- From: Charles McCathieNevile <chaals@opera.com>
- Date: Mon, 02 Mar 2009 17:53:06 +0100
- To: "Simon Harper" <simon.harper@manchester.ac.uk>, "UAWG list" <w3c-wai-ua@w3.org>
On Mon, 02 Mar 2009 17:10:54 +0100, Simon Harper <simon.harper@manchester.ac.uk> wrote: > Hi there, > > week before last I brought up a possible problem as the Web Apps Working > Group wanted to define Web work as "an API that allows Web application > authors to spawn background workers running scripts in parallel to their > main page, allowing for thread-like operation with message-passing as > the coordination mechanism" > > Jim asked me to see if there any implications or possibilityfor > implications, and bring it back to the group. I think that we're OK > however from a very early draft on their wiki, things that look to > suggest there is an isolation between worker and agent are: > > 1) Implementations should not have to expose Node or Document objects to > workers. > 2) Workers should not share anything with the outside world. The objects > representing the worker in the worker itself and in the context that > created the worker should be different, for instance. > > and this one may need more thought > > 3) Capabilities granting: It should be possible for code running in one > iframe to negotiate a connection to another iframe, with that connection > granting certain rights (e.g. adding to an address book but not reading > from it). > > The full draft is below but I think it may be useful to get Charles > McCathieNevile from Opera in to talk with us about it if maybe Henny can > ask. You can ask me directly. I am on this list. But I am pretty busy and not really an expert myself on Web Workers. I will try to find someone from the Web apps group who you really should ask - Ian Hickson would be good, but is generally loath to go to teleconferences, so I will assume that you will ask him, and look for alternatives. cheers Chaals > === > > Full Draft Requirements List > 1) Background workers: A Web application needs to keep its data > synchronised with the server, both sending updates to the server and > receiving updates from the server, including handling buffering of > updates for when the application goes offline. The code to do this would > ideally be independent of the UI code. > 2) URLs: Workers should be spawned from URLs, not from strings, since > script rarely has access to its own source. > 3) Message queuing: Messages sent to a worker before the worker has > initialised should not be lost. > 4) Workers should have access to timers. > 5) Workers should have access to the network. > 6) Workers should be able to use libraries. > 7) Implementations should not have to expose Node or Document objects to > workers. > 8) Workers should not share anything with the outside world. The objects > representing the worker in the worker itself and in the context that > created the worker should be different, for instance. > 9) Shared workers: Multiple instances of the same Web application would > want to keep just one connection back to the server. > 10) Capabilities granting: It should be possible for code running in one > iframe to negotiate a connection to another iframe, with that connection > granting certain rights (e.g. adding to an address book but not reading > from it). > 11) Delegation: It should be possible for one worker to spawn another > worker and efficiently delagate a request to that worker, without the > caller being aware of the delagate and without the original worker > having to proxy all the messages. > 12) Workers whose parents are not longer useful should be killed. > Workers should be able to detect this is about to happen and exit > gracefully. > > > Cheers > Si. > > ======================= > > Simon Harper > University of Manchester (UK) > > Human Centred Web Lab: http://hcw.cs.manchester.ac.uk > > My Site: http://hcw.cs.manchester.ac.uk/people/harper/ > My Diary (Web): http://hcw.cs.manchester.ac.uk/people/harper/ > phpicalendar/week.php > > My Diary (Subscribe): http://hcw.cs.manchester.ac.uk/diaries/harper/ > SimonHarper.ics > > > > > -- Charles McCathieNevile Opera Software, Standards Group je parle français -- hablo español -- jeg lærer norsk http://my.opera.com/chaals Try Opera: http://www.opera.com
Received on Monday, 2 March 2009 16:54:00 UTC