Introduction to Memory Management (2018)
memorymanagement.org
memorymanagement.org
Resources on learning modern C++ cover RAII and resources on learning Rust cover its approach. There are good talks on the fairly new polymorphic allocator model for C++ that cover the motivations for it and use cases. Experience with modern C++ is valuable for understanding how much you can do with mostly stack allocation and how you can write non library code without ever writing a raw new or delete.
RAII is covered under "smart pointer": https://www.memorymanagement.org/glossary/s.html#term-smart-...
Stack allocation is here: https://www.memorymanagement.org/glossary/s.html#term-stack-...
Object pooling is covered under "segregated free list": https://www.memorymanagement.org/glossary/s.html#term-segreg...
Multithreaded GC is covered under "parallel garbage collection": https://www.memorymanagement.org/glossary/p.html#term-parall...
Even though it's a bit dated, memorymanagement.org is one of my favorite resources. It's opinionated, in a good way. The techniques that were developed in the 2000s, which this site thoroughly covers, are still the state of the art for garbage collection in my opinion.
[1]: http://web.archive.org/web/20140616011030/https://www.memory...
Insofar as computer programming is concerned, the "actual problem" is always the transformation of specific data on a specific set of computing hardware. Automating memory management doesn't imply working on the actual problem, it's just outsourcing a part of the actual problem in the pursuit of other objectives - decreasing development time, reducing the likelihood of specific bugs, etc. I'm not arguing that people shouldn't use automatic memory management, it often makes perfectly good technical and business sense to do so - but pretending that memory management is not a crucial part of solving any real problem in computer programming (even if you're not doing it explicitly) does no good to anyone.
If I write in C, I don't have to worry about register allocation (which variable goes in which register, when should I spill to the stack, etc.). I can just write things like (a+b+c)/3 and it "just works". Perhaps the compiler will do a bad job with allocating the registers, and a good assembly programmer would have done far better, even to the extent that the program goes from "way too slow" to "plenty fast". (Unlikely these days, but in the past knowing when to use the "register" keyword was worth knowing.) But even then register allocation is incidental complexity, in that they are an artifact of the solution, not of the problem itself.
But even though C programmers don't have to worry which registers are callee-save vs caller-save every time they call of function, they do have to worry about who is supposed to free every allocated data structure. Java programmers don't; they can just write
("1+2="+3).getBytes()
Of course, just because the problem is incidental doesn't mean it need not be solved! You really do need to free those strings or else you'll run out of memory and crash. (but not too soon, or else you have a use-after-free problem.) And likewise, at the end of the day, the values better end up in the right registers. But whether you're writing a game or web app or an FPGA simulator, memory management is not the "actual problem" you care about solving. The proof is that you don't think about when you're writing the user guide to your software.
You give "writing a game" as an example where memory management is not the actual problem. Games however often care a lot about performance and achieving good performance is part of the actual problem you're solving. For many games projects on current hardware you won't be able to solve the performance problem without thinking about memory allocation and blindly relying on the garbage collector will result in a game that doesn't solve the actual problem of performing adequately on the target hardware.
But the analogy is otherwise fine: reviews of your game will mention the performance (because it matters), but they will not mention your memory management strategy (because the don't care and may not even know). They will mention the rules, the mechanics, the story, the graphics and music and sound effects. Those are all part of the actual problem.
Memory management is an implementation detail. Don't get me wrong: this implementation detail is so vital that it may very well make sense to structure the entire code base around it, but that doesn't mean it's part of the "actual" problem, at least if you use my definition.
(See also my other reply in this thread.)
The actual problem (as in, the thing you are actually solving whether you realize it or not) of computer programming is not creating a product (that's business) or even data transformation (that's applied math). All computer programming is ultimately the transformation of data on real hardware (however abstracted by everything from firmware to virtual machines). Obviously, computer programmers don't exist in a vacuum and have to take into account technical (including mathematical) and social (including business) concerns, make tradeoffs, etc., but that doesn't change the basic facts. I'm just arguing we should be more explicit about them, not write them off.
And to address your analogy directly, register allocation is as much part of the actual problem as memory management. Even though most of us rarely resort to actually doing it by hand, it's still there and examining it in the resulting assembly is still often an important part of optimizing code. My argument is that regardless of whether you directly encounter something like register allocation every day, it is both conceptually important and useful to recognize it as part of what computer programming actually is, the technical and social properties that lead to the degree to which it is automated and the associated tradeoffs. Pretending that the actual problem of getting computers to do what we want is some annoying series of "incidental" problems is a recipe for bad software.
If that's your point then I agree, but I still think it's worth at least making a vague mental note that the problem is still incidental (and then carefully avoid the above conclusion).
If you're building a road bridge you could say that the actual problem is getting vehicles from one side of the river to the other and not the engineering details required to realize a physical structure capable of doing that. Things like the tensile strength of steel would be no more important to the bridge builders than mere memory allocation is to the average programmer in a GC'd language. You could also argue that taking that approach would lead to bridges that fail as badly at their primary function as much modern software does.
I feel slightly attacked when you say "written off". I don't mean to "write off" memory management as something undeserving of attention. I think that if performance matters at all, then even if you program in a GC'd language you better know roughly how your GC works and what it's good and bad at, and preferably have a plan for switching to a different GC if need be.
More generally, "incidental" stuff deserves attention. It may very well deserve the MAJORITY of your attention. I don't want to "write it off". I just want to classify it properly. Am I increasing my own risk of creating bad software by thinking this way?
On the latter point, however - and to answer your question regarding bad software - all other factors being equal, I think the answer is "probably, yes". The fundamental reason is that someone who is used to regarding memory management (which is really just one example among many) as incidental complexity to be outsourced away by default is less likely to reason carefully and intelligently about the actual implications of that decision. Just to pick a trivial example, someone who has internalized the RAII pattern in C++ without really understanding its implications may find it difficult to solve (or even find) memory fragmentation issues leading to bad performance - not something easily found in current profilers if you don't know what you're looking for already. There's a lot of issues like that which may seem either obvious or subtle depending on whether your mindset is to properly understand how the solution you've chosen actually works or regard it as incidental until proven otherwise.
In the modern computer programming industry you can go a long way without really dealing with any of the issues I've mentioned. However, the fact that much of modern software is unbelievably bloated and slow for no good technical reason is indicative that perhaps it would be better if more programmers took direct responsibility not just for the code they actually write, but for the code they outsource to others, often without truly grappling with the implications of those decisions.
Now THERE I agree completely! (Will watch the talk next weekend I hope.)
IIRC, Linux and FreeBSD both use a buddy allocator for physical memory, and I'm pretty sure it is used (in addition to other allocators) in jemalloc as well.
In any case, the glossary is up front about their disadvantages: https://www.memorymanagement.org/glossary/b.html#term-buddy-...