My travels with WDF : Random

We’re gonna need a bigger stick!

patman — Tue, 06 Oct 2009 23:42:17 GMT

So, some of you may recognize Eliyas’ name from WinHECs and various other driver dev presentations, but guess what he’s done now?! He’s become a blogger.

Go on feel free to hound him about your USB driver problems. :)

We’ve got more bloggers than we can shake a stick at!

patman — Thu, 10 Sep 2009 00:18:50 GMT

Welcome to the blog-o-sphere Neslihan. She’s our resident WLK guru, so you guys and gals can go pester here with all your WDF logo questions. :)

There goes the Sun...there goes the sun and I say...

patman — Mon, 20 Apr 2009 18:44:00 GMT

Oracle Buys Sun - Gearlog

I’m not sure how to feel about this. I know it probably went under a lot of people’s radar, but it almost feels like the passing of a rival. Something you wished would happen earlier, but not something you really wanted to happen because they made life interesting. Scott McNealy’s keynote blastings of Microsoft were legendary and at times very humorous. The “we’re the dot, in dot com” ads always gave me a chuckle. Yup, they part of what made being an employee of Microsoft during the late 90s and early 2000s fun.

It wasn’t all about the products, they made hockey interesting as well. There were a few charity Sun v. Microsoft hockey games played through the early part of this decade. They ended up being events all to themselves. A good way to let out some frustrations and have some fun with your rivals at the same time.

All in all it was a good little feud, some barbs, a little blood (very little at a hockey game) and a lawsuit here and there. But as a good feud should do, it drove of us to make our products better in the end.

Bon chance Sun.

That said, ol’ Larry Ellison has never been a close friend of Microsoft either. :)

I’ll have the next part in the UMDF Filter series later this week.

When it leaks, it pours

patman — Sat, 17 Jan 2009 00:09:00 GMT

Greetings from the Pacific Northwet. After our recent Snow-pocalypse, we also suffered a run of flooding. Amazingly enough, it wasn't directly due to the 13+ inches of snow I had at my house, it was a combination of the snow and the monumental amounts of rain that followed. Quite a few people were literally cutoff from the rest of Washington State as their egress roads were under rivers. The only hassle I had to suffer was one of FedEx being a day late with a new laptop. Oh bother.

The leaking I did have to suffer was of my own doing. It was my usage of IWDFIoRequest::GetCompletionParams in a test driver. In trying to be a good boy and clean up my I/O requests, and especially since I was going to be using asynchronous I/O, I wanted to get the completion parameters with out having to mess around with a completion routine. Funny thing is, that call takes a reference on the pointer returned. All was fine and dandy until I turned on Object leak detection (using WdfVerifier) and reference tracking. Debugger breaks prevent things from running smoothly I've found. :)

Now those of you much smarter than me would have told me I could have avoided that by using the CComPtr class on the CompletionParams interface as shown in the sample, but if you're like me and still think you know better and didn't use the CComPtr class, you had best make a subsequent Release() call.

pWdfRequest->GetCompletionParams (&CompletionParams);

hr = CompletionParams->GetCompletionStatus ();
CompletionParams->Release();

Now to answer a question nobody asked, yes my dog LOVES snow.

I'll spare you all part two of my FiOS TV installation rant because the guy who came out and installed the CableCard in my TiVO made up for the previous incident, ten fold. All I can say is wow. I really enjoyed watching Rush R30 in un-bitstuffed HD via the Palladia channel. Thank you FiOS.

*Currently playing - Porcupine Tree Blackest Eyes

The ups and downs of laser ownership.

patman — Thu, 11 Dec 2008 03:26:00 GMT

WARNING: Rambling and ranting ahead. Read at the risk of losing time you could be spending doing other things!

As I noted in my last post, I was to be migrating to FiOS TV on 21-November. Well, first let me say that every person I've talked to on the phone with Verizon has been very nice and helpful. Even if they weren't able to help me get things resolved.

You'll notice there's a decidedly inclusive statement there. Every person. As you guys have demonstrated to be quite the smart bunch, you probably will have gathered that I've been on the phone with Verizon a number of times recently. So here is the first part of my frustrations with FiOS.

All was going well on the 21st. I had a scheduled time between 10-12 and they had informed that I would be called ~30 minutes before they showed up. As I was on vacation that day (and the subsequent week), I decided to see if I couldn't cut down on some of the installation steps they needed to go through by disconnecting our DirecTV boxes and getting the A/V rack in the living room setup for easy access.

I had been told that since I had FiOS Internet service already, the TV service install shouldn't take more than a couple of hours. They simply had to run cable from the Optical Network Terminal (ONT) to the exiting cable lines in the house then simply setup and then register their Set Top Boxes (STBs). Well, much to my chagrin, 15:00 rolled around and I had heard nary a word from the installer. So I called the lovely people at Verizon and asked where my installer was. I know those windows are rough estimates and that things can (and often) do creep up in other installs. Which is the reason I had waited until 15:00 to call. Three hours past my window is reasonable in my opinion.

The very helpful man on the other end of the phone apologized, and then placed me on hold in order to call the installer and find out what was going on. When he got back to me, he apologized again and said that the installer was about 90 minutes away from completion of the other job. My first (and biggest gripe really) is that I never got a call from the installer saying he was running behind.

I have another slight problem here and some of you can probably figure out what that may be, but I'll explain it later.

I wasn't happy with that result, but what can I do at this point. I fired up my Xbox 360 and started watching some episodes of 30 Rock over Netflix to keep me occupied. For some reason that was allowed to last for another 3 hours.

Yes, 18:00 rolled up on me and still nary a word from the installer. From being done with the previous job in 90 minutes to 3 hours passing and still not a word. Yup, at this point my patience was gone, I had been with DirecTV for 14 years and had never had anything close to this happen. This was the kind of service I expected from Comcast honestly, not Verizon. My FiOS Internet installation experience was awesome, end to end. The guys that came and did the service, their handling of my request during setup, the whole show was great.

Anyway, I called Verizon again at 18:00 and told them I no longer wanted any part of this, I had yet to cancel my DirecTV service and I'd be more than happy to carry on with them if this was how things were going to be handled. They were very apologetic and informed me that I would have to be transferred to my local billing office to cancel the order. Which they kindly did, or at least attempted to do... Yes, I was transferred only to find out that my local billing office closed at 18:00 PST, and would not be back open until Monday morning.

18:30 the installer called. He had the gall to call me and submit that he would be more than willing to come out and do the installation right now. By 22:00 he was finished with the install. Now let me be very clear here, the ONT was some 25' away from my existing cable feed to the house, we only had two STBs to be installed (which I did in about 5 minutes while he was outside, 2xPower Outlet + 2xHDMI = 2xDone).

All he had to do was run cable from the ONT to the existing line in to the house, then come inside and run their little registration application to log the boxes as live for service. That took nearly 3 hours.

So here's where the race condition comes in - After doing all the exterior work, he came in to register the boxes, which partially failed. The DVR STB had a partial registration, the other failed wholly. After another 30 minutes of retrying and resetting the boxes, he called their Technical Support center to find out...they had taken down the registration servers for maintenance. Meaning I had one box in my house that only got part of the programming package I had paid for, the other box wasn't functional and my multi-room DVR service was not functioning. The kid doing the install apologized ad nauseam. At this point I seriously just wanted my DirecTV back. But again, I'm a sucker for new technologies, and I was already on this boat floating down the river Styx, so might as well ride it out.

At this point the kid promised he would get the box registration done tomorrow morning first thing and I'd be up and running by the time I got up. Sure enough, he kept his promise on that one.

Now in my "playing" around with the STBs Saturday morning, I discovered that my multi-room DVR was not working. One of my reasons for moving to FiOS TV was so I could watch stuff recorded on the DVR in my bedroom with out needing to have another DVR. So I called my new friends at Verizon FiOS tech support. The lovely lady had me run through some of their STB menu items for her, then she showed me the super secret method to access the STBs diagnostic and installer menus. Everything in there checked out okay on both boxes. Which left her stumped. So she put me on hold to talk to the senior support person. Upon her return, I was informed that the two boxes the installer dropped off were incompatible. Yes, you read that right. So after hanging up and entering a fit of cursing, I decided to call back again. This CSR person was stumped as to why the previous person told me such a thing. So after he and I went through the same things, he asked me a few more questions and then told me they might actually BE incompatible. But he was asking a senior technical support person a few questions.

In the background I can hear the familiar noise of the MSN Messenger service. A few "mmm" and "ahhh"s later he informed me (via his contact over Messenger)that they WERE compatible, but for some inane reason the registration application he was using wasn't resetting the feature flag on the box, so he was going to use his super secret registration application to fix this. A scant 2 minutes later, it was working just fine. All was well in my house finally. It only took 18+ hours to get my FiOS TV installed and running 100%....well not really 100%.

So in deference to the one person who managed to read this far, I'll let you have a break before I start with the second Act. :)

Now, there's one thing in this that I'm sure some of you have picked up on, and I lightly called out previously. It's way back at the top of this babble; my installation window was set between 10-12. I would normally assume that I was 2nd or maybe 3rd on a list of work items for that person on that day. And my assumption here also was that none of those work tickets prior to mine would take more than a couple of hours.

According to the kid that did the install, every work ticket he got was setup between 10-12 and they stacked him up with 6 or 7 of them.

Yeah, I thought the same thing.

This blog is reader supported

patman — Sat, 15 Nov 2008 04:39:48 GMT

Thanks to the intrepid reader, TJ, who notified me that NHL Center Ice was now available on FiOS TV. After 14 years of service, I will bid a adieu next Friday to DirecTV. For those of you wondering why I've been touting FiOS, it's currently the only TV service that does not recompress their HD signals before throwing it down the wire. Well, other than OTA, but show me where I can get Montreal Canadiens or San Jose Sharks games in HD via OTA in Seattle.

Just so this post isn't devoid of anything other than another gloat, here's something we were just throwing up to stumble each other;

void
main ()
{
    int * m;

    m [1,2] = 5;
}

This does what?

WinDarn!

patman — Wed, 05 Nov 2008 01:45:00 GMT

Bob, Peter and Ilias are on their way to WinHEC as I'm typing, so if any of you are attending, please make a point to ask them if they miss me. :)

A while ago I was debugging something in my office and I had an observer over my shoulder. This observer was shocked to see that I still used a command window based debugger, good ol' KD. "But you can debug with source code and have all these windows open that show registers and local variable values..." I get that in KD as well. As Doron showed a while ago, the 'trace' command provides you a nice stepping stone(pun intended), but combine that with an 'r' (tr) and it displays the registers as you walk along. So right there is all I ever needed to debug.

Now you can start having some real fun; trace to address, trace to next call / return, and then for the icing on the cake, break on access. I don't need a GUI debugger, I like to live in the world of black and white, well actually just to be even more old school;

I'm still trying to figure out how to replicate screen burn in on a command window. ;)

So on to some random housekeeping - No I haven't played Fallout 3 yet. Yes I have it. No I haven't played GoW2 yet, I didn't land on any internal betas so I have to wait for retail release. And finally, no I haven't played Fable 2 yet, the company store was sold out.

I think that's it for now.

*Currently playing - King's X Freedom

It's flick, then swish

patman — Thu, 11 Sep 2008 23:17:00 GMT

So the next part of the little Q&A series on...well, QA;

3.) What security considerations do you take into account when designing and developing a kernel mode driver?

Validate user mode pointers and check the buffers to and from user mode. ;)

That was a little inside joke for the person who asked the question. Seriously security and kernel mode are almost at odds with one another when you really think about it. Kernel mode is implied to be a trustworthy environment so anybody that's down there with you is expected to behave like a good citizen. And anybody that can talk to you from the nether region (user mode) should be treated as an enemy. As security for kernel mode drivers is something of a loaded question in the end, the best advice I can offer here is; Anything that can be accessed by anybody outside your driver should have some form of defense built in to it. I.e. if you have an external callback, think about how that that could be used as an attack entry point. Could somebody float recursive calls to that callback and cause a stack over flow?

That's about the only weird tip I can give other than using what's published here and here as a base.

And finally, my apologize to Bob, I guess I stole some of his thunder. :)

*Currently playing - Rush Faithless

Finally, a practical use for the LHC!

patman — Thu, 11 Sep 2008 00:53:32 GMT

Hadron Pizza in 30 nanoseconds or it's free!

*Currently playing - Rush Natural Science

And Or what?

patman — Fri, 27 Jun 2008 21:04:00 GMT

From the, "it's funny because it happened to me" file, I did it again. While debugging a recent issue in the test lab, I had pushed the root cause out as an attempt to free an invalid handle. I cracked open the code to find the line and looked at it in passing, "yup, simple logic error, if ((deviceHandle != NULL) && (deviceHandle != INVALID_HANDLE_VALUE))" What I saw was really not what I thought I saw. Yup, I saw the reverse of this where it was checking if they were equal so I suggested the fix that state the && be changed to || and it should be if (! (deviceHandle == NULL) || (deviceHandle == INVALID_HANDLE_VALUE)). Then Bob pointed out the obvious. :)

On the testing side, we had a meeting recently to discuss some new test tools and there the continual theme Bob started and I picked up on came to pass; Testers should be the most paranoid people in the world. Over the years I've had my concepts of design and coding altered greatly. I went from the simple error handling should the odd API / DDI fail to the belief that they will always fail. As a result, my error handling routines have become exponentially more robust and adaptive. So during this meeting Bob and I were always thinking negative, "how are you going to handle when this fails, because it will fail. Believe it or not, at some point, it will fail." Yessir, I'm just a negative guy.

And finally, so long and thanks for all the fish Bill. Yes, I'm feeling terribly melancholy today.

*Currently playing - Sloan All Used Up

I would have waited forever, and ever, and ever, and ever...

patman — Fri, 16 May 2008 20:29:53 GMT

I'm on a pet peeve kick lately and another one of my big ones is WaitFor<Single | Multiple>Object with an INFINITE time out period.

You do realize it's INFINITE right? And while you can mitigate the risk of actually spinning forever on an object, there's really never 100% certainty that it will get signaled. As Bob pointed out, we SDETs should be and quite often are, fastidious and paranoid people and my paranoia rate increases when I see an INFINITE flag in test code.

Case in point;

    retVal = WaitForMultipleObjects(
                                HandleCount,
                                Handles,
                                FALSE, 
                                INFINITE);

Seems harmless enough right? You've got some in your own code, right? And if in testing you find this blurb hanging, the normal behavior is to fix where that handle is not being triggered, right?

Not so fast, in this particular case, the handles are events, and these events are packaged up and sent to a test driver which then signals the events (there's a case condition which verifies the signaled event is actually the one we want).

All works well until you get a malicious tester like me who runs around and does something to intentionally block the driver from successfully loading. And BOOM goes your test, or in some cases your driver. This leads to emails from our lab engineers generally titled; <test> is hanging on <os | arch | build> in lab. And invariably, it's because there's a condition which wasn't expected causing this stall.

So, change the timer!

    retVal = WaitForMultipleObjects(
                                 HandleCount,
                                 Handles,
                                 FALSE,
                                 120000);

I know what some of you are going to say, "but I can't guarantee the operation will be completed in two minutes". No you can't, but somewhere between 0 and INFINITE - 1 it should be done, and if it isn't, it's a bug. Maybe not in your code, but in somebody's code. I know there are corner conditions where INFINITE is a valid flag, and I'm fine with that, but I have a tough time believing there are that many. :)

m_Grumpy_Old_Man_Mode->Off();

*Currently playing - Dream Theater Status Seeker

snark, snark!

patman — Thu, 01 May 2008 01:45:00 GMT

Things are crazy around here, but I figured I couldn't leave all my loyal reader in the dark as to my whereabouts.

As you remember we had something of a hiccup with the coinstallers, and that just seemed to be followed by a flood of work items, bugs and such for the Windows 7 project.

I swear as soon as I can tell you anything about what we're doing I will and as soon as I can post something more interesting that the following, I will. :)

So, as I get older I find that my list of pet peeves or things I get all cranky about grows, I'd say exponentially, but it's more in the leaping incremental stage right now. The latest addition to my peeve list follows the onslaught of multicore CPUs and the staggering amount of confusing information out there that poor Average Joe / Josephine has to sift through. Of all that information, for some reason the one that really honks me is when people say, "you won't see any difference because <insert application name here> is single threaded..." *faint*

Wow, I didn't realize we were still in 1982! What usually confuses the purveyors of such statements is when I start explaining the Operating System thread scheduler with sprinkles of how the thread quantums and queues work. Then for some frosting, I follow this with some diatribe on how <insert application name here> is actually multithreaded, but just "weighted" towards a working single thread. Add a little demonstration on how many threads are actually running around in that process space and a touch of how <insert application name here> really just has some bad resource contention, synchronization and clunky included libraries that cause those child threads to just twiddle their thumbs until daddy thread tells them it's okay to do something.

Yes, I realize it's a stupid semantics issue, but I don't care. I'm old and cranky and the Sharks are playing horrible hockey and so are my beloved Canadiens. :(

Oh and get off my lawn. ;)

*Currently playing - Pink Floyd One Slip

Time flies like an arrow, fruit flies like a banana

patman — Tue, 01 Apr 2008 21:07:00 GMT

First apologies for the disappearing act. I would like to say I was trapped under a fallen 10- year collection of Dobb's C++ Journals and couldn't get free, but it'd be a lie. A good lie, but a lie none the less.

I would also like to apologize for not providing you with a bit of April Foolery, but I'm suffering a lack of 'teh funnee' right now.

The Intellisense project is on the very, very back burner right now. Consider it a crock pot / slow cooker project. But I will actually strive to release it as a tool for you all and as such I'm going to have to go through a lot more hoops. It was going to simply be a little script, but I figured at that point I'd just make a nice Visual Studio plug in and see about distributing it.

Lastly, Jonathan Coulton is my new Hero. I just picked up full Thing A Week collection after having bits and pieces of them here and there. He so easily transitions from one musical style to another and has some great melodic hooks in his songs. Add to that his fascination with monkeys, robots and evil geniuses and he speaks to me on many levels.

I'll get back to some more beefy flavored posting soon.

*Currently playing - Jonathan Coulton Skullcrusher Mountain (Demo)

What goes up fast, must come down as fast (in theory) -

patman — Sat, 16 Feb 2008 03:31:00 GMT

It's actually the 15Mbps / 15Mbps package, but I can't find any test servers that will actually push the 15Mbps up limit, so it may not be a "pure" 15Mbps up, but man is it close.

Next question is "why"? It does make it easier to work from home and also access my home machine from work...and stream music from it...and host really big GTR2 multiplayer races...you know, all the good stuff.

Don't know how much of the second act of the Musical I'll have for you this weekend, I may have to publish it in two parts.

*Currently playing - Spocks' Beard, The Planet's Hum

I never promised you a rose garden, but I did promise Act 2 of a Musical

patman — Sat, 09 Feb 2008 05:13:00 GMT

And I'm sad to say that I won't have it ready this weekend. I'll work on it next week I promise.

In the mean time, how about we write a kernel in a Managed Language eh? So cool to see they have some proof of concepts going.

*Currently playing - Living Colour, Open Letter (to a Landlord)