Yep, I work on low level networking software professionally and this post is largely meaningless dribble and is probably motivated by grandstanding.
It’s like an engineer who says “how does a screen show black” and then says “nope” to every response. It’s maybe a way to make people think, but beyond that the negativity and grandstanding of it is ultimately a turn off for many receivers which eventually either then has them bully others this way or deters them from the field, depending on how it affects them. There are far better teaching methods that work better for everyone and teach faster and result in higher accuracy and retention.
I thought you were probably exaggerating, but yes. I've never heard anyone make anything resembling any of those claims.
What I have said is something to the effect that if TCP isn't reliable over a given path, there's not a whole lot I can do about it as an application engineer short of making my own ad hoc, informally-specified, bug-ridden, slow implementation of half of TCP inside my own app, which I'm not going to do.
> 14. Weird networks that are not transparent to standard protocols are an aberration. I can safely ignore them.
I certainly can and will. If you wanna run an RFC 2549 network, I'm going to spend approximately 0 seconds making my app support it. If you want to do something weird, you make it work. I'm going to optimize for the other 99.99999% of customers.
Doesn't the author basically admit that when he prompts someone else to write "falsehoods programmers believe about TCP"? After all, if the author did have the understanding himself he could do it himself.
The reset of the writing just laments the pain of using products that make incorrect assumptions – continuing in same lamenting from the quoted segment he includes. It almost has nothing to do with TCP at all, so it is not clear where the parent comment here got the idea that it was trying to teach something about it.
The screen knows what color it displays at all times. It knows this because it knows what it doesn't. By subtracting what it does from what it doesn’t, or what it doesn’t from what it does (whichever is greater), it obtains a difference, or deviation. The controller board uses deviations to generate corrective commands to drive the display from a state where it does not display black to a state where it does, and arriving at a state where it displays black, it now doesn't display anything.
Each of the pixels is actually a little shining eye which watches your every move. When the pixel’s eyelid closes, that pixel turns black. That’s why they call it putting a display “to sleep.”
I like your explanation, but to be fair, it depends.
Some displays are implemented with dual-eyelid technology for the blackest of blacks. Naturally, like all genius engineering, we see this in nature: cats.
It depends afaict. OLED screens have a per-pixel light, and they turn off pixels to make black. LCDs have a single large backlight and pixels that the light shines through and they can change color (but not turn off) so in that case they turn as opaque as possible, but don't completely block the light.
I don't think you're taking into account the context or intended audience. It's a casual forum message posted in reply to someone else's message.
They have not written a "falsehoods programmers believe" article. They have proposed that one ought to be written and have given a starting point for what it might cover.
They offered their list to "get the ball rolling", confirming that they don't see it as a finished product.
They sent it to other readers of the same forum, who might be expected to have more knowledge of this topic, not to whoever runs across it on the front page of HN.
Every point is not self-explanatory, and some are clearly true (while the assumption is they must be false). For instance, it surely is true that any name will fit in under a Terabyte of text, if it can be encoded at all (and assuming the contrary is counter-productive). Claiming you should not assume any name can be spelled in Unicode is absurd as well. And, yes, it's perfectly fine to assume that if your system must have "real" (i.e. proved by any kind of document) names, you won't have to deal with Klingon names (even though it isn't a huge relief, honestly, since they still can have pretty much whatever format). For most systems, even more restrictive assumptions than that are totally fine.
You don't have to defend the "original" post just because it was patio11's. This idea was awful and stupid from the very beginning, and every new post of this "series" just repeats the offence.
> People’s names fit within a certain defined amount of space.
For any given fixed size that people use in practice, there is a name that does not fit. This is saying "use a variable-length field for names, because there are always edge-cases".
> Jullien was born in Sisteron, Alpes-de-Haute-Provence, and was baptised Louis George Maurice Adolphe Roche Albert Abel Antonio Alexandre Noë Jean Lucien Daniel Eugène Joseph-le-brun Joseph-Barême Thomas Thomas Thomas-Thomas Pierre Arbon Pierre-Maurel Barthélemi Artus Alphonse Bertrand Dieudonné Emanuel Josué Vincent Luc Michel Jules-de-la-plane Jules-Bazin Julio César Jullien. His father was Antonio Jullien, a violinist. The explanation of his unusual number of names is that when the time came for the baby to be baptised, his father had been invited to play at a concert given by the Sisteron Philharmonic Society, and considered it only polite to ask one of the members of the orchestra to be godfather: but since every member wished to be considered for the privilege, he was christened with the names of all thirty-six members of the society.
I'm pretty sure that patio11, having spent his life in Japan, would know that technology like SING glyphlets exists because of this exact issue.
(and before you answer "what are you talking about, it is in Unicode?", these characters are literally added after the relevant issue surfaced, and some characters like 𱅒 (U+31152) are recent additions that don't even render properly)
No, he one proved that other people don't need to put up with your bs if you try to break conventions. Hence your use of ASCII "Prince" being entirely adequate.
Besides, AFAIK he only changed his stage name, not his legal name.
I wonder what he means by France having a “weird” naming system in common use. As far as I can tell, the traditional French naming system works exactly the same way as the traditional American one (except that it’s more common for French people to have several middle names rather than zero or one, but I don’t think that’s too rare in the US either).
Maybe he’s referring to the fact that some last names are two words (e.g. Marine Le Pen), but I don’t think that’s very common…
Anyway, it could be anything, so I wish he’d said!
Perhaps he is thinking of how marriage does not change your last name, but rather gives you an extra, optional last name. [1] The French ID card has two last name fields!
Err. It still does by default change your name (if you're a woman). But you can ask and keep your 'maiden' (ugh) name or have both. It gets a bit trickier for kids' family names...
Anecdotal, but the only people I've met in the US with more than one middle name are people who originally came from another country.
Although, I wonder if maybe that is enforced by the fact tha legal forms and similar typically assume you only have first, last, and optionally a (single) middle name.
George Herbert Walker Bush comes to mind as a native son of the US with multiple middle names. He used H. W. in politics, but that still includes some whitespace and non-traditional characters.
i thought this list was also self-explanatory. i didn't have a hard time thinking of counterexamples to any of the points, which is not true of patio11's article. but what's self-explanatory depends on your knowledge base. maybe i just know less about foreign cultures than i do about tcp
This. If these lists contained things that programmers actually believed and explained why they are false, they might actually be useful. It's hard to imagine an unsupported assertion that an ambiguous statement is "false" and yet its contradiction is also "false".
I agree. This isn't even a good one of those lists. It's more like "dubious pedantry to make me feel smart about my TCP knowledge".
1-4. Yes we know about the 2 generals problem. And yes we know what "reliable" means in this context.
5-6. This is just stupid.
7. Obviously not true. Nobody thinks this.
8-9. The reasons for and flaws of Nagle's algorithm are well known.
10. This isn't even true. Most of the time you don't need to care about it. That's the whole point of abstraction. You need to care about it if you are doing extensive performance optimisation, but usually you aren't.
11. Again untrue. You can think of TCP as a two way pipe. Again that's the whole point of abstraction.
12. Not sure exactly what they're trying to say here but again it's very well known that TCP and UDP are pretty much the only protocols that are likely to work on the internet.
13. Ditto. We all know why so many protocols are "over HTTPS", e.g. DoH.
14. This isn't a technical point.
15. Dunno what this is talking about but I'm guessing it's along the lines of "a byte is 8 bits", i.e. it is actually true in the modern world.
Right, I was about to comment that. One of the first ones I remember was this one, about addresses[1]; or this one, about names[2]. Both provide examples and information, which is the only thing making the whole article useful.
I think the original "names" and subsequent "addresses" were useful in that a conclusion(that programmers should embrace defeatism and refrain from parsing or evaluating or even trying to separate them into fields) can be drawn, and the lessons learned were slightly more specific than often realized...
I noticed that too and thought I was missing something. Some cool resources that are actually decent for network programming:
https://beej.us/guide/bgnet/ -- Covers what abstractions the OS provides for network programming and the guarantees that are possible.
https://www.madwizard.org/programming/tutorials/ - This is the very first ever good tutorial I read on socket programming. It's OG winsock. Introduces network programming from the most basic level. Aimed at C.
When you understand these guides you'll learn that how you structure your entire programs networking depends on whether you want to use blocking or non-blocking sockets. If you go with blocking you'll probably be using threads or processes. Otherwise you can't do any other work. With non-blocking it will be more about polling sockets and eventually you might end up with something resembling an event loop.
Until you come towards to the current approach to networking which is mostly async await -- an event loop works with non-blocking sockets, watches them for changes, and passes data from them to event handlers. There's a lot more that can be done on sockets to effect things like how data is flushed, how TCP errors are handled, and so on, but its a good start.
I think these lists are often primarily intended as humorous, and perhaps a way to get you thinking about exceptions, not as a way to teach you more about the topic.
“Falsehoods programmers believe…” articles are designed to make you THINK about problematic assumptions. They are not like the 10 commandments and they are not decrees of absolute truth.
Now imagine how much time could have been saved globally if one person spent half an hour writing a short description of why each point is false instead of making hundreds (or thousands) of people spend hours thinking about and researching every one of them. You're probably left with more knowledge in the end if you're not spoon-fed by the author, but how many of us need really deep knowledge of the TCP inner workings?
Yep, the original "names" one was mostly written so negating each of the points gave you the exception you needed to handle. Even the cases written with both were done on a way it was obvious the negation didn't apply universally, so both worked.
I look at "Falsehoods programmers believe..." articles as a good source of test cases. If I'm parsing a date (don't do that), I'm going to look at "Falsehoods programmers believe about dates" to help build out my list of unit tests for that function. Same for names, street addresses and so on.
It’s like an engineer who says “how does a screen show black” and then says “nope” to every response. It’s maybe a way to make people think, but beyond that the negativity and grandstanding of it is ultimately a turn off for many receivers which eventually either then has them bully others this way or deters them from the field, depending on how it affects them. There are far better teaching methods that work better for everyone and teach faster and result in higher accuracy and retention.