The Daily WTF: Curious Perversions in Information Technology

Wait Low Down

by Remy Porter in Feature Articles on 2018-06-21

As mentioned previously I’ve been doing a bit of coding for microcontrollers lately. Coming from the world of desktop and web programming, it’s downright revelatory. With no other code running, and no operating system, I can use every cycle on a 16MHz chip, which suddenly seems blazing fast. You might have to worry about hardware interrupts- in fact I had to swap serial connection libraries out because the one we were using misused interrupts and threw of the timing of my process.

And boy, timing is amazing when you’re the only thing running on the CPU. I was controlling some LEDs and if I just went in a smooth ramp from one brightness level to the other, the output would be ugly steps instead of a smooth fade. I had to use a technique called temporal dithering, which is a fancy way of saying “flicker really quickly” and in this case depended on accurate, sub-microsecond timing. This is all new to me.

25 comments - Last comment @ 2018-06-22

A Unique Specification

by Remy Porter in CodeSOD on 2018-06-19

One of the skills I think programmers should develop is not directly programming related: you should be comfortable reading RFCs. If, for example, you want to know what actually constitutes an email address, you may want to brush up on your BNF grammars. Reading and understanding an RFC is its own skill, and while I wouldn’t suggest getting in the habit of reading RFCs for fun, it’s something you should do from time to time.

To build the skill, I recommend picking a simple one, like UUIDs. There’s a lot of information encoded in a UUID, and five different ways to define UUIDs- though usually we use type 1 (timestamp-based) and type 4 (random). Even if you haven’t gone through and read the spec, you already know the most important fact about UUIDs: they’re unique. They’re universally unique in fact, and you can use them as identifiers. You shouldn’t have a collision happen within the lifetime of the universe, unless someone does something incredibly wrong.

27 comments - Last comment @ 2018-06-21

The Sanity Check

by Remy Porter in CodeSOD on 2018-06-18

I've been automating deployments at work, and for Reasons™, this is happening entirely in BASH. Those Reasons™ are that the client wants to use Salt, but doesn't want to give us access to their Salt environment. Some of our deployment targets are microcontrollers, so Salt isn't even an option.

While I know the shell well enough, I'm getting comfortable with more complicated scripts than I usually write, along with tools like xargs which may be the second best shell command ever invented. yes is the best, obviously.

36 comments - Last comment @ 2018-06-21

Maximum Performance

by Remy Porter in CodeSOD on 2018-06-12

There is some code, that at first glance, doesn’t seem great, but doesn’t leap out as a WTF. Stephe sends one such block.

double SomeClass::getMaxKeyValue(std::vector<double> list)
{
    double max = 0;
    for (int i = 0; i < list.size(); i++) {
        if (list[i] > max) {
            max = list[i];
        }
    }
    return max;
}

34 comments - Last comment @ 2018-06-21

The Enabler

by Remy Porter in CodeSOD on 2018-06-11

Shaneka works on software for an embedded device for a very demanding client. In previous iterations of the software, the client had made their own modifications to the device's code, and demanded they be incorporated. Over the years, more and more of the code came from the client, until the day when the client decided it was too much effort to maintain the ball of mud and just started demanding features.

One specific feature was a new requirement for turning the display on and off. Shaneka attempted to implement the feature, and it didn't work. No matter what she did, once they turned the display off, they simply couldn't turn it back on without restarting the whole system.

25 comments - Last comment @ 2018-06-14

A Test Configuration

by Remy Porter in Representative Line on 2018-06-05

Tyler Zale's organization is a automation success story of configuration-as-code. Any infrastructure change is scripted, those scripts are tested, and deployments happen at the push of a button.

They'd been running so smoothly that Tyler was shocked when his latest automated pull request for changes to their HAProxy load balancer config triggered a stack of errors long enough to circle the moon and back.

16 comments - Last comment @ 2018-06-13

A/F Testing

by Remy Porter in CodeSOD on 2018-06-04

A/B testing is a strange beast, to me. I understand the motivations, but to me, it smacks of "I don't know what the requirements should be, so I'll just randomly show users different versions of my software until something 'sticks'". Still, it's a standard practice in modern UI design.

What isn't standard is this little blob of code sent to us anonymously. It was found in a bit of code responsible for A/B testing.

22 comments - Last comment @ 2018-06-08

Modern Art: The Funnel

by Remy Porter in CodeSOD on 2018-05-29

They say a picture is worth a thousand words, and when it's a picture of code, you could say that it contains a thousand words, too. Especially when it's bad code.

A 35 line enum definition which channels down to a funnel shape, I apologize for not providing the code in textual form, but honestly, this needs to be seen to be believed

Here we have a work of true art. The symmetry hearkens back to the composition of a frame of a Wes Anderson film, and the fact that this snippet starts on line 418 tells us that there's more to this story, something exotic happening just outside of frame. The artist is actively asking questions about what we know is true, with the method calls? —I think they're method calls— which take too many parameters, most of which are false. There are hints of an Inner Platform, but they're left for the viewer to discover. And holding it all together are the funnel-like lines which pull the viewer's eyes, straight through the midline, all the way down to the final DataType.STRING, which really says it all, doesn't it? DataType.STRING indeed.

38 comments - Last comment @ 2018-06-01