software engineering;  was: Is this official blog article intended as a joke?

Actually, the 'blog makes a useful point:

Most computer science students get to learn high-level programming languages and application development but they don’t really understand computers.

JMO/YMMV:

Now, while interfacing to the real world is fun, RasPi doesn't really address the high-level application problem.  It's still a GNU/Linux box, running a mainframe operating system with dozens of processes.  It's darn cheap for a mainframe, but it's still a mainframe.

If you really want to learn what computers do IMO you really need to learn assembly language and run it on a real mini- or micro-computer with no operating system present to protect you from stomping all over your code and data so that your program goes off to la-la land.  That's when you really see that all that's in computer memory is bit-strings, and the computer will interpret them as instructions or data depending on where you told it to execute -- whether you meant to or not.  Once you've mastered the machine-language level, then you can understand why your C program is misbehaving in that extraordinary fashion.  IMO this mastery is necessary for someone to be called a computer scientist, just as you expect an EE to know how to use Kirchhoff's Laws and a mathematician to be able to do Epsilon-Delta proofs.

> IMO this mastery is necessary for someone to be called a computer scientist,

Of course, computer science is a big field, with many specialties, and many layers

of abstraction, and it's entirely possible for hardware specialists to know very little

about software, and vice versa.  And theoretical computer scientists often know very

little about either software or hardware, focusing their attention on topics like

algorithmic efficiencies that don't provide any benefit on realisitic sized data sets.

Dijkstra famously said "computer science is no more about computers than

astronomy is about telescopes."

Of course, it's still important to know how to read an abend dump when you have to.

John Beetem wrote:

 

I have met way too many soi-disant software engineers who hate writing software (not to mention documentation), so they mash together inappropriate modules from Edsger Dijkstra knows where.  I have also met way too many engineering managers who want something quick-and-dirty now instead of doing it right -- and then re-doing it righter after learning from the first go-around.

My experience is that a large proportion of software engineers actually like writing software, or at least did at some point.  But anyone who's done a couple of projects will have seen the pattern of the clueless engineering managers who just won't listen and will have quickly become jaded to the whole process.  They know they're probably going to have to do at least a couple of ground-up re-writes due to whatever daft managerial decisions get imposed.

If they learn anything the first time round it should be to never listen to the manager!

selsinork wrote:

 

My experience is that a large proportion of software engineers actually like writing software, or at least did at some point.  But anyone who's done a couple of projects will have seen the pattern of the clueless engineering managers who just won't listen and will have quickly become jaded to the whole process.  They know they're probably going to have to do at least a couple of ground-up re-writes due to whatever daft managerial decisions get imposed.

 

If they learn anything the first time round it should be to never listen to the manager!

This is an interesting discussion that I've been lurking on with some interest. I think everyone makes valid points, and I think that any language is the wrong language to use when it is used wrong. Java (my language of choice), which many touted as being the answer to many people's problems, still has a lot of problems inherited from C and C++, Ultimately, it's quite possible to write bad code in any language. The more powerful the language, the easier it is to paint yourself into a corner, and find yourself with a sticky problem that you have to fudge your way out of.

Speaking from my own experience, deadlines are necessary, you need something to focus the mind and finish up. But as the deadline looms, you have to make short term compromises that tell yourself you will come back to at a later date, and then don't because after the deadline has passed you have new work to work on. Those compromises, or the the code that is built on those compromises, cause problems further down the line. Good commenting or peer review can deal with this, but too often, neither happen.

The real problems arise when the people setting the deadlines are focussing too much on the short term. Sure, it makes good business sense to minimise your spend, but all too often PMs decide on the quickest or cheapest solution offered to them, without caring about the effects this causes. "Act in haste, repent at leisure". Quick and dirty solutions often cost a lot more in the long term than the slower, better solution, but some engineers have a terrible time trying to persuade a PM of why they should get 8 weeks to do a solution when a Q&D one can be done in 2. A PM in a previous job once said to me "Do the quick and dirty solution, but do it without writing the bugs". These days I show people the iron triangle.

Now, that all said, it's fair to say that all software ships with bugs; it is part of the nature of software, and it happens for all the reasons everyone said. Bad coders, wrong choice of language, poor management decisions, quick & dirty solutions, sloppy testing, the list goes on and on. The trick is to accept that there will be defects, and making sure that none of them break functionality or cause a terrible user experience. A good iterative QA cycle is essential for good software.

However, what got me out of lurking on this post and actually posting on this discussion was the last post by Selsinork, which reminded me of an excellent article once written by Orson Scott Card. This is a jaded example, but it definitely points at some of the key problems in software development - how it is handled by non-software types, and especially by management. The world has changed in many ways since this article was written, but in many ways, it remains the same. A large number of problems are caused by external people not understanding either how software works, or how the people who work on software work.

I think it's as important to teach young coders how to deal with bad managers as it is to teach coders how to code.

coder27 wrote:

 

The solution to complexity is abstraction.  A single person can run a large company

or run a large nation, but not by doing all the jobs that a sole proprietor does.  Instead,

they operate at much higher levels of abstraction.

Not sure I really agree with that.  I accept that abstraction is necessary, but I'd argue that it's a necessary evil.

The problem with abstraction is that by definition it leads to the problem Morgaine brought up that no one person has a clue how it all works, or even how it's supposed to work. It also leads to the problem that once it becomes obvious that somethings broken it's often impossible to fix in any meaningful way.

You mention large companies or nations. I think they're often a perfect example - you look at the individual, abstracted, parts and they all look perfectly reasonable, but put them together and the result is incoherent and often fails even the most basic common sense analysis.

I accept that abstraction is necessary, but I'd argue that it's a necessary evil.

Yes, no doubt that large companies, nations, etc. are run with huge inefficiencies.

Sometimes that is intentional.

Similarly, there are a lot of examples where inefficiency is inherent. 

For example, airliner load factors.  It's tempting to see an airliner flying

with empty seats, and say that's inefficient because the seats are

going to waste and any revenue that could be obtained by filling them

would go directly to the bottom line profit. 

But an airline intentionally flys more seats on any particular route than

it expects to fill, in order to accommodate last-minute bookings from

high-paying business travelers.  It's just as important to avoid the waste

of turning away last-minute bookings because your plane is full than it is

to avoid the waste of flying empty seats.

The idea of abstraction is that low-level details are often not of critical

importance at higher levels of design.  For example in coding, an

assembly language programmer might care a lot about which register

holds which variable, in order to maybe keep two variables in adjacent

registers so they can be moved at the same time in a single double-word

move instruction.  But that's of no concern to the project's chief architect.

Every low-level detail needs to be worried about by someone, but

no single person needs to worry about every low-level detail.

Great post, Nelson.  I really like the Orson Scott Card essay -- hilarious and insightful.

Dudley Nelson wrote:

 

Ultimately, it's quite possible to write bad code in any language. The more powerful the language, the easier it is to paint yourself into a corner, and find yourself with a sticky problem that you have to fudge your way out of...

Reminds me of some classic C versus C++ jokes (from memory):

1.  C gives you enough rope to hang yourself.  C++ gives you enough rope to tie up everybody in your neighborhood, rig a small ship, and still have enough left over to hang yourself from the yard-arm.

2.  With C, it's easy to shoot yourself in the foot.  With C++ it's harder, but when you do you blow your whole leg off.

Dudley Nelson also wrote:

 

Now, that all said, it's fair to say that all software ships with bugs; it is part of the nature of software, and it happens for all the reasons everyone said.

All software that performs a non-trivial function has bugs.  There are just way too many moving parts, and when you try to fix the code the bugs scurry away to other parts of the program, just like in the song:

99 little bugs in the code,
99 bugs in the code...
Take one out, compile again,
100 little bugs in the code.
[Repeat until bug count goes to zero.]

As long as we're sharing humorous bits about software engineering, here's one of my favorites: Software Engineering: Now with Cats.

Dudley Nelson wrote

 

However, what got me out of lurking on this post and actually posting on this discussion was the last post by Selsinork, which reminded me of an excellent article once written by Orson Scott Card. This is a jaded example, but it definitely points at some of the key problems in software development - how it is handled by non-software types, and especially by management. The world has changed in many ways since this article was written, but in many ways, it remains the same. A large number of problems are caused by external people not understanding either how software works, or how the people who work on software work.

A great example of no matter how much things change they really just stay the same. I don't think that has lost any relevance in all these years.

coder27 wrote:

 

Every low-level detail needs to be worried about by someone, but

no single person needs to worry about every low-level detail.

I couldn't agree more.. Unfortunately it's also exactly the problem.  Someone five levels up the abstraction tree makes an innocuous decision because he doesn't think he needs to care about the person trying to keep those two values in the same register, but by the time the decision makes it all the way down, that assembly language programmer can no longer do what's required without forcing a re-write at every other level. Resulting bodged solution unsurprisingly has issues because a very frequently executed action goes from a single cycle to something that takes very many orders of magnitude longer.

I know of at least one example where this sort of thing forced changes in hardware to compensate for software design that was unchangeable due to this way of thinking.

John Beetem wrote:

 

As long as we're sharing humorous bits about software engineering, here's one of my favorites: Software Engineering: Now with Cats.

I like it

Someone five levels up the abstraction tree makes an innocuous decision because he doesn't think he needs to care ...

Yes, sometimes abstractions leak, but hopefully it's the exception rather than the rule.

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

Some people think information hiding is bad in that it prevents them from maximizing

efficiency by taking advantage of implementation details that they don't expect will

actually change, such as multiplying an integer by 2 by shifting it left one bit, on the

assumption that it's represented in base 2 and always will be.

Someone five levels up the abstraction tree makes an innocuous decision because he doesn't think he needs to care ...

Yes, sometimes abstractions leak, but hopefully it's the exception rather than the rule.

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

Some people think information hiding is bad in that it prevents them from maximizing

efficiency by taking advantage of implementation details that they don't expect will

actually change, such as multiplying an integer by 2 by shifting it left one bit, on the

assumption that it's represented in base 2 and always will be.

coder27 wrote:

 

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

I think the key is designing excellent interfaces between layers and writing excellent documentation to define those interfaces so that people can develop separate pieces and have them work together properly when integrated.  This goes along with information hiding, since if the interfaces are designed and documented well enough there is rarely a need to peek beyond the interface.

coder27 wrote:

 

As you probably know, there is a software engineering notion of "information hiding"

I'm aware of the idea, and that most current programmers have fallen for it.

You can't seriously think that if the interface specifies that you're getting an integer binary value that it's ok for the implementation to change it to a trinary integer (or anything else for that matter - opaque value maybe).  To do that obviously breaks the agreement the interface provides, the consumer no longer knows how to store the value it's been given never mind what to do with it.

Indeed, whether we like it, agree or not, the consumer is inextricably and unavoidably reliant on the implementation - even if it's not allowed to know any of the hidden details.

I was reminded about this discussion while reading the stuff on avoid_safe_mode=1 in the other thread earlier - everything hidden behind an interface that the user likely doesn't even know exists. Closed source too, so no way to know the details. You're presented with something that's not right, not expected, and with no explanation. Not helpful.  What's worse is that he's not only dependant on the implementation, he needs to know all those hidden details to work out how to fix it.

Morgaine's right, the whole thing is a mess. I don't have a better alternative, or have a clue how to fix it, but I know what we're doing today is the wrong thing and we're unlikely to solve it while we keep digging.