Alan Hargreaves' Blog

The ramblings of a former Australian SaND TSC* Principal Field Technologist

More on Finding leaks in application space

The document I referenced is now available on sunsolve as 76774

There are a few typos that needed fixing in there that have now been fixed. We are just waiting for the final review to replace the currently published document.

There was a comment about getting Sun to help out the folks at the Mozilla Foundation. These comments have been passed on and have flagged an interesting discussion about possibilities.

The response that I got after publishing that blog entry shows just how useful this can be as a medium for getting information out. Hopefully it’s one we can keep positive and worthwhile.

On a similar vein, as I referenced a document on sunsolve, we would appreciate any feedback that anyone wanted to give on it’s usefulness (see my prior entry on sunsolve). That being said, we appreciate feedback on pretty much everything that we push out to sunsolve.

Update

Looking back on what I wrote previously it may not be very clear the path that I took to detetmine that the source of the leaks was inside particular modules. Well, it wasn’t really that difficult. The trick being that if we get the stack from the ::bufctl_audit command inside mdb, we get a list of the stack return addresses. Now all we have to do to find which module it is from is to look at the memory map of the core file from with mdb. This is done with $m. In the case of one of the leaks that I looked at, the address was 0xfce7ac40. Taking an excerpt of the $m output we see that this is…

> $m
BASE    LIMIT     SIZE NAME
10000    52000    42000 /tmp/mozilla/mozilla-bin
60000    64000     4000 /tmp/mozilla/mozilla-bin
64000 1112e000 110ca000 /tmp/mozilla/mozilla-bin
...
fce00000 fceda000    da000 /tmp/mozilla/components/libmsgimap.so
...

and hence in libmsgimap.so

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Written by Alan

June 14, 2004 at 1:01 am

Posted in General

One Response

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  1. . . . on the topic of the comment:

    <div style=”margin-left: 10px; width: 400px;”>There was a comment about getting Sun to help out the folks at the Mozilla Foundation. These comments have been passed on and have flagged an interesting discussion about possibilities.</div>
    posted on this blog on June 14, 2004, I have the following to offer:

    Mozilla & Safari are Part of the Problem; Speaker Panel to
    Address the Issue

    One of the greatest ironies in business today seems only to be
    understood by those who have spent a significant amount of time trying
    to develop rich-GUI Web applications according to W3C (World Wide Web
    Consortium) standards. Ironically, Microsoft has done a far superior
    job of reliably implementing the core W3C standards than Mozilla, since
    about 1997. I have been working in this area for five years.

    I believe that we sorely need competition in the Web browser market.
    But it must be finally said that the release of faulty Web browsers
    such as Mozilla and Safari as “ready for prime time” is damaging to the
    Web. I have spent a total of 23 months doing heavy client-side
    JavaScript almost all the time, including 15 in a 8-front-end developer
    team setting. Additionally, I’ve maintained active involvement in this
    type of software development since 1998.

    The sad fact that seems so hard for most supporters of “choice on the
    Web” and open-standards to face is that everyone I know who has had a
    similar experience to mine in working with client-side JavaScript/DOM
    finds Mozilla and especially Safari absolutely maddening. These Web
    browsers should be released as “experimental-only” until their major
    bugs are fixed. I’ve filed several of them with Mozilla’s BugZilla, but
    to the best of my knowledge none have been permanently fixed.

    To illustrate, one of my favorite bugs is how Mozilla sometimes
    “doubles” all the HTML written to deeply nested markup containers (such
    as ‘div’). To better bring the important implications of these issues
    to light, I am holding a Carnegie-Mellon-West Speaker Panel on the
    topic. I’m looking for more panelists who can speak from experience
    (business or technical) to this “controversial” issue. Please contact
    me at cbalz@andrew.cmu.edu
    if you have suggestions for panelists. So far, I have some very good
    speakers signed up for the panel. Please find the description of the
    panel below.

    Announcement about a Speaker Panel on Current Web Browsers

    As we continue to see rich-GUI Web software slide into proprietary
    formats, and the pressure on Microsoft to play nicely from legal
    battles ease, the time is right to address the future of the Web. I
    would like to invite you to come to a <a
    href=”http://west.cmu.edu/specialPrograms/speakers/”>speaker
    panel at Carnegie-Mellon
    University’s West Coast Campus
    , at Moffett Field (45 minutes south
    of San Francisco), entitled, “Back to Proprietary Client-Server, or Web
    Renaissance?”, on November 10th, 2004, at 6:30pm.

    Details:

    In this panel, I would like to have the panelists speak to the
    following questions:

    What role did open standards (specifically, HTTP and HTML) play
    in the initial adoption (from 1994 onward) of the Web and its
    development into a giant new business market and more?
    How did these open standards come to take hold? What were
    the major obstacles? Was the driving force to adoption a mix of
    technological evangelism and market forces?
    Compare and contrast HTML to DHTML (Dynamic HTML) with the
    JavaScript binding.
    Give your perspective on client-side Web software development,
    and its importance today on the Web.

    What is the importance of Dynamic HTML and the binding to
    JavaScript on the Web today?
    Do you view the application of OO techniques to JavaScript,
    particularly simulation of Java-like class-based inheritance in
    JavaScript, as helpful in deploying Web software?

    Is JavaScript a more realistic choice on the Web than Java for
    the client-side of consumer Web applications, due to JavaScript’s
    current near-ubiquity, lack of need for installation, fast start-up
    time, and security (especially, it’s lack of a file API)?
    Give your view of the pros and cons of server-centric Web
    development (i.e., JSP, ASP) as opposed to a Web based on the
    distributed application or client-server concept.

    What are the pros and cons to the consumer Web user, who
    needs high usability, interactivity, and speed, on dial-up and on
    high-speed?
    What are the pros and cons to the server center, from the
    perspectives of IT (i.e., scalability), engineering, and security?

    Why is it that the “other” Web browsers — the non-Microsoft Web
    browsers — do not support the W3C standards correctly enough to
    support building “next generation” Web applications based on public Web
    standards?
    What is the impact of this situation, as we see rich-GUI Web
    applications migrate to proprietary formats such as Flash and
    IE-specific extensions?

    What are the security implications of a Web highly fragmented
    among Flash browsers, Microsoft Longhorn Client browsers, Web-standard
    browsers, and Internet Explorer-specific Web sites?

    Would this amount to an unmanageable blizzard of security
    patches for consumers?

    What can be done to improve the support of Web browsers for
    rich-GUI Web applications built solely on W3C standards?

    Would an industry consortium be an appropriate vehicle for
    this task?
    Can the market alone, in its current state, take care of this
    situation?
    Is technological evangelism needed?

    Imagining a supportive climate for distributed Web applications
    built on Web standards, what market spaces would this create?

    What would be the role of current vendors of traditional Web
    application frameworks, such as BEA, IBM, and Sun/Netscape?

    Christopher M. Balz

    September 30, 2004 at 11:32 am


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