We should probably discuss this point on the whatwg list, but I'll give you my understanding of why this is desirable: 1) Since SharedWorkers aren't explicitly tied to a specific Document, it doesn't make sense to have them possibly get loaded from an out-of-date version of the app cache. If you have two separate documents running from different caches, it's weird (and indeterminate) if the version of the cache used to load the SharedWorker script is dependent on which one happens to call "new SharedWorker()" first.
2) Since SharedWorkers may outlive a given document, it makes sense to allow them to manage their own appcache state, especially once we start supporting PersistentWorkers (which may run for days, weeks, or years). 3) SharedWorkers may have a different criteria determining when it wants to update its app cache. As for what happens to a SharedWorker whose cache was updated? My presumption is that all future resource loads would use that cache. At that point, the SharedWorker has a few different things it could do: - Reload all of its scripts again using importScripts(). This implies that its script loading is idempotent, but that's not too hard to do. - Send messages to all of its client documents letting it know that it is shutting down, then invoke close() to shut itself down. The client documents can re-create the SharedWorker the next time they want one. This is inherently race-y, though, since you can't easily coordinate the shutdown of the worker with instantiations of new ones. - Do nothing at all -atw 2009/6/1 Alexey Proskuryakov <a...@webkit.org> > > 22.05.2009, в 3:20, Drew Wilson написал(а): > > > - SharedWorkers have explicit access to the ApplicationCache APIs, > while dedicated Workers merely inherit the ApplicationCache from their > parent window. > > What is the use case for this? It doesn't seem useful to me - to invoke > update explicitly, one normally needs to have UI anyway, at which point it's > much easier to call update() directly from a page. > > A tangentially related question: what will happen to a SharedWorker whose > cache got updated? Will the repository use a new source for new instances, > while the old ones will continue to run? Looks like there is a significant > potential for mistakes here, as scripts won't normally expect several > instances of the same SharedWorker to be active. > > - WBR, Alexey Proskuryakov > >
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
