Alex -
No feathers ruffled at all... I just wanted to make it clear that I take
the accuracy of the information very seriously. My goal is to help
others avoid the types of problems that I ran into. When more accurate
information becomes available I will be sure to update as appropriate.
In the mean time, I will attempt to find time to write a simple
application that demonstrates this issue clearly. Glad you are planning
to look into it too :)
Thanks
Scott
Alex Harui wrote:
Scott,
I don't doubt you saw what you saw, and everything you've posted could
be true (naturally I hope it isn't cuz that'll mean we don't have a
bug there).
My frustration comes from the following:
In your post you state that XMLListColleciton leaked less. In theory,
dumping e4x into a datagrid is the same as XMLLIstCollection since we
just wrap the xml in a XMLListCollection. You also state a
theory that XMLListCollection convert xml to objects, which is
misleading to post since it isn't quite true These things make your
whole post suspect. You may in fact have some scenario where
XMLListCollection behaves differently from straght e4x, but normally
it shouldn't.
I often miss threads on FlexCoders since we're pretty busy and I was
away for a couple of weeks, but did the memory leak aspect of this
issue get discussed on this forum? Is there a bug filed for this
issue? It might be in process and I haven't seen it yet.
Usually, these kinds of issues catch my attention. I'm generally more
than willing to squeeze some time out of my day to try to help with
investigating things like this and love it when, once we figure out
the issue, you post blog articles that help the community since it
saves me time and makes one more person out there who can help others
in similar situations. However, I would much prefer to work with you
before you post so we get the right information out there. IMHO,
memory usage is a trcky topic and easy to either misdiagnose, and/or
offer up solutions/workarounds that either don't really work, or
aren't optimal.
Sorry, if I ruffled feathers,
-Alex
------------------------------------------------------------------------
*From:* flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]
*On Behalf Of *Scott - FastLane
*Sent:* Saturday, August 25, 2007 1:33 PM
*To:* flexcoders@yahoogroups.com
*Subject:* Re: [flexcoders] Memory leaks - binding to e4x XML?
Alex -
That is my posting, and I would hate for it to be "misinformation" in
any way. If your research turns up no evidence that I am correct then
I will endeavor to re-create my problem in a sample application that I
can send along to you for inspection. If I cannot successfully
demonstrate that binding to e4x is leaking memory I will be more than
happy to withdraw my posting. However, I should note, that I had a
friend who was working on a similar application (datagrid bound
directly to e4x)... knowing this I told him about my experiences. He
then added memory logging to his application. Although his leak was
less rapid than mine (he says with 1 minute refreshes he lost 1M or so
per hour) he also saw the issue. He then changed his application over
to strongly typed objects and noted that his memory leak had also been
resolved. It was at this point that I decided to publish the post in
case it might help others.
Scott
Alex Harui wrote:
I thought it was a performance issue only. I do expect sealed
classes to perform better than XMLLIstCollection (which does not
convert to object). I'll have to investigate further.
Always frustrating when misinformation get out there...
------------------------------------------------------------------------
*From:* flexcoders@yahoogroups.com
[mailto:[EMAIL PROTECTED] *On Behalf Of *Tracy Spratt
*Sent:* Saturday, August 25, 2007 11:47 AM
*To:* flexcoders@yahoogroups.com
*Subject:* RE: [flexcoders] Memory leaks - binding to e4x XML?
I came across this article, wherein the author alleges that binding
to e4x XML objects cause memory leaks:
http://blog.fastlanesw.com/?p=14 <http://blog.fastlanesw.com/?p=14>
His arguments / findings, seemed well reasoned and supported, and I
do not have the background to refute them. Perhaps someone here
might discuss this.
Tracy
------------------------------------------------------------------------
*From:* flexcoders@yahoogroups.com
[mailto:[EMAIL PROTECTED] *On Behalf Of *Alex Harui
*Sent:* Saturday, August 25, 2007 2:21 PM
*To:* flexcoders@yahoogroups.com
*Subject:* RE: [flexcoders] Memory leaks
There are two major memory usage scenarios in Flex. One involves
creating a new instance of a component, displaying, and later
destroying it. The other involves bringing in one or more classes of
components in a module and trying to get rid of that module later
when its classes are no longer needed.
Honestly, I don't know of any issues of the first kind at this
point. A major problem with ViewStack related components was
addressed in Hotfix2, and a DateField issue was either addressed in
the same hotfix, or a workaround was provided and the issue fixed for
Moxie. A recent issue with Menus was fixed for Moxie and a
workaround was provided. I'm sure there are still issues out there,
and they should be filed as bugs so we can investigate and fix them.
I also encourage you to try to isolate problems of this nature and
post examples on this forum as often there can be a misunderstanding
of how memory management works in Flash/Flex.
The second kind of issues is sort of a fact-of-life for Flex. The
first module to introduce shared code via Styles or Managers must
remain in memory to serve all other code. This has been explained on
my blog.http://blogs.adobe.com/aharui/2007/03/modules.html. The blog
article includes an example of a way to deal with this situation,
although often the easiest way is just to include all managers in the
main app, and bring in styles via runtime CSS.
As you'll see in the article, browser memory management has little to
do with it. It simply has to do with how GC works (described further
elsewhere on my blog) and how styles and singleton managers are
shared. Any memory changes when minimizing is probably due to IE
releasing its own browser resources, although the player may release
some at that time as well.
If you have further questions, this forum should be able to help you
out. In the future, please ask sooner before you spend time creating
eloborate infrastructures.
-Alex
------------------------------------------------------------------------
*From:* flexcoders@yahoogroups.com
[mailto:[EMAIL PROTECTED] *On Behalf Of *André Rodrigues Pena
*Sent:* Saturday, August 25, 2007 10:44 AM
*To:* flexcoders@yahoogroups.com
*Subject:* [flexcoders] Memory leaks
Hi all,
It might be a well-known that Flex has several memory issues. It
doesn't completely free the memory of the components you add runtime,
when you remove them from their containers, and when it comes to
large-scale applications, this is a huge concern. The way my
co-workers found to pass by it was to create a Javascript/Flex
framework to allow Flex to load modules in separate HTML frames and
provide communication between them. So, when a module gets out of
scene, the browser frees the entire SWF. But this approach limits the
user interaction like drag-n-drop support between modules. It's not
natural.
It seems that the browser may have a great part of the blame. They
realized, for instance, that Internet Explorer releases the memory
when the window is minimized and FireFox doesn't.
I'm here to ask what else can be done regarding memory issues. And
how you professionals have dealt with it.
Thanks
--
André Rodrigues Pena
