In a web-application implemented in java using JSP and Servlets; if I store information in the user session, this information is shared from all the tabs from the same brows
Storing the timeStamp in window.sessionStorage if it is not already set. This will give a unique value for each tab(even if the URLs are same)
http://www.javascriptkit.com/javatutors/domstorage.shtml
https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Storage
Hope this helps.