W3C home > Mailing lists > Public > w3c-wai-ua@w3.org > January to March 2009

Re: Web Workers

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>
Message-ID: <op.up6busz9wxe0ny@widsith.local>
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

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 14:49:37 UTC