as pointed out in a report by Android Police.
It will be interesting to see how the detection of long tasks will help in improving the page responsiveness and in turn user experience when Long Task API finally comes into action.