[lug] More on slimserver and AJAX

[D. Stimits]

Daniel Webb wrote:

>On Tue, Jul 04, 2006 at 12:48:25PM -0600, George Sexton wrote:
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>>Daniel Webb wrote:
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>>>it's like the whole application is running across the remote connection.
>>>Even things like clicking the top menu buttons lags as if it was
>>>transmitting them across the network and back.  Even if I open a new tab
>>>this behavior happens
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>>AJAX=Asynchronous Javascript and XML
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>>Yes. A lot of what happens with AJAX is that you activate a control the 
>>script sends a request to the server, and then it uses the XML return 
>>from the server to create a user interface.
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>I didn't realize it could hook into things like the File or Tools menu in
>Firefox, though.  That's what I was getting at, because those things were
>lagged too, not just stuff within the web page in question.  I thought
>javascript could only interact with the stuff within the web page.  If it can
>go outside that it could wreak all kinds of havoc!
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Much of what you're talking about can just be a lack of threading. Any 
single-threaded app that has to switch between components can bog down 
on one and stop serving the others. Threading is not just a performance 
thing for SMP, it's also about responsiveness. I don't know how finely 
threaded any of the javascript/ecmascript is, but it's common to run the 
gui in 1 thread even if the rest of the app uses many threads. The 
result being that if the loop does not have a way to preempt parts which 
are slow, then everything seems to slow down when that one part breaks. 
It's a denial of service that doesn't even require javascript to touch 
anything else...all it has to do is hold the cpu's attention. E.G., if 
you're scaling an image which consumes the entire system ram inside of 
gimp, I'd expect mozilla to slow down without gimp having any contact 
with mozilla. The same is true among components of a single application.

D. Stimits, stimits AT comcast DOT net