Monthly Archives: October 2011

c-ares, cURL and libcurl, Development, IT Politics, libssh2, Open Source

Three out of one hundred

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If I’m not part of the solution, I’m part of the problem and I don’t want to be part of the problem. More specifically, I’m talking about female presence in tech and in particular in open source projects.

3 out of 100I’ve been an open source and free software hacker, contributor and maintainer for almost 20 years. I’m the perfect stereo-type too: a white, hetero, 40+ years old male living in a suburb of a west European city. (I just lack a beard.) I’ve done more than 20,000 commits in public open source code repositories. In the projects I maintain, and have a leading role in, and for the sake of this argument I’ll limit the discussion to curl, libssh2, and c-ares, we’re certainly no better than the ordinary average male-dominated open source projects. We’re basically only men (boys?) talking to other men and virtually all the documentation, design and coding is done by male contributors (to a significant degree).

Sure, we have female contributors in all these projects, but for example in the curl case we have over 850 named contributors and while I’m certainly not sure who is a woman and who is not when I get contributions, there’s only like 10 names in the list that are typically western female names. Let’s say there are 20. or 30. Out of a total of 850 the proportions are devastating no matter what. It might be up to 3%. Three. THREE. I know women are under-represented in technology in general and in open source in particular, but I think 3% is even lower than the already low bad average open source number. (Although, some reports claim the number of female developers in foss is as low as just above 1%, geekfeminism says 1-5%).

Numbers

Three percent. (In a project that’s been alive and kicking for thirteen years…) At this level after this long time, there’s already a bad precedent and it of course doesn’t make it easier to change now. It is also three percent of the contributors when we consider all contributors alike. If we’d count the number of female persons in leading roles in these projects, the amount would be even less.

It could be worth noting that we don’t really have any recent reliable stats for “real world” female share either. Most sources that I find on the Internet and people have quoted in talks tend to repeat old numbers that were extracted using debatable means and questions. The comparisons I’ve seen repeated many times on female participation in FOSS vs commercial software, are very often based on stats that are really not comparable. If someone has reliable and somewhat fresh data, please point them out for me!

“Ghosh, R. A.; Glott, R.; Krieger, B.;
Robles, G. 2002. Free/Libre and Open Source Software: Survey and Study. Part
IV: Survey of Developers. Maastricht: International Institute of Infonomics
/Merit.

A design problem of “the system”

I would blame “the system”. I’m working in embedded systems professionally as a consultant and contract developer. I’ve worked as a professional developer for some 20 years. In my niche, there’s not even 10% female developers. A while ago I went through my past assignments in order to find the last female developer that I’ve worked with, in a project, physically located in the same office. The last time I met a fellow developer at work who was female was early 2007. I’ve worked in 17 (seventeen!) projects since then, without even once having had a single female developer colleague. I usually work in smaller projects with like 5-10 people. So one female in 18 projects makes it something like one out of 130 or so. I’m not saying this is a number that is anything to draw any conclusions from since it just me and my guesstimates. It does however hint that the problem is far beyond “just” FOSS. It is a tech problem. Engineering? Software? Embedded software? Software development? I don’t know, but I know it is present both in my professional life as well as in my volunteer open source work.

Geekfeminism says the share is 10-30% in the “tech industry”. My experience says the share gets smaller and smaller the closer to “the metal” and low level programming you get – but I don’t have any explanation for it.

Fixing the problems

What are we (I) doing wrong? Am I at fault? Is the the way I talk or the way we run these projects in some subtle – or obvious – ways not friendly enough or downright hostile to women? What can or should we change in these projects to make us less hostile? The sad reality is that I don’t think we have any such fatal flaws in our projects that create the obstacles. I don’t think many females ever show up near enough the projects to even get mistreated in the first place.

I have a son and I have a daughter – they’re both still young and unaware of this kind of differences and problems. I hope I will be able to motivate and push and raise them equally. I don’t want to live in a world where my daughter will have a hard time to get into tech just because she’s a girl.

Windows

Who’s 0xabadbabe and why?

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It is Friday after all, so I’ll offer this little glimpse as an example from what I do at work…

A while ago, I was working for a customer (who shall remain unnamed here) doing system simulation software. I worked on this project for a year or so. I ran full x86 systems completely simulated. During that time I was chasing some nasty bugs in the simulated usb-disk device that caused my Windows boot to end up in a blue screen.

I struggled to figure out why Windows 7 would write 0xABADBABE to EHCI register index 0x1C – which is a reserved register – during boot some 10 milliseconds before the blue screen appears, and I was convinced that it was due to a flaw in the EHCI simulation code and thus was the first indication of the failure. If I didn’t have any simulated usb-disk inserted that write wouldn’t occur, and similarly that write would occur even if I inserted the usb-disk much later – like even after Windows 7 had started and I was passed the login screen.

An interesting exercise is to grep for this (little-endian so twist it around!) 32 bit pattern in a freshly installed windows 7 file system – I found it on no less than 16 places in a 20GB file system. This bgrep utility was handy for this.

To properly disassemble that code, I hacked up a quick bcut tool so that I could cut out a suitable piece of the 20GB file to pass to objdump, as objdump very inconveniently does not offer an option to skip an arbitrary amount from the beginning of a file! Also, as it is not really possible to easily tell on which byte x86 code starts at, I had to be able to fine-adjust the beginning of the cut so that objdump would show correctly (this is x86-64):

      callq  *0x9061(%rip)        # 0x9080
      mov    0x40(%rsi),%r11d
      mov    %rsi,0x58(%rdi)
      mov    %r11d,(%rdi)
      mov    0x40(%rsi),%eax
      mov    %rsi,0x60(%rdi)
      mov    %eax,0x4(%rdi)
      mov    0xa0(%r13),%rax
      movl   $0xabadbabe,0x1c(%rax)

But then, reading that code never gave me enough clues to figure out why the offending MOV is made.

Thanks to a friend with a good eye and useful resources, I finally learned that Windows does this write on purpose to offer some kind of break-point for a debugger. It always does this (assuming a USB device or something is attached)!

A red herring as far as I’m concerned. Nothing to bother about, just MOV on! I simply made the simulation accept this.

Oh. You want to know what happened to the blue screen? It had nothing at all to do with the bad babe constant, but turned out to be because the ehci driver finds out that some USB data structs the controller fills in get pointers that point to memory outside of the area the driver has mapped for this purpose. In other words it was a really hard to track down bug in the simulated device.

Rockbox

Rockbox Steering again

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I’m proud and happy to once again having been voted into the Rockbox Steering Board. Thanks for your trust and confidence in me, friends! I’m hereby starting my 4th season in this role, which also happens to be all years the RSB has existed.

The RSB has really only had to act once. I don’t foresee any drastic change in this regard this year. The complete board consists of:

Alex Parker
Björn Stenberg
Daniel Stenberg
Frank Gevaerts
Jens Arnold

Rockbox

Network

Hear me talk at FSCONS 2011

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First, allow me to mention that I like FSCONS. I’ve been there several years, I’ve spoken there every year I’ve been there and I know and like a bunch of the persons in the team putting it together. Good stuff!

I wasn’t supposed to do any talk at FSCONS this year, and I did feel a little empty and lost because of it.

FSCONS… then an empty slot appeared, a question was asked, a subject was suggested and suddenly I ended up having agreed to do a talk and the void has been filled again. I’m glad. I hope someone else will be too and I will try to excite the audience with a talk titled “SPDY: An experimental protocol for a faster web” or something like that. It will have to do for now. It is currently planned to take place at 17:15 on Saturday 12th of November.

My thinking is to explain SPDY in detail, explain the reasoning behind it, the problems that have lead up to its creation and I’ll try to shed the lights on the alternatives and make some guesses what I think the future will hold in terms of web transports and what we will NOT see… I might even manage to acquire further insights of this from my ventures into libspdy.

If you have any related thoughts or questions, feel free to ask me ahead of time and I might be able to adjust my talk for it.

Blogging

a 20 to 1 spam to comment ratio

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It has been a little over 1500 days since I started this (wordpress’ed) version of my blog. During this time, I’ve posted entries, people have submitted comments and most of all there have been spammers posting “comments”.

During these 1500 days I’ve posted over 600 blog entries. Roughly one entry every 2.5 days. We can see that my visitors aren’t that talkative in comparison as I’ve received some 550 comments in total to my blog posts.

10,000 spam comments have been submitted. That means roughly 20 times more spam than legitimate comments. The world can indeed be a sad place at times! 🙁

cURL and libcurl, Network

libspdy

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SPDY is a neat new protocol and possible contender to replace HTTP – at least in some areas and for some use cases. SPDY has been invented and developed mostly by Google engineers.

SPDY allows better usage of fewer TCP connections (since it sends multiple logical streams over a single physical TCP connection) and it helps clients overcome problems with TCP (like how a new connection starts slowly) while at the same time reducing latency and bandwidth requirements. Very similar to how channels are handled over an SSH connection.SPDY

Chrome of course already supports SPDY and Firefox has some early experimental support being worked on.

Of course there are also legitimate criticisms against SPDY as well, including subjects like how it makes caching proxies impossible (because everything goes over SSL), how it makes debugging a lot harder by using compressed headers, how it is impossible to extract just a single header from the stream due to its compression approach and how the compression state buffers make each individual stream use more memory than plain old HTTP (plain TCP) ones.

We can expect SPDY<=>HTTP gateways to appear so that nobody gets locked into either side of these protocols.

SPDY will provide faster transfers. libcurl is currently used for speed reasons in many cases. To me, it makes perfect sense to have libcurl use and try to use SPDY instead of HTTP exactly like how the browsers are starting to do it, so that the libcurl using applications will get their contents transferred faster.

My thinking is that we introduce some new magic option(s) that makes libcurl use SPDY, and for normal easy interface transfers it will remain to use a single connection for each new SPDY transfer, but if you use the multi interface and you enable pipelining you’ll instead make libcurl do multiple transfers over the same single SPDY connection (as long as you speak with the same server and port etc). From an application’s stand-point it shouldn’t make any difference, apart from being faster than otherwise. Just like we want it!

Implementation wise, I would like to use a reliable and efficient third-party library for the actual SPDY implementation. If there doesn’t exist any, we make one and run that one independently. I found libspdy, but I found some concerns about it (no mailing list, looks like one-man project, not C89 compliant, no API docs etc). I mailed the libspdy author, I hoping we’d sort out my doubts and then I’d base my continued work on that library.

After some time Thomas Roth, primary libspdy author, responded and during our subsequent email exchange I’ve gotten a restored faith and belief in this library and its direction. Not only did he fix the C89 compliance pretty quickly, he is also promising rather big changes that are pending to get committed within a week or so.

Comforted by what I’ve learned from Thomas, I’ll wait for his upcoming changes and I’ll join the soon to be created mailing list for the libspdy project and I’ll contribute some ideas and efforts to help shape it into the fine SPDY library we all want. I can only encourage other fellow SPDY library interested persons to do the same!

Updated: Join the SPDY library development

Uncategorized

11-10-09 08:07:06

3 Comments

It seems the US-centric world of date geeks have noticed the 09/10/11 12:34:56 time stamp, but I prefer doing the dates in the only order that makes sense, the ISO8601 order: year month day hour minute second. So I have to celebrate the same day at a different time!

So this time just happened. Move on.