[Laszlo-dev] LzMediaLoader and "already loaded" error message

[Antun Karlovac]

This looks like a regression. I can reproduce it almost immediately in 
lps-dev, and it's happening in lps-3.1.1. I've built lps-3.0, and I 
cannot reproduce it there.

I have to get a bunch of images together to so that I can put together a 
test case. Will do soon.

-Antun

Antun Karlovac wrote:
> I can reproduce this very consistently even with a scaled down test case 
> that includes nothing but:
> 
>   - Clipping view.
>   - Lazily replicated set of views that load an image.
>   - Scrollbar.
> 
> I'm pretty sure this was never a problem in the past. I need to get some 
> images that I can distribute before I can share this test case.
> 
> -Antun
> 
> Henry Minsky wrote:
>> Yep it sounds like the media loader is holding onto the two available 
>> network connections and not releasing them. Which browser and OS are you 
>> using?
>> The media loader has all sorts of logic to try to determine if the image 
>> has
>> successfully loaded, but I can imagine some case that it gets confused 
>> and thinks that the image has not loaded. In that case though,the 
>> timeout is supposed to kick in and free up the connection eventually. It 
>> sounds like things may be more wedged than that.
>>
>>
>>
>>
>>
>> On 6/2/06, *Antun Karlovac* <antun at laszlosystems.com 
>> <mailto:antun at laszlosystems.com>> wrote:
>>
>>     Hi Henry
>>
>>     I'm working the issue myself; I have all the code locally. The images
>>     are coming from my local box, and I can see the responses come in
>>     afterwards.
>>
>>     The timeout is set to 5 seconds, so what the comment describes is
>>     probably very relevant. Although I think there is another bug here
>>     that's actually triggering the timeout (and hence the confusing error
>>     message).
>>
>>     When quickly slowly scroll through a lazily-replicated list of items
>>     that include run-time loaded images, the list works fine. However when
>>     you scroll quickly, the lockup happens, and no images load.
>>
>>     I'm suspecting this is a media-loading a bug because the
>>     lazily-replicated views are useless after this error happens. Also the
>>     debugger stops working; I can't eval code.
>>
>>     I'm going to try to come up with a simpler test case that I can share.
>>
>>     -Antun
>>
>>     Henry Minsky wrote:
>>      > There's a comment in data/LzLoader:
>>      >
>>      > LzLoader.prototype.returnData = function ( loadobj , data ){
>>      >     // Check if returnData has already been called on this
>>      >     // object. This can happen if a serverless data load timed out in
>>      >     // the LFC, but eventually returned something via the
>>      >     // LoadVars.sendAndLoad() callback.
>>      >     if (loadobj.loaded) {
>>      >         if ($debug) {
>>      >             Debug.warn("%w.returnData: %w already loaded",
>>      >                        this, loadobj);
>>      >         }
>>      >         return;
>>      >     }
>>      >
>>      > What resource is the app loading? Is it possible it is getting an
>>     error
>>      > or timeout?
>>      > Can the customer manually try to fetch the URL using wget or a web
>>      > browser with tracing on HTTP, and see what response is being returned
>>      > from the server?
>>      >
>>      >
>>      > On 6/2/06, *Antun Karlovac* <antun at laszlosystems.com
>>     <mailto:antun at laszlosystems.com>
>>      > <mailto:antun at laszlosystems.com
>>     <mailto:antun at laszlosystems.com>>> wrote:
>>      >
>>      >     I'm seeing a bug in a customer's (SOLO) application where
>>     once the
>>      >     following warning is reported:
>>      >
>>      >     ----
>>      >     WARNING: «LzMediaLoader#7| «MediaLoadObj#6| <FILENAME>
>>      >     (timedout)»».returnData: «MediaLoadObj#6| <FILENAME> (timedout)»
>>      >     already
>>      >     loaded
>>      >     ----
>>      >
>>      >     When the warning(s) show up, the views that were supposed to
>>     display
>>      >     runtime-loaded resources fail to attach them. All media
>>     requests appear
>>      >     to fail after the error shows up.
>>      >
>>      >     Has anyone got any clues as to what this error means, or
>>     where it comes
>>      >     from? I've searched the source code tree, and that error does
>>     not appear
>>      >     in there.
>>      >
>>      >     Thanks,
>>      >
>>      >     Antun
>>      >     _______________________________________________
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>>      >     Laszlo-dev at openlaszlo.org <mailto:Laszlo-dev at openlaszlo.org>
>>     <mailto: Laszlo-dev at openlaszlo.org <mailto:Laszlo-dev at openlaszlo.org>>
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>>      >
>>      >
>>      >
>>      >
>>      > --
>>      > Henry Minsky
>>      > Software Architect
>>      > hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
>>     <mailto:hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>>
>>      >
>>
>>
>>
>>
>> -- 
>> Henry Minsky
>> Software Architect
>> hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
>>
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