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Re: [chromium-html5] LocalStorage inside Worker

From: Charles Pritchard <chuck@visc.us>
Date: Thu, 27 Jan 2011 12:06:08 -0800
Message-Id: <A305BD5B-F988-41D9-84F8-2D614E7E58D0@visc.us>
Cc: Felix Halim <felix.halim@gmail.com>, Jonas Sicking <jonas@sicking.cc>, Boris Zbarsky <bzbarsky@mit.edu>, João Eiras <joao.eiras@gmail.com>, public-webapps WG <public-webapps@w3.org>
To: Jeremy Orlow <jorlow@chromium.org>




On Jan 27, 2011, at 11:01 AM, Jeremy Orlow <jorlow@chromium.org> wrote:

> On Thu, Jan 27, 2011 at 12:39 AM, Felix Halim <felix.halim@gmail.com> wrote:
> 2011/1/7 Jonas Sicking <jonas@sicking.cc>:
> > On Thu, Jan 6, 2011 at 7:14 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote:
> >> On 1/6/11 5:25 PM, João Eiras wrote:
> >>>
> >>> Not different from two different tabs/windows running the same code.
> >>
> >> In which current browsers do same-origin tabs/windows end up interleaving
> >> their JS (that is, one runs JS before the other has returned to the event
> >> loop)?
> >
> > I'm fairly sure it happens both in Chrome and IE. One way it can happen is:
> >
> > Tab 1 opens with a page from site A
> > Tab 2 opens with a page from site B
> > The page in tab 2 contains an iframe with a page from site A.
> >
> > But I'm not even sure that Chrome and IE makes an effort to use the
> > same process if you open two tabs for the same site.
> 
> It seemed that Chrome doesn't interleave the JS when the same page is
> opened in multiple tabs.
> 
> Try running this script in multiple tabs and monitor the console output:
> 
> http://felix-halim.net/interleave.html
> 
> In Chrome console log, you will see many "FAIL", but not in Firefox.
> 
> So does this mean localStorage in Chrome is broken? or this is an
> intended behavior?
> 
> Although the updates to localStorage are "interleaved", the two tabs are not: both are running in different processess/event-loops.  I.e. they run parallel.  i.e. localStorage (and cookies) don't support "run to completion".
> 
> We don't implement the storage mutex as specced because it'd severely limit this concurrency.  If you search the archives, you'll find a lot of discussions about this.
> 
> If this is a problem for you, then I suggest you look at WebSQLDatabase or (soon) IndexedDB.
> 
> J

FWIW: websql is mostly abandoned, though super handy on ios mobile devices. IndexedDB is live in Chrome, Firefox and the MS interop team released a prototype for IE.

Moz and webkit both just implement IDB atop of their internal sqlite processes. That is, thy create a simple websql schema.

Afaik, websql does not support blobs. 
Received on Thursday, 27 January 2011 20:07:34 GMT

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